@INPROCEEDINGS{A.0811:Reinforcement, AUTHOR="Jasmin A. and Imthias Ahamed", TITLE="A Reinforcement Learning Algorithm to Economic Dispatch Considering Transmission Losses", BOOKTITLE="IEEE Region 10 Conference", ADDRESS="Hyderabad, Andhra Pradesh, India", DAYS=18, MONTH=nov, YEAR=2008, KEYWORDS="Economic Dispatch; Multi-stage Decision Making Problem; Reinforcement Learning; Q learning", ABSTRACT="Reinforcement Learning (RL) refers to a class of learning algorithms in which learning system learns which action to take in different situations by using a scalar evaluation received from the environment on performing an action. RL has been successfully applied to many multi stage decision making problem (MDP) where in each stage the learning systems decides which action has to be taken. Economic Dispatch (ED) problem is an important scheduling problem in power systems which decides the amount of generation to be allocated to each generating unit so that the total cost of generation is minimized without violating system constraints. In this paper we formulate economic dispatch problem as a multi stage decision making problem. In this paper, we also develop RL based algorithm to solve the ED problem. The performance of our algorithm is compared with other recent methods. The main advantage of our method is it can learn the schedule for all possible demands simultaneously." } @INPROCEEDINGS{A.El0000:Model, AUTHOR="Amar {A. El-Sallam}", TITLE="Model {Selection-Based} Blind Adaptive Channel Estimation Algorithms for Parsimonious Receivers in {CDMA} Systems", BOOKTITLE="2008 Fourth International Conference on Intelligent Sensors, Sensor Nertworks and Information Processing", ADDRESS="Sydney, Australia", DAYS=15, MONTH=dec, YEAR=2008, KEYWORDS="LMS, RLS, SVD, MDL, Blind Estimation, RAKE receivers, Minimum variance receivers", ABSTRACT="We consider a blind channel estimation and a model selection algorithms for the estimation and identification of significant channel parameters in CDMA systems. In conventional estimation algorithms, channel parameters are usually estimated using a channel length that is related to the maximum delay spread of the channel. However, this can result in estimating too many parameters where many of them are either zero or insignificant. In this work we propose algorithms that estimate then identify only significant channel parameters, leading to parsimonious receivers. First, we use users’ spreading codes and the received signal to form a data model for the system. Then, a blind adaptive channel estimation algorithm is derived to estimate the channel response. This is followed by a model selection algorithm to identify significant channel parameters among the estimated ones. Compared with conventional algorithms, simulation results show that our algorithm: (i) estimates the channel response with a faster convergence rate (ii) has lower estimation errors (iii) identifies significant parameters with high probabilities and at low SNRs (iv) has a lower BER performance." } @INPROCEEDINGS{A0000:Approach, AUTHOR="Lakshmi A and Hema Murthy", TITLE="A New Approach to Continuous Speech Recognition in Indian Languages", BOOKTITLE="National Conference on Communications 2008", ADDRESS="IIT Bombay, Mumbai., India", DAYS=1, MONTH=feb, YEAR=2008, ABSTRACT="This paper presents a novel approach to building syllable-based continuous speech recognizers for Indian languages. Syllables are known to be acoustically and perceptually stable units for recognition. The speech signal is automatically segmented into syllables both during training and testing. The syllable boundary information is used to build better syllable models and also to reduce the search space during recognition. A group delay based two level segmentation algorithm is used to find the syllable boundaries in the acoustic data. During training, a rule based text segmentation algorithm syllabifies the transcriptions. The syllabified signal and syllabified text generates automatically annotated data. The annotated data is then used to build isolated style syllable models. During test, the acoustic waveform is again automatically segmented using group delay. Unlike the conventional recognizers, the boundary information is used during testing to find the possible sub-word units in the spoken test utterance. A syllable based lexicon and language models are used to extract the word output from the recognizer. Several modifications on the language model based directed search takes care of the insertions and deletions in the test utterance. An improvement in word error rate of about 20\\% over a conventional recognizer is obtained." } @INPROCEEDINGS{A0000:Localization, AUTHOR="Gopakumar A and Lillykutty Jacob", TITLE="Localization in Ultra Wideband Sensor Networks using Tabu Search", BOOKTITLE="The Third International Conference on COMmunication Systems softWAre and middlewaRE", ADDRESS="Bangalore, India", DAYS=6, MONTH=jan, YEAR=2008, ABSTRACT="Localization of sensor nodes has become an important research topic in the area of Wireless Sensor Networks (WSN). Ever since the Federal Communications Commission (FCC) allowed the use of unlicensed Ultra-Wideband (UWB) communications, the accurate positioning and low cost characteristics of UWB made it a suitable physical layer standard for WSN. The localization of the sensor nodes can be done either by using direct method that gives exact solutions by solving a set of simultaneous non-linear equations or by using any non-linear optimization techniques. This paper proposes a novel and computationally efficient range-based localization method for WSN that uses Time of arrival (TOA) based ranging and Tabu Search (TS) based global optimization for the position estimation of sensor nodes. The sum of squared range errors of all neighboring anchor nodes is taken as the objective function for this optimization problem. Tabu search ensures that this objective function is minimized without being trapped into local optima. Computational experiments on data drawn from simulated WSNs show better convergence characteristics than the existing Simulated Annealing based WSN localization. Experiments are carried out for IEEE 802.15.4a channel model." } @INPROCEEDINGS{A0000:Scalable, AUTHOR="Gopakumar A and Lillykutty Jacob", TITLE="A Scalable and Computationally Efficient Localization Algorithm for {WSNs}", BOOKTITLE="Second IEEE International Conference on Advanced Networks and Telecommunication Systems (ANTS)", ADDRESS="Mumbai (Bombay), India", DAYS=15, MONTH=dec, YEAR=2008, KEYWORDS="Stochastic Proximity Embedding; Multidimensional Scaling; Wireless sensor networks; Distributed Localization", ABSTRACT="In this paper we propose an accurate, scalable and computationally efficient distributed Wireless Sensor Network (WSN) localization method based on Stochastic Proximity Embedding (SPE), which is a dimensionality reduction technique that finds a low dimensional embedding of a high dimensional data by preserving the pair-wise distance data information. The linear scaling property of SPE provides a reduced computational cost, compared to the localization schemes based on popular dimensionality reduction techniques like classical Multidimensional Scaling (MDS). Also the stochastic gradient approach adopted in SPE, provides an accurate position estimate with less susceptibility to local minima in reasonable number of iterations. The simulation study carried out on the proposed method establishes its better computational efficiency as well as localization performance in both regular and irregular shaped sensor networks." } @INPROCEEDINGS{A0811:Model, AUTHOR="Suresh Kumar A and Subba Rao Mopidevi and Srinivasa Kishore Babu Yadlapati", TITLE="Model Reference Linear Adaptive Control of {DC} Motor Using Fuzzy Controller", BOOKTITLE="IEEE Region 10 Conference", ADDRESS="Hyderabad, Andhra Pradesh, India", DAYS=18, MONTH=nov, YEAR=2008, KEYWORDS="DC motor, Fuzzy Logic, Speed Control, Model Reference adaptive control", ABSTRACT="This paper deals with the conventional model reference adaptive control (MRAC) and replaces conventional control technique such as PI control with model reference adaptive control scheme with fuzzy linear adaptation. It enhances the performance of the DC drive compared to conventional MRAC.The performance of the drive system, thus obtained, is forming a set of test conditions with model reference fuzzy adaptive control. The performance of the drive is tested for load disturbances along with reference model. This work also compares the performance of Model Reference Fuzzy Adaptive scheme over conventional MRAC." } @INPROCEEDINGS{A0811:Power, AUTHOR="Arvindan A", TITLE="Power Quality Assessment in a Bi-directional {AC/AC} Converter with {Four-Quadrant} Switch Realizations", BOOKTITLE="IEEE Region 10 Conference", ADDRESS="Hyderabad, Andhra Pradesh, India", DAYS=18, MONTH=nov, YEAR=2008, KEYWORDS="harmonic profile; phase-control; power quality; symmetrical multipulse modulation", ABSTRACT="Single-phase and three-phase topologies of the bi-directional a.c. controller, comprising power MOSFET embedded four-quadrant switch (4QSW) realizations operating in high-frequency chopping mode are presented. The performance of the controller with resistive load is assessed from the power quality perspective. A three-phase three-wire resistive load is considered for the three-phase topology and the corresponding gate control logic has been developed. The symmetrical multipulse modulation (SMM) technique is adopted, wherein; several equidistant pulses per half cycle (M) are used. The r.m.s. value of the fundamental component of the output voltage is smoothly varied by varying the duty cycle () of the pulses. It is shown that the lower order harmonics can be substantially reduced by SMM compared to the phase-control scheme, certain harmonics, even being eliminated for certain values of M. Simulated results are presented for both topologies, and, experimental results are also furnished for the single-phase one." } @INPROCEEDINGS{A0812:Load, AUTHOR="Antony Franklin A", TITLE="A Load Aware Channel Assignment and Link Scheduling Algorithm for {Multi-Channel} {Multi-Radio} Wireless Mesh Networks", BOOKTITLE="15th Annual IEEE International Conference on High Performance Computing", ADDRESS="Bangalore, India", DAYS=17, MONTH=dec, YEAR=2008, KEYWORDS="Wireless Mesh Networks; Multi-Channel Multi-Radio; Channel Assignment; Link Scheduling; Flow Allocation", ABSTRACT="Wireless Mesh Networks with multiple-channels and multiple-radios on the mesh routers have a great potential to increase the capacity of the network. To obtain the complete benefit of the increased capacity of such networks, efficient channel assignment and link scheduling algorithms are extremely important. A static channel assignment and link scheduling may not be optimal for every traffic demand in the network. In this paper, we try to find the channel assignment and link scheduling for the given traffic demand. We formulate an MILP for the channel assignment and link scheduling problem by considering the traffic demand for each source-destination pairs, with the objective of maximizing the aggregate achievable throughput on the network. We also propose Load aware Channel Assignment and Link Scheduling (LoCALS), a polynomially bound heuristic algorithm for channel assignment and link scheduling and compare with a distributed channel assignment algorithm which is unaware of the traffic demand." } @INPROCEEDINGS{Aada0810:DSBCA, AUTHOR="Sahar Aadabi and Sam Jabbehdari and Amir Masoud Rahmani and Sepideh Adabi", TITLE="{DSBCA:Distributed} Score Based Clustering Algorithm for Mobile {AD-hoc} Networks", BOOKTITLE="4th Distributed Frameworks for Multimedia Applications", ADDRESS="Penang, Malaysia", DAYS=21, MONTH=oct, YEAR=2008, KEYWORDS="Ad-hoc Networks; Distributed clustering algorithm; Cluster head.", ABSTRACT="Mobile Ad-hoc Networks (MANET) are multi-hop wireless packet networks in which all the nodes cooperatively maintain the network connectivity without the aid of infrastructure networks. This paper proposes a new Distributed Score Based Clustering Algorithm (DSBCA) for MANETs. The proposed Clustering Algorithm considers the Battery Remaining, Number of Neighbors, Number of Members, and Stability in order to calculate the node’s score with a linear algorithm. After each node calculates its score independently, the neighbors of the node must be notified about it. Also each node selects one of its neighbors with the highest score to be its cluster head and, therefore the selection of cluster heads is performed in a distributed manner with most recent information about current status of neighbor nodes. The proposed algorithm is compared with Weighted Clustering Algorithm in terms of number of clusters, lifespan of nodes in the system, and the end-to-end throughput. The simulation results proved that the proposed algorithm has achieved the goals." } @INPROCEEDINGS{AalS0804:Providing, AUTHOR="Mohammed AalSalem and Javid Taheri and Mohsin Iftikhar and Albert Zomaya", TITLE="Providing {QoS} Guarantees to Multiple Classes of Traffic in Wireless Sensor Networks", BOOKTITLE="AICCSA-08 Networking and Multimedia Track", ADDRESS="Doha, Qatar", DAYS=1, MONTH=apr, YEAR=2008, KEYWORDS="Sensor Networks; QoS; Queueing System; M/G/1;M/D/1; Delay", ABSTRACT="Recent advances in miniaturization and low power design have led to a flurry of activity in wireless sensor networks. However, the introduction of real time communication has created additional challenges in this area. The sensor node spends most of its life routing packets from one node to another until the packet reaches the sink, and therefore functioning as a small router most of the time. Since sensor networks deal with time-critical applications, it is often necessary for communication to meet real time constraints. However, research dealing with providing QoS guarantees for real time traffic in sensor networks is still in its infancy. In this paper, an analytical model for implementing Priority Queueing (PQ) in a sensor node to calculate the queueing delay is presented. The model is based on M/D/1 queueing system (a special class of M/G/1 queueing systems). Here, two different classes of traffic are considered. The exact packet delay for corresponding classes is calculated. Further, the analytical results are validated through an extensive simulation study." } @INPROCEEDINGS{Aasm0808:Activity, AUTHOR="Jans Aasman", TITLE="Activity Recognition Using a Web {3.0} Database", BOOKTITLE="Second IEEE International Conference on Semantic Computing", ADDRESS="Santa Clara, California, USA", DAYS=4, MONTH=aug, YEAR=2008, KEYWORDS="rdf, rdf database, query, federation, semantic web, web 3.0, knowledge store, rdfs", ABSTRACT="Web 3.0 envisages software agents that know how to reason over activities, events, locations, people, companies, and their inter-relationships. Learning more about customers through behavioral and activity recognition is here today through currently available Semantic Technologies and is a showcase for how these technologies will evolve. The demonstration will show real world examples of activity recognition using a combination of industry standard RDF and OWL, reasoning with basic Geotemporal primitives and some well-known Social Network Analytics" } @INPROCEEDINGS{Aasm0808:Utilizing, AUTHOR="Jans Aasman", TITLE="Utilizing Federated Knowledge in Semantic Web Applications", BOOKTITLE="Second IEEE International Conference on Semantic Computing", ADDRESS="Santa Clara, California, USA", DAYS=4, MONTH=aug, YEAR=2008, KEYWORDS="rdf, rdf database, query, federation, semantic web, web 3.0, knowledge store, rdfs", ABSTRACT="Your future knowledge store will be a collection that lives in-memory, on your local hard disk, on your intranet and/or distributed on the global web. It will be a collection of inter-related triple-stores federated into an ever-changing whole. We will demonstrate a flexible architecture for creating 'federated knowledge stores' on the fly that allow for transparent RDFS++ reasoning and SPARQL queries. We will demonstrate this new architecture with billions of triples from distributed sources including the Census database, the DBPedia, Wordnet, Geonames and the Enron e-mail corpus in an RDF federation." } @INPROCEEDINGS{AAzi0812:Solving, AUTHOR="Izzatdin {A Aziz} and Nazleeni Haron and Mazlina Mehat and Tang Low and Aisyah Mustafa", TITLE="Solving Traveling Salesman Problem on High Performance Computing using Message Passing Interface", BOOKTITLE="Fifth International Conference on Innovations in Information Technology", ADDRESS="Al Ain, UAE", DAYS=16, MONTH=dec, YEAR=2008, KEYWORDS="TSP,High Performance Computing,MPI", ABSTRACT="In this paper, we present a parallel implementation of solving Traveling Salesman Problem (TSP) which is the problem of finding the shortest path from point A to point B, given a set of points and passing through each point exactly once. Initially a sequential algorithm is fabricated from scratch and written in C language. The sequential algorithm is then converted into a parallel algorithm by integrating it with the Message Passing Interface (MPI) libraries so that it can be executed on a cluster computer. Our main aim by creating the parallel algorithm is to accelerate the execution time of solving TSP. Experimental results conducted on Beowulf cluster are presented to demonstrate the viability of our work as well as the efficiency of the parallel algorithm." } @INPROCEEDINGS{Ab.R0000:Multiple, AUTHOR="Nor Zairah {Ab.Rahim} and Jennie Carroll and Rose Alinda Alias", TITLE="Multiple Perspectives of Open Source Software Appropriation: A Case Study of a City Council", BOOKTITLE="Fifth International Conference on Innovations in Information Technology", ADDRESS="Al Ain, UAE", DAYS=16, MONTH=dec, YEAR=2008, KEYWORDS="Open Source Software, Technology Appropriation, Multiple Perspectives", ABSTRACT="Adoption of technology is one of the important issues in organization especially when it involves new technology such as Open Source Software (OSS). Despite being considered as cost effective by many organizations, the OSS implementation still usually faces lots of challenges. This paper describes a case study conducted to one of a City Council in Malaysia which had taken the approach to migrate to Open Source based desktop applications. An integrated framework consists of multiple perspective approach and Model of Technology Appropriation is used in this study. This framework allows the researcher to understand the multiple perspectives criteria that influence appropriation of OSS in each level of the process. By identifying and understanding the criteria which influence each level of the appropriation process, will assist in effective implementation decisions and lead to a more effective use of the technology." } @INPROCEEDINGS{Ab.R0811:Analysis, AUTHOR="Rosminazuin {Ab.Rahim} and Badariah Bais and Burhanuddin Majlis", TITLE="Design and Analysis of {MEMS} Piezoresistive {SiO2} Cantilever-based Sensor with Stress Concentration Region for Biosensing Applications", BOOKTITLE="2008 IEEE International Conference on Semiconductor Electronics", ADDRESS="Johor Bahru, Malaysia", DAYS=25, MONTH=nov, YEAR=2008, KEYWORDS="Piezoresistor, Cantilever, Biosensor, MEMS technology", ABSTRACT="Design and analysis of MEMS piezoresistive cantilever-based sensor for biosensing applications Rosminazuin Ab. Rahim, Badariah Bais and Burhanuddin Yeop Majlis Institute of Microengineering and Nanoelectronic (IMEN), Universiti Kebangsaan Malaysia 43600, Bangi, Selangor, Malaysia Microcantilever has been proven as an outstanding platform for extremely sensitive chemical and biological sensors. MEMS cantilever-based sensor is becoming popular in recent years due to its high sensitivity, high selectivity, easy to fabricate, and can be easily integrated with on-chip electronic circuitry. A MEMS cantilever-based sensor integrated with piezoresistive read out is normally used to measure the surface stress change induced from biochemical reaction. The piezoresistive read out system offers many advantages such as it is convenient to calibrate, readily deployable into integrated electromechanical system and does not require external detection devices. However, the read out system has a lower resolution than the optical-based system which limits its sensing capability as the magnitude of the forces or stresses involved in the system is very small. Therefore, one solution to overcome the low resolution of the read out system is by increasing the sensitivity of the microcantilever beam. This paper uses finite element method to obtain the optimal performance of piezoresistive microcantilever sensor by optimizing the geometries and placement of the piezoresistor on the cantilever. A finite element analysis was used to analyze and optimize the sensor sensitivity. A 350 μm x 35 μm x 1 μm silicon cantilever was used in this study based on the one done by Pei J. et al. (2004). The maximum displacement value was observed at about 0.2 µm for an applied load of 1.5 Nm-2. Simulation result showed that maximum current change (in comparison with no-stress current) was obtained when the piezoresistor was placed just next to the cantilever clamped edge (offset = 1) with 1 V input voltage applied on the piezoresistor (Figure 1). The optimum piezoresistor width and depth were found to be 32 µm and 0.2 µm, respectively. The incorporation of Stress Concentration Region (SCR) in silicon based cantilever to enhance the piezoresistive stress and displacement sensitivities was also considered. SCR is a region on the cantilever, with a thickness smaller than the cantilever thickness and of an appropriate length to localize the stress where piezoresistor should be implanted. It was found out that length, thickness and placement of the SCR on the cantilever have to be optimized in order to improve the cantilever sensitivity. Performing the SCR geometrical optimization resulted in improvement on the cantilever displacement and stress sensitivity. Few designs of SCR have been considered to determine the optimum design that produces maximum stress on the cantilever. It was observed that SCR with structural discontinuity placed just next to the cantilever clamped edge (L2 = 0) yielded a maximum Mises stress of 2.3 MPa compared to 2.2 MPa for the one placed away from the clamped edge (Figure 2). For the same design, SCR with minimum thickness of 0.2 µm yielded maximum stress which resulted in maximum sensitivity of the cantilever (Figure 3). In conclusion, by obtaining optimal geometrical parameters of the piezoresistor and the stress concentration region on the cantilever, the sensitivity of the piezoresistive microcantilever-based sensor can be optimized." } @INPROCEEDINGS{Abab0000:Building, AUTHOR="Mohammad Ababneh", TITLE="Building an Effective {Rule-Based} Light Stemmer for Arabic Language to Improve Search Effectiveness", BOOKTITLE="Fifth International Conference on Innovations in Information Technology", ADDRESS="Al Ain, UAE", DAYS=16, MONTH=dec, YEAR=2008, KEYWORDS="Stemmer; Root; preffix; Arabic Language; Information retrieval", ABSTRACT="Building an effective stemmer for Arabic language has been always a hot research topic in the IR field since Arabic language has a very different and difficult structure than other languages, that’s because it is a very rich language with complex morphology. Many linguistic and light stemmers have been developed for Arabic language but still there are many weakness and problems, in this paper we introduce a new light stemming technique and compare it with other used stemmers and show how it improves the search effectiveness." } @INPROCEEDINGS{Aban0810:SOA, AUTHOR="Hamidreza Abangar and Mirko Presser and Rahim Tafazolli", TITLE="{SOA} Principles for {WSAN} Internet Integration", BOOKTITLE="3rd European IEEE Conference on Smart Sensing and Context", ADDRESS="Zurich, Switzerland", DAYS=29, MONTH=oct, YEAR=2008, KEYWORDS="Wireless Sensor and Actuator Networks; Service Oriented Architecture; Web Services", ABSTRACT="This paper describes a demonstration of near sink-less operation of Wireless Sensor and Actuator Networks (WSAN) integrated into the Internet using Service Oriented Architecture (SOA) principles. We demonstrate a WSAN-Explorer including a mash-up application that explores the neighbourhood for available services. The proposed architecture is entirely built using Web Services (WS) technologies. The Device Profile for Web Services (DPWS), a complimentary subset of WS specifications, is providing the underlying WS infrastructure." } @INPROCEEDINGS{Abas0805:Neighbor, AUTHOR="Behzad Abasgholi and Ramtin Kazemi and Masoud Arezoomand and Ali Reza Enayati", TITLE="Neighbor Detection Power Control {(NDPC)} {MAC} Protocol in Mobile Ad Hoc Networks", BOOKTITLE="International Symposium on Wireless Pervasive Computing 2008", ADDRESS="Santorini, Greece", PAGES="508-512", DAYS=7, MONTH=may, YEAR=2008, KEYWORDS="MANET, Neighbor Detection, Power Control, Throughput", ABSTRACT="Media Access Control (MAC) protocol design is a challenging problem in wireless ad hoc networks. Network resource management like battery life and bandwidth are two design factors in these networks. Some power control MAC protocols try to increase throughput or decrease energy consumption or both of them. We propose a power control scheme based on number of neighbor in mobile ad hoc network and consider both physical and connectivity design issues. There is a trade off between physical and network connectivity when transmission power is selected. With knowledge of local information on network, we can influence global network statistics. If the number of one-hop neighbors increase, then the transmission power will decrease, and vice versa. Simulation results show better performance of our protocol in throughput and energy consumption in various scenarios and mobility models." } @INPROCEEDINGS{Abat0805:ASSYST, AUTHOR="Andrea Abate and Vincenzo Loia and Michele Nappi and Stefano Ricciardi and Enrico Boccola", TITLE="{ASSYST:} Avatar baSed {SYStem} mainTenance", BOOKTITLE="2008 IEEE Radar Conference", ADDRESS="Rome, Italy", PAGES="1334-1339", DAYS=26, MONTH=may, YEAR=2008, ABSTRACT="In many advanced industrial contexts, Collaborative Working Environments (CWEs) provide interesting opportunities to improve service and maintenance procedure, significantly reducing the time to repair and the risks related to system inactivity. The ASSYST framework aims to enhance existing CWEs by developing a novel maintenance paradigm based on the integration of augmented reality technologies and a tele-assistance network architecture enabling to support radar system operators during system failure detection, diagnosis and fixing. According to this approach, the support to maintenance procedures is provided by means of a virtual assistant (avatar) visualized onto the operational field and able to communicate with human operator through an interaction paradigm close to the way in which humans are used to collaborate. The avatar, whose actions are based on a semantic representation of system’s service/maintenance workflows, provides the maximum possible level of adaptivity to user’s needs and a pro-active behaviour, aiding him during failure search and repair protocols in a much more effective way than conventional screen based interfaces." } @INPROCEEDINGS{Abba0000:Computerized, AUTHOR="Ali Abbas and Atef Fahim", TITLE="Computerized Auscultation and Diagnostic System for Pulmonary Diseases", BOOKTITLE="Canadian Society for Mechanical Engineers Forum 2008", ADDRESS="Ottawa, Ontario, Canada", DAYS=5, MONTH=jun, YEAR=2008, KEYWORDS="Automated auscultation, computerized diagnostic system, respiratory system, Neural Network, biomedical signals processing, bioinstrumentation", ABSTRACT="Respiratory Sounds are of significance as they provide valuable information on the health of the respiratory system. Sounds emanating from the respiratory system are uneven, and vary significantly from one individual to another and for the same individual over time. In themselves they are not a direct proof of an ailment, but rather an inference that one exists. Auscultation diagnosis is an art/skill that is acquired and honed by practice. Hence it is common to seek conformation using invasive and potentially harmful imaging diagnosis techniques like x-rays. This research focuses on developing an automated auscultation diagnostic system that overcomes the limitations inherent to traditional auscultation techniques. The system uses a front end sound signal filtering module that uses adaptive filters and Neural Networks (NN) to eliminate spurious sound signals like those from the heart, intestine, and ambient noise. To date, the core diagnosis module is capable of identifying lung sounds from non-lung sounds, normal lung sounds from abnormal ones, and identifying wheezes from crackles lung sounds as indicators of different ailments." } @INPROCEEDINGS{Abba0000:Protocol, AUTHOR="Ash Mohammad Abbas", TITLE="A Protocol for Quality of Service Aware Routing in Ad hoc Networks", BOOKTITLE="Second IEEE International Conference on Advanced Networks and Telecommunication Systems (ANTS)", ADDRESS="Mumbai (Bombay), India", DAYS=15, MONTH=dec, YEAR=2008, KEYWORDS="Routing, QoS aware, lifetime, queue length.", ABSTRACT="Designing a routing protocol with a provision of quality of service (QoS) for mobile ad hoc networks is a challenging task. In this paper, we present a routing protocol that identifies multiple node-disjoint paths that satisfy QoS constraints. We focus on two major QoS constraints that are lifetime of paths and queue length along the paths. We study the effect of transmission range of nodes, and thresholds for lifetime and queue length over the number of paths that satisfy the given QoS constraints in an ad hoc network." } @INPROCEEDINGS{Abba0000:Results, AUTHOR="Noureddine Abbadeni", TITLE="General and Invariant Image Retrieval from Visual Databases Based on Multiple Search Strategies", BOOKTITLE="Fifth International Conference on Innovations in Information Technology", ADDRESS="Al Ain, UAE", DAYS=16, MONTH=dec, YEAR=2008, KEYWORDS="Image/Visual Database; Image Retrieval; Multiple Representations; Multiple Queries; Results Fusion; Retrieval Effectiveness; Benchmarking", ABSTRACT="This paper is related to visual information systems in general, and to information retrieval from image databases in particular. We propose an approach based on the fusion of retrieval results returned by multiple retrieval strategies to improve the effectiveness of image retrieval from image databases. Multiple retrieval strategies proposed and used in this paper are multiple content representations and multiple queries. We consider the case of textures and consider both the general retrieval case as well as the case of invariant image retrieval. Experimental results show, through benchmarking on two image databases, that retrieval effectiveness is improved in a very appreciable way with the fused model." } @INPROCEEDINGS{Abba0807:MOTE, AUTHOR="Ali Abbasi and Ahmad Khonsari and Navid Farri", TITLE="{MOTE:} Efficient Monitoring of Topk Set in Sensor Networks", BOOKTITLE="13th IEEE Symposium on Computers and Communications", ADDRESS="Marrakech, Morocco", DAYS=6, MONTH=jul, YEAR=2008, KEYWORDS="Top-k Monitoring, Sensor Data Modeling, Sensor Networks", ABSTRACT="Top-k monitoring is a noteworthy query that recently has been put into practice in wireless sensor networks (WSN). In top-k monitoring (i.e., an instance of continuous distributed monitoring), base station or coordinator continuously monitors k sensors with the highest (or lowest) values. Since the goal in such applications is to perform monitoring task while incurring minimum communication (data traffic) overhead, local constraints should be set at remote sites to filter unnecessary updates. Thereby, the novelty of this paper lies on the investigation of a method called MOTE where model-based optimization technique is utilized to set filters at remote sensors. In the proposed technique, the problem of optimal filter setting for maintaining top-k set is formulated as a variant of set cover which is an np-hard problem with well studied approximation methods. Simulation results demonstrate the validity of the proposed MOTE algorithm in improving the performance compared to other filter setting methods." } @INPROCEEDINGS{Abba0809:Use, AUTHOR="James Abbas", TITLE="On the Use of Adaptive Control in {Stimulation-Assisted} Neuromotor Therapy", BOOKTITLE="13th International FES Society Conference", ADDRESS="Freiburg, Germany", PAGES="125-127", DAYS=21, MONTH=sep, YEAR=2008, ABSTRACT="Neuromuscular stimulation may provide an efficient means to enhance the effectiveness of neuromotor therapy. In previous work, we developed an adaptive control system (PG/PS control system) that may be particularly useful in neuromotor retraining paradigms that seek to supplement volitional activity with electrical stimulation to generate cyclic movements. This system has previously demonstrated very good performance in controlling single-joint movements at a given movement period. In this work, we further characterized the capabilities of this system with a focus on issues that are likely to arise in neuromotor retraining paradigms: varying movement periods, intermittent rest periods, and multi-joint movements. Preliminary results suggest that the PG/PS system can address each of these issues and therefore may be well-suited for use in neuromotor therapy." } @INPROCEEDINGS{Abba0810:State, AUTHOR="Ghulam Abbas", TITLE="A State Estimation based Framework for Control and Management of Data Communication Networks", BOOKTITLE="4th Distributed Frameworks for Multimedia Applications", ADDRESS="Penang, Malaysia", DAYS=21, MONTH=oct, YEAR=2008, KEYWORDS="Communication Networks; Congestion Avoidance; Management System; State Estimation", ABSTRACT="This paper proposes a novel framework, based on State Estimation, as a Network Management System approach in order to control the traffic flow, routing, hardware malfunctioning, congestion and resource management in Data Communication Networks. Our proposed approach is aimed at eliminating anomalies and other discrepancies between network system models that typically lead to poor network performance and threaten the network integrity and security. The framework is initially validated using a case study which focuses on congestion avoidance and has demonstrated favourable results in terms of enhanced data delivery with fewer packet losses and retransmissions. The results also suggests that State Estimation based congestion avoidance mechanism not only offers improved system monitoring but it also enables better control and network security." } @INPROCEEDINGS{Abba0812:Structure, AUTHOR="Meysam Abbasinia and Abdollah Khoei", TITLE="A New Structure {Voltage-Mode} Digital Fuzzifier with Low Power and High Accuracy", BOOKTITLE="20th International Conference on Microelectronics (ICM) 2008", ADDRESS="Sharjah, UAE, UAE", PAGES="139-142", DAYS=14, MONTH=dec, YEAR=2008, ABSTRACT="This paper presents a new structure of high speed and low power voltage-mode digital fuzzifier for digital fuzzy microcontrollers. We implement a new method voltage-mode with resistors for achieving high speed and high accuracy with low power consumption. Input signals are digital words and outputs are analog in voltage-mode. The circuit is designed and simulated using HSPICE simulator by level 49 parameters in 0.35μm standard CMOS technology. The simulation results show that the proposed circuit has maximum 716μw power consumption and maximum delay for this fuzzifier is 5ns and maximum error is 1.8\%." } @INPROCEEDINGS{Abbi0809:Analysis, AUTHOR="Revlin Abbi and Elia El-Darzi and Christos Vasilakis and Peter Muillard", TITLE="Analysis of stopping criteria for the {EM} algorithm in the context of patient grouping according to length of stay", BOOKTITLE="2008 IEEE Conference on Intelligent Systems", ADDRESS="Varna, Bulgaria", DAYS=4, MONTH=sep, YEAR=2008, KEYWORDS="GMM fitting, LOS data, patient classification, stopping criteria, EM, likelihood.", ABSTRACT="The expectation maximisation (EM) algorithm is an iterative maximum likelihood procedure often used for estimating the parameters of a mixture model. Theoretically, increases in the likelihood function are guaranteed as the algorithm iteratively improves upon previously derived parameter estimates. The algorithm is considered to converge when all parameter estimates become stable and no further improvements can be made to the likelihood value. However, to reduce computational time, it is often common practice for the algorithm to be stopped before complete convergence using heuristic approaches. In this paper, we consider various stopping criteria and evaluate their effect on fitting Gaussian mixture models (GMMs) to patient length of stay (LOS) data. Although the GMM can be successfully fitted to positively skewed data such as LOS, the fitting procedure often requires many iterations of the EM algorithm. To our knowledge, no previous study has evaluated the effect of different stopping criteria on fitting GMMs to skewed distributions. Hence, the aim of this paper is to evaluate the effect of various stopping criteria in order to select and justify their use within a patient spell classification methodology. Results illustrate that criteria based on the difference in the likelihood value and on the GMM parameters may not always be a good indicator for stopping the algorithm. In fact we show that the values of the difference in the variance parameters should be used instead, as these parameters are the last to stabilise. In addition, we also specify threshold values for the other stopping criteria." } @INPROCEEDINGS{Abbo0000:Planar, AUTHOR="Amin Abbosh", TITLE="Planar Tapered Slot Antenna for Intrachip Wireless Interconnection", BOOKTITLE="Mosharaka International Conference on Communications, Networking and Information Technology", ADDRESS="Amman, Jordan", DAYS=5, MONTH=dec, YEAR=2008, KEYWORDS="Intrachip communication; wireless interconnect; ultra large scale technology", ABSTRACT="This paper presents the design of a wireless link for intrachip communication. Tapered slot antennas of compact size are proposed for efficient transmission of signals within the frequency range 20 GHz to 30 GHz between different parts of a microelectronic module in ultra large scale (ULS) integration technology. The simulated results using full-wave electromagnetic simulations indicate the superiority of the proposed antenna compared with other designs available in the literature. The presented antenna has a differential input to cancel any noise and/ or interference that may affect negatively on performance of the wireless intrachip link." } @INPROCEEDINGS{Abbo0800:Modelling, AUTHOR="Maysam Abbod and Tawfeeq Al-Kanhal", TITLE="Modelling and Optimisation of Reheat Furnace", BOOKTITLE="European Modelling Symposium 2008", ADDRESS="Liverpool, United Kingdom", DAYS=8, MONTH=sep, YEAR=2008, KEYWORDS="Intelligent Manufactirung system, optimisation", ABSTRACT="Some problems are known to have a computationally demanding objective function, which could turn to be infeasible when large problems are considered. Therefore, fast approximations to the objective function are required. This paper employs portfolio of intelligent systems algorithms for optimising a metal reheat furnace scheduling problem. The proposed system has been evaluated for different techniques of the reheat furnace scheduling problem. Particle Swarm Optimisation (PSO), Genetic Algorithm (GA) with different classic and advanced versions: GA with chromosome differentiation (GACD), Age GA (AGA), and Sexual GA (SGA), and finally a Mimetic GA (MGA), which is based on combining the GA as a global optimiser and the PSO as a local optimiser. Simulations have been performed to validate the system on the reheat furnace scheduling problem." } @INPROCEEDINGS{Abbo0809:Mapping, AUTHOR="Anteneh Abbo and Abhiram Ganesh and Vincent Jeanne and Caifeng Shan and Ralph Braspenning and Martin Ouwerkerk and Henk Corporaal", TITLE="Mapping Facial Expression Recognition Algorithms on a {Low-Power} Smart Camera", BOOKTITLE="Second ACM/IEEE International Conference on Distributed Smart Cameras", ADDRESS="Stanford University, Palo Alto, CA, USA", DAYS=7, MONTH=sep, YEAR=2008, KEYWORDS="Facial Expression Recognition, Video Scene Analysis, Parallel Processing, Low-Power Smart Camera", ABSTRACT="Recent developments in the field of facial expression recognition are advocating the use of feature vectors based on Local Binary Patterns (LBP). Research focus on algorithmic side addresses robustness issues when dealing with non-ideal illumination conditions. In this paper, we address the challenges related to mapping these algorithms on smart camera platforms. Algorithmic partitioning taking into account the camera architecture is investigated with a primary focus of keeping the power consumption low. Experimental results show that the compute-intensive feature extraction phase can be mapped on a massively-parallel processor with good processor utilization. Although the feature classification phase can also benefit from parallel processing, mapping on a small sequential processor could suffice." } @INPROCEEDINGS{AbdA0811:Characterization, AUTHOR="Norazreen {Abd Aziz} and Badariah Bais and Hamzah {Azrul Azlan} and Burhanuddin {Yeop Majlis}", TITLE="Characterization of {HNA} etchant for silicon microneedles array fabrication", BOOKTITLE="2008 IEEE International Conference on Semiconductor Electronics", ADDRESS="Johor Bahru, Malaysia", DAYS=25, MONTH=nov, YEAR=2008, KEYWORDS="HNA etchant; wet isotropic technology; solid microneedles", ABSTRACT="Research on microneedles has been increasing rapidly to overcome the drawbacks of hypodermic needle which can results in painful injection, tissue damage and uncontrollable delivery rate. This paper presents process characterization of wet isotropic etching for solid microneedles array development. Work has been carried out to investigate the isotropic etching behavior in 17 different compositions of HNA solution. The experimental responses of vertical etch rate and lateral etch rate are presented. Resulting surface profiles from various HNA compositions are also reported. The etching properties will be applied to develop recipe to fabricate the optimum solid microneedles." } @INPROCEEDINGS{Abde0000:Energy, AUTHOR="Hady AbdelSalam and Syed Rizvi", TITLE="Energy Efficient Workforce Selection In {Special-Purpose} Wireless Sensor Networks", BOOKTITLE="Infocom 2008 - Student Workshop", ADDRESS="Phoenix, Arizona, USA", DAYS=13, MONTH=apr, YEAR=2008, KEYWORDS="Energy Sensor Longevity Wireless", ABSTRACT="Due to the limited energy budget of sensors, many protocols have been proposed to optimize energy consumption in different areas of WSNs (e.g. MAC, routing, data aggregation ... etc). Literature has given less attention to energy efficient workforce management. In this work, we show that ignoring the way sensors are being recruited for tasks results in severely uneven consumption of sensors energy, hence it reduces network lifetime significantly. For the limited communicational capabilities of sensors, communication in WSNs deployed in large areas is multihop by nature. However for some special WSN applications (e.g firefighting and handicapped assistance) where the Aggregating Node(AN) (mounted on the firefighter helmet or the handicapped stick) has low mobility, the monitored area of interest is temporarily limited to a small disk centered at the AN. Sensors deployed on the moving disk and the AN form a dynamic WSN where a single hop communication model is appropriate and beneficial. For such scenarios, we propose and evaluates a new protocol that provides an energy efficient workforce management for single and multihop WSNs. Analytical and simulation results for single hop demonstrate that the proposed approach significantly increases network lifetime by evenly consuming sensors energy. Currently, we are working to analyze and simulate the proposed protocol for multihop WSN." } @INPROCEEDINGS{Abde0000:GSM, AUTHOR="Nemat {Abdel Kader}", TITLE="{GSM} Effect on the Speaker Identification Performance", BOOKTITLE="Mosharaka International Conference on Communications, Signals and Coding", ADDRESS="Amman, Jordan", DAYS=17, MONTH=oct, YEAR=2008, KEYWORDS="speech coding; GSM system; speaker recognition; vector quantization", ABSTRACT="This paper introduces the influence of GSM encoder/decoder on text independent speaker recognition performance based on Vector Quantization (VQ) classifiers. A database consisting of 136 speakers is used to investigate the system performance. The speaker recognition is evaluated using the original database. The speech files are then passed through the GSM coder/decoder. The coded speech is finally used for training and testing the speaker recognition system. The effect of the additive white Gaussian noise (AWGN) and Rayleigh fading channels on the system performance is also investigated." } @INPROCEEDINGS{Abde0000:OOV, AUTHOR="Bellaachia Abdelghani and Ghita Amor-Tijani", TITLE="{OOV} Words in an {English-Arabic} {CLIR} System", BOOKTITLE="13th IEEE Symposium on Computers and Communications", ADDRESS="Marrakech, Morocco", DAYS=6, MONTH=jul, YEAR=2008, KEYWORDS="CLIR, transliteration, n-gram, POS disambiguation", ABSTRACT="Proper nouns are usually primary keys in a query. Their correct translation might be necessary to maintain a good retrieval performance in a Cross Language Retrieval (CLIR) system. However, dictionaries usually only include the most commonly used proper nouns like major countries and capitals. As they are spelling variants of each other in most languages, using a string matching technique against the target database index is the common approach taken to find the target language correspondents of the original query key. N-gram technique proved to be the most effective among other string matching techniques. As we are dealing with an English-Arabic CLIR system which involves two languages of different alphabets, we decided to combine transliteration with n-gram to generate the different spelling variants of Out Of Vocabulary (OOV) words, specifically proper nouns. One issue that arises with the Arabic language is that words that are spelled similarly can have different meanings depending on how they are used in the sentence. This is particularly true for proper names, which usually have a meaning if used as a verb or adjective. To further enhance our transliteration approach, we chose to use Part Of Speech (POS) disambiguation to reduce the number of unrelated words from the set transliterations obtained." } @INPROCEEDINGS{Abde0000:Optimal, AUTHOR="Tamer AbdelKader and Kshirasagar Naik and Amiya Nayak", TITLE="Optimal Link Scheduling for Multimedia {QoS} Support in Wireless Mesh Network", BOOKTITLE="International Conference on Internet Multimedia Services Architecture and Applications", ADDRESS="Bangalore, India", DAYS=10, MONTH=dec, YEAR=2008, KEYWORDS="Wireless mesh networks, link scheduling, power allocation", ABSTRACT="Supporting multimedia quality of service (QoS) is a necessary and critical requirement for next generation wireless networks. Wireless Mesh Networking is envisioned as an economically viable paradigm and a promising technology for supporting multimedia QoS. The non-mobile mesh routers with the capability of having less-constrained transmission power are the distinct characteristics for this type of wireless networks. Exploiting these capabilities provides better solutions for allocating network resources such as bandwidth, and supports satisfying QoS requirements. Using these characteristics, we propose a QoS-aware link scheduling scheme for wireless mesh networks (WMNs). The scheme allocates time slots and transmission power to the network nodes in a way that maximizes the spatial reuse of the network bandwidth. In this paper, we study two cases: a mesh network with battery-powered devices and a network with outlet-powered devices. Using computer simulations, we show that the QoS constraints for the different traffic flows can be met, for the two cases, in addition to maximizing the network throughput." } @INPROCEEDINGS{Abde0000:Security, AUTHOR="Hajami Abdelmajid", TITLE="Security and key management in {OLSR} routing", BOOKTITLE="The Second International Conference on New Technologies, Mobility and Security", ADDRESS="Tangier, Morocco", DAYS=5, MONTH=nov, YEAR=2008, KEYWORDS="Digital signature, Key management, Mobile Ad hoc Network, OLSR, Security", ABSTRACT="This paper is about security of routing protocols in ad hoc networks. We begin by a survey of different attacks occurred on routing protocols used in ad hoc environments, and then we focus particularly on the OLSR (Optimized Link State Routing) vulnerabilities. We proceed by dividing the problem into two parts. First we treat the ways to sign OLSR traffic, and secondly we address how to manage encryption keys. We then propose a new approach to secure this routing protocol using a symmetric key and we present the impact of our solution on the OLSR performance. Thereafter, we present an extension hybrid using symmetric and asymmetric key. This extension helps to strengthen encryption mechanisms. At the end of this article, we present solutions that can resolve key management problem." } @INPROCEEDINGS{Abde0000:Transliteration, AUTHOR="Bellaachia Abdelghani and Ghita Amor-Tijani", TITLE="A Novel Transliteration Technique in {English‑Arabic} Cross Language Information Retrieval", BOOKTITLE="13th IEEE Symposium on Computers and Communications", ADDRESS="Marrakech, Morocco", DAYS=6, MONTH=jul, YEAR=2008, KEYWORDS="Cross language information retrieval; proper nouns; transliteration; n-gram", ABSTRACT="One of the main issues faced by Cross Language Information Retrieval (CLIR) is Out Of Vocabulary (OOV) words. Those are words not found in the dictionary. Bilingual dictionaries in general do not cover most proper nouns which are usually primary keys in the query. As they are spelling variants of each other in most languages, using a string matching technique against the target database index is the common approach taken to find the target language correspondents of the original query key. N-gram technique proved to be the most effective among other string matching techniques. The issue arises when the languages dealt with have different alphabets. Transliteration is then applied based on phonetic similarities between the languages involved. In this study, both transliteration and the n-gram technique are combined to generate possible transliterations in an English - Arabic CLIR system. We refer to this technique as Transliteration N-Gram (TNG)." } @INPROCEEDINGS{Abde0800:Architecture, AUTHOR="Mohammad Abdeen and Heba Mohammad and Mustapha Yagoub", TITLE="An Architecture for {Multi-Lingual} {Hands-Free} Desktop Control System for {PC} Windows", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, KEYWORDS="HCI; Speech recognition; Windows", ABSTRACT="Technology in the 21st century has achieved quantum leaps in serving many communities; from home, to school children, to government and municipalities, to nation. Personal Computers (PC) have been central to these achievements and it is essential to facilitate their accessibility to people who have difficulties using the keyboard and mouse. In this work we present a framework for controlling the computer desktop with voice commands. This framework is based on PC windows (Microsoft windows XP) and it is language independent. The framework is tested for English (a Latin language) and Arabic (a Semitic language). At the end of the paper we provide a comparison between this work and a similar work of windows Vista" } @INPROCEEDINGS{Abde0800:Fast, AUTHOR="Mohamed Abdelhalim and Serag Habib", TITLE="Fast {FPGA-Based} Area And Latency Estimation For A Novel {Hardware/Software} Partitioning Scheme", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, KEYWORDS="HW/SW Partitioning, Area Estimation, Latency Estimation.", ABSTRACT="In this paper a fast and accurate area and latency estimation tool for FPGA-based designs is presented. The tool is developed in the context of a HW/SW partitioning tool. Rather than modeling the hardware implementation as a single alternative, our approach for HW/SW partitioning models the hardware as two extreme alternatives that bound latency range for different hardware implementations. The presented estimation tool estimates the area and latency for these two hardware alternatives. The computational cost of the presented estimation tool depends linearly on the design complexity, and hence, it is very useful for fast design space exploration. Testing this estimation tool on several designs showed that this tool is also accurate. Area estimations are within ±7.5\% of the actual number of logic elements consumed with an average error of 3.2\% for Cyclone FPGAs and 3.5\% for Stratix FPGAs." } @INPROCEEDINGS{Abde0801:Enhancing, AUTHOR="Marwen Abdennebi and Marc Ibrahim and Samir Tohme", TITLE="Enhancing {MAC} {IEEE} {802.16} Voice Support with Statistical Multiple Access for {UMTS} Integration", BOOKTITLE="2008 IEEE Consumer Communications and Networking Conference - Network Access and Communications", ADDRESS="Las Vegas, USA", DAYS=10, MONTH=jan, YEAR=2008, ABSTRACT="With the growing deployments of UMTS/HSDPA and recently WiMAX, the integration of these two broadband radio networks becomes an important challenge. However, the convergence of UTRAN and IEEE 802.16 as a radio access network is still limited. In this paper we propose a simple adaptation in WiMAX to enhance voice over IP support for end to end telephonic applications between UMTS and WiMAX. Our goal is to allow an operator to propose UMTS service via an 802.16 radio access network or UTRAN as well. First, we super-framed the 802.16 frame to enhance AMR codec compatibility. In addition, we use ON/OFF periods detection of voice sources to decrease the bandwidth allocated for the same number of calls. We then take advantage from the WiMAX uplink frame structure and from the loss tolerance of voice. Performance evaluation (analytical and simulation) is given to illustrate the benefits of our proposal." } @INPROCEEDINGS{Abde0804:Durable, AUTHOR="Hady AbdelSalam and Syed Rizvi and Stephan Olariu", TITLE="A Durable Sensor Enabled Lifeline Support for Firefighters", BOOKTITLE="The Second IEEE International Workshop on Mission-Critical Networking", ADDRESS="Phoenix, Arizona, USA", DAYS=13, MONTH=apr, YEAR=2008, KEYWORDS="Wireless Sensor Networks, Navigation, Network Longevity, Wearable Computing, Design Management Algorithms", ABSTRACT="When moving through a building structure under impaired visibility, firefighters use lifelines. These lifelines (example, ropes) can get stuck or become entangled and provide only one retreat path which limits the operational range. Also, a lifeline does not communicate critical information to the outside support staff. A recently proposed concept is that the firefighters automatically deploy wireless sensor nodes along their paths effectively establishing an ad-hoc infrastructure for positioning, sensing and communication. Firefighters interact with these Wireless Sensor Networks (WSN) by way of wearable computing equipment and receive navigational information on e.g. a head-mounted display or over a headset. Durability with respect to energy available in WSN is one of the primary challenges to the firefighters of mission-critical networks in a newly deployed or pre-installed on-site ubiquitous emergency purpose WSN. Workforce selection strategies which unevenly consume sensor energy can reduce the lifetime of the network significantly. This work proposes and evaluates a new class of strategies that provides an energy efficient workforce management for mission-critical WSNs e.g. on-site support for slow moving firefighters at indoor-navigation under impaired visibility. Analytical and simulation results demonstrate that the proposed approach significantly increases network lifetime by evenly consuming sensors power." } @INPROCEEDINGS{Abde0804:Efficient, AUTHOR="Abdelkrim Abdelli and Dahbia Yahiatene", TITLE="Efficient computation of state space {DBM-approximation} of real-time preemptive systems.", BOOKTITLE="AICCSA-08 Software Systems and Applications Track", ADDRESS="Doha, Qatar", DAYS=1, MONTH=apr, YEAR=2008, KEYWORDS="DBM, preemtive systems, state class graph, polyedron system, Time Petri net, inhibitor arc.", ABSTRACT="In preemptive real time systems, clocks are associated with tasks which could be reset, suspended and resumed. Their timeliness and reachability analyzes consume exponential computation complexities. In this paper, an algorithm is presented allowing an efficient computation of a DBM approximation of the state class graph of such systems modeled using Time Petri Nets with inhibitor arcs. For this effect, each class of the approximate graph is a pair (M,D) where M is the current marking and D is a matrix holding the DBM time constraints. Therefore, thanks to the use of an adapted class equivalence condition, the enumeration process yields a much compact graph than other existing DBM approximation techniques, so that the computation complexity of each class is assessed to o(n²). To advocate our proposition, we give experimental results comparing our algorithm with other existing approaches." } @INPROCEEDINGS{Abde0804:Enhanced, AUTHOR="Ayman Abdel-Hamid and Lobna Eslim and Yasser Hanafy", TITLE="Enhanced Mobile Node’s Reachability through Anycasting for {MIPv6} Regional Registrations", BOOKTITLE="AICCSA-08 Networking and Multimedia Track", ADDRESS="Doha, Qatar", DAYS=1, MONTH=apr, YEAR=2008, KEYWORDS="MIPv6, regional registrations, anycasting, fault tolerance, reachability", ABSTRACT="Mobile IPv6 (MIPv6) provides an efficient solution to solve the wide-area host mobility problem. MIPv6's registration process introduces overhead in case of local-area mobility when coupled with a high rate of change of the mobile node’s point of attachment. Regional-aware router hierarchies along with a regional registration framework have been introduced to reduce binding update overhead in case of local-area mobility. In this paper, a framework which leverages the availability of IPv6 anycasting functionality is introduced to enhance MIPv6 regional registrations. The novel framework is designed to promote fault tolerance and improve the mobile node’s reachability in the foreign domain. In this framework, roots of regional-aware router hierarchies are members of the same anycast group. The anycast address is employed in home registrations as a care-of-address for mobile nodes. Mobility management state is accessible from all hierarchies either by utilizing a push data replication mechanism among roots of regional-aware router hierarchies or by deploying a mobility support service in the foreign domain, which acts as a repository of such state. Our framework enables the mobile node to be reachable, while moving across domain hierarchies, even if the domain suffers from n-1 failures of hierarchies’ roots where n is the number of hierarchies in the domain." } @INPROCEEDINGS{Abde0805:Co, AUTHOR="Ahmed {Abdelsalam Ahmed} and Ian Marsland", TITLE="Co-channel Interference Cancellation in Multihop Relay Networks", BOOKTITLE="IEEE BWA", ADDRESS="Beijing, China, P.R. China", DAYS=19, MONTH=may, YEAR=2008, KEYWORDS="Multihop; Interference cancellation; multiuser detection", ABSTRACT="In this paper, we propose using iterative multiuser detectors for co-channel interference suppression in wireless cellular systems. We demonstrate that a receiver with a single receive antenna is capable of detecting and cancelling a single in-band interferer that uses the same coding and modulation scheme as the desired signal. We investigate the benefits of using such an interference canceller in the mobile receiver in the downlink scenario of a two-hop relay network. Results show significant improvements with iterative interference cancellation in terms of the average system throughput and outage probability. Because the interference canceller is so effective, more aggressive frequency reuse schemes can be now considered, such as using smaller cluster sizes, using 3-sectored cells where all sectors share the same frequency band, and using non-orthogonal channels for relaying." } @INPROCEEDINGS{Abde0805:PDSMA, AUTHOR="Marwen Abdennebi and Samir Tohme", TITLE="{PDSMA:} {Pseudo-Deterministic} Statistical Multiple Access for Voice Packets Uplink Scheduling", BOOKTITLE="ICC'08 - Wireless Networking Symposium", ADDRESS="Beijing, China, P.R. China", DAYS=19, MONTH=may, YEAR=2008, ABSTRACT="Statistical multiple access gives opportunity to decrease bandwidth wastes in radio cellular networks when sources activities are variable. Usually, 2 states exponential ON-OFF models are used for voice sources and to study statistical multiplexing in telephony. In this paper, we propose a distributed algorithm based on a 3-states model with downlink activity detection for a refined prediction. The proposed algorithm makes the distinction between silent sources according to their downlink activities to enhance the statistical multiple access for telephony. Then, silent sources are pre-allocated available channels on the uplink according to their respective switching probabilities; hence the designation “pseudo-deterministic” for our proposed statistical multiple access scheme. Performance evaluation (analytical and simulation model) is given to illustrate the benefits of our proposal." } @INPROCEEDINGS{Abde0806:Time, AUTHOR="Chehri Abdellah and Paul Fortier and Pierre-Martin Tardif", TITLE="{Time-Of-Arrival} Estimation for {IR-UWB} Systems based on Two Step Energy Detection", BOOKTITLE="24th Queen's Biennial Symposium on Communications", ADDRESS="Kingston, Ontario, Canada, Canada", DAYS=23, MONTH=jun, YEAR=2008, KEYWORDS="TOA, UWB, Underground mines, Ranging", ABSTRACT="Time of arrival (ToA) estimation using Ultra-Wideband (UWB) transmission is currently the most popular technique for accurate geolocation. In this paper, we address the performance of no-coherent TOA estimation schemes of IR-UWB signals. The algorithm of estimation is based on two steps (coarse and fine) energy detection. The algorithm is evaluated for particular environment (i.e., underground mines). Hence, all simulations are performed using generated UWB channel in underground mines. Results show that the proposed detector greatly outperforms other conventional method like peak detection and threshold crossing method. Statistical characterizations of the normalized ranging error using this algorithm are evaluated for LOS and NLOS scenario." } @INPROCEEDINGS{Abde0807:Apparent, AUTHOR="Kouzou Abdellah", TITLE="Apparent Power Evaluation of Series Active Power Filter with Recent Definitions", BOOKTITLE="Fifth International Multi-conference on Systems, Signals, and Devices", ADDRESS="Amman, Jordan", DAYS=20, MONTH=jul, YEAR=2008, KEYWORDS="Series active power filter, voltage unbalance, apparent power, IEEE Std 1459-200, European school approach, power ratio.", ABSTRACT="The main purpose of this paper is the study of the Series Active Power Filter (SAPF) compensation capability for different unbalance perturbations of three-phase three wire AC power systems such as voltage unbalance, phase-shift unbalance. Indeed SAPF has been proved to be an effective solution to compensate for different voltage disturbances in the power system. The capability of the Series APF is determined by the maximum rate of the apparent power that can be delivered. This study present a comparison based on the approaches presented by the definition of the effective apparent power as defined in IEEE 1459-2000, the European school approach and the apparent power classical approach. The two first approaches were proved to be the best methods for the calculation of the apparent power, that is presenting the suitable amount to be concerned in the design process of different devices. It allows a good estimation of the Series APF dimensions with low economic burden. Some applications which may be occur in the AC power systems were presented , mainly for three-phase, three-wire AC power systems without neutral wire." } @INPROCEEDINGS{Abde0807:Concept, AUTHOR="Djahbar- Abdelkader", TITLE="A novel concept for multimachine drive systems with rotor time constant estimation", BOOKTITLE="Fifth International Multi-conference on Systems, Signals, and Devices", ADDRESS="Amman, Jordan", DAYS=20, MONTH=jul, YEAR=2008, KEYWORDS="Six-phase Induction Machine, Three-phase Induction Machine, Vector Control", ABSTRACT="In recent years, multiphase machines are gaining an increasing interest due to the advantages they possess compared to the conventional three phase machines. One of these advantages is their additional degrees of freedom.In this paper, extensive simulation studies of series connected multimachines system supplied by a single inverter are presented. This system consists of a six-phase induction machine and a three-phase induction machine. The stators windings of both machines are connected in series in appropriate manner.The dynamic decoupling of each machine from the group is obtained using the indirect vector control algorithm. Mathematical modeling of the multimachine system showed the possibility of independent control of each machine in the group. The independent control is demonstrated by analyzing the characteristics of the torque and speed of each machine obtained via simulation of multimachine system under indirect vector control scheme. However, the independent control scheme is model-based thus very sensitive to changes in certain parameters of the series connected machines. To overcome this problem, these parameters are estimated on line and used to update the control scheme. The simulation results obtained demonstrate the improved robustness of the multimachines system under the proposed control algorithm." } @INPROCEEDINGS{AbdE0807:High, AUTHOR="Ahmed {Abd El Al} and Tarek Saadawi", TITLE="High Throughput Path Selection Mechanism for {Multi-Path} Video Streaming in {Ad-Hoc} Networks", BOOKTITLE="13th IEEE Symposium on Computers and Communications", ADDRESS="Marrakech, Morocco", DAYS=6, MONTH=jul, YEAR=2008, KEYWORDS="Multipath routing, Ad-hoc Networks, Wireless Video", ABSTRACT="Owing to the absence of any static structure, Ad-hoc networks are prone to packet losses and link failures. Selecting the shortest path may not lead to high quality routes. The consequent high loss rates can lead to the degradation of throughput and increase in the end-to-end delay on the selected path, which can lead to devastating effects for the transport of compressed video. This paper suggests selection mechanism for multi-path routing protocols that selects routes on the basis of the expected throughput of the candidate routes. We have studied the performance of the proposed mechanism by incorporating it into a multi-path routing protocol, and examining the quality of compressed video streams in this network. Simulation results show that the proposed selection mechanism maintains the video quality under different loss rates and mobility speeds. Also we have found that our mechanism significantly outperform shortest path selection." } @INPROCEEDINGS{Abde0807:Stochastic, AUTHOR="Maouche Abdelaziz", TITLE="A Stochastic Failure Compensation Controller of Induction Motor Based State Estimation Technique", BOOKTITLE="Fifth International Multi-conference on Systems, Signals, and Devices", ADDRESS="Amman, Jordan", DAYS=20, MONTH=jul, YEAR=2008, KEYWORDS="Modelling, stochastic optimal control, fault tolerance, induction motor.", ABSTRACT="The purpose of this paper deals with the stochastic failure compensation controller of induction motor based state estimation technique. It is well known that induction motor drives are widely used as important parts in industrial applications. In consequence it must be carefully controlled to ensure optimum, profitable and reliable operations. However induction motor drive systems are also known as complex non-linear time-varying systems. Based on the fact that the system model can be significantly simplified if one applies in addition with the d-q Park transformation an appropriate field orientation technique, an adequate model structure of the induction motor is obtained. The observer-based state variable estimation technique, stochastic and determinist, is used for control and monitoring of the considered induction motor system. Finally a simulation example of is given to point out the merits of the proposed approach for stochastic optimal compensation and control for induction motor." } @INPROCEEDINGS{Abde0808:Rotated, AUTHOR="Charbel {Abdel Nour} and Catherine Douillard", TITLE="Rotated {QAM} Constellations to Improve {BICM} Performance for {DVB-T2}", BOOKTITLE="The 10th ISSSTA 2008 - Creating New Dimensions in the Wireless World", ADDRESS="Bologna, Italy", DAYS=25, MONTH=aug, YEAR=2008, ABSTRACT="A technique intended to increase the diversity order of Bit-Interleaved Coded Modulations (BICM) over non Gaussian channels is presented. It introduces simple modifications to the mapper and to the corresponding demapper. They consist of a constellation rotation coupled with signal space component interleaving. Iterative processing at the receiver side can provide additional improvement to the BICM performance. This method has been shown to perform well over fading channels with or without erasures. It has been adopted for the 4-, 16-, 64-, and 256-QAM constellations considered in the DVB-T2 standard. Resulting gains can vary from 0.2 dB to several dBs depending on the order of the constellation, the coding rate and the channel model." } @INPROCEEDINGS{Abde0809:Advanced, AUTHOR="Humberto Abdelnur and Radu State and Olivier Festor", TITLE="Advanced Network Fingerprinting", BOOKTITLE="Recent Advances in Intrusion Detection", ADDRESS="Boston, Massachusetts, USA", DAYS=15, MONTH=sep, YEAR=2008, KEYWORDS="fingerprinting, protocol reverse engineering", ABSTRACT="Fingerprinting network devices and applications is an important action on network assessment and security monitoring. Although standardized behavior should be implemented in these devices and applications, subtle differences allow to identify and to discriminate among traffic sourced and originated on a given network. In this paper we will present a technique that can automatically identify the specific features characteristic to a given device. We will show experimental results on the automatic fingerprinting of SIP devices and describe how these concepts have been implemented in a software prototype." } @INPROCEEDINGS{Abde0809:Energy, AUTHOR="Hady AbdelSalam and Stephan Olariu", TITLE="{Energy-Based} Task Load Balancing in Wireless Sensor Networks", BOOKTITLE="The First IEEE Workshop on the Theory of Ad-Hoc and Sensor Networks (ThASN '08)", ADDRESS="Atlanta, Georgia, USA", DAYS=29, MONTH=sep, YEAR=2008, KEYWORDS="Energy Aware; Task Assignment; Network Management ; Sensor Nework; Load Balancing; Network Longevity; Network Lifetime", ABSTRACT="We investigate how to maximize network lifetime by devising a task assignment protocol that balances task load on sensors based on their remaining energy. First, we show that energy-unaware protocols can excessively assign tasks to a set of sensors more than others. Consequently, the energy of those heavily loaded sensors will be depleted much faster than lightly loaded ones. This results in reducing network density around heavily loaded sensors and eventually creates energy holes that isolate the network into separated islands. This kind of behavior has its negative impacts on network durability and reliability. To avoid these problems, we propose a management protocol that assigns tasks to sensors based on their remaining energy so that energy consumption is almost even among network sensors." } @INPROCEEDINGS{Abde0809:Improving, AUTHOR="Charbel {Abdel Nour} and Catherine Douillard", TITLE="Improving {BICM} performance of {QAM} constellations for broadcasting applications", BOOKTITLE="5th International Symposium on Turbo Codes and Related Topics", ADDRESS="Lausanne, Switzerland", DAYS=2, MONTH=sep, YEAR=2008, KEYWORDS="Bit-interleaved coded modulation, constellation rotation, component delay, diversity, iterative demapping, fading and erasure channel", ABSTRACT="A technique intended to improve the performance of Bit-Interleaved Coded Modulations (BICM) over non Gaussian channels is presented. It introduces modifications to the mapper and to the corresponding demapper. These changes consist of a rotation of the constellation followed by a signal space component interleaving. Iterative processing at the receiver side is shown to provide additional performance improvement. This method outperforms state-of-the-art systems over flat fading channels. Substantial gains with respect to BICM are obtained for severe channel conditions. It has been adopted for the 4 , 16 , 64 and 256 QAM constellations in the upcoming next generation Digital Video Broadcasting-Terrestrial (DVB-T2) standard. The improvement in performance can vary from 0.2 dB to several dBs depending on the order of the constellation, the coding rate and the channel model." } @INPROCEEDINGS{Abde0811:Analytical, AUTHOR="Mostapha {Abdel Naby} and Mohamed {Abdel Aziz} and Abdel Aziz Shalaby and Ali El-Abd", TITLE="An Analytical Expression for The I {–} V Characteristics of {AlGaN/GaN} {HEMTs}", BOOKTITLE="2008 IEEE International Conference on Semiconductor Electronics", ADDRESS="Johor Bahru, Malaysia", DAYS=25, MONTH=nov, YEAR=2008, KEYWORDS="I - V Modeling; GaN HEMT; Voltage Parameter", ABSTRACT="AlGaN/GaN high electron mobility transistors(HEMTs) have application recently attracted great interest for in high-temperature, high-power and high-frequency microelectronic devices due to their high thermal stability, high electron saturation velocity, and high operating voltages. In order to maximize the benefits of AlGaN/GaN HEMTs, accurate analytical I-V models should be developed to precisely describe the device phenomena. Most theoretical I-V models appeared in the literature fail to exactly fit the experimental data and a large deviation is reported, specially at large gate bias. In a previous work, we succeeded to find a standard method to get an accurate I-V characteristics by introducing a new dimensionless voltage parameter K that relates the computed average channel voltage to the actual value. In this paper, we suggested two analytical functions to express this voltage parameter in order to help obtaining an accurate analytical I-V model. The first will be useful in CAD routines for computing the AlGaN/GaN HEMT I-V characteristics. The second function is less accurate than the first but it is simpler and may be helpful in understanding the physical meaning of the voltage parameter. The suggested functions are introduced into analytical I – V model for high electron mobility transistor. And a good agreement between our I – V model results and the measured results have been obtained ." } @INPROCEEDINGS{Abde0811:ENHANCED, AUTHOR="Ibrahim Abdel-hafez and Yaser Khalaf and Fathi Farag", TITLE="{ENHANCED} {TRANSCONDACTANCE} {BUFFER} {FOR} {DRIVING} {LARGE} {CAPACTIVE} {LOAD}", BOOKTITLE="2008 IEEE International Conference on Semiconductor Electronics", ADDRESS="Johor Bahru, Malaysia", DAYS=25, MONTH=nov, YEAR=2008, KEYWORDS="Analog circuits, analog integrated circuits, low-power design, low voltage design.", ABSTRACT="This paper describes two new configurations of CMOS buffer circuits. The new buffers are based on a Flipped Voltage Follower (FVF) cell with feedback in order to enhance the transconductance of the buffer as well as linearity. The proposed cells “Voltage Follower (VF) with diode-connected load and VF with current source” can be used as a wide bandwidth buffer to drive large capacitive loads. The employed feedback enhances the overall transconductance while minimizing the loading effect. The circuits are designed and simulated using 0.13µm CMOS process. Simulation results of the proposed buffers show bandwidths of 171 and 243 MHz for a capacitive load of 30 pF. The power consumption for all buffers is 2.4 mw for 1.5 V power supply. The total harmonic distortion THD is -42.95 and -45.27 dB and the phase margin is 65.3 and 71degree." } @INPROCEEDINGS{Abde0811:GMRES, AUTHOR="Abdaoui Abderrazek and Marion Berbineau and Hichem Snoussi", TITLE="{GMRES} Interference Canceler for {MIMO} Relay Network", BOOKTITLE="IEEE Globecom 2008 Communication Theory Symposium", ADDRESS="New Orleans, LA, USA", DAYS=30, MONTH=nov, YEAR=2008, KEYWORDS="MIMO Relay Network; Cooperative relaying; GMRES method; Krylov sub-space; IC-MMSE; Capacity estimation", ABSTRACT="In this paper, we introduce a collaborative Minimum Mean Squared Error (MMSE) interference canceler in MIMO relay networks. The Proposed receiver architecture is characterized by the integration of the Generalized Minimum RESidual method (GMRES) for symbol detection. In this scheme, the GMRES method detects the transmitted symbols by solving iteratively a linear system representing the MMSE interference canceler without matrix inversion. The Relay - Destination channels are assumed orthogonal. We evaluate the instantaneous capacity of the equivalent MIMO relay network equipped with $K$ parallel relay nodes for TDMA and MC-CDMA modes, using the assumption that the source node does not communicate directly with the destination node. In order to evaluate the system performances, the Bit Error Rate (BER) is evaluated with respect to the number of relay nodes $K$ and to the Signal to Noise Ratio (SNR) measured at the destination." } @INPROCEEDINGS{Abde0811:Tiling, AUTHOR="Hady AbdelSalam", TITLE="{Tiling-Based} Localization Scheme for Sensor Networks Using Single Beacon", BOOKTITLE="IEEE Globecom 2008 Ad Hoc, Sensor and Mesh Networking Symposium", ADDRESS="New Orleans, LA, USA", DAYS=30, MONTH=nov, YEAR=2008, KEYWORDS="Localization; Sensor Network; Hexagon ; AOA; Tiling", ABSTRACT="In this work, we propose and evaluate a new localization protocol for sensor networks. Contrary to most current localization schemes, this protocol relies on the existence of only a single beacon node. The main idea is to hypothetically tile the deployment area with identical equilateral geometric shapes (e.g. Hexagons, Triangles). Tiling should be such that the positions of the centers of these shapes can be mathematically computed relative to the position of the beacon node. After that, the set of nodes that are as close as possible to the centers of these shapes is determined. We refer to these nodes as central nodes. Basically, the positions of these central nodes can be approximated by the positions of the centers of the geometric shapes which can be calculated mathematically. These central nodes can be treated as beacons and the positions of all non-central nodes can be estimated using any range-free protocol (e.g. the centroid). Simulation results show that the accuracy of the proposed protocol is comparable to the accuracy of current localization protocols especially near the beacon node. In addition to this, the achieved localization accuracy increases significantly as the network density increases." } @INPROCEEDINGS{Abde0812:Exponential, AUTHOR="Ahmed {Abd el Halim} and Darek Korzec", TITLE="Design of an Exponential Stage for Organic Pixel Addressing", BOOKTITLE="20th International Conference on Microelectronics (ICM) 2008", ADDRESS="Sharjah, UAE, UAE", PAGES="441-444", DAYS=14, MONTH=dec, YEAR=2008, KEYWORDS="Organic thin Film transistor; Organic light emitting diode; Weber's Law", ABSTRACT="This paper presents a new approach for driving an organic light emitting diode (OLED) pixel circuit using organic thin film transistor (OTFT). Depending on the linear relation between the current passing through the OLED and its luminosity and relying on Weber’s law which states that the sensation of the eye to the change in brightness is logarithmic to the change itself an improved column driver is proposed. An exponential stage is added to the column driver after the digital to analog converter (DAC) block to supply the pixel circuit with exponential current. The design is done with OTFT (n-type and p-type). The model is extracted according to the current technology of organic elec-tronics." } @INPROCEEDINGS{Abdi0000:Information, AUTHOR="Reza Abdi", TITLE="Information System for Disruption Management of Emirates Flight Operations", BOOKTITLE="International Conference on Management of Technology 2008", ADDRESS="Dubai, UAE", DAYS=6, MONTH=apr, YEAR=2008, ABSTRACT="Airlines operate in a macro-economic environment characterised by stiff competition and stringent regulatory constraints. Disruption management can play a key role to assist the industry towards a minimum unit cost. This paper investigates communication process business drivers required for flight operations and disruption management. The disruption management in Emirates Airlines is studied to derive an operational strategy, in which input resources and transformation process are reconsidered in order to deliver effective output services to passengers. Effects of different types of flight disruptions are studied and the role of Network Control Centre (NCC) is identified through subsequent stages. A Management Information System (MIS) approach is proposed to offer solutions to disruption management. The flight disruption at the company are analysed along with their impacts on airport, aircraft and passengers through a real case study The paper is intended to investigate the influencing factors on the strategic flight operations/disruption management using the PEST analysis. This paper is to examine the current processes to handle disruptions in flight operations and discover proactive measures in order to avoid disruptions while running operational activities. In particular, an Information Technology (IT) framework is developed to manage the operations disruptions as well as flight operations. The proposed IT strategy can assist managers to explore existing disruptions and build a knowledge-based approach on the basis of historical data for handling the upcoming disruptions. The IT-based analysis can facilitate managing the disruptions and might result an alternative solution, which can eventually reduce the disruptions and the cost incurred. The data used in the research has mainly been gathered from interviews and discussions with different stakeholders and from the existing documentations." } @INPROCEEDINGS{Abdo0000:Boolean, AUTHOR="Afshin Abdollahi", TITLE="Boolean Matching for Incompletely Specified Functions Using Satisfy Counts", BOOKTITLE="International Workshop on Logic and Synthesis 2008", ADDRESS="Lake Tahoe, CA, USA", DAYS=4, MONTH=jun, YEAR=2008, ABSTRACT="Boolean matching is to determine whether two functions are equivalent under input permutation and input/output phase assignment. This paper will address the Boolean Matching problem for incompletely specified functions. Signatures have previously been used for Boolean matching of completely specified functions. In this paper for the first time we use signatures to determine the equivalency of incompletely specified functions." } @INPROCEEDINGS{Abdo0000:Do, AUTHOR="Farha {Abdol Ghapar}", TITLE="Do Malaysian Researchers Commercialize Their Research Results? An Empirical Study on Malaysian Public Universities and Research Institutions", BOOKTITLE="International Conference on Management of Technology 2008", ADDRESS="Dubai, UAE", DAYS=6, MONTH=apr, YEAR=2008, ABSTRACT="Economically, Malaysia has evolved from import-substitution to industrialization through export-oriented growth. Such a development has also changed the factors of competitive advantage, such as low cost labor, land availability and capital incentives to an intangible asset, which is primarily information and knowledge. Hence, this has bred a new economy known as “knowledge-based economy”. In the era of the knowledge economy, much importance is given to innovation and creativity and subsequently focuses the operations and task in bringing innovation to the market and to the hands of users or customers. The burden to bring idea to market is now on the shoulder of the Malaysian government through universities, research institutes and the multi-national corporations (MNC’s). Universities and research institutions around the world are being forced to venture in new directions to exploit the wealth of knowledge they possess and turn them into intellectual property, which may eventually be re-exploited to bring about monetary returns. Wealth will increasingly accrue to the nation with the capacity and capability to transform knowledge into new products and processes. It is through technology commercialization that Malaysian could join the rank of advanced nations. In this study, an empirical analysis using multinomial logistic regression via survey questionnaires in selected Malaysian public universities is run. There were 2 main models generated from this study. Model 1 is generated for “actual technology commercialization” and Model 2 is generated for “potential technology commercialization”, which will be the dependent variables in this study. Both models are divided into 2 segments which are the public universities and research institutions. We have used the multinomial logistic regression for this study. As for the independent variables, we have identified 3 main variables with each has its own sub-section. The main variables for the independent variables are 1) the awareness level, 2) the collaboration level and 3) the organizational practices. The result shows that, Model 1 identified the collaboration level and the awareness on market requirement as significant variables for the research results to be actually commercialized. On the other hand, Model 2 captures the awareness on intellectual property for research results to be potentially commercialized, followed by the collaboration level and the awareness on institutional practices. In a nutshell, Malaysia, as a developed country should exploit our findings to the fullest in ensuring its public universities and research institutions commercialize their research results vigorously. Keywords: Technology commercialization, innovation, Research \& Development (R\&D), Intellectual Property (IP)" } @INPROCEEDINGS{Abdo0800:Study, AUTHOR="Ali Abdollahian and Ayman El-Hag and Ali {Naderian Jahromi} and Mahdieh Farahani and Gholam Abbas Ranjbar", TITLE="A Study on the Aging Characteristics of {RTV} Insulator Coatings", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, KEYWORDS="high voltage, insulator, RTV, leakage current, aging", ABSTRACT="This paper presents the results of an investigation into the erosion and tracking resistance and the mechanical characteristics of three types of room temperature vulcanized (RTV) silicone rubber coatings for high voltage insulators when subjected to accelerated tests in acid water. Although all coatings have ATH as filler, different performance was observed under simulated acid rain condition. Erosion area, length of erosion and the development of the 3rd harmonic in the leakage current during inclined plane tests are employed to evaluate the tracking and erosion of acid aged samples. Thermo-gravimetric analysis (TGA) and thermal conductivity was employed to investigate the thermal performance of the coatings. Scanning electron microscope photographs are also used to assess surface changes after aging. Factors that have significant influence on the aging performance of RTV coatings include filler size and prior treatment, which can improve the performance of RTVs in severe ambient conditions." } @INPROCEEDINGS{Abdr0811:Statistical, AUTHOR="Atef Abdrabou and Weihua Zhuang", TITLE="Statistical Call Admission Control for {IEEE} {802.11} Multi-hop Wireless Ad hoc Networks", BOOKTITLE="IEEE Globecom 2008 Ad Hoc, Sensor and Mesh Networking Symposium", ADDRESS="New Orleans, LA, USA", DAYS=30, MONTH=nov, YEAR=2008, KEYWORDS="IEEE 802.11 MAC, multihop, ad hoc network, resource allocation, call admission control, delay.", ABSTRACT="In this paper, we introduce a fully distributed model-based call admission control (CAC) scheme for IEEE 802.11 multihop ad hoc networks. Our proposed CAC predicts the resources that a new call will consume by using both source traffic modeling and link-layer channel modeling, and hence guarantees sufficient network resources for the calls in service. Unlike most of the model-based CAC schemes in the literature, our CAC offers stochastic delay guarantees instead of average delay guarantees for multihop multimedia connections, based on the effective bandwidth theory and its dual effective capacity concept. Simulations results show that our scheme combines both efficient resource utilization and delay guarantees to a certain probabilistic limit." } @INPROCEEDINGS{Abdu0000:Performance, AUTHOR="Omar Abdul-Latif and Peter Shepherd and Stephen Pennock", TITLE="Performance Of {UWB} Telecommunication System in the Presence Of Multiple Access Interference", BOOKTITLE="IFIP Wireless Days", ADDRESS="Dubai, UAE", DAYS=24, MONTH=nov, YEAR=2008, KEYWORDS="CCI, diversity combining, MAI, RMSGC, UWB.", ABSTRACT="Ultra Wideband technology (UWB) is an emerging technology that has proven to be quite suitable for short range applications. This paper is part of an ongoing research for using UWB technology for positioning and remote sensing biometric information for team-sport players on a pitch, Simulation is conducted for a number of “players” who are carrying RFIDs transmitting signals with biometric information data about each player to a number of receiving antennas positioned around the field. We investigate the effect of multiple access interference (MAI) on the performance of UWB wireless systems using a novel MISO diversity combining scheme. The main goal is to determine the number of interferers that the system can handle before producing an unacceptable Quality of Service (QoS). The results show that, due to UWB low power spectral density characteristics, the system can handle a relatively large number of interferers." } @INPROCEEDINGS{Abdu0000:Using, AUTHOR="Wasan Abdulatef and Amin Abbosh", TITLE="Using a Hybrid {LMS/ML} Technique for {MIMO} Channel Estimation and Decoding", BOOKTITLE="Mosharaka International Conference on Communications, Networking and Information Technology", ADDRESS="Amman, Jordan", DAYS=5, MONTH=dec, YEAR=2008, KEYWORDS="Channel estimation; Channel coding; MIMO", ABSTRACT="In this paper, the least mean square adaptive technique is used for channel estimation for multiple-input multiple-output (MIMO) systems which employed the space division multiplexing (SDM) technique. The maximum likelihood algorithm is used to decode the information data. Results of simulation show the high accuracy of the proposed method for the channel estimation compared with the existing methods when applied for the new generations of high speed and high capacity communication systems. The application of the proposed method enables the successful estimation of the channel conditions, and hence the capability to increase capacity of the system via the use of the channel information for optimum data transmission/ reception." } @INPROCEEDINGS{Abdu0803:Decoding, AUTHOR="Ali AbdulHussein and Anand Oka and Lutz Lampe", TITLE="Decoding with Early Termination for Rateless (Luby Transform) Codes", BOOKTITLE="IEEE Wireless Communications and Networking Conference", ADDRESS="Las Vegas, Nevada, USA", DAYS=31, MONTH=mar, YEAR=2008, KEYWORDS="Coding, rateless codes, Luby Transform codes, belief propagation, message passing, termination", ABSTRACT="Fountain codes have recently gained wide attention in communications due to their capacity-approaching performance and rateless properties that allow them to seamlessly adapt to unknown channel statistics. In this paper, we consider the problem of low complexity decoding of Luby transform codes, which are a class of linear fountain codes. We adapt the recently proposed technique of informed dynamic scheduling to the rateless regime, and combine it with the method of incremental decoding to obtain a decoder that has a significantly reduced computational load compared to the commonly used alternative of message-reset decoding with a flooding schedule. This reduction in complexity, in some cases as large as a factor of sixty, is obtained without affecting the error rate performance of the code." } @INPROCEEDINGS{Abdu0805:Visualization, AUTHOR="Kulsoom Abdullah and Gregory Conti and Raheem Beyah", TITLE="A Visualization Framework for Self-monitoring of Web-based Information Disclosure", BOOKTITLE="ICC'08 - Information and Network Security Symposium", ADDRESS="Beijing, China, P.R. China", DAYS=19, MONTH=may, YEAR=2008, ABSTRACT="Free online tools such as search, email and mapping come with a hidden cost. Web users obtain such services by making micropayments of personal and organizational information to the web service providers. Web companies use this information to create customized advertising and tailored user experiences. Individually, each transaction appears innocuous, but when aggregated, the result is often highly sensitive. The impact of AOL’s inadvertent disclosure of 20 million nominally anonymized search queries underscores the pressing need for increasing web privacy and raising user awareness of the problem. Rather than advocate extreme legal and policy measures to address the dilemma, this paper proposes an equitable self-monitoring solution. Self-monitoring allows individual users and large enterprises to regulate their web-based interactions intelligently and still allow online companies to innovate and flourish. The primary contributions of our work include exploration of visualization techniques that support self-monitoring based on a user requirements survey, a human- centric evaluation, and a Firefox extension based on one of the visual monitoring solutions developed." } @INPROCEEDINGS{Abdu0806:FPGA, AUTHOR="Abdul-Rafeeq Abdul-Shakoor and Ron Kerr and John Lodge", TITLE="An {FPGA} Implementation of a Soft-in Soft-out Decoder for Block Codes", BOOKTITLE="24th Queen's Biennial Symposium on Communications", ADDRESS="Kingston, Ontario, Canada, Canada", DAYS=23, MONTH=jun, YEAR=2008, KEYWORDS="Vector SISO decoder; BCH and EH codes.", ABSTRACT="This paper presents an FPGA implementation of the Vector SISO algorithm for the (64, 57) extended Hamming code (EH) and (64, 51) extended Bose, Chaudhri and Hocquenghem code (EBCH). The decoder architecture is defined in VHDL and circuit is implemented on a Xilinx XC2VP100-1704ff–5 FPGA device. To achieve the required throughput, a pipelined data path architecture operating off a master clock was selected. To reduce gate count the dynamic range of intermediate results was limited through use of saturation arithmetic. The decoder functionality was verified by means of a test bench that compared the decoded bit stream with error free transmitted signals. SISO decoder design choices that impact the bit error rate (BER) are also presented." } @INPROCEEDINGS{Abdu0808:Iterative, AUTHOR="Ahmed {Abdul Quadeer} and Tareq Al-Naffouri and Maha Shadaydeh", TITLE="Iterative Blind Data Detection in Constant Modulus {OFDM} Systems", BOOKTITLE="European Conference on Signal Processing 2008", ADDRESS="Lausanne, Switzerland", DAYS=25, MONTH=aug, YEAR=2008, KEYWORDS="OFDM; Blind Channel Estimation; Maximum Likelihood Detection", ABSTRACT="In this paper, we consider blind data detection for OFDM transmission over block fading channels. Specifically, we show how constant modulus data of an OFDM symbol can be blindly detected using output symbol and associated cyclic prefix. Our approach relies on decomposing the OFDM channel into two subchannels (cyclic and linear) that share the same input and are characterized by the same channel parameters. This fact enables us to estimate the channel parameters from one subchannel and substitute the estimate into the other, thus obtaining a nonlinear relationship involving the input and output data only that can be searched for the maximum likelihood estimate of the input. This shows that OFDM systems are completely identifiable using output data only, irrespective of the channel zeros, as long as the channel delay spread is less than the length of the cyclic prefix. We also propose iterative methods to reduce the computational complexity involved in the maximum likelihood search of input." } @INPROCEEDINGS{Abdu0809:Dynamic, AUTHOR="Nurul Muazzah {Abdul Latiff} and Charalampos Tsimenidis and Bayan Sharif and Cassim Ladha", TITLE="Dynamic Clustering using Binary {Multi-Objective} Particle Swarm Optimization for Wireless Sensor Networks", BOOKTITLE="IEEE PIMRC 2008 Mobile and Wireless Networks Track", ADDRESS="Cannes, France", DAYS=15, MONTH=sep, YEAR=2008, KEYWORDS="Clustering; energy efficient; sensor networks", ABSTRACT="In wireless sensor networks, the use of energy efficient infrastructure such as clustering may be used to lengthen the network lifetime and prevent network connectivity degradation. In such systems, the performance of the clustering scheme is generally influenced by the cluster head selection method and the number of clusters. This paper presents a dynamic clustering method with multi-objectives that automatically determines the optimum number of clusters in the network. The algorithm, which is based on binary Particle Swarm Optimization (PSO), eliminates the need to set the number of clusters a priori. In addition, a multi-objective approach is utilized in the cluster head selection algorithm in order to select the best set of cluster heads. Simulation results demonstrate that the proposed protocol can achieve an optimal number of clusters, as well as prolong the network lifetime and increase the data delivery at the base station when compared to other well known clustering algorithms." } @INPROCEEDINGS{Abdu0809:Measurement, AUTHOR="Noreha {Abdul Malik} and Paul Chappell and Duncan Wood and Paul Taylor", TITLE="Measurement of relative joint angle and acceleration of the lower limb during walking", BOOKTITLE="13th International FES Society Conference", ADDRESS="Freiburg, Germany", PAGES="79-81", DAYS=21, MONTH=sep, YEAR=2008, ABSTRACT="With a sensor mounted on the shank the measurement of the relative joint angle and acceleration of a normal subject walking is presented. The sensor used consists of two dual axis accelerometers that are arranged in a specific configuration. The result shows a consistent and repetitive signal pattern during stance and swing phase. Also, in the result the vertical acceleration has showed the heel strike events with the footswitch acting as a reference. Some experimental results to demonstrate the relative angle and acceleration of the lower limb seg-ment when the leg swings in a pendular motion are also presented in this paper. In the future, further investiga-tion is required to determine more events through the gait cycle to control a two channel Functional Electrical Stimulation (FES) device for gait correction in stroke patients. Kinematic measurement from the other segments of the lower limb such as thigh and foot will also be studied as potential control signals." } @INPROCEEDINGS{Abdu0811:Effect, AUTHOR="Lennie Abdullah and Saifuddin {M. Jalil} and Ibrahim Ahmad and Huda Abdullah", TITLE="The Effect of Surface Texturing on {GaAs} Solar Cell using {TCAD} Tools", BOOKTITLE="2008 IEEE International Conference on Semiconductor Electronics", ADDRESS="Johor Bahru, Malaysia", DAYS=25, MONTH=nov, YEAR=2008, KEYWORDS="Texturing surface, GaAs solar cell, efficiency, Silvaco", ABSTRACT="Abstract: Solar cell simulation could be useful for time saving and cost consumption. This project discusses on the method to resolve the optical losses problem that have been hindering the totality efficiency of the photovoltaic. The different models surface texturing on GaAs solar cell have been simulated by using the Virtual Wafer Fab (VWF), SILVACO software in this project. It was expected that the modification of the surface texturing might distinctly improved the spectral sensitivity of the photovoltaic by reducing the light reflection and improving the light trapping. There are four models surface texture of photovoltaic devices. It was the simple structure, V-trench structure, fours-sided structure and semi-sphere structure. Hence, the incoming light will hit the GaAs surface several times. Light, which is not absorbed in its first passage through the cell, has the additional opportunities to be absorbed into the cell. It has been shown that the modified surface of GaAs solar cell have improved the efficiency up to more than 3\% and its quality application performance about 9\%. From the modification result, the V-trench structure is the best surface texture for GaAs solar cell compared to the others, which has Isc is 3.5752 x 10-6 mA, Voc is 0.800146 V and efficiency is 26.05\%." } @INPROCEEDINGS{Abdu0811:Improvement, AUTHOR="Khairizam {Abdul Rani}", TITLE="Improvement of Backside Emission Analysis Sample Prep Process for {BGA}", BOOKTITLE="2008 IEEE International Conference on Semiconductor Electronics", ADDRESS="Johor Bahru, Malaysia", DAYS=25, MONTH=nov, YEAR=2008, ABSTRACT="Title : Improvement of Backside Emission Analysis Sample Prep Process Authors : Khairizam Abd Rani Address : Spansion (M) Sdn Bhd Phase II, Bayan Lepas FTZ, 11900 Bayan Lepas, Penang Email Address : khairizam.abd-rani(at)spansion.com Phone No. : 04-8882512/ 2599 Abstract : Current method of sample preparation repackaging process for backside emission analysis is by applying direct bonding from the exposed gold wire on the bottom of the package to the lead frame of the secondary open top package. The exposed gold wire on the package bottom is achieved through the back grinding process. The very small diameter of the exposed gold wire on the backside of the BGA which is about 1.0mil in diameter has imposed difficulty during the manual re-bonding process. The re-bonding process requires a skillful person as it requires high precision bonding. A single wire bonding itself may require several attempts in order to form a good bond/ joint on the exposed gold wire. With this scenario we will also be facing more challenges in the future as we are moving towards qualifying thinner wire for production. The work presented here shows the alternative BGA repackaging technique for the Backside Emission Analysis. The paper will discuss the advantages of the new methodology over the current technique. Evaluation and optimization performed on the gold wire to bare copper lead frame bonding process is also demonstrated. After the implementation of the new sample preparation repackaging technique, the overall sample preparation process have been tremendously improved. The cycle time, success rate and efficiency has been improved especially on the wire re-bonding process. This is due to the larger bonding area has been created by exposing lead frames at the backside of BGA package that is achieved through the selected area polishing method." } @INPROCEEDINGS{Abdu0811:Ion, AUTHOR="Wan Fazlida Abdullah and Masuri Othman and Mohd Alauddin {Mohd Ali}", TITLE="{Ion-Selective} {Field-Effect} Transistor Sensor Response for Neural Network Supervised Learning", BOOKTITLE="2008 IEEE International Conference on Semiconductor Electronics", ADDRESS="Johor Bahru, Malaysia", DAYS=25, MONTH=nov, YEAR=2008, KEYWORDS="chemical sensor, ISFET", ABSTRACT={Introduction Ion-selective field transistors (ISFETs) are electrochemical sensors similar to the MOSFET structure. ISFETs can selectively detect ion activities of chemical elements by virtue of the gate membrane reaction with selected ions present in the investigated solution [1]. Electrical response of the sensors indicate the level of ion activity of chemicals. However, in the presence of mixed ions other than the main ion of interest, there are issues of low selectivity causing significant interference [2]. Post-processing stage is suggested to handle the issue of mixed ion interference [3,4]. The ions of interest in this work are potassium and calcium. This work presents the extraction of data using semiconductor device electrical characterization technique for the purpose of neural network multilayer perceptron supervised learning. Methodology Standard MOSFET electrical characterization is performed on ISFETs using Agilent B1500A Semiconductor Device Analyzer. Transfer characteristics indicating threshold voltage differences of potassium (K+), calcium (Ca++) and pH ISFETs in solutions of mixed ion of different molarities are investigated. Reference electrode is placed in the solution with its voltage swept and the corresponding drain current is measured [5]. The setup is shown in Figure 1. Figure 1: ISFET measurement with semiconductor device analyzer system With the intention to extract electrical response from the ISFET in a readout interface circuit, the gate-source voltage corresponding to 100 uA drain current is extracted using low-pass interpolation method within MATLAB. The measurement setup using a readout interface circuit that holds the current between the source and drain constant at 100 uA [6] is shown in Figure 2. Figure 2: Measuring system implemented for K+, Ca++ and pH sensors. The levels of ion potentials are pH{4,6,7,8}, pK{-5,-4,-3,-2,-1} and pCa{-5,-4,-3,-2,-1}. The choice of ion types and levels of activity are based on the availability of sensors and related to the purpose of agricultural soil application. The method in preparing the solutions conforms to the procedure in fixed interference method (FIM) recommended by the International Union of Pure and Applied Chemistry (IUPAC) standard [7]. Results and Discussion Typical IdVg characteristics obtained from the setup in Figure 1 of the depletion-mode K+ sensors are shown in Figure 3. The shift between the IdVg curves are due to the difference in potassium ion potential in the solution. Figure 3: Drain current vs reference electrode voltage sweep of K+ ISFET in solutions of different pK. The value of the K+ ISFET sensor gate voltage corresponding to drain current 100 uA extracted using low-pass interpolation method for all solutions are shown in Figure 4. Figure 4: Potassium sensor reading in different pH/pK/pCa Mean and standard deviation of data of each sensor performance in the solutions with interfering ions are shown in Table 2. Table 2: Basic statistical investigation of electrical response of three different types of sensors grouped in different levels of potassium ion activities in mixed-ion environment. One-way analysis of variance (ANOVA in MATLAB) test on the data of K+ sensor in different groups categorized by pK{-5,-4,-3,-2,-1} with variation of pCa and pH within each group results in a small p-value with large error variance. Table 3: One-way analysis of variance test on K+ sensor readings divided into groups based on the pK of the solution. For the purpose of demonstrating that the data is worth to work on from the neural network point of view, the data is subjected to trial runs using neural network toolbox within Matlab. In the simple one hidden layer MLP, output to target correlation to test data [8] results in 75\% correlation. Figure 5: Correlation between output and target data of neural network testing on extracted data. Conclusion Electrical response of potassium, calcium and pH sensors are taken using readout interface circuit and confirmed by semiconductor device characterization techniques. The data shows reasonably well p-values for different levels of pK solutions. However, the error variance are great, as expected, due to the intentionally introduced interfering ions. The data obtained can be used for training of neural networks by supervised learning algorithms. REFERENCE [1] Bergveld, P. (2003). {"}Thirty years of ISFETOLOGY: What happened in the past 30 years and what may happen in the next 30 years.{"} Sensors and Actuators B: Chemical 88(1): 1-20. [2] Janicki, M., M. Daniel, et al. (2004). {"}Ion sensitive field effect transistor modelling for multidomain simulation purposes.{"} Microelectronics Journal 35(10): 831-840 [3] Bedoya, G., C. Jutten, et al. (2004). Improving semiconductor-based chemical sensor arrays using advanced algorithms for blind source separation. Sensors for Industry Conference, 2004. Proceedings the ISA/IEEE [4] Bermejo, S., C. Jutten, et al. (2006). {"}ISFET source separation: Foundations and techniques.{"} Sensors and Actuators B: Chemical 113(1): 222-233 [5] Daniel Tomaszewski, Chia-Ming Yang, Bohdan Jaroszewicz, Michał Zaborowski, Piotr Grabiec, and Dorota G. Pijanowska (2007). “Electrical Characterization of ISFETs”Journal of Telecommunications and Information Technology (JTIT) 3/2007 [6] Gotoh, M., S. Oda, et al. (1989). {"}Construction of Amorphous Silicon ISFET{"}, Sensors and Actuators 16(1-2): 55-65 [7] Umezawa, Y.; Umezawa, K.; Sato, H. (1995) “Selectivity coefficient for ion-selective electrodes: recommended methods for reporting KAB pot values”. Pure \& Appl. Chem. 67, 507-518. [8] S. S. Haykin, Neural Networks : A Comprehensive Foundation. Upper Saddle River, N.J., Prentice Hall, 1999} } @INPROCEEDINGS{Abdu0811:Multi, AUTHOR="Rozina {Abdul Rani}", TITLE="Multi-finger gate {ISFET} {(Mf-ISFET)} for pH sensor applications", BOOKTITLE="2008 IEEE International Conference on Semiconductor Electronics", ADDRESS="Johor Bahru, Malaysia", DAYS=25, MONTH=nov, YEAR=2008, KEYWORDS="ISFET, pH", ABSTRACT="Study on Ion Sensitive Field Effect Transistor (ISFET) based on multi-finger gate design is presented. This paper deals with the design, fabrication and experimental evaluation of Mf-ISFET as a pH sensor. Mf-ISFET is fabricated by using commercial submicron 1.0 µm CMOS technology and deposited with PECVD Si3N4 as a sensing membrane. The electrical data such as IdVd, IdVg and the sensitivity of ISFET are measured to identify the behaviours of ISFET. Furthermore, light testing to evaluate the effect of operating condition to ISFET is also discussed in this paper." } @INPROCEEDINGS{Abdu0811:Optimization, AUTHOR="Nor Azlian {Abdul Manaf}", TITLE="Design and Optimization of Distributed Bragg Reflector for 1310nm Vertical Cavity Surface Emitting Lasers.", BOOKTITLE="2008 IEEE International Conference on Semiconductor Electronics", ADDRESS="Johor Bahru, Malaysia", DAYS=25, MONTH=nov, YEAR=2008, KEYWORDS="Distributed Bragg Reflector (DBR), various composition, 1310nm Vertical Cavity Surface Emitting Laser (VCSEL),", ABSTRACT="Vertical Cavity Surface Emitting Laser (VCSEL) is widely used in the high-speed optical-fiber systems for information transmission and processing. However, despite extensive research and development efforts during the past decade, the commercial breakthrough of such VCSEL has still to be achieved. A major problem in their realization is the lack of a lattice-matched material system providing both high refractive index contrast DBR and high gain quantum well (QW).While excellent DBR can be built up in the GaAs/AlGaAs material system, long wavelength QW are only well established in InP system. Although InGaAsP DBR mirrors are lattice-matched with InP based active layers, they suffer from small index differences and poor optical, electrical, and thermal properties compared to GaAs/AlGaAs DBR [2]. High-performance 1310 nm VCSEL have been realized using wafer bonding between InP based active materials and GaAs/AlGaAs DBR mirrors [3]. However, this approach and other wafer fusion schemes, lack of the low-cost manufacturability of a monolithic design. The primary challenge in making a 1310 nm VCSEL has been the integration of high reflectivity DBR with a suitable active region. GaInNAs was first proposed and created in 1995 by Kondow and it was a promising materials to be employed as active materials in both edge-emitting laser diodes and VCSELs in long wavelength range [5]. Since GaInNAs VCSEL can be lattice matched to GaAs, stacking the high refractive index contrast GaAs/AlGaAs DBR mirrors on GaAs substrate and directly integrate it with GaInNAs active material can be realized in a single epitaxial growth [6]. Therefore, GaAs/AlxGa1-xAs material system has been gaining lots of interests as DBR mirror for long wavelength VCSELs applications. This paper presents modeling and simulation of DBR mirrors for 1310 nm VCSEL. The simulation was prepared with six different composition consisted of 35 pairs of Al(x)Ga(1-x)As/Al(x)Ga(1-x)As quarter-wave stacks epitaxial mirrors. Simulation results and analysis for the reflectivity spectrum and absorption coefficient are compared for each material. The different of the maximum reflectivity between the experimental and simulation also will be be discussed." } @INPROCEEDINGS{Abdu0811:Performance, AUTHOR="Kamarul Jalal {Abdul Jalil}", TITLE="Performance of Restricted Earth Fault Protection Scheme in the Presence of Current Transformer Remanence", BOOKTITLE="IEEE Region 10 Conference", ADDRESS="Hyderabad, Andhra Pradesh, India", DAYS=18, MONTH=nov, YEAR=2008, KEYWORDS="Current transformer; power system protection", ABSTRACT="In modern power system protection, an accurate transformation of primary short circuit current is vital to ensure correct operation of the high impedance Restricted Earth Fault (REF) protection scheme used for transformer protection. The dc component in the fault current as well as the remanent flux may causes severe saturation conditions if the current transformer is not selected correctly. Behavior of the current transformer during the transient condition is important as this will determine the stability of the REF protection scheme. This paper discusses how the remanence phenomenon beside the dc component in the fault current may causes severe saturation to the current transformer and affects the stability of the REF protection scheme." } @INPROCEEDINGS{Abdu0812:Using, AUTHOR="Hussam Abdulla and Vaclav Snasel", TITLE="Using Singular Value Decomposition {(SVD)} as a solution for search result clustering", BOOKTITLE="Fifth International Conference on Innovations in Information Technology", ADDRESS="Al Ain, UAE", DAYS=16, MONTH=dec, YEAR=2008, KEYWORDS="Search result organization, document clustering, regression Analysis, Singular Value Decomposition", ABSTRACT="There are many search engines in the web, but they return a long list of search results, ranked by their relevancies to the given query. Web users have to go through the list and examine the titles and (short) snippets sequentially to identify their required results. In this paper we present how usage of Singular Value Decomposition (SVD) as a very good solution for search results clustering." } @INPROCEEDINGS{Abe0811:Three, AUTHOR="Masataka Abe", TITLE="Three Dimensional Evaluation of Parallelepiped Flaw using Amorphous {MI} Sensor and Neural Network in Biaxial {MFLT}", BOOKTITLE="3rd International Conference on Sensing Technology", ADDRESS="Tainan, Taiwan", PAGES="173-176", DAYS=30, MONTH=nov, YEAR=2008, KEYWORDS="NDT;MFLT;flaw detection;amorphous MI sensor;neural network", ABSTRACT="In this paper, we attempt to evaluate the dimension of a parallelepiped flaw and to identify the location, i.e., the horizontal position and the located surface, by biaxial MFLT with a neural network. The specimen is a magnetic material subjected to the magnetic field, and the magnetic flux in the specimen leaks near the flaw. We measure the biaxial MFL, i.e., the tangential and the normal components of MFL by the amorphous MI sensor. The amorphous MI sensor is the wide range, high sensitivity and high spacial resolution magnetic sensor, so that it is suitable for biaxial MFLT. Then we approximate the measured biaxial MFL distributions near the flaw by elementary functions with a few parameters, say, MFL parameters. The horizontal position of a flaw along the measured line is characterized by some of MFL parameters. Neural network is used to infer the cross section of the flaw, i.e., the width, the depth and the located surface from the MFL parameters. By repeating a similar process along several lines parallel to the specimen surface, we can identify the three dimensional shape of the flaw including its horizontal position. The neural network trained with respect to several known flaws is found to evaluate the three dimensional shape and location of a flaw in a good accuracy." } @INPROCEEDINGS{Abed0000:Simple, AUTHOR="Walid AbedIseid", TITLE="A Simple Receiver Design Approach for {Space-Time} Coded {Serial-MSK} that Achieves {Full-Transmit} Diversity", BOOKTITLE="IFIP Wireless Days", ADDRESS="Dubai, UAE", DAYS=24, MONTH=nov, YEAR=2008, KEYWORDS="Serial MSK, Space-time coding, ISI", ABSTRACT="In this paper, the design criterion for space-time coded \textit{serial}-MSK that achieves full-transmit diversity is presented. It is shown that space-time codes applied to linear modulation schemes that achieve full transmit diversity can be used in serial-MSK modulation to achieve the same diversity order. However, inter-symbol interference (ISI) exists in such coded signal which degrades the performance. In order to improve the performance one has to resort to a more complex receiver such as maximum-likelihood sequence estimator. It is shown that by appropriately designing the space-time encoder ISI can be totally removed at the expense of decreasing the space-time code rate. Therefore, a simple \textit{symbol-by-symbol} detector can be used to optimally recover the information symbols." } @INPROCEEDINGS{Abed0000:XML, AUTHOR="Azita Abedini", TITLE="{XML} to {RDF} Conversion: a Semantic based Approach", BOOKTITLE="Mosharaka International Conference on Communications, Networking and Information Technology", ADDRESS="Amman, Jordan", DAYS=5, MONTH=dec, YEAR=2008, KEYWORDS="ontology; meta data; semantic web; digital image description", ABSTRACT="Despite the efforts being made in converting XML Schema-based metadata standards into OWL ontologies, there is still an important link missing: the connection between the existing XML data and the domain knowledge as respresented in ontologies. Therefore, a transformation of these XML data into RDF instances has to be established, to overcome the gap between the XML data and the OWL ontologies. In this paper, we present a novel approach for the transformation of XML data into RDF instances." } @INPROCEEDINGS{Abed0800:Linearizing, AUTHOR="Walid AbedIseid and Peter Galko", TITLE="A Linearizing Approach to Code Design for Generalized {MSK} with Four Symbol Pulse Duration", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, KEYWORDS="Generalized MSK, Repetition Code, Euclidean Distance, Hamming Distance, I-Q Receiver", ABSTRACT="Quadruple repetition code exhibits unique properties when combined with \textit{precoded} generalized minimum-shift keying signals of upto four symbol period pulse duration. It is shown that using two stages of channel encoding, the last being a quadruple repetition code, the code design for such modulation schemes simplifies. Also, it is shown that the nonlinear continuous-phase frequency-shift keying modulator can be replaced by a simple linear $I$-$Q$ modulator to generate the same coded signals. The detection problem for the recovery of the symbols sequence from the decision variables is shown to be one corresponding to memoryless modulation, avoiding the use of maximum likelihood sequence detection." } @INPROCEEDINGS{Abed0804:Commodity, AUTHOR="Khalid Abedlkader and Jan Broeckhove", TITLE="Commodity Resource Pricing in Dynamic Computational Grids", BOOKTITLE="AICCSA-08 Parallel and Distributed Systems Track", ADDRESS="Doha, Qatar", DAYS=1, MONTH=apr, YEAR=2008, KEYWORDS="Computational Market; Grid Computing; Grid Economics; Market-based Resource Management", ABSTRACT="In this paper we investigate the pricing of resources in dynamic grids that are modeled as computational commodity markets. Price determination based on achieving supply-and-demand equilibrium has been shown to work for small grids with a static fabric. Using simulations, we show that this approach can be extended to grids with a large number (thousands) of resources and to grids with a dynamic fabric." } @INPROCEEDINGS{Abed0804:Performance, AUTHOR="Walid AbedIseid", TITLE="Performance and Power Spectrum Calculations for Convolutionally Coded Generalized {MSK} with Two Symbol Periods Pulse Shape Duration", BOOKTITLE="IEEE Sarnoff Symposium 2008", ADDRESS="Princeton , NJ, USA", DAYS=28, MONTH=apr, YEAR=2008, KEYWORDS="Power Spectrum; MSK; Euclidean Distance; Hamming Distance; Receiver Complexity", ABSTRACT="We show that by applying a cascaded convolutional encoder using two stages of coding, the last being a double repetition code, to ``precoded'' generalized minimum-shift keying (MSK) signals with pulse shape of duration two symbol periods a significant improvement in power and spectral efficiency is achieved. With only a double repetition code, it is shown that the signal has a power spectrum identical to uncoded MSK-like. When outer encoder is applied to improve the power efficiency, the bandwidth expansion is just a reciprocal of the outer encoder rate. It is demonstrated that considering performance, bandwidth and receiver complexity, generalized MSK signal coded using our special cascaded convolutional codes is an improvement over MSK and generalized MSK coded with ``optimum'' convolutional codes for the same code rate and receiver complexity reported previously for the same modulation scheme." } @INPROCEEDINGS{Abed0806:Simplified, AUTHOR="Walid AbedIseid and Peter Galko", TITLE="A Simplified Approach to Coding, Modulation, and Detection Design for Generalized {MSK} with Two Symbol Period Pulse Duration", BOOKTITLE="24th Queen's Biennial Symposium on Communications", ADDRESS="Kingston, Ontario, Canada, Canada", DAYS=23, MONTH=jun, YEAR=2008, KEYWORDS="Generalized MSK; Repetition Code; I-Q Receiver; Euclidean Distance; Hamming Distance", ABSTRACT="Double repetition code exhibits unique properties when combined with ``precoded'' generalized minimum-shift keying signals of two symbol period pulse shape duration. It is shown that using two stages of channel encoding, the last being a double repetition code, the code design for such modulation scheme simplifies to the case applied for linear modulation such as BPSK and QPSK. Also, it is shown that the nonlinear continuous-phase frequency-shift keying modulator can be replaced by a simple linear inphase-quadrature modulator to generate the same coded signal. This suggests another strategy to demodulate the coded signal using a simple inphase-quadrature receiver. It is shown that the detection problem for the recovery of the symbols sequence from the decision variable is one corresponding to memoryless modulation, avoiding the use of the maximum likelihood sequence detection, which would otherwise be needed for optimal detection." } @INPROCEEDINGS{Abed0806:System, AUTHOR="Walid AbedIseid", TITLE="New System Design for {Serial-MSK} Based On Laurent Decomposition", BOOKTITLE="24th Queen's Biennial Symposium on Communications", ADDRESS="Kingston, Ontario, Canada, Canada", DAYS=23, MONTH=jun, YEAR=2008, KEYWORDS="Serial-MSK; Laurent Decomposition; Duobinary MSK; Convolutional Code; Maximum-Likelihood Estimator; Matched Filter", ABSTRACT="In this paper, a new approach to coding, modulation, and detection design for serial minimum-shift keying (MSK) modulation scheme is presented. The design of the new linear modulator is based on the Laurent decomposition of a well-known modified MSK scheme termed duobinary MSK. It is shown that a simple linear receiver can be designed to optimally detect the coded symbols. The detection problem for the recovery of the symbols sequence from the decision variable sequence is one corresponding to memoryless linear modulation. It is also demonstrated that the Euclidean distance between different signals is directly related to the Hamming distance between corresponding coded sequence. Therefore, optimum encoders (for a given rate and constraint length) that maximize the minimum Hamming distance can be applied." } @INPROCEEDINGS{Abee0810:Unlikeability, AUTHOR="Vero Abeele and Bieke Zaman and Mariek {Vanden Abeele}", TITLE="The Unlikeability of a Cuddle Toy Interface: A experimental study of preschoolers’ likeability and usability of a {3D} game played with a cuddle toy versus a keyboard.", BOOKTITLE="International Conference on Fun and Games", ADDRESS="Eindhoven, The Netherlands", DAYS=20, MONTH=oct, YEAR=2008, KEYWORDS="Tangible Embedded Interaction, Gestural Interaction, Children, Likeability, Usability", ABSTRACT="In this research paper we report on a comparative study of the likeability and usability of a cuddle toy interface versus a keyboard interface for playing a 3D game. We put 35 preschoolers to the test and asked them to play a 3D game via a keyboard and via a cuddle toy interface. Afterwards the usability (user-friendliness) and the ‘likeability’ (of joy-of-use) of both interfaces were assessed. Our results indicate that the Cuddle Toy Interface was not more likeable nor usable than the keyboard interface. Based on additional qualitative data, we argument that the causes might be fatigue, a lack of meaningful use of gestures, and the occurrence of ‘satisficing’." } @INPROCEEDINGS{Abey0000:Impact, AUTHOR="Dhammika Abeysinghe and Sanjitha Rajasekaran", TITLE="The Impact of Mergers and Acquisitions on Value Creation: An Empirical Investigation", BOOKTITLE="International Conference on Management of Technology 2008", ADDRESS="Dubai, UAE", DAYS=6, MONTH=apr, YEAR=2008, ABSTRACT="Decisions that alter the scope of the firm are among the most important faced by management, and among the most studied by academics. Mergers and Acquisitions (M\&A) are classic examples of such decisions. Companies have always used this strategy to grow and consolidate, and to eliminate competitors. Moreover, one of the main arguments for carrying out these deals has been that they create synergies. For many companies M\&As represent the fastest possible route to growth. For other companies, formally aligning oneself with another company makes it possible to enter new markets unavailable before. M\&As also represents an opportunity to achieve economies of scale and scope and pare operating costs, or to increase their capabilities and innovative capability. M\&As facilitates the acquisition and transfer of new knowledge, technologies or systems that are critical for competitive advantage. M\&As have been taking place from the age-old times all over the world and more companies than ever before are turning to Mergers and Acquisition (M\&As), at a pace that is not expected to abate any time soon. Sri Lanka too has witnessed a fair number of M\&As in the past few years and there is an immense increase in this trend in the country. Not only the local companies but also the foreign firms are engaged in merging with and acquiring local companies. There is considerable evidence that many acquisitions fail, often because of post-acquisition problems. Studies show that most of the modern day M\&As fail due to improper management of the organizational systems and technology. For a Merger or an acquisition to be successful, organizational changes such as cultural, structural, process, systems and technological changes are vital. The effect these strategic decisions have on the organizational systems and technology of the companies involved is enormous since they are essential elements for value creation. Researches and studies have shown that failure to carefully analyze and change the organizational systems and technology would lead to the failure of the M\&As. Thus, proper management of the systems and technologies in and after the M\&As phase is of paramount importance. Therefore, it is very vital to identify the risks and problems in executing these strategic decisions and to have a proper set of guidelines that suit the local context to successfully navigate the M\&As. The focus of the research is to pinpoint opportunities for savings and revenue growth within the operating infrastructure by creating a unified approach to integrating people and technology. Therefore, in order to find out the problems and risks associated with the post performance of the systems and technology, a comprehensive literature survey was carried out and a conceptual framework was developed. A questionnaire was administered among the professionals in some of the M\&As in Sri Lanka to identify and verify the factors in the conceptual framework. Detailed discussions and interviews were also carried out with the experts in the industry to gather their views and opinions and an in-depth investigation was carried out on some of the selected local cases. Based on these discussions and case studies the study proposes strategies to mitigate these problems and manage them thereby aiming to enhance value creation and as a whole maximizing the growth and returns of the local companies." } @INPROCEEDINGS{Abey0000:Managing, AUTHOR="Dhammika Abeysinghe and Deepthi Hambange", TITLE="Managing Risks in Offshore System {Development:A} Sri Lankan Perspective", BOOKTITLE="International Conference on Management of Technology 2008", ADDRESS="Dubai, UAE", DAYS=6, MONTH=apr, YEAR=2008, ABSTRACT="Information technology (IT) has become a key success factor for almost every organization. Most of the developed countries such as USA, Europe, and Japan are running their businesses successfully using IT as a tool. Without developing software in-house, they outsource their projects or parts of them to developing countries thereby enjoying number of benefits such as making use of the highly skilled programming specialists in these countries, cutting down on their labor costs, achieving technical excellence and etc. Although India is the largest offshore systems developer, other countries in Asian and West Europe region have also entered into this field. In Sri Lanka IT is one of the fastest growing sectors and every year, more than 1000 graduates from local and foreign universities with sufficient IT knowledge and skills join the industry. Sri Lanka has number of registered as well as unregistered companies which carries out offshore software development. These companies bring large amounts of foreign exchange every year to the country strengthening the local economy. When the quality of the software products developed is better they gain a higher reputation for Sri Lankan software development, thereby attracting more projects and gaining of more foreign exchange to the country. Even though offshore system development has many benefits, it also has many problems as well as risks. Communication problems between the client (onshore company) and offshore sourced unit is a key problematic area due to infrequent communications, cultural differences, accents and language disability. Time zone differences leads to coordination difficulties, since working hours of foreign and local companies are different this leads to the difficulty of finding the necessary time to have a dialogue with the client. Often the offshore team lacks domain knowledge in the business application in question and transferring this knowledge is weak due to the distance problem. Due to these problems the offshore company may not meet the objectives of the onshore company and in addition to that they may also not meet the deadlines of the project. Impact of this will be high to the local IT industry because it may affect the reputation of local IT firms decreasing the demand for the local IT careers which would ultimately have a great influence on the local economy. Therefore it is important to find out the risks associated with the offshore system development and try to minimize it. In order to find out the risks associated with offshore software development a comprehensive literature survey was carried out and a conceptual framework was developed based on these factors. A questionnaire was administered among the IT professionals in the industry to identify and verify the factors in the conceptual framework. Detailed discussions were also carried out with the experts in the industry to gather their views and opinions on the risks identified. Based on these discussions the study creates a plan and a set of guidelines to mitigate these risks thereby aiming to develop the industry as a whole and maximizing the returns for the industry." } @INPROCEEDINGS{Abey0812:Vibration, AUTHOR="Pradeep Abeygunawardhana", TITLE="Vibration Suppression of Two Wheel Mobile Manipulator using Resonance Ratio Control", BOOKTITLE="15th International Conference on Mechatronics and Machine Vision in Practice, 2008", ADDRESS="Massey University,Auckland, New Zealand", PAGES="408-413", DAYS=2, MONTH=dec, YEAR=2008, KEYWORDS="Two wheel mobile manipulator, Resonance ratio control, Vibration suppression control, Null space,", ABSTRACT="Two wheel mobile manipulator has the potential of becoming a multi-skilled robot in the field of robotics and it is already implemented by using inverted pendulum control. Centre of gravity position (COG) is controlled to achieve the balancing of robot. Since vibration of manipulator arms affect to the COG positions of the inverted pendulum, balancing of the robot deteriorates. Therefore, vibration control of manipulator arms of the mobile manipulator is proposed in this paper. Feedback signal for vibration suppression is introduced to null space of manipulator. Simulation and experiment was carried out to check the validity of the proposed method and the results prove the effectiveness of the proposed method." } @INPROCEEDINGS{Abha0800:HTTP, AUTHOR="Abdolreza Abhari and Adam Serbinski", TITLE="{HTTP} Modification to Reduce Client Latency", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, KEYWORDS="HTTP; proxy cache; embedded objects;Apache server; performance measurement", ABSTRACT="In this paper, we have developed an additional enhancement to the HTTP protocol. This modification eliminates the need for the client to wait for the delivery of the HTML file before being able to request the embedded objects. In our solution, the server delivers the embedded objects of a web page to the client without being explicitly requested. In essence, the requests for the embedded objects are generated by the server instead of by the client. We introduced, in the form of a module for Apache HTTP Server, a mechanism for preloading web page from server to client. The client web browser is able to receive this modified response through the use of a custom built proxy." } @INPROCEEDINGS{Abid0000:Practical, AUTHOR="Meriem Abid and Mathieu Ligocki and Lionel Molinier and Gerard Nguenguang and Guy Pujolle and Dominique Gaiti and Hubert Zimmermann", TITLE="Practical Handover Optimization Solution", BOOKTITLE="IFIP Wireless Days", ADDRESS="Dubai, UAE", DAYS=24, MONTH=nov, YEAR=2008, ABSTRACT="With the multiplication of wireless communication networks and the increasing capabilities of the user devices equipped with multiple technology interfaces, being always connected tends to be a reality in the near future. In this article we propose to pilot the current weak handover algorithms using an autonomic agentbased piloting system. We specifically focus on the pre-execution handover process. The proposed system main contributions are to recover the useful information and compute them to obtain useful knowledge. This latter will be used for feeding a sophisticated handover decision algorithm in order to pick the most appropriate access network. We have developed a real testbed to evaluate and validate our solution unlike most proposed works analyzed only by simulations and thus avoid practical problems encountered in such cases. Above this real platform we performed an experimentation in 802.11 wireless networks that shows promising results." } @INPROCEEDINGS{Abid0806:Fuzzy, AUTHOR="Mohamed Abid and Hassnaa Moustafa and Hossam Afifi and Gilles Bourdon", TITLE="Fuzzy Biometric Authentication in Home Networks for Personalized Users’ Access", BOOKTITLE="15th International Conference on Telecommunications", ADDRESS="St. Petersburg, Russia", DAYS=16, MONTH=jun, YEAR=2008, KEYWORDS="Biometric Authentication; Home Network; Personalized access; Fuzzy vault", ABSTRACT="Thanks to the advances in communication and wireless technologies, many personal devices are able to interact within a new type of network called Home Networks (HNs). However, we need to protect the privacy of the users and secure their data during transfert. A number of works has been carried out recently to allow users’ authentication within these networks using a biometric approach. In this paper, we propose a new biometric authentication method in HNs having broadband access to the Internet. The proposed solution employs the Fuzzy Vault biometric scheme and enables each user to access to his applications’ profiles in a personalized and secure manner. Our proposed solution brings additional privacy and does not disclose the biometric data of the users. This solution is consistent with the operator constraints regarding the performance and technical aspects." } @INPROCEEDINGS{Abie0805:Bridging, AUTHOR="Rami Abielmona and Voicu Groza and Ricardo Villalobos", TITLE="A Bridging Layer for {Run-Time} Reconfigurable Hardware Operating Systems", BOOKTITLE="International Instrumentation and Measurement Technology Conference", ADDRESS="Victoria, Vancouver Island, British Columbia, Canada", DAYS=12, MONTH=may, YEAR=2008, KEYWORDS="reconfigurable computing, hardware operating system, run-time environment", ABSTRACT="Current computer systems have evolved following a near exponential increase in performance of the different hardware components that they are based on. However, problems are appearing at various fronts. There are issues related to the production of semiconductors and others related to the tools used to design new electronics systems. This paper presents a solution that provides a new paradigm in the design of hardware systems which uses proven methods found in the field of software design. In specific, it presents the bridging layer of a hardware operating system (HOS) that provides the link between the abstract model of a reconfigurable architecture and its actual hardware. A description of how the bridging layer uses a protocol to manage the application execution is also presented. Finally, the performance of an implemented system is evaluated." } @INPROCEEDINGS{Abio0000:Mobile, AUTHOR="Olatunde Abiona and Yu Cheng", TITLE="Mobile Agent based Authentication for Wireless Network Security", BOOKTITLE="IWCMC 2008 General Symposium", ADDRESS="Chania Crete Island, Greece, Greece", DAYS=5, MONTH=aug, YEAR=2008, KEYWORDS="Wireless network security; Mobile agent; Authentication; Next generation networks.", ABSTRACT="The explosive growth witnessed by wireless networks is largely due to the flexibility offered to both users and service provider. However, the open wireless medium makes traditional link-layer attacks readily available to anyone within the range of the network. Confidentiality, integrity and authentication pose several challenges to wireless network security implementations. The IEEE 802.11i security framework has some flaws, making the traditional cryptographic mechanism provide weak security for the wireless environment. In this paper, we explore the feasibility of mobile agents to provide secured access control for next generation wireless infrastructure networks." } @INPROCEEDINGS{Abiy0805:Modified, AUTHOR="Adalet Abiyev", TITLE="Modified Walsh Function Based Technique for Evaluation of the Reactive and Distortion Power", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, ABSTRACT="In this paper a new modified Walsh function (WF) based method for measuring of reactive power (RP) in sinusoidal as well as in noise conditions is presented. Proposed method simplifies the multiplication procedure to evaluate the reactive components from instantaneous power signal using peculiar properties of the WF. One of the advantages of proposed measurement approach is that in contrast to the known existing methods which involve phase shift operation of the input signal, the proposed technique does not require the time delay of the current signal to the with respect to the voltage signal. Another advantage is related to the computational saving properties of the proposed approach coming from use of the Walsh Transform (WT) based signal processing method. Proposed method eliminates an influence of the prevalent third order current harmonics to and reduces the effect of the highest order current harmonics on the RP measurement results. Validity and effectiveness of the suggested method for evaluation of the RP components of the electrical power have been tested by use of a simulation tools developed on the base of “Matlab”." } @INPROCEEDINGS{Abiy0805:Reactive, AUTHOR="Adalet Abiyev and Kamil Dimililer", TITLE="Reactive Power Measurement in Sinusoidal and Nonsinusoidal Conditions by use of the Walsh Functions", BOOKTITLE="International Instrumentation and Measurement Technology Conference", ADDRESS="Victoria, Vancouver Island, British Columbia, Canada", DAYS=12, MONTH=may, YEAR=2008, KEYWORDS="analog signal processing; DSP; distortion power; instantaneous power signal; modified Walsh function; phase shift; reactive power measurement;", ABSTRACT="This paper presents a new modified Walsh function (MWF) based method for measuring of reactive power (RP) in sinusoidal as well as in noise conditions. Proposed method simplifies the multiplication procedure to evaluate the reactive components from instantaneous power signal using peculiar properties of the WF. One of the advantages of proposed measurement approach is that in contrast to the known existing methods which involve phase shift operation of the input signal, the proposed technique does not require the time delay of the current signal to the with respect to the voltage signal. Another advantage is related to the computational saving properties of the proposed approach coming from use of the Walsh Transform (WT) based signal processing method. Proposed method eliminates an influence of the prevalent third order current harmonics to and reduces the effect of the highest order current harmonics on the RP measurement results. Validity and effectiveness of the suggested method for evaluation of the RP components of the electrical power have been tested by use of a simulation tool developed on the base of “Matlab”." } @INPROCEEDINGS{Aboe0810:Reliability, AUTHOR="Hosam Aboelfotoh and Ehab Elmallah", TITLE="Reliability of Wireless Sensor Grids", BOOKTITLE="the 33rd Annual IEEE Conference on Local Computer Networks (LCN)", ADDRESS="Montreal, Canada", DAYS=14, MONTH=oct, YEAR=2008, KEYWORDS="Wireless sensor networks; wireless sensor grids; flows in sensor networks;", ABSTRACT="Wireless sensor networks (WSNs) have many applications in industry and environmental monitoring where sensor nodes are deployed at fixed places for monitoring some phenomena. One of the commonly used deterministic deployment topologies is a rectangular grid. In [1], a WSN reliability measure that considers the aggregate flow of sensor data into a sink node is formulated, and it has been shown that computing this measure for an arbitrary WSN is \#P-hard. Thus, it is unlikely that efficient algorithms for solving the problem exist. In this paper we consider a WSN deployed on rectangular $W \times L$ grid (WSG) and show that the problem remains \#P-hard even when restricted to the grid graph model. We then present a routing scheme upon which we develop an $O(nL2^W)$ algorithm to compute the exact WSG reliability. Therefore, for $W << L$ (thin grid or strip area) the algorithm is polynomial in $n$, while for a rectangle with arbitrary dimensions the running time is $O(n \sqrt{n} 2^{\sqrt{n}})$. We also present numerical results that demonstrate some of the potential applications of the algorithm. One of the important findings is that a remarkable improvement in the WSG reliability can be achieved using more reliable sensors at the two boundaries adjacent to the sink node." } @INPROCEEDINGS{Abol0804:Subspace, AUTHOR="Maryam {Abolfath Beygi}", TITLE="A Novel Subspace Based Method for Direction of Arrival Estimation of Signals in a Multi-path {CDMA} System", BOOKTITLE="IEEE Sarnoff Symposium 2008", ADDRESS="Princeton , NJ, USA", DAYS=28, MONTH=apr, YEAR=2008, KEYWORDS="CDMA system; Coherent signals; MUSIC algorithm; Subspace methods; Temporal spatial signature", ABSTRACT="This paper presents a method for finding the directions of arrival of coherent signals in a multi-path asynchronous DS-CDMA system. The method is a time-space processing method and works with the temporal-spatial signatures of the signals. It is a blind method which exclusively uses the desired user’s spreading code sequence and the path delays of the desired user to eliminate the contribution of undesired paths. The basic idea is to exploit the desired user’s temporal characteristics to apply a linearly transformation to the existing signal subspace to find a new subspace onto which the desired path’s signal’s temporal-spatial signature lies. Once it is accomplished, the well-known MUSIC algorithm can be applied to find the desired direction of arrival. For evaluation purposes, some simulation results are presented." } @INPROCEEDINGS{Abou0000:Integrating, AUTHOR="Mona {Abou El-Seoud}", TITLE="Integrating {Six-Sigma} and Systems Thinking: A New Approach To Improvement of Transportation Monitoring Systems", BOOKTITLE="International Conference on Management of Technology 2008", ADDRESS="Dubai, UAE", DAYS=6, MONTH=apr, YEAR=2008, ABSTRACT="At a time when the future competitiveness of the infrastructure system presents an engineering leadership challenge, serious consideration need to be given to the national programs for monitoring the highway transportation system. The main service the highway transportation system provides is mobility: movement of people and goods. The main output of the system is people-miles or goods traveled; which depend on the number, type, and weight of vehicles using the system. The inputs to the system are the capital and labor inputs used to design, build, operate and maintain the infrastructure; and the cost in time and money imposed on the consumers of the service. Thus, the importance of traffic monitoring data lies in the information they provide and could be utilized to optimize the production, operation, consumption, and maintenance of the service provided by the transportation enterprise. Traffic monitoring data is used in making many critical decisions at federal, state, and local levels. Therefore, improvements of the highway monitoring systems require comprehension of how all parts of the transportation system work together. The outcomes of the traffic monitoring subsystem affect many subsystems in the transportation system, including planning, project development and environment, project design, operations management, and safety. Additionally, traffic monitoring subsystem’s outcomes impact effective application of intelligent transportation subsystem (ITS); and protection of the aging roadway infrastructure to ascertain that the design requirements has not been exceeded. The value of quality traffic data is nonnegotiable. Utilizing sophisticated processing, analysis, and modeling techniques can not overcome the detrimental effect of poor traffic monitoring system. The question posed here is “How can we improve the quality of traffic monitoring technologies to provide a more reliable, durable, accurate, and cost effective traffic data collection system?” The efforts to develop new traffic data collection technologies have been underway for many years without any successful breakthrough. With the thrust on lower cost, this study presents a new approach that integrate Six-Sigma and Systems Thinking in an effort to improve highway data collection management and quality given practical and economical considerations. In this study Six-Sigma methodology has been successfully utilized to improve traffic data collection quality and maximize customer satisfaction through reduction of variability in all phases of the traffic data collection processes. Application of Six-Sigma resulted in developing better, faster, and more economical ways to accurately collect and analyze vehicular data. From Systems Thinking perspective, this data will be used to support informed decision making of other transportation subsystems, subsequently to an efficient and effective allocation of resources. This would positively impact social mobility and economic development. This paper introduces a new avenue for application of Six-Sigma: application of Six-Sigma in transportation industry. Six-Sigma has proven track record of adding significant value to organizations in different industries. However, transportation industry has not yet utilized Six-Sigma in improving quality and management of the transportation enterprise. To improve future competitiveness of the transportation infrastructure system, Six-Sigma and Systems Thinking need to be utilized to bridge the gaps between the highway data collection, planning, design, operation, and asset management processes. Keywords: Six-Sigma, Systems Thinking, Highway Transportation System, Traffic Monitoring Data" } @INPROCEEDINGS{Abou0000:Modified, AUTHOR="Soubhi {Abou Chahine}", TITLE="A New Modified Ultra Wideband Circular Disc Dipole Antenna for {UWB} Systems", BOOKTITLE="IWCMC 2008 Workshop on Antenna Technology - Antennas, Structures and Materials and Applications", ADDRESS="Chania Crete Island, Greece, Greece", DAYS=6, MONTH=aug, YEAR=2008, KEYWORDS="Circular disc dipole; coaxial feed line; Ultra-wideband (UWB); Wireless Communications.", ABSTRACT="In this paper, we present a modified ultra-wideband (UWB) antenna for ultra-wideband applications such as Wireless Communication and WiMax systems. It consists of a two circular-disc patch fed by a 50 Ω coaxial feed line. The obtained bandwidth by simulation (SWR ≤ 2) is about 10 GHz (from 0.650 to10 GHz with a bandwidth ratio (1:15.4). The radiation characteristics are as expected for dipole antennas" } @INPROCEEDINGS{Abou0000:Performance, AUTHOR="Mohamad {Abou El-Nasr}", TITLE="Performance of Coded {MC-CDMA/MSK} {4G} Synchronous Downlink Cellular Systems with {CFO}", BOOKTITLE="Mosharaka International Conference on Communications, Signals and Coding", ADDRESS="Amman, Jordan", DAYS=17, MONTH=oct, YEAR=2008, KEYWORDS="Communications; Coding; Multiple Access Interference; Simulation", ABSTRACT="Effects of Multiple Access Interference (MAI) and frequency offset on bit error rate (BER) performance of synchronous Coded Minimum Shift Keying/ Multi-Carrier Code Division Multiple Access (MSK/MC-CDMA) systems were considered using Standard Gaussian Approximation (SGA). Simulations were carried out in AWGN and frequency selective Rayleigh fading channels. Results showed that the un-coded MSK/MC-CDMA system under investigation outperforms the corresponding system with BPSK modulation. Furthermore, coded MSK/MC-CDMA can achieve a better performance than the theoretical performance in AWGN channel for a single user, even in the presence of MAI" } @INPROCEEDINGS{Abou0800:Improving, AUTHOR="Tarek Aboul-Seoud and Juri Jatskevich", TITLE="Improving Power Quality in Remote Wind Energy Systems Using Battery Storage", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, KEYWORDS="Power system dynamics; power quality; power system simulation; wind energy; wind power generation.", ABSTRACT="Renewable energy sources have the great advantage of being able to provide power in rural areas when available. A main disadvantage of wind energy generation (WEG) is the variation of its output power with the variation of wind speed. Such variation may lead to significant consequences on the power quality. When a critical load is fed from both the infinite grid and a wind farm, such that, it is predominantly fed from the WEG while it is connected to the infinite grid via a much weaker transmission line, variation of wind speed will produce serious voltage fluctuations on the load bus. Such fluctuations could result in losing the load. This paper describes a simple test network presenting a rural critical load which is partially fed from a wind farm in addition to the grid. The effect of wind variation on the power quality is studied. A battery bank is connected to the load bus, and its effect is simulated and discussed. Although expensive, connecting a battery bank to critical loads predominantly fed from a wind farm establishes a significant improvement to power quality." } @INPROCEEDINGS{Abou0800:PCI, AUTHOR="Mohammed Aboul-Magd and James Green", TITLE="{PCI-SS:} {Web-Based} Human And Machine Interfaces for Protein Secondary Structure Prediction", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, KEYWORDS="Protein secondary structure prediction; PCI; SOAP", ABSTRACT="PCI-SS is a web-based protein secondary structure prediction service that makes use of novel dynamic nonlinear system identification techniques. When used to combine multiple prediction systems, PCI-SS exhibits state-of-the-art prediction accuracy while reducing the occurrence of a particularly detrimental class of error by up to 25\%. Unlike other available secondary structure prediction methods, PCI-SS provides both human-readable and machine-machine web interfaces. In addition to a dynamic PHP-generated web interface for humans, a Simple Object Access Protocol (SOAP) interface is added to permit invocation of the PCI-SS service remotely. This facilitates incorporation of PCI-SS into systems biology analysis pipelines that require protein secondary structure information, and greatly simplifies high-throughput analyses. XML is used to represent the input protein sequence data and also to encode the resulting structure prediction in a machine-readable format. To our knowledge, this represents the only publicly available SOAP-interface for a protein secondary structure prediction service." } @INPROCEEDINGS{Abou0801:Scalable, AUTHOR="Yasmine Abouelseoud and Hassan ElKamchouchi", TITLE="A Scalable Trace and Revoke Scheme with Security Enhancements", BOOKTITLE="The 4th IEEE International Workshop on Digital Rights Management Impact on Consumer Communications", ADDRESS="Las Vegas, USA", DAYS=12, MONTH=jan, YEAR=2008, KEYWORDS="Digital Rights Management Constructions; Broadcast; Trace and Revoke Schemes; Verifiable Secret Sharing", ABSTRACT="Publishing digital content covered by intellectual property or copyright is faced by the challenge of countering illegal access to the digital good, while still enabling consumers to exercise their usage rights on purchased contents. Digital Rights Management (DRM) systems consist of architectures, protocols and technologies aimed at providing satisfactory solutions to the above problem. Trace and revoke schemes present one attractive cryptographic solution. This paper presents a scalable trace and revoke scheme that enables users verify their secret keys and thus protects them against corrupt ones due to malicious distributors or errors in communications. Moreover, the scheme is scalable supporting an unlimited number of revocations. Furthermore, the users secret keys are renewed which makes the task of external adversaries and traitors more difficult. In addition, broadcast messages are secure against chosen ciphertext attacks." } @INPROCEEDINGS{Abou0803:Effect, AUTHOR="Mohamed {Abou El Saoud}", TITLE="The Effect of {Inter-Link} Dependencies on the Connectivity of Wireless Mesh Networks", BOOKTITLE="IEEE Wireless Communications and Networking Conference", ADDRESS="Las Vegas, Nevada, USA", DAYS=31, MONTH=mar, YEAR=2008, ABSTRACT="This paper presents a novel methodology for finding the network connectivity in wireless mesh networks. This methodology takes into account link dependencies in neighboring nodes. The methodology was used to determine the upper bound for the connectivity in a one-dimensional chain topology as well as in the two-dimensional triangular lattice topology. We show that the assumption of link independence almost always underestimates the network connectivity. Our derived closed form expressions hence serve as more accurate upper bounds for network connectivity. The conducted comparison studies show that the error due to the assumption of node independence depends on the link connectivity, and can be very significant. The devised methodology can also be used to quantify the error and define the range of link connectivities within which the assumption of link independence can be used." } @INPROCEEDINGS{Abou0805:Analysis, AUTHOR="Neda Aboutorab and Abbas Mohammadi", TITLE="Design and Analysis of Wireless Systems Using {CAC} and {M-QAM} Adaptive Modulation for Throughput Improvement", BOOKTITLE="IEEE International Conference on Circuits and Systems for Communications 2008", ADDRESS="Shanghai, P.R. China", DAYS=26, MONTH=may, YEAR=2008, KEYWORDS="Adaptive Modulation; Call Admission Control; IP-based Traffic; Next-Generation Wireless Networks; QoS Provisioning; M-QAM; Multiple-Class Traffic", ABSTRACT="In this paper we introduce an effective bandwidth-based Call Admission Control (CAC) with adaptive modulation technique to manage the traffic in a cellular IP-based network. Since the next generation of communication networks will carry different classes of traffic, e.g., voice, video, fax, data and multimedia, over the same network and these different classes of traffic usually require different Quality-of-Service (QoS) requirements , the CAC plays an important role in future networks. Furthermore, to enhance the throughput in future wireless communication and efficiently use of the physical resources of the network, we take the advantage of using adaptive modulation M-QAM in order to match transmission rates to time-varying channel conditions. The simulation results show the performance of the proposed architecture." } @INPROCEEDINGS{Abou0805:Connectivity, AUTHOR="Mohamed {Abou El Saoud}", TITLE="Connectivity Model for Wireless Mesh Networks", BOOKTITLE="ICC'08 - Wireless Networking Symposium", ADDRESS="Beijing, China, P.R. China", DAYS=19, MONTH=may, YEAR=2008, ABSTRACT="This paper presents a novel methodology for finding the network connectivity in wireless mesh networks while taking into account the dependencies existing between links of geometrically co-located nodes. We demonstrate our methodology by applying it to a one-dimensional chain topology as well as to the optimal two-dimensional triangular lattice topology. We show that the assumption of link independence almost always underestimate the network connectivity. Our derived closed form expressions hence serve as new upper bounds for network connectivity. Results show that the error due to the assumption of node independence depends on the link connectivity, and can be very significant. The devised methodology can also be used to quantify the error and define the range of link connectivities within which the assumption of link independence can be used." } @INPROCEEDINGS{Abou0805:Heterogeneity, AUTHOR="Elias Aboutanios and Bernard Mulgrew", TITLE="Heterogeneity detection for Hybrid {STAP} Algorithm", BOOKTITLE="2008 IEEE Radar Conference", ADDRESS="Rome, Italy", PAGES="823-826", DAYS=26, MONTH=may, YEAR=2008, ABSTRACT="Traditional STAP detectors require a secondary training data set that is target free and homogeneous with the cell under test (CUT). Hybrid detectors have been proposed for heterogeneous environments where the secondary data suffers from a statistical mismatch with respect to the interference in the CUT. These algorithms emply the generalised inner product (GIP) as a heterogeneity measure and eliminate the training data snapshots that are deemed heterogeneous. The GIP, however, does not take the presence of discretes or target in the secondary data into account. If the target, or discrete, is sufficiently displaced from the signal of interest in the angle-Doppler plane, then this discrete will not lead to any significant losses in the detection. Its presence, however, biases the GIP and leads to an undesirable rejection of the training data snapshot. This problem is examined in this paper where we propose the use of an MSMI-like statistic for heterogeneity detection. We show that this addresses the high target density problem." } @INPROCEEDINGS{Abou0805:Knowledge, AUTHOR="El-Sayed Abou-Zeid", TITLE="Knowledge Management Systems from Description to Prescription: An Actor Network Approach", BOOKTITLE="2008 International Conference on Information Resources Management", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=18, MONTH=may, YEAR=2008, KEYWORDS="Actor-Network Theory; Knowledge Management; Development Methodologies", ABSTRACT="As the awareness of the importance of managing organizational knowledge grows, the issue of how to build information and communication technology (ITC)-based systems to support knowledge management activities, i.e., knowledge management support systems (KMSSs), has been raised. However, knowledge and its manipulating activities, by their very nature, are socio-technical phenomena in which social and technical factors interweave the ways in which people work. Therefore, the success of any knowledge management support system depends not only on its technical excellence, but also on its compatibility with the social and cultural fabric of the firm in which it is embedded. In this exploratory work it is argued that actor-network theory (ANT) provides theoretical foundations for the KMSS development process. In order to apply ANT in the context of knowledge management, several concepts are introduced, namely, Business Thing, Knowledge Thing and Knowledge Actor, together with a Role ontology." } @INPROCEEDINGS{Abou0805:Near, AUTHOR="Mohamed Abou-Khousa and Reza Zoughi", TITLE="Novel {Near-Field} Microwave and Millimeter Wave Differential Probe Using a {Dual-Modulated} Single Aperture", BOOKTITLE="International Instrumentation and Measurement Technology Conference", ADDRESS="Victoria, Vancouver Island, British Columbia, Canada", DAYS=12, MONTH=may, YEAR=2008, KEYWORDS="Differential probes, loaded dipoles, near-field imaging, modulated apertures, microwave and millimeter wave NDT, standoff variations.", ABSTRACT="A novel differential probe design is introduced in this paper for near-field microwave and millimeter wave non-destructive testing (NDT) and imaging applications. In such applications, the variations in the distance between the probing antenna and the structure under inspection, i.e., standoff distance, can potentially mask the signal of interest, and hence, adversely impact the detection capability of the probe. Differential near-field probes and compensation methods were developed in the past to null out the standoff distance variation effect from the measured signal. The available methods, however, suffer from some limitations such as using two balanced apertures or offering limited range of compensation. While the differential probe proposed here exhibits an excellent immunity against standoff distance variation, it overcomes the limitations of the aforementioned methods. The proposed probe is based on electronically modulating the aperture of a rectangular waveguide using PIN diode-loaded dipoles placed symmetrically in the aperture region. It will be shown that the adverse effect of standoff distance variation can be eliminated, or otherwise, significantly reduced by non-coherently subtracting the signals measured at two different aperture modulation states." } @INPROCEEDINGS{Abou0806:Antenna, AUTHOR="Hassan {Abou Saleh} and Walaa Hamouda", TITLE="Antenna Selection Approach for {Decision-Feedback} Detectors over {MIMO} Flat Fading Channels", BOOKTITLE="24th Queen's Biennial Symposium on Communications", ADDRESS="Kingston, Ontario, Canada, Canada", DAYS=23, MONTH=jun, YEAR=2008, ABSTRACT="Abstract—In this paper, we investigate an antenna-selection (AS) approach for the decision-feedback detector (DFD) over Rayleigh fading channels. In particular, for a multiple-input multiple-output (MIMO) channel with M transmit and N receive antennas, we derive a lower bound on the outage probability for the AS approach. Note that the selected transmit antennas are those that maximizes both the post-processing signal-to-noise ratio (SNR), at the receiver end, and the system capacity. It is shown that the AS approach achieves a performance comparable to optimal selection based on exhaustive search, but at a lower complexity. Extensive simulations are presented to validate and demonstrate performance." } @INPROCEEDINGS{Abou0807:Optimal, AUTHOR="Mohamed {Abou El Saoud}", TITLE="Optimal Number and Class Selection of Nodes in Wireless Mesh Networks", BOOKTITLE="13th IEEE Symposium on Computers and Communications", ADDRESS="Marrakech, Morocco", DAYS=6, MONTH=jul, YEAR=2008, KEYWORDS="Network Planning; Wireless Mesh Networks; Ad Hoc Networks; Optimal Planning", ABSTRACT="In this work, the optimal network plan in terms of node class selection and number of nodes required to achieve a given network reliability in a Wireless Mesh Network (WMN) was investigated. The network is said to be optimal if it minimizes the network implementation cost while achieving the application matrix requirements. In this work, these requirements are described in terms of communication range, minimum network reliability, and achievable throughput. A node class is generally characterized by its capabilities (such as transmitted power and sensitivity) and associated cost. In order to tackle this problem, we developed an analytical model and methodology for WMN optimization. The proposed model differs from previously used models in that it takes into account links’ dependencies of geometrically co-located nodes, the effect of boundary nodes’ connectivity, in addition to fading and shadowing effects. This methodology was used to find the structure of the optimal policy for two important topologies: the one-dimensional linear network topology, and the two-dimensional triangular lattice topology. The proposed methodology resulted in a qualitative and quantitative description of the optimal WMN planning policy." } @INPROCEEDINGS{Abou0809:Alamouti, AUTHOR="Chadi Abou-Rjeily and Mario Bkassiny", TITLE="{Alamouti-Type} {Space-Time} Coding for {TH-UWB} Systems with Unipolar Pulse Position Modulations", BOOKTITLE="IEEE PIMRC 2008 Fundamentals \& PHY Track", ADDRESS="Cannes, France", DAYS=15, MONTH=sep, YEAR=2008, KEYWORDS="UWB; ultra-wideband; PPM; space-time coding; MIMO; modulation", ABSTRACT="In this paper, we consider the problem of Space-Time (ST) coding with unipolar Pulse Position Modulations (PPM). The proposed code satisfies a large number of construction constraints that render it superior to the existing PPM encoding schemes. In particular, the proposed 2*2 code achieves a full transmit diversity order while transmitting at a rate of 1 PPM-symbol per channel use. The proposed scheme can be associated with M-ary PPM constellations for all even values of M without introducing any constellation extension. This renders the proposed scheme suitable for low cost carrier-less Ultra- Wideband (UWB) systems where information must be conveyed only by the time delays of the modulated sub nanosecond pulses without introducing any amplitude amplification or phase rotation. Finally, the proposed scheme is symbol-by-symbol decodable where the information can be reconstituted by performing simple linear operations at the receiver side. A possible extension to transmitters equipped with three antennas is also discussed in situations where a certain number of feedback bits is available." } @INPROCEEDINGS{Abou0809:Simple, AUTHOR="Chadi Abou-Rjeily and Georges El-Howayek", TITLE="A Simple Analog {Space-Time} Coded {Transmitted-Reference} {MIMO} {UWB} Transceiver", BOOKTITLE="IEEE PIMRC 2008 Fundamentals \& PHY Track", ADDRESS="Cannes, France", DAYS=15, MONTH=sep, YEAR=2008, KEYWORDS="UWB; ultra-wideband; PPM; space-time coding; MIMO; modulation", ABSTRACT="In this paper, we propose a new Multiple-Input-Multiple-Output (MIMO) transceiver for Transmitted-Reference Impulse-Radio Ultra-Wideband (TR-IR-UWB) communications. The proposed scheme is capable of achieving full spatial and multi-path diversity orders while assuring a simple symbol-by-symbol decodability with analog autocorrelation receivers that do not require any kind of channel estimation. This approach results in high performance levels while keeping the natural advantages of simple and low-cost TR-UWB receivers that do not require local oscillators or analog-to-digital converters." } @INPROCEEDINGS{Abou0811:Gateway, AUTHOR="Mohamed Abouelseoud and Aria Nosratinia", TITLE="The Gateway Channel: Outage Analysis", BOOKTITLE="IEEE Globecom 2008 Communication Theory Symposium", ADDRESS="New Orleans, LA, USA", DAYS=30, MONTH=nov, YEAR=2008, KEYWORDS="relay, cooperation, opportunistic communication", ABSTRACT="We consider a relay that simultaneously assists multiple source-destination pairs that do not have a direct link, the so-called gateway channel, and explore the sum capacity of this network in the presence of quasi-static fading. In the absence of transmitter-side channel state information (CSI), we study superpostion as well as orthogonal channel access. In the presence of transmitter CSI, we consider opportunistic channel access with full CSI, as well as limited CSI via a 1-bit feedback (per user). In each case, the outage capacity and the diversity-multiplexing tradeoff are calculated. It is observed that orthogonal channel access is almost as good as superposition coding, and that opportunistic access provides signficiant gains. It is shown that a 1-bit feedback per user captures most of the gains available in opportunistic communication." } @INPROCEEDINGS{Abr, AUTHOR="Taufik {Abrão} and Fernando Ciriaco and Leonardo Oliveira and Bruno Angelico and Paul Jean Jeszensky and Ferran Casadevall", TITLE="Weighting Particle Swarm Optimization {SIMO} {MC-CDMA} Multiuser Detectors", BOOKTITLE="The 10th ISSSTA 2008 - Creating New Dimensions in the Wireless World", ADDRESS="Bologna, Italy", DAYS=25, MONTH=aug, YEAR=2008, ABSTRACT="This paper analyzes the performance of two heuristic approaches applied to a synchronous multicarrier multiuser detection (MuD) of multiple receive antennas code division multiple access (SIMO MC-CDMA) system. The particle swarm optimization (PSO) with weighting particle position based on combining multi-fitness functions (woPSO) is proposed and compared with the conventional PSO SIMO MC-CDMA. The woPSO strategy deal with the multi-objective dilemma imposed by the spatial diversity that results in independent likelihood function for each receive antenna. Additionally, the computational complexity of these algorithms was taken into account in order to show which one has the best trade-off in terms of performance and implementation complexity aspects." } @INPROCEEDINGS{Abra0804:Case, AUTHOR="Henrik Abrahamsson and Per Kreuger", TITLE="A Case for Resource Management in {IPTV} distribution", BOOKTITLE="The Fifth Swedish National Computer Networking Workshop 2008", ADDRESS="Karlskrona, Sweden", DAYS=9, MONTH=apr, YEAR=2008, KEYWORDS="content distribution, IPTV, resource management", ABSTRACT="Recently many new IPTV providers have appeared, typically telephone and broadband companies, that now distribute scheduled TV channels, sometimes high-definition TV and video-on-demand (VoD) over IP in their own network. In this paper we present a case for resource management in IPTV distribution. We present a model and first results for a simple scenario to show that scheduling and optimisation techniques can be used to make the distribution of TV and VoD more efficient by pushing content out in the network to the right place at the right time." } @INPROCEEDINGS{Abra0805:Joint, AUTHOR="Yuri Abramovich and Pavel Turcaj and Nicholas Spencer", TITLE="Joint Transient and {CW} {External-Noise} Mitigation in Heavy Clutter", BOOKTITLE="2008 IEEE Radar Conference", ADDRESS="Rome, Italy", PAGES="1803-1808", DAYS=26, MONTH=may, YEAR=2008, ABSTRACT={Modern radars such as high-frequency over-the-horizon (HF OTH) radars operate in a congested electromagnetic environment, with external noise and transients (lightning, meteor back-scatter, etc) as well as heavy clutter. The problem of simultaneously reducing both these interference types is quite complicated since the techniques for the {"}best{"} mitigation of each are often poorly compatible. Space-time adaptive processing can deliver a reasonable overall performance provided that the competing techniques are optimized. We proposed a beam-specific training data collection algorithm for joint external-noise and transient mitigation. The adaptive beamformer does not intend to spatially reject transients impinging via the main lobe, and rejects external noise and {"}sidelobe{"} transients if required. Transient removal and replacement by the predicted clutter samples, is performed at the output of the adaptive beamformer. Significant improvements are illustrated with examples of data collected by a JORN HF OTH radar.} } @INPROCEEDINGS{Abra0805:Optimal, AUTHOR="Yuri Abramovich and Ben Johnson and Nicholas Spencer", TITLE="Optimal Training Sample Partitioning for {Two-Stage} Adaptive Detectors", BOOKTITLE="2008 IEEE Radar Conference", ADDRESS="Rome, Italy", PAGES="1128-1133", DAYS=26, MONTH=may, YEAR=2008, ABSTRACT="Adaptive signal detection for scenarios with a limited number of sources of interest and background interferers (less than the number of antenna elements) can be efficiently executed using diagonally loaded covariance matrix estimates, but the resultant detectors are not strictly constant false-alarm rate (CFAR). The loss of “CFARness” means that the problem of adaptive interference mitigation and the problem of adaptive false-alarm threshold control must be treated separately, yet draw on the same collection of secondary training samples. Here we consider a “two-stage” adaptive detection scheme that optimally partitions the total sample support T into two sets: TCME data samples are used to design the adaptive filter (beamformer), then the remaining TCFAR samples are used to calculate the adaptive scalar false-alarm threshold. We present a comparative analysis of the detection performance of “one-stage” CFAR and “twostage” adaptive detectors." } @INPROCEEDINGS{Abra0805:Performance, AUTHOR="Yuri Abramovich and Muralidhar Rangaswamy and Ben Johnson and Philip Corbell and Nicholas Spencer", TITLE="Performance of {2-D} Mixed Autoregressive Models for Airborne Radar {STAP:} {KASSPER-Aided} Analysis", BOOKTITLE="2008 IEEE Radar Conference", ADDRESS="Rome, Italy", PAGES="696-700", DAYS=26, MONTH=may, YEAR=2008, ABSTRACT={Autoregressive (AR) models have been recently explored for use in space-time adaptive processing (STAP) of airborne radar; these require a small number of training data samples (compared with sample-matrix inversion) and are based on adaptively selecting a parametric model for the interference covariance matrix. Covariance models seek to help estimate the covariance matrix accurately with less sample support. Selecting an appropriate model is the problem of finding the {"}best{"} trade-off between stochastic losses (associated with finite training support) and the losses associated with model mismatch. We use a recently proposed new class of mixed AR models: in the temporal (slow-time) domain such models are stationary AR, whereas in the spatial domain they are like multivariate time-varying AR processes. We use the DARPA KASSPER program (dataset 1) to analyze and demonstrate significant improvements in radar processing over traditional techniques.} } @INPROCEEDINGS{Abra0807:MIMO, AUTHOR="Yuri Abramovich and Gordon Frazer", TITLE="{MIMO} radar performance in clutter: limitations imposed by bounds on the volume and height distributions for the {MIMO} radar ambiguity function", BOOKTITLE="Fifth IEEE Sensor Array and Multichannel Signal Processing Workshop", ADDRESS="Darmstadt, Germany", PAGES="441-445", DAYS=21, MONTH=jul, YEAR=2008, KEYWORDS="MIMO radar; ambiguity function; clutter", ABSTRACT={The multiple-input multiple-output (MIMO) radar delay-Doppler ambiguity function is introduced as the sum of all auto- and cross-ambiguity functions of the set of K spatially diverse waveforms. The integral of this function over the range-Doppler frequency region occupied by spread clutter relates to clutter's power at the output of the matched MIMO receiver, and serves as a measure of orthogonality of the waveforms in this region. We derive the upper bound on the attainable {"}clear area{"} for the ambiguity function, and show that, with respect to the conventional single-waveform ambiguity function, the maximum clear area is K times smaller for the MIMO system.} } @INPROCEEDINGS{Abra0807:Multivariate, AUTHOR="Yuri Abramovich and Ben Johnson and Nicholas Spencer", TITLE="Multivariate spectral reconstruction of {STAP} covariance matrices: {Block-Toeplitz} solution", BOOKTITLE="Fifth IEEE Sensor Array and Multichannel Signal Processing Workshop", ADDRESS="Darmstadt, Germany", PAGES="229-233", DAYS=21, MONTH=jul, YEAR=2008, KEYWORDS="Toeplitz matrices; covariance matrices; autoregressive processes;maximum entropy methods, spectral factorization", ABSTRACT={In space-time adaptive processing (STAP) applications, temporally stationary clutter results in a block-Toeplitz clutter covariance matrix. In the reduced-order parametric matched filter STAP technique, this covariance matrix is reconstructed from a small number of estimated parameters, resulting in a much more efficient use of training samples. This paper and a companion one addresses the issue of STAP filter performance from covariance matrices reconstructed with a strict adherence to the block-Toeplitz structure versus a {"}relaxed{"} reconstruction which employs a maximum entropy completion criteria, but does not enforce a strict block-Toeplitz structure on that completion. Both techniques analyzed use a multivariate spectral reconstruction approach which preserve the Burg spectrum. In this paper, the reconstruction is constrained to result in a block-Toeplitz covariance matrix model, and the solution requires positive definite matrix-valued stable polynomial factorization that can be derived via the multivariate Levinson algorithm. Performance of the reconstructed covariance matrix model as a STAP filter is evaluated using the DARPA KASSPER dataset in the companion paper.} } @INPROCEEDINGS{Abra0807:Multivariate, AUTHOR="Yuri Abramovich and Ben Johnson and Nicholas Spencer", TITLE={Multivariate spectral reconstruction of {STAP} covariance matrices: Hermitian {"}relaxation'' and performance analysis}, BOOKTITLE="Fifth IEEE Sensor Array and Multichannel Signal Processing Workshop", ADDRESS="Darmstadt, Germany", PAGES="459-462", DAYS=21, MONTH=jul, YEAR=2008, KEYWORDS="Toeplitz matrices; covariance matrices; autoregressive processes; maximum entropy methods; space-time adaptive processing", ABSTRACT={In space-time adaptive processing (STAP) applications, temporally stationary clutter results in a block-Toeplitz clutter covariance matrix. In the reduced-order parametric matched filter STAP technique, this covariance matrix is reconstructed from a small number of estimated parameters, resulting in a much more efficient use of training samples. This paper explores a computationally advantageous {"}relaxed{"} maximum entropy (Burg) reconstruction technique which does not restore a strict block-Toeplitz structure, but does preserve the Burg spectrum. Performance of the reconstructed covariance matrix model as a STAP filter is evaluated using the DARPA KASSPER dataset and compared with {"}proper{"} block-Toeplitz reconstruction.} } @INPROCEEDINGS{Abra0808:Normalized, AUTHOR="Shafayat Abrar and Asoke Nandi", TITLE="Normalized Constant Modulus Algorithm for Blind Channel Equalisation", BOOKTITLE="European Conference on Signal Processing 2008", ADDRESS="Lausanne, Switzerland", DAYS=25, MONTH=aug, YEAR=2008, KEYWORDS="Adaptive Equalizers; Blind Equalization; Constant Modulus Algorithms", ABSTRACT="A new constant modulus algorithm and two of its variants are presented for blind equalisation of complex-valued communication channels. The proposed algorithm is obtained by solving a novel deterministic optimization criterion which comprises the dispersion minimization of a priori as well as a posteriori quantities leading to an update equation having a particular zero-memory continuous nonlinearity. The convergence analysis of a variant of the proposed algorithm is presented." } @INPROCEEDINGS{Abra0808:Optimization, AUTHOR="Andrea Abrardo and Gianluigi Ferrari and Fabio Perna", TITLE="Optimization of {Closed-Loop} Power Control for Wireless Multiple Orthogonal Access Schemes with Correlated Sources", BOOKTITLE="The 10th ISSSTA 2008 - Creating New Dimensions in the Wireless World", ADDRESS="Bologna, Italy", DAYS=25, MONTH=aug, YEAR=2008, ABSTRACT="In this paper, we study the performance of wireless multiple-access communication systems, where two correlated sources communicate to an access point (AP). The communication links are affected by Rayleigh fading, and the source correlation is exploited only at the AP, which makes use of closed-loop power control (CLPC) to counter-act the effects of fading. We first propose an analytical framework to valuate the theoretical performance limits in the presence of feedback (power control). Then, we consider coded communication schemes, where the sources make use of turbo codes and the AP performs joint source-channel decoding. A simple feedback power control strategy is considered and its performance is evaluated through simulations." } @INPROCEEDINGS{Abra0809:Optimal, AUTHOR="Andrea Abrardo and Paolo Detti and Gaia Nicosia and Andrea Pacifici and Mara Servilio", TITLE="Optimal channel allocation in {OFDMA} multi-cell systems", BOOKTITLE="Second Workshop on Network Control and Optimization", ADDRESS="Paris, France", DAYS=8, MONTH=sep, YEAR=2008, KEYWORDS="radio resource allocation, network flow models, heuristic algorithms", ABSTRACT="This paper addresses the problem of allocating users to radio resources (i.e., sub-carriers) in the downlink of an OFDMA cellular system. Most of the literature so far has focused on the single cell scenario, where interference among users can be easily avoided by orthogonal assignments. Here, we consider a classical multi-cellular environment and a realistic interference model, such that the ability of two nodes to reliably communicate depends not only on their distance but also on the actual interference level which depends on other users assigned to the same resource. We carry out a margin adaptive approach where total transmission power is minimized while guaranteeing a certain given rate for each user. We characterize the computational complexity of the resulting optimization problem. This is strongly NP-hard, in its general setting, but many special cases admit suitable network flow formulations and hence they are polynomially solvable. On this grounds, we present a heuristic approach---based on an adaptation of a network flow polynomial algorithm---that finds optima under certain conditions or, in the general case, ``reasonably good'' solutions. Computational tests have been executed to evaluate the performance of our heuristc algorithm. In a comparison of the results obtained by a commercial state-of-the-art optimization solver and by our algorithm, on a set of about a hundred very congested instances, our approach proves to be effective in terms of both infeasibilities and transmitted powers and dramatically more efficient in terms of computation times." } @INPROCEEDINGS{AbRa0811:Characterization, AUTHOR="Mohammad Syuhaimi Ab-Rahman and Affa Rozana Abd-Rashid and Sahbudin Shaari and Abang Annuar Ehsan", TITLE="The Characterization of {FTTH} Wavelength Selective Coupler", BOOKTITLE="2008 IEEE International Conference on Semiconductor Electronics", ADDRESS="Johor Bahru, Malaysia", DAYS=25, MONTH=nov, YEAR=2008, KEYWORDS="Waveguide selective coupler, waveguide, FTTH", ABSTRACT="The purpose of this paper is to design and characterize the wavelength selective coupler (WSC) which use the concept of coupled mode theory. The device is designed on silica substrate with compliance of FTTH wavelength such as wavelengths 1310 nm (upstream data/voice), 1480 nm (downstream data/voice), 1550 nm (video) and 1625 nm (testing). The designed WSC coupler is used as a router for specific wavelength in order to detect any optical line failure in FTTH network application in which the OTDR launched wavelength (1625 nm) is used as troubleshooting signal. The performance of the devices was modeled using the beam propagation method (BPM-Cad) product from the Optiwave Inc. This paper also highlights the parameter studies and the effect to the design specification and performance. We analyze the following parameters such as: wavelength, separation between waveguides (a), waveguide width (d), number of mesh, TE and TM polarization, and refractive indices for substrate (n2) and waveguide (n1)." } @INPROCEEDINGS{Abra0811:FDTD, AUTHOR="Chikku Abraham and Shrikrishna Kulkarni", TITLE="{FDTD} Simulated Propagation of Electromagnetic Pulses due to {PD} for Transformer Diagnostics", BOOKTITLE="IEEE Region 10 Conference", ADDRESS="Hyderabad, Andhra Pradesh, India", DAYS=18, MONTH=nov, YEAR=2008, KEYWORDS="Transformer Diagnostics; Partial Discharge; EM Wave propagation; FDTD", ABSTRACT="Partial discharge (PD) is one of the main causes for eventual equipment failure and it occurs where the electric field exceeds the local dielectric strength of the insulation. The PD signal captured at UHF has many advantages. The Finite Difference Time Domain (FDTD) technique, which is a widely used electromagnetic computational method, has been used to model propagation PD discharges generated in the form of a Gaussian pulse. The wave propagation in free space, oil and with a cylindrical metallic obstruction representing core/winding, in the two dimensions is realized and presented in this work. The perfectly matched layer (PML) which is a flexible and efficient absorbing boundary condition (ABC) has been incorporated in the simulation. Further, for localization Time Difference of Arrival (TDOA) approach has been used." } @INPROCEEDINGS{AbRa0811:FTTH, AUTHOR="Mohammad Syuhaimi Ab-Rahman and Affa Rozana Abd-Rashid and Sahbudin Shaari and Abang Annuar Ehsan", TITLE="Design of {FTTH} Demultiplexer Based on Cascaded Wavelength Selective Coupler", BOOKTITLE="2008 IEEE International Conference on Semiconductor Electronics", ADDRESS="Johor Bahru, Malaysia", DAYS=25, MONTH=nov, YEAR=2008, KEYWORDS="Demultiplexer, cascaded WSC, waveguide, FTTH", ABSTRACT="The purpose of this paper is to design and characterize the Mux/Demultiplexer which use the concept of coupled mode theory. The design is based on cascading the wavelength selective coupler (WSC) device utilizing commercial specification. The device is designed on silica substrate with compliance of FTTH wavelength such as wavelengths 1310 nm (upstream data/voice), 1480 nm (downstream data/voice), 1550 nm (video) and 1625 nm (testing). The proposal of designed WSC coupler is used as a router for specific wavelength in order to detect any optical line failure in FTTH network application in which the OTDR launched wavelength (1625 nm) is used as troubleshooting signal. The performance of the devices was modeled using the beam propagation method (BPM-Cad) product from the Optiwave Inc." } @INPROCEEDINGS{Abra0812:Range, AUTHOR="Aminreza {Abrahimi Saba} and Hassan Abolhassani and Mohammad Ghodsi", TITLE="{Range-Free} Passive Acoustic Localization", BOOKTITLE="2008 Fourth International Conference on Intelligent Sensors, Sensor Nertworks and Information Processing", ADDRESS="Sydney, Australia", DAYS=15, MONTH=dec, YEAR=2008, KEYWORDS="Sensor Networks; Localization; Bayesian Filtering; Acoustic Sensor", ABSTRACT="We propose a range-free localization framework in which a network of randomly deployed acoustic sensors can passively use natural acoustic phenomena within its environment to localize itself. We introduce a noble approach for registration of sensors observations which takes advantage of a clustering technique on triplets of associated observations. A Bayesian filtering method is employed to incrementally improve system state estimation as more observations become available. To the best of our knowledge this is the first work done on range-free passive acoustic localization. Simulation experiments of the proposed algorithms are presented." } @INPROCEEDINGS{AbRa0812:VLSI, AUTHOR="Ab Al-Hadi {Ab Rahman} and Izam Kamisian and Ahmad Zuri Sha'ameri", TITLE="{VLSI} Design Techniques and Strategies for Implementing Adaptive Equalizer", BOOKTITLE="20th International Conference on Microelectronics (ICM) 2008", ADDRESS="Sharjah, UAE, UAE", PAGES="349-352", DAYS=14, MONTH=dec, YEAR=2008, KEYWORDS="VLSI Design; adaptive signal processing; channel equalizer", ABSTRACT="VLSI design of signal processing algorithm involves multiple selections and trade-off in order to achieve performance that is required for a particular application. In the case of realizing adaptive channel equalizer, digital circuit designers are confronted with three main design criteria that significantly affect the outcome of the circuit; filter structure and architecture, adaptive algorithm, and arithmetic components. This paper reviews some of the design techniques and strategies to achieve high performance adaptive equalizer based on optimal trade-off between the criteria. In addition to this, ASIC design of adaptive equalizer targeted to TSMC 0.25µm process technology is also presented. Simulation results show that the designed VLSI adaptive equalizer can successfully equalize distorted signals with ISI, with core cell layout area and throughput of 0.562mm2 and 223 Kb/s respectively, which is suitable for mobile communication applications." } @INPROCEEDINGS{AbuA0800:Advanced, AUTHOR="Ma'moun Abu-Ayyad", TITLE="Advanced Control Schemes Using {Multi-Model} Approach For Nonlinear Processes", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, ABSTRACT="The objective of this work is to demonstrate that the methodology of multi-model can be applied to other advanced control strategies making the methodology generic. The multi-model strategy was implemented on several advanced controllers such as PI controller using Smith-Predictor, Dahlin controller and Generalized Predictive Control (GPC) algorithm. Computer simulations and experimental work using these strategies combined with multi-model approach were conducted on nonlinear single-input-single-output (SISO) systems and compared with the original forms of these advanced controllers. Practical work was carried out on controlling the temperature of a steel cylinder." } @INPROCEEDINGS{Abua0803:Subchannel, AUTHOR="Ibrahim Abualhaol and Mustafa Matalgah", TITLE="{Subchannel-Division} Adaptive Resource Allocation Technique for Cooperative {Relay-Based} {MIMO/OFDM} Wireless Communication Systems", BOOKTITLE="IEEE Wireless Communications and Networking Conference", ADDRESS="Las Vegas, Nevada, USA", DAYS=31, MONTH=mar, YEAR=2008, KEYWORDS="MIMO/OFDM; Cooperative Diversity; Adaptive Resource Allocation", ABSTRACT="In this paper, cooperative relay-based resource allocation technique is proposed for adaptive bit and power loading multiple-input-multiple-output/orthogonal frequency division multiplexing (MIMO/OFDM) system. In this technique, subchannels allocation, M-QAM modulation order, and power distribution among different subchannels in the relay-based MIMO/OFDM system are jointly optimized according to channel state information (CSI) of the relay and the direct link. The transmitted stream of bits is divided into two parts according to a suggested cooperative division protocol. The first part is sent directly from the source to the destination and the second part is relayed to the destination through an indirect link. Such a cooperative relay-based system enables us to exploit the inherent system diversities in the frequency, space, and time to maximize the system power efficiency, and to guarantee the fulfillment of the required quality of service (QoS) including bit error rate (BER) and transmission rate. The BER performance using this cooperative division protocol with adaptive subchannel assignment and adaptive bit/power loading are presented and compared with non-cooperative one. The use of cooperation in relay-based MIMO/OFDM system showed high BER performance improvement. The advantage of cooperation increases as the order of MIMO system increases." } @INPROCEEDINGS{Abua0804:Capacity, AUTHOR="Ibrahim Abualhaol and Mustafa Matalgah", TITLE="Capacity Analysis of {MIMO} System Over Nakagami-m Fading Channels Using Finite Mixture with Expectation Maximization Algorithm", BOOKTITLE="AICCSA-08 Networking and Multimedia Track", ADDRESS="Doha, Qatar", DAYS=1, MONTH=apr, YEAR=2008, ABSTRACT="The capacity of multiple input multiple output (MIMO) system over wireless channels has been investigated analytically and by simulation over different types of wireless fading channels, such as Rayleigh and Nakagami fading channels. In this paper, Finite Mixture (FM) with Expectation-Maximization (EM) algorithm is utilized to derive simple approximate expression for the probability density function (pdf) of the capacity distribution over Nakagami-m fading channels. This approximation converts the complicated capacity distribution to a simple weighted sum of univariate normal distributions with appropriate weighting coefficients, means, and variances for a predefined system model and channel statistics. The resultant approximation simplified the mathematical analysis of the average capacity and the outage capacity in terms of well known Q-functions." } @INPROCEEDINGS{AbuA0804:Measured, AUTHOR="Najah {Abu Ali}", TITLE="Measured Delay Distribution in a Wireless Mesh Network Test-bed", BOOKTITLE="AICCSA-08 Networking and Multimedia Track", ADDRESS="Doha, Qatar", DAYS=1, MONTH=apr, YEAR=2008, KEYWORDS="Wireless mesh networks; Measurement; Performance", ABSTRACT="A lot of work has been done to evaluate the real time applications’ performance over wireless networks. Some work focused on delay as a performance metric. However, no work studied the delay random behavior over a test-bed which imitates as much as possible actual operative networks. In this paper, we designed and run different experiments over heterogeneous 802.11 Wireless Mesh Network (WMN) test-bed with a scope of studying the delay probability distribution over multihop WMN. We anticipate that by knowing the link delay distribution, we will be able to use this information to design sound algorithms to provide for QoS. For example, designing a partitioning algorithm capable of partitioning multiple end-to-end QoS requirements into link QoS requirements. We designed different experiments to measure the link and end-to-end delays over the WMN test-bed. The measured link delays are used to construct an empirical histogram. Our experiments reveal that irrespective of the number of hops along the paths and type of traffic crossing the link, the empirical histograms almost have same general shapes. The empirical histograms are fitted into different types of standard pdf distributions. We found that the best fits for almost 90\% of the empirical distributions are two standard distributions; gamma and logistic." } @INPROCEEDINGS{AbuA0805:Cross, AUTHOR="Najah {Abu Ali} and Hossam Hassanein and Mohammad Hayajneh", TITLE="Cross Layer Scheduling Algorithm for {IEEE} {802.16}", BOOKTITLE="ICC'08 - Wireless Communications Symposium", ADDRESS="Beijing, China, P.R. China", DAYS=19, MONTH=may, YEAR=2008, ABSTRACT="In order to support different types of user applications, the IEEE 802.16 standard defines different service classes together with their associated Quality of Service (QoS) parameters. However, the standard lacks a MAC scheduling architecture that guarantees these defined QoS requirements. The importance of efficient scheduling is crucial to QoS provisioning for multimedia flows. Thus, in this paper we propose an opportunistic and optimized downlink scheduler that pledges fairness among admitted connections. Our approach involves separating the scheduling problem into two sub-problems. In the first problem, which addresses inter-class slot allocation, the proposed scheduler calculates the number of time-slots in each time frame corresponding to the service classes with the objective minimizing the blocking probability of each class. In the second problem, the intra-class slot allocation problem, timeslots for each class are allocated using an integrated cross-layer priority functions that guarantees proportional fairness. The simulation results reveal that the proposed scheduler realizes our objectives, and provides efficient QoS scheduling without starving the connections of the best effort class." } @INPROCEEDINGS{AbuA0806:Comparison, AUTHOR="Ma'moun Abu-Ayyad and Rickey Dubay", TITLE="Comparison of Unconstrained Model Predictive Control Schemes on Nonlinear Processes", BOOKTITLE="Canadian Society for Mechanical Engineers Forum 2008", ADDRESS="Ottawa, Ontario, Canada", DAYS=5, MONTH=jun, YEAR=2008, KEYWORDS="MPC, Ill-conditionality, Nonlinear Predictive Control, MIMO Systems", ABSTRACT="Many model predictive control (MPC) algorithms have been proposed in the literature depending on the conditionality of the system matrix and the choice of its cost-function. This paper presents the newer MPC schemes such as extended predictive control (EPC) and shifted MPC as well as other well known forms. The control performances of these controllers are compared using two systems that are slow and fast reacting. The closed-loop responses are compared and the differences and similarities are explained on the basis of the structure of the control schemes. Disturbance rejection and the tracking of various setpoint trajectories are performed with good closed-loop results from all the controllers. It was found that the controllers that were specifically designed to reduce the system matrix ill-conditionality such as EPC and generalized predictive control provided better control performance when compared to other MPC methods." } @INPROCEEDINGS{AbuA0806:Tuning, AUTHOR="Ma'moun Abu-Ayyad and Rickey Dubay", TITLE="A new Tuning Strategy for Ill-conditioned Nonlinear Multivariable Processes", BOOKTITLE="Canadian Society for Mechanical Engineers Forum 2008", ADDRESS="Ottawa, Ontario, Canada", DAYS=5, MONTH=jun, YEAR=2008, KEYWORDS="MPC, Ill-conditionality, Nonlinear Predictive Control, MIMO Systems", ABSTRACT="The objective of this work is to develop a new tuning strategy for multivariable predictive control. A natural concern is the problem of ill-conditionality in controlling multi-input multi-output (MIMO) systems. The main advantage of the proposed method is that it has a simple and effective tuning strategy that results in a well-conditioned system which can achieve tight closed-loop response. The main features of the new tuning strategy are practically illustrated on controlling three temperature zones on a steel cylinder that used to melt the plastic material inside the barrel of an injection molding machine which is a highly nonlinear MIMO system. The results of the proposed method are compared to move suppressed predictive control with improved performance." } @INPROCEEDINGS{AbuA0807:Space, AUTHOR="Ala {Abu Alkheir} and Khalid Qaraqe and Mohamed-Slim Alouini", TITLE="On the {Space-Time} Correlation of {MIMO} Fading Channels in {3D} Scattering Models", BOOKTITLE="13th IEEE Symposium on Computers and Communications", ADDRESS="Marrakech, Morocco", DAYS=6, MONTH=jul, YEAR=2008, KEYWORDS="Space-Time correlation, MIMO, and Rician, Narrowband, scattering", ABSTRACT="In this paper, the time-space correlation function for narrowband MIMO channels is derived. We consider two 3D models, the cylinder model and the sphere model. In both cases, Rician fading is assumed. Scatterers are assumed around the mobile station alone to model macrocell situation. The results show that under reasonable assumptions, both models simplify to the 2D model proposed in \cite{Abdi}. Eventually, the construction of the correlation matrix used in the vector autoregressive (VAR) simulation method is studied." } @INPROCEEDINGS{Abua0808:Implicit, AUTHOR="Rami Abu-alhiga and Harald Haas", TITLE="Implicit {Pilot-Borne} Interference Feedback for Multiuser {MIMO} {TDD} Systems", BOOKTITLE="The 10th ISSSTA 2008 - Creating New Dimensions in the Wireless World", ADDRESS="Bologna, Italy", DAYS=25, MONTH=aug, YEAR=2008, ABSTRACT="In closed-loop future time division duplex (TDD) wireless systems, where channel reciprocity is maintained, uplink (UL) channel sounding method is considered as one of the most promising feedback methods due to its bandwidth and delay efficiency. However, in TDD interference-limited systems, conventional channel sounding pilots only provide instantaneous channel state information at the transmitter (CSIT), but no knowledge about the level of the interference at the receiver can be obtained. Due to this, a scheduler cannot optimally exploit the available degree of freedoms (DoF) in order to maximize the system capacity (e.g. the downlink (DL) sum capacity). In this paper, a novel interference feedback scheme is proposed to timely provide the base station (BS) with an implicit knowledge about the interference level received by each mobile station (MS). It is proposed to weight the uplink channel sounding pilots by the level of the received interference at each MS. The weighted uplink channel sounding pilots act as a bandwidth-efficient and delay-efficient mean for instantaneously providing the BS with knowledge of both CSI and interference level received by each active user. The performance of a system using weighted sounding pilots will be compared against a system using non-weighted sounding pilots for both greedy and fair scheduling criteria. Simulation results show that using the weighted sounding pilots significantly enhances the system throughput for the studied greedy and fair scheduling criteria." } @INPROCEEDINGS{AbuA0811:Adaptive, AUTHOR="Najah {Abu Ali} and Mohammad Hayajneh and Hossam Hassanein", TITLE="Adaptive Bandwidth Provisioning in {IEEE} {802.16} Broadband Wireless Networks", BOOKTITLE="IEEE Globecom 2008 Ad Hoc, Sensor and Mesh Networking Symposium", ADDRESS="New Orleans, LA, USA", DAYS=30, MONTH=nov, YEAR=2008, ABSTRACT="Congestion based pricing algorithms are considered efficient approaches to control congestion and to distinguish services provided for users in computer networks. Game theory lends itself as a prevailing tool to design such algorithms. In this work, we propose a game theoretic congestion based bandwidth provisioning algorithm to address the scarcity for bandwidth provisioning scheme in IEEE 802.16 standard. To the best of our knowledge, the proposed algorithm is the first one to simultaneously control congestion and fairness while providing differentiated QoS guarantees. Simulation results reveal that the proposed scheme realizes our objective of controlling congestion, and provides differentiated QoS guarantees and proportional fairness among the different network classes." } @INPROCEEDINGS{Abub0805:Frequency, AUTHOR="Mohd Abubakr", TITLE="Frequency Analysis of Decoupling Capacitors for Three Voltage Supplies in {SoC}", BOOKTITLE="IEEE International Conference on Circuits and Systems for Communications 2008", ADDRESS="Shanghai, P.R. China", DAYS=26, MONTH=may, YEAR=2008, KEYWORDS="Decoupling Capacitor;power aware IC;frequency analysis", ABSTRACT="Reduction in power consumption has become a major criterion of design in modern ICs. One such scheme to reduce power consumption by an IC is the use of multiple power supplies for critical and non-critical paths. To maintain the impedance of a power distribution system below a specified level, multiple decoupling capacitors are placed at different levels of power grid hierarchy. This paper describes about three-voltage supply power distribution systems. The noise at one power supply can propagate to the other power supply, causing power and signal integrity problems in the overall system. Effects such as anti-resonance and remedies for these effects are studied. Impedance of the three-voltage supply power distribution system is calculated in terms of RLC-model of decoupling capacitors. Further the obtained impedance depends on the frequency; hence brief frequency analysis of impedance is done." } @INPROCEEDINGS{Abub0809:IEEE, AUTHOR="Hamza Abubakari and Shivakumar Sastry", TITLE="{IEEE} 1588 Style Synchronization over a Wireless Link", BOOKTITLE="International Symposium on Precision Clock Synchronization for Measurement, Control, and Communication", ADDRESS="Ann Arbor, Michigan, USA", DAYS=22, MONTH=sep, YEAR=2008, KEYWORDS="Synchronization; Motes; IEEE 1588; Networked Embedded Systems", ABSTRACT="IEEE 1588 precision time protocol (PTP) is important for a broad spectrum of applications. PTP has been largely implemented in wired networks with multicast capabilities. We present a technique for implementing PTP and IEEE Style synchronization in networked embedded systems. To compensate for the poor stability of local clocks and the lossy wireless medium, we use a Kalman filter to estimate the skew. We feed this skew directly to a PTP clock servo that disciplines the local clock. We demonstrate the performance of this technique using to Mica2 motes. The results show that this clock servo provides a stable clock across all time scales. In the future, this technique can be extended to improve fault tolerance for PTP and to achieve determinism in networked embedded systems." } @INPROCEEDINGS{AbuE0805:Security, AUTHOR="Ahmad Rami Abu-El-Quran and Rafik Goubran and Adrian Chan", TITLE="Security Instrument using Talker Identification and Microphone Arrays in Variable Noisy Environments", BOOKTITLE="International Instrumentation and Measurement Technology Conference", ADDRESS="Victoria, Vancouver Island, British Columbia, Canada", DAYS=12, MONTH=may, YEAR=2008, KEYWORDS="Feature extraction; Microphone arrays; Noisy environment; Security instrument; SNR estimation; Talker identification", ABSTRACT="In paper, we propose a robust security instrument that can detect the location and identity of talker in variable noisy environment. This instrument calculates the value of the signal-to-noise (SNR) using a discrete-valued SNR estimator. This SNR value is used to adapt the performance of speech/nonspeech classifier to the surrounding noisy environment. If the detected signal is speech then a novel multi-engine talker identification (TI) will determine the identity of the talker, else an audio classification system will determine the audio type of the detected signal (e.g. widows breaking, and wind sounds). Multi-engine TI utilizes the SNR value to select the TI engine, from a set of six engines (five different SNR environments and a “clean” environment), with the SNR training condition that best matches the surrounding environment; greater TI accuracy should be achieved when training and test environments are similar. The performance of this instrument is evaluated using twelve test environments, with the SNR ranging from -10 dB to clean environ-ment (SNR > 50 dB). The proposed instrument achieves an average classification accuracy of 92\% over an SNR range of 10 dB to clean environments; an enhancement of 38\% over the instrument trained in a clean environment." } @INPROCEEDINGS{AbuE0805:Ultra, AUTHOR="Ahmed Abu-Elanien and Ramadan El-Shatshat and Salama Magdy", TITLE="An Ultra High Speed Relay for Protection of {Series-Compensated} Transmission Lines", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, KEYWORDS="Series-compensated transmission line protection; traveling waves; wavelet transform", ABSTRACT="A fault classification in the Transmission Lines (TLs) equipped with series capacitors is a difficult task specifically if the fault impedance is high. Also, the location of the fault in series compensated lines requires a considerable effort if it is calculated using traditional impedance based methods. This is because of the nonlinear behavior of a series capacitor protection arrangement (Metal Oxide Varistor, MOV), and the rapidly changing characteristics of circuit impedance. In this paper, an ultra high speed algorithm for protecting series compensated TLs is proposed to overcome the problems associated with the nonlinearity of the series capacitor bank and its protection (MOV). The algorithm uses the Discrete Wavelet Transform (DWT) to extract the high frequency transients contained in the fault current to detect and classify the fault. Locating the fault will be determined using the traveling waves theory to avoid the nonlinear behavior of the impedance of the series capacitor-MOV set. The DWT will be used to extract the traveling waves and recording their arrival times. The high speed, accuracy, and reliability are the main advantages of the proposed algorithm. The analytical expectations are verified by digital simulation using EMTDC simulation package." } @INPROCEEDINGS{Abue0809:OPERA, AUTHOR="Mahmoud Abuelela and Stephan Olariu and Ivan Stojmenovic", TITLE="{OPERA:} Opportunistic Packet Relaying in Disconnected Vehicular Ad Hoc Networks", BOOKTITLE="The Fifth IEEE International Conference on Mobile Ad-hoc and Sensor Systems", ADDRESS="Atlanta, GA, USA", DAYS=29, MONTH=sep, YEAR=2008, KEYWORDS="Vehicular Ad Hoc Networks; Packet Relaying; Routing", ABSTRACT="Vehicular Ad Hoc Networks (VANET) have recently received increasing attention in the media. And with good reason: VANET promises to integrate driving into a ubiquitous and pervasive network that will redefine the way we live and work. Empirical evidence, accumulated over time, has shown that under many highway scenarios VANETs tend to be disconnected, consisting of a collection of disjoint clusters. Our first contribution is to provide an analytical explanation of this rather counterintuitive result, thus confirming the findings of many researchers. We show that this phenomenon is present even in relatively dense traffic and provide an analytical expression of the expected size of a cluster, as a function of traffic density and communication range. We also show that the cluster size is quite stable and easy to maintain. In disconnected VANET, packet relaying takes on a new meaning: a vehicle that stores a packet may have to carry it for a while, acting as a ``data mule'', before a suitable next hop can be identified. Although some protocols have been introduced to take advantage of this fact, they are still suffering from some disadvantages such as wasting bandwidth and delayed propagation. Motivated by this fact, our second contribution is an Opportunistic Packet Relaying protocol (OPERA) for disconnected VANETs. In OPERA a packet progresses towards destination opportunistically, by a combination of data muling and local routing with the help of both co-directional and oncoming clusters in a smart way to avoid wasting resources. Finally, we offer simulation results to evaluate the performance of OPERA." } @INPROCEEDINGS{AbuG0000:Performance, AUTHOR="Haitham Abu-Ghazaleh and Jun Cai and Attahiru Alfa", TITLE="Performance Analysis for Polling Service in {IEEE} {802.16} Networks Under {PMP} Mode", BOOKTITLE="IWCMC 2008 General Symposium", ADDRESS="Chania Crete Island, Greece, Greece", DAYS=5, MONTH=aug, YEAR=2008, KEYWORDS="IEEE 802.16 ; Wireless Networks ; Queueing Analysis", ABSTRACT="In this paper, we focus on the polling mechanism adopted in IEEE 802.16 networks operating in PMP (Point-to-Multipoint) mode between the base station and the subscriber stations. We develop a queueing model for computing the performance of the polling service traffic, which takes into account the polling period amongst the various subscriber stations served by a single base station. Our model considers the correlation in performance of the multiple subscriber stations with traffic for polling service. Using our model, the waiting time distribution, the blocking probability, and other relevant performance measures are computed. The model can be used to investigate how the traffic in the polling service for each subscriber station can be allocated the necessary network resources to meet some certain QoS requirements." } @INPROCEEDINGS{Abug0812:Low, AUTHOR="Khaldoon Abugharbieh and Shoba Krishnan and Jitendra Mohan and Devnath Varadarajan", TITLE="A Low Power 10 Gbps Voltage Mode Output Driver with Good Return Loss Performance", BOOKTITLE="20th International Conference on Microelectronics (ICM) 2008", ADDRESS="Sharjah, UAE, UAE", PAGES="341-344", DAYS=14, MONTH=dec, YEAR=2008, KEYWORDS="driver, return loss, low power", ABSTRACT="Abstract-This paper describes a new topology and implementation of a 10 Gbps voltage mode output driver designed for high speed data transfer applications. Using a positive feedback technique, the low power driver achieves the proper internal chip impedance required for matching the line impedance. As a result, return loss is minimized and good signal integrity is achieved. The driver, which consists of a pre-driver and an output stage, consumes a total of 17mW at speed power and S22 return loss performance better than -15dB. It provides a single ended output swing of 400mV. In measurements, the driver, which was a part of an equalizer chip, achieved peak to peak jitter of 11psec at 10Gbps. The chip is fabricated in a standard 2.5V/1.2V SiGe BiCMOS technology with 100 GHz peak ft, and packaged in a commercial LLP package." } @INPROCEEDINGS{AbuH0000:Fast, AUTHOR="Bassam Abu-Hijleh and Richard Smith", TITLE="Fast Track Research to Practice: The New Way for Business to Meet the Worlds Environmental Challenges.", BOOKTITLE="International Conference on Management of Technology 2008", ADDRESS="Dubai, UAE", DAYS=6, MONTH=apr, YEAR=2008, ABSTRACT="The rate of technology developments is becoming more feverish. New studies, discoveries and tools are being introduced on daily bases by different institutions. One of the most important of these institutions is universities and other higher educational establishments. However, without putting these developments into practice they do not achieve their full potential. The challenge has always been to implement these developments into practical projects in a timely manner. The speed of achieving this “Research to Practice” track is very importance for attaining the maximum benefits form these developments. The time lag between traditional methods of information decimation and the industry implementation is too long for the current markets. This is particularly the case in areas where time is of the essence. The environmental challenges the world is facing are actuate and require immediate remedies. Thus, there is a need to promptly implement any new research or development that can help reduce the current trend. The construction industry, in all its phases, is the major user of the earth’s limited resources and is a major contributor to the adverse environmental challenges we are currently facing. This is more the case in the Middle East, especially Dubai, were the construction boom is at an all time high and is expected to continue for a long time to come. This places greater responsibility on the construction industry in this region. WS Atkins is one of the leading international companies that operate in this region of the world. Atkins has made a conscious decision to seek and implement the latest technology and developments available to improve the “ecological footprint” of their designs and in the process make them more sustainable. Toward this end, Atkins is actively supporting research in several top class universities all over the world that work on new technologies and practices that can help achieve this goal. The British University in Dubai (BUiD) and Cardiff University in the UK are two such universities. This paper details the level of integration achieved between Atkins and Sustainable Design of the Built Environment (SDBE) programme, a joint BUiD – Cardiff University programme, in environmentally related research. A high level of research to practice integration has been achieved allowing a fast track implementation of relevant environmental research into current designs. Research at SDBE is driven by the day-to-day issues faced by Atkins in their quest for more environmentally friendly designs. Toward this end, the researchers at BUiD work closely with the Atkins’ designers from the initial phase of the design project. Advanced analytical and numerical simulation techniques are frequently used to assess the effectiveness of different proposed solutions. Also, BUiD and Cardiff University jointly provided a custom made sustainability awareness programme that was delivered to Atkins offices over three continents. This awareness programme plays an important part in changing the mindset of their designers." } @INPROCEEDINGS{Abuh0000:Open, AUTHOR="Abdullah Abuhamed and Joe Tidd", TITLE="Open Innovation Strategy in the Jordanian Pharmaceutical Industry", BOOKTITLE="International Conference on Management of Technology 2008", ADDRESS="Dubai, UAE", DAYS=6, MONTH=apr, YEAR=2008, ABSTRACT="The aim of the paper is to examine how and why some firms that are embedded within the same weak National Systems of Innovation and Sectoral Systems of Innovation differ in the way and rate of performing innovation. It also identifies an association a strategy of open innovation, specifically participation in international collaboration, and firms’ innovation performance, in terms of new patents and products. The research is concerned with how management style, practices and methods within Jordanian generic drug manufacturers, specifically, with the analysis of how strategy decision-making processes and methods are associated with different levels of participation in international collaboration, and degrees and types of innovation. The research employs a mixed methods approach. An innovation survey was conducted across 17 generic local manufacturers in order to understand the nature of innovation in generic manufacturers. Moreover, the survey identified four cases for in-depth interviews with the key managers. The empirical results show that the higher the participation of firms in collaboration, as defined by the level of integration that underpins the collaboration deal, the higher the achievement in innovation and non-traditional market penetration. A strategy of open innovation has propelled two of the cases toward technological frontiers. As a result, these two firms have been able to develop their own proprietary capabilities through a combination of their R\&D, acquisition, and collaboration. Extending existing research on latecomer countries, these findings indicate that executive characteristics may provide additional explanation for the variation in the firms’ innovation performance. The research results show that top management international experience, external social capital and political background appear to be primary factors in distinguishing top management cognition and attitude toward participation in international collaboration. Moreover, the research results show that the characteristics of the search process for partner and technology explain differences in participation in collaboration, while top management style, integration mechanisms, and employee involvement explain differences in innovation performance. Conference paper, for Tracks 16 or 17" } @INPROCEEDINGS{AbuN0811:Bypassing, AUTHOR="Saeed Abu-Nimeh and Suku Nair", TITLE="Bypassing Security Toolbars and Phishing Filters via {DNS} Poisoning", BOOKTITLE="IEEE Globecom 2008 Computer and Communications Network Security Symposium", ADDRESS="New Orleans, LA, USA", DAYS=30, MONTH=nov, YEAR=2008, KEYWORDS="DNS poisoning; Pharming; Phishing; Phishing Filters; Security Toolbars", ABSTRACT="Security toolbars are used to protect naive users against phishing attacks by displaying warnings on suspicious sites. Recently, web browsers have added built-in phishing filters mimicking the same functionality to detect phishing sites. The present study proposes a new attack to bypass security toolbars and phishing filters via DNS poisoning. Spoofed DNS cache entries are used to forge the results provided to security toolbars and thus misleading information is displayed to the victim. Although there are several studies that demonstrate DNS poisoning attacks, none to our best knowledge, investigate whether such attacks can circumvent security toolbars or phishing filters. Four well-known security toolbars and three reputable browser builtin phishing filters are scrutinized. None of the seven tools detect the attack; however, security toolbars provide the victim with false confirmative indicators that the phishing site is legitimate." } @INPROCEEDINGS{Abuo0800:Utilizing, AUTHOR="Khalil Abuosba and Asim {El Sheikh} and Clemens Martin", TITLE="Utilizing Security Requirements Engineering Methods for Operational Security Maintenance Purposes", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, KEYWORDS="Security, requirements, fault, event, tree", ABSTRACT="Secure systems are achieved by implementing appropriate controls and policies specified based on appropriate selection of minimum security requirements. Maintaining security for these systems is a major challenge. Systems may encounter threats that may arise due to exploitation of vulnerabilities or due to programming flaws. In this work we address on security requirements engineering approaches and focus primarily on methods that may be utilized for the purpose of investigating incidents. We have shown empirically that using methods such as faults trees threats may be identified; and systematically, other methods such as events trees, incidents may be avoided or prevented." } @INPROCEEDINGS{Abur0000:Hop, AUTHOR="Kentaro Aburada and Yusuke Sato and Naonobu Okazaki and Shigeyuki Tomita and Mirang Park", TITLE="A hop-vector based routing scheme for {Data-Centric} Sensor Networks", BOOKTITLE="The Fourth International Conference on Mobile Computing and Ubiquitous Networking", ADDRESS="Miraikan, Tokyo, Japan", DAYS=11, MONTH=jun, YEAR=2008, KEYWORDS="Routing, Data-Centric Sensor Networks, Ad hoc Networks, Mobile Network Protocols", ABSTRACT="For sensor networks consisting of battery-powered sensor nodes, power saving is significant challenge. It is effective to reduce the amount of communication for sensor networks where power resource is scarce, because sensor nodes consume energy most in communication. We propose a routing protocol which reduces the amount of communication and does not need geographic information. In this method, we introduce n base nodes, and assign n-dimensional hop-vector consist of number of hops from each base node to each node. Then, each node forwards packets greedily based on distance between hop-vectors of the node and destination. The simulation results show that proposal method works well in the low density network compared to existing greedy forwarding method using information of geographic location." } @INPROCEEDINGS{AbuR0806:Evaluation, AUTHOR="Ehab {Abu Ramadan} and Eric Savory and Robert Martinuzzi", TITLE="Evaluation Of {RANS} Models for Flow Normal to a Flat Plate", BOOKTITLE="Canadian Society for Mechanical Engineers Forum 2008", ADDRESS="Ottawa, Ontario, Canada", DAYS=5, MONTH=jun, YEAR=2008, KEYWORDS="Bluff body, turbulence modeling, flat plate, Vortex Shedding", ABSTRACT="The current work aims at providing guidelines on how to computationally model the flow around bluff bodies, from an industrial point of view. To this end, the efficiency of various turbulence models in predicting integral quantities, namely the drag and lift coefficients, and Strouhal number is assessed. Since the aim is to locate a model that introduces the minimum amount of complexity while capturing the essence of the relevant physics, turbulence models will be limited to those based on the Unsteady Reynolds-averaged Navier-Stokes (URANS) equations retaining the Boussinesq eddy-viscosity hypothesis. Both the one equation model, the Spalart-Allmaras model, and two-equation models (k-e and k-w) and their variants are employed to examine the flow normal to a flat plate. The results are compared against experimental data. The inability of previous attempts to render the fundamental physics of bluff body aerodynamics using these models is discussed in terms of wall treatments. It is established here that regardless of the turbulence model, the two-layer approach must be adopted to correctly model the flow around bluff bodies. In this approach, the whole domain is subdivided into two regions; a fully-turbulent region and near-the-body viscosity-affected region. The results demonstrate the superiority of the realizable k-e model in predicting flow normal to a flat plate." } @INPROCEEDINGS{Abus0809:Collaborative, AUTHOR="Murad Abusubaih", TITLE="Collaborative Setting of {RTS/CTS} in {Multi-Rate} {Multi-Cell} {IEEE} {802.11} Wireless {LANs}", BOOKTITLE="16th IEEE Workshop on Local and Metropolitan Area Networks", ADDRESS="Cluj-Napoca, Transylvania, Romania", DAYS=3, MONTH=sep, YEAR=2008, KEYWORDS="RTS/CTS;wlan;802.11", ABSTRACT="Despite the fact that the Request-To-Send/Clear-To-Send (RTS/CTS) protocol significantly reduces collisions and retransmissions due to the hidden node problem, it is well known that it adds considerable overhead specially with small payload packets. The IEEE 802.11 standard defined a manageable parameter RTS threshold above which a data packet should be preceded with RTS/CTS handshake. In this paper, we propose new dynamic criteria for setting the RTS/CTS mechanism. We believe that RTS/CTS settings should consider the characteristics of users’ traffic, data rates, users’ activities and their locations. While most of the algorithms proposed for controlling RTS/CTS have been investigated with single transmission rate for all users, we also show that these algorithms should be re-evaluated in a multi-rate scenario. We validate our ideas using both synthetic and real traces as well as real experiments." } @INPROCEEDINGS{Abus0809:Interference, AUTHOR="Murad Abusubaih and Adam Wolisz", TITLE="{Interference-Aware} Decentralized Access Point Selection Policy for {Multi-Rate} {IEEE} 802.11Wireless {LANs}", BOOKTITLE="IEEE PIMRC 2008 MAC \& Cross-Layer Design Track", ADDRESS="Cannes, France", DAYS=15, MONTH=sep, YEAR=2008, KEYWORDS="Access Point Selection, WLANs, IEEE 802.11", ABSTRACT="This paper proposes a new decentralized Access Point Selection Policy for 802.11 Wireless Local Area Networks (WLANs). We derive a decision metric towards AP selection improvement. The derived metric comprises both Inter- BSS and Intra-BSS interference. Our proposed policy is decentralized in the sense that the decision is performed by each station. The core of the policy is based on measurement reports standarized in the IEEE 802.11k standard. The main question we would like to address is: To what extent can the impact of interference be reduced at the selection phase ? The performance of the proposed policy is evaluated through detailed simulation experiments. We identify the scenarios where the proposed policy is likely to provide great gain, and scenarios where the gain is minimal." } @INPROCEEDINGS{AbuT0805:Adaptive, AUTHOR="Mamun Abu-Tair and Geyong Min and Qiang Ni and Hong Liu", TITLE="Adaptive Medium Access Control for {VoIP} Services in {IEEE} {802.11} {WLANs}", BOOKTITLE="IEEE International Conference on Circuits and Systems for Communications 2008", ADDRESS="Shanghai, P.R. China", DAYS=26, MONTH=may, YEAR=2008, ABSTRACT="Voice over Internet Protocol (VoIP) is an important service with strict Quality-of-Service (QoS) constraints in Wireless Local Area Networks (WLANs). The popular Distributed Coordination Function (DCF) of IEEE 802.11 Medium Access Control (MAC) protocol adopts a Binary Exponential Back-off (BEB) procedure to reduce the packet collision probability in WLANs. In DCF, the size of contention window is doubled upon a collision regardless of the network loads. This paper presents an adaptive MAC scheme to improve the QoS of VoIP in WLANs. This scheme applies a threshold of the collision rate to switch between two different functions for increasing the size of contention window based on the status of network loads. The performance of this scheme is investigated and compared to the original DCF using the network simulator NS-2. The performance results reveal that the adaptive scheme is able to achieve higher throughput and medium utilization as well as lower access delay and packet loss probability than the original DCF." } @INPROCEEDINGS{AbuT0807:Connected, AUTHOR="Hattan AbuTarboush and Hamed Al-Raweshidy", TITLE="A Connected {E-Shape} and {U-Shape} {Dual-Band} Patch Antenna for Different Wireless Applications", BOOKTITLE="Second International EURASIP Workshop on RFID Technology", ADDRESS="Budapest, Hungary", DAYS=7, MONTH=jul, YEAR=2008, KEYWORDS="E-shape, U-shape, Dual-Band, Patch Antenna, Antenna for wireless applications.", ABSTRACT="In this paper, dual operation E-shape and U-shape Patch Antenna feed by transmission line is presented. The proposed antenna is designed on a two-layer (FR4 \& Air) substrate with an area of 35 mm by 40 mm. The dual operation frequencies are 4.7 GHz and 5.4 GHz. A (-10 dB) bandwidths of return loss S11 characteristic for the dual band are 4.6 \% and 4.3 \% respectively. E-plane and H-plane for the dual operation frequencies is satisfactory within this bandwidth. Return loss and E-plane and H-plane radiation patterns are provided." } @INPROCEEDINGS{AbuT0810:Triple, AUTHOR="Hattan AbuTarboush and Hamed Al-Raweshidy and Rajagopal Nilavalan", TITLE="Triple Band Double {U-Slots} Patch Antenna for {WiMAX} Mobile Applications", BOOKTITLE="The 14th Asia-Pacific Conference on Communications", ADDRESS="Tokyo, Japan", DAYS=14, MONTH=oct, YEAR=2008, KEYWORDS="Triple band, U-Slot, WiMAX Antenna, Patch Antenna", ABSTRACT="A small triple-band 2.7 GHz, 3.2 GHz and 5.3 GHz compact microstrip patch antenna with two U-shaped slots and a small ground plane is presented. It has been developed to be used in future WiMAX technology. The required bandwidths are fulfilled the WiMAX technology 4.8 \%, 3 \% and 2.5 \% respectively. The return loss for the triple band are -18.5 dB, -14.5 dB and -19 respectively." } @INPROCEEDINGS{Abuz0808:Armor, AUTHOR="Abdelshakour Abuzneid and Mohammed Abuhelaleh and Thabet Mismar", TITLE="{Armor-LEACH} {–} Energy Efficient, Secure Wireless Networks Communication", BOOKTITLE="2nd International Workshop on Performance Modeling and Evaluation in Computer and Telecommunication Networks (PMECT2008)", ADDRESS="St. Thomas, US Virgin Islands, USA", DAYS=4, MONTH=aug, YEAR=2008, KEYWORDS="LEACH (Low Energy Adaptive Clustering Hierarchy), TCCA (Time Controlled Clustering Algorithm), Sensor Networks, Network Security, Network Performance, Random Key Distribution.", ABSTRACT="Abstract-The use of sensor networks is increasing day by day; which offer more research topics to be discuss and modified; one of these topics is the power consumption that has to be reduced as possible, where the resources are limited; another topic is the security level that should be offer by such kind of networks. Clustered networks have been proposed in many papers to reduce the power consumption in sensor networks. LEACH is one of the most interested techniques that offer an efficient way to minimize the power consumption in sensor networks. TCCA provides LEACH with higher performance, by applying some modification to the way LEACH works. In this paper we propose a hybrid technique that offers a complete solution for routing in sensor networks. This technique reduces power consumption, increases security level, and decrease data overload for sensor networks communication." } @INPROCEEDINGS{AC0811:Implementation, AUTHOR="Vikram {Arkalgud Chandrasetty}", TITLE="Design and Implementation of Motion Estimation Technique for {H.264} {AVC} on {FPGA}", BOOKTITLE="IEEE Region 10 Conference", ADDRESS="Hyderabad, Andhra Pradesh, India", DAYS=18, MONTH=nov, YEAR=2008, KEYWORDS="Video Coding; Motion Estimation, Motion Compensation, Block Matching", ABSTRACT="Video coding technology is an active area for potential research. Due to the limitations in the available bandwidth and storage space for high quality multimedia content like - video broadcasting and DVD video data, video compression has become very much necessary to keep up the ever growing demand, yet maintaining the quality in decoded video. Most video compression systems operates based on the reason that much of the data present before compression is not necessary for achieving good perceptual video quality. Motion Estimation technique in a Video coder takes advantage of the temporal redundancy present in video data to achieve substantial compression. Optimum data compression can be achieved using Motion Estimation technique when compared to other compression units in an encoder. Efficient Motion Estimation is absolutely necessary for obtaining good compression and is the key for the overall performance of a video coder. In this paper work, a Blot Search or One Step Search Motion Estimation algorithm is chosen for hardware modeling, based on the performance results obtained from the simulation of software reference model. The architecture of the model is designed to maximize the throughput of the system. The current frame and reference frame data is pipelined to the Motion Compensation block consisting of dual Residual Energy computation and comparison units. The advantage of using dual Residual Energy computation units is discussed in this paper. Suitable test environment using RS232 interface is created and the design is tested on Xilinx Virtex4 FPGA development kit. The implemented Motion Estimation unit has LUT based search area selection for Motion Estimation algorithm, which makes faster selection of search area macroblock for block matching process and also provides flexibility in plugging in different Motion Estimation Algorithms with minimal design changes. The design is modeled to store the macroblock data in dedicated Block RAM available in the Virtex4 FPGA architecture for optimum device utilization. The Motion Estimation unit implemented generates stream of Motion Vectors and Residue macroblock without reconstruction of reference frame. The design can process each macroblock of N pixels in N+2 clock cycles at a maximum operating frequency of 116MHz. At this frequency, the designed Motion Estimation unit can process HDTV resolution frame of 1920x1080 pixels at 55 frames per second with an estimated total power consumption of 543mW." } @INPROCEEDINGS{Acar0808:Impact, AUTHOR="Guray Acar and Barry Evans", TITLE="Impact of Proactive Retransmissions on Forward {TCP} Throughput over {DVB-S/S2} Railroad Satellite Links with Power Arches", BOOKTITLE="Fourth Advanced Satellite Mobile Systems Conference", ADDRESS="Bologna, Italy", DAYS=26, MONTH=aug, YEAR=2008, KEYWORDS="TCP, DVB-RCS, DVB-S, DVB-S2, satellite, railway, railroad, proactive", ABSTRACT="High-speed trains are one of the major collective mobile communities that will exploit broadband satellite services. ETSI DVB-S/S2 and DVB-RCS specifications have enjoyed tremendous success and global acceptance. Recently, both EU and ESA have sponsored R\&D programmes [1][2][4] to introduce mobility adaptations to DVB-S2 and DVB-RCS specifications. Power supply arches that are equidistantly placed over railway tracks pose a specific challenge for satellite transmission to high-speed trains. These structures result in quasi-periodic and quasi-deterministic deep fades, which are particularly deteriorating to TCP throughput over high bandwidth-delay-product satellite links. The focus of this extended abstract is on the mitigations for such deep fades that are triggered due to power arches. Specifically, the extended abstract considers proactive retransmissions of IP datagrams over the forward link to maintain high levels in forward TCP throughput. The article shall present ns-based DVB-S2/RCS simulation results with several TCP variants (Reno, Newreno, and SACK). We will present our conclusions regarding the applicability of the mitigation together with the performance levels that can be expected." } @INPROCEEDINGS{Acha0000:Timing, AUTHOR="Joydeep Acharya and Harish Viswanathan and Sivarama Venkatesan", TITLE="Timing Acquisition for Non Contiguous {OFDM} based Dynamic Spectrum Access", BOOKTITLE="Third IEEE International Symposium on Dynamic Spectrum Access Networks 2008 (DySPAN 2008)", ADDRESS="Chicago, USA", DAYS=14, MONTH=oct, YEAR=2008, KEYWORDS="Symbol Timing Acquisition, Non Contiguous OFDM, Cyclic Prefix Correlation, Dynamic Spectrum Access", ABSTRACT="Most current and upcoming communication systems like 802.11x, WiMAX etc. deploy some variant of Orthogonal Frequency Division Multiplexing as their physical layer technology. Symbol timing acquisition is the first operation performed at the receiver after which other signal processing, such as orthogonalizing the received data into parallel streams using Fast Fourier Transform (FFT), can take place. To ensure reliable communication, extensive work has been done in designing robust algorithms that estimate the symbol timing with high accuracy. Most of these works assume that there is some total bandwidth which is utilized by a single user. However in future cognitive radio systems, the spectrum access will be dynamic and multiple devices in a geographical region will sense a common pool of spectrum for the presence of vacant frequency bands to transmit in. In the OFDM context, this means that a device may transmit in non contiguous tones (termed as Non-Contiguous OFDM or NC-OFDM). It is not clear how the existing symbol timing acquisition algorithms will perform in this situation. The current research around cognitive radios is mostly focused on the sensing and resource allocation aspects but to our knowledge the symbol timing acquisition issues have not yet been studied. In this work we study the performance of cyclic prefix correlation based symbol timing acquisition algorithms for NC-OFDM transmission. We first derive the ML estimator when the channel is frequency non-selective and show that it has high computational complexity. Consequently we study the performance of low complexity, sub-optimal approaches both for frequency non-selective and frequency selective channels. Our simulations indicate that in some likely situations such as the users occupying multiple discontiguous sub-bands and having large differences in the timing offsets between their transmitters and receivers, cyclic prefix based timing acquisition algorithms can perform quite poorly. This points to the need for better algorithms of reasonable complexity, or entirely different approaches to symbol timing acquisition, for example based on the periodic transmission of known sequences." } @INPROCEEDINGS{Acha0806:Congestion, AUTHOR="Prashanth Acharya and Ashish Sharma and Elizabeth Belding and Kevin Almeroth and Konstantina Papagiannaki", TITLE="{Congestion-Aware} Rate Adaptation in Wireless Networks: A {Measurement-Driven} Approach", BOOKTITLE="Fifth Annual IEEE Communications Society Conference on Sensor, Mesh, and Ad Hoc Communications and Networks", ADDRESS="San Fransisco Bay Area, USA, USA", DAYS=16, MONTH=jun, YEAR=2008, ABSTRACT="Traditional rate adaptation solutions for IEEE 802.11 wireless networks perform poorly in congested networks. Measurement studies show that congestion in a wireless network leads to the use of lower transmission data-rates and thus reduces overall network throughput and capacity. The lack of techniques to reliably identify and characterize congestion in wireless networks has prevented development of rate adaptation solutions that incorporate congestion information in their decision framework. To this end, our main contributions in this paper are two-fold. First, we present a technique that identifies and measure congestion in an 802.11 network in real time. Second, we design Wireless cOngestion Optimized Fallback (WOOF), a measurement-driven rate adaptation scheme for 802.11 devices that uses the congestion measurement to identify congestion related packet losses. Through experimental evaluation, we show that WOOF achieves up to 300\% higher throughput in congested networks, compared to other well-known adaptation algorithms." } @INPROCEEDINGS{Acha0811:Performance, AUTHOR="Ayan Acharya and Aritra Banerjee and Kaushik Chattopadhyay", TITLE="Performance Improvement of Basic Particle Swarm Optimization Algorithm by Lyapunov Function Modeling of Fitness Function", BOOKTITLE="IEEE Region 10 Conference", ADDRESS="Hyderabad, Andhra Pradesh, India", DAYS=18, MONTH=nov, YEAR=2008, KEYWORDS="Global Optimization; Particle Swarm Optimization; Lyapunov Function.", ABSTRACT="The paper presents a novel concept of improving the convergence speed and solution quality of particle swarm optimization algorithm by Lyapunov modeling of fitness function. Most of the fitness functions that appear in practice can be transformed into positive definite function by using some minor transformations and shifting the coordinates system in the multidimensional space. The paper demonstrates how these positive definite functions can be transformed to Lyapunov functions and as a consequence how the equation of motion of the particles gets altered to lead to a better convergence speed and superior solution quality compared to those of basic particle swarm optimization algorithm." } @INPROCEEDINGS{Acha0811:SAT, AUTHOR="Sriyankar Acharyya", TITLE="A {SAT} Approach for Solving The Nurse Scheduling Problem", BOOKTITLE="IEEE Region 10 Conference", ADDRESS="Hyderabad, Andhra Pradesh, India", DAYS=18, MONTH=nov, YEAR=2008, KEYWORDS="Scheduling; Constraint Satisfaction; Local Search; Satisfiability; Simulated Annealing; Genetic Algorithm", ABSTRACT="Nurse Scheduling Problem (NSP) represents a subclass of Constraint Satisfaction Problems (CSP), involving a set of constraints. The problem is highly constrained and difficult to solve. The goal is to find high quality shift assignments to nurses satisfying constraints related to labor contract rules, requirements of nurses as well as the employers in health-care institutions. The constraints are classified as hard and soft, considering their importance. In this paper, a real case of a cyclic nurse rostering problem is introduced. This means that the generated roster can be repeated indefinitely if no further constraint is introduced. In earlier investigation we saw that Simulated Annealing performed better than other local search techniques. In this paper we have converted NSP to a Satisfiability Problem(SAT) and applied GSAT to solve it. We show that GSAT incorporated with a tabu list has outperformed other methods, like, Simulated Annealing and Genetic Algorithm in all instances." } @INPROCEEDINGS{Acha0812:Deterministic, AUTHOR="Ayan Acharya and Deepyaman Maiti and Konar Amit and Janarthanan Ramadoss", TITLE="A Deterministic Model for Analyzing the Dynamics of Ant System Algorithm and Performance Amelioration through a New Pheromone Deposition Approach", BOOKTITLE="2008 4th International Conference on Information and Automation for Sustainability", ADDRESS="Galle Face Hotel, Sri Lanka", DAYS=12, MONTH=dec, YEAR=2008, KEYWORDS="Ant System algorithm; Stability Analysis of Ant System dynamics; Uniform deposition rule; Non-uniform pheromone deposition approach; Solution Quality; Convergence Speed.", ABSTRACT="Ant Colony Optimization (ACO) is a metaheuristic for solving difficult discrete optimization problems. This paper presents a deterministic model based on differential equation to analyze the dynamics of basic Ant System algorithm. Traditionally, in all Ant System algorithms developed so far, the deposition of pheromone on different parts of the tour of a particular ant is always kept unvarying. This implies that the pheromone concentration remains uniform throughout the entire path of an ant. This article introduces an exponentially increasing pheromone deposition approach by artificial ants to improve the performance of basic Ant System algorithm. The idea here is to introduce an additional attracting force to guide the ants towards destination more easily by constructing an artificial potential field identified by increasing pheromone concentration towards the goal. Apart from carrying out analysis of Ant System dynamics with both traditional and the newly proposed deposition rules, the paper presents an exhaustive set of experiments performed to find out suitable parameter ranges for best performance of Ant System with the proposed deposition approach. Simulations with this empirically obtained parameter set reveal that the proposed deposition rule outperforms the traditional one by a large extent both in terms of solution quality and algorithm convergence. Thus, the contributions of the article can be presented as follows: i) it introduces differential equation and explores a novel method of analyzing the dynamics of ant system algorithms, ii) it initiates an exponentially increasing pheromone deposition approach by artificial ants to improve the performance of algorithm in terms of solution quality and convergence time, iii) exhaustive experimentation performed facilitates the discovery of an algebraic relationship between the parameter set of the algorithm and feature of the problem environment." } @INPROCEEDINGS{Achi0000:Pervasive, AUTHOR="Achilleas Achilleos and Nektarios Georgalas and Manooch Azmoodeh", TITLE="Pervasive Service Creation using a Model Driven Petri Net based Approach", BOOKTITLE="IWCMC 2008 Mobile Computing Symposium", ADDRESS="Chania Crete Island, Greece, Greece", DAYS=6, MONTH=aug, YEAR=2008, KEYWORDS="Pervasive service creation; Petri nets; Model-driven", ABSTRACT="Service creation is a complex process that involves service analysis design, implementation and testing. Traditionally, the service is validated at the late stage of testing. This increases development costs since any necessary amendments would require an iterative improving cycle on service design and implementation; until the desired result is eventually reached. This paper proposes a service creation methodology and tooling with a twofold contribution: (i) based on its design, a service is validated early on and prior to implementation, (ii) the service code is automatically generated out of the validated service designs. To achieve this, our approach integrates model-driven architecture (MDA) with Petri Nets (PN). MDA is used to define the (i) Information, (ii) Service Oriented Petri Net (SOPN) and (iii) User Interface modelling languages, which support the service design and implementation phases. Petri Nets facilitate the service validation phase through the use of the SOPN language. By merging the two techniques we obtain a systematic and cost-effective approach for the creation of pervasive services. Concluding the methodology is applied in practice for the creation of a Flight Itinerary booking service." } @INPROCEEDINGS{Achi0804:Extensible, AUTHOR="Nikos Achilleopoulos and Christos Theoharatos and Fotis Andritsopoulos and Serafeim Papastefanos", TITLE="An extensible scheme for direct searching in audiovisual archives: The {DIVAS} system", BOOKTITLE="International Symposium of Consumer Electronics 2008", ADDRESS="Vilamoura, Algarve, Portugal", DAYS=14, MONTH=apr, YEAR=2008, KEYWORDS="Video;Audio;Search;Fingerprint;System;WEB;Direct search;Multimedia search;compressed", ABSTRACT="In this paper, the most recent version of the DIVAS system is presented. The system designs and develops a multimedia search engine based on advanced direct video and audio search techniques operating directly on compressed content. The basic scheme explores novel media content indexing and search technologies and integrates them into a scalable multimedia search engine. The developed algorithms facilitate for direct searching in large repositories of compressed audiovisual content, providing an alternative and complementary path for metadata based audio/video search. In addition, DIVAS adopts a module-based, expandable architecture, facilitating the ongoing expansion of the system based on researchers’ contributions. In this study, the high-level architecture of the DIVAS system is provided, giving rise to the functional components of the main framework and the basic scheme incorporated for indexing and searching audiovisual repositories." } @INPROCEEDINGS{Achi0811:Model, AUTHOR="Achilleas Achilleos and Kun Yang and Nektarios Georgalas", TITLE="A Model Driven Approach to Generate Service Creation Environments", BOOKTITLE="IEEE Globecom 2008 Communications Software and Services Symposium", ADDRESS="New Orleans, LA, USA", DAYS=30, MONTH=nov, YEAR=2008, KEYWORDS="Service creation environment; domain specific modelling; model driven development", ABSTRACT="The creation of services is a complex activity that involves several tasks. Furthermore this complexity is augmented by the fact that supporting service creation environments are technology-specific. Consequently a technology-independent approach and framework are required to generate service creation environments and drive service creation. In this paper we present such an approach and a generic framework for supporting service creation. The approach realizes service creation via the phases of: (i) domain specific language definition, (ii) model definition and validation, (iii) model-to-model transformation and (iv) model-to-code generation. Each phase maps to a corresponding phase in service creation starting from service analysis to service implementation. The applicability of the approach and its accompanying framework is demonstrated via an example scenario that illustrates the automatic generation of a service creation environment for an online survey system." } @INPROCEEDINGS{Acko0804:Next, AUTHOR="Nevena Ackovska and Stevo Bozinovski", TITLE="Next Generation Operating Systems: A Biologically Inspired Future", BOOKTITLE="2nd Annual IEEE Systems Conference", ADDRESS="Montreal, Quebec, Canada", DAYS=9, MONTH=apr, YEAR=2008, KEYWORDS="operating system, storage system, distributed processing, concurrent programming, program compilation, embedding, cell operating systems, cell robotics", ABSTRACT="This paper takes a biologically inspired approach towards the operating systems. It views the DNA through a “system software microscope”. It discusses related issues, examples being file system, program preparation, and it’s parallel and distributed features, including inter-process communication. Our work explores the analogy between the computer operating systems and the molecular biology control systems, concerning the issues of improving the computer operating systems and its parallel and distributed capabilities." } @INPROCEEDINGS{Acol0808:SCFDE, AUTHOR="Kodzovi Acolatse and Yeheskel Bar-Ness", TITLE="A New {SCFDE} {STS} Scheme with Joint Channel Estimation and Multiuser Detection", BOOKTITLE="The 10th ISSSTA 2008 - Creating New Dimensions in the Wireless World", ADDRESS="Bologna, Italy", DAYS=25, MONTH=aug, YEAR=2008, ABSTRACT="In this contribution, a single carrier frequency domain equalization (SCFDE) transmission using space-time spreading (STS) for multiuser broadband wireless frequency selective fading channel is investigated. The scheme employs time domain spreading and provides transmit and frequency diversities with joint multiuser detection (MUD) and channel estimation. Each user equipped with two transmit antennas is assigned two orthogonal data spreading codes and a third pilot spreading code to facilitate channel estimation. Our study shows that by appropriately choosing the system parameters, we can achieve 4M diversity order with full rate transmission in a (2×M) MIMO system where the receiving base station has M antennas. Moreover, because a single carrier transmission is used, the peak-to- average power ratio (PAPR) is greatly reduced which makes the technique a promising uplink transmission scheme." } @INPROCEEDINGS{Acos0000:Exploiting, AUTHOR="William Acosta and Surendar Chandra", TITLE="Exploiting the Properties of Query Workload and File Name Distributions to Improve {P2P} Synopsis-based Searches", BOOKTITLE="The 27th IEEE International Conference on Computer Communications", ADDRESS="Phoenix, Arizona, USA", DAYS=13, MONTH=apr, YEAR=2008, KEYWORDS="P2P, Synopsis, Search", ABSTRACT="Modern P2P systems use hybrid searches to improve search efficiency. They use a synopsis of neighborhood content to determine whether to use a structured or unstructured overlay to satisfy a particular query. Because of their size restrictions, synopsis cannot hold all the terms from every file in the neighborhood. The challenge is to choose the terms that should be represented in the synopsis. In this work, we investigated the distribution of query terms and file terms in Gnutella networks. We observed that there was a mismatch between terms that were popular among file names and the terms that were popular among the queries generated by the user. Because the query behavior changed with time, a synopsis based on only static set of popular file terms was ill-suited to support efficient searches. We used these observations to design a synopsis creation algorithm that dynamically adapts to the query workload and selects terms for the synopsis to reflect popular terms in both the query workload and file distribution. Through extensive experimental analysis, we show that our Query-Adaptive synopsis can improve the search performance over the traditional file-based synopsis model." } @INPROCEEDINGS{Acos0804:Need, AUTHOR="William Acosta and Surendar Chandra", TITLE="On the need for query-centric unstructured peer-to-peer overlays", BOOKTITLE="Fifth International Workshop on Hot Topics in Peer-to-Peer Systems", ADDRESS="Miami, Florida, USA", DAYS=18, MONTH=apr, YEAR=2008, ABSTRACT="Hybrid P2P systems rely on the assumption that sufficient objects exist nearby in order to make the unstructured search component efficient. This availability depends on the object annotations as well as on the terms in the queries. Earlier work assumed that the object annotations and query terms follow Zipfian long-tail distribution. We show that the queries in real systems exhibit more complex temporal behavior. To support our position, first we analyzed the names and annotations of objects that were stored in two popular P2P sharing systems; Gnutella and Apple iTunes. We showed that the names and annotations exhibited a Zipf like long tail distribution. The long tail meant that over 98\% of the objects were insufficiently replicated (less than 0.1\% of the peers). We also analyzed a query trace of the Gnutella network and identified the popularity distribution of the terms used in the queries. We showed that the set of popular query terms remained stable over time and exhibited a similarity of over 90\%. We also showed that despite the Zipf popularity distributions of both query terms and file annotation terms, there was little similarity over time (< 20\%) between popular file annotation terms and popular file terms. Prior P2P search performance analysis did not take this mismatch between the query terms and object annotations into account and thus overestimated the system performance. There is a need to develop unstructured overlays that are aware of the temporal mismatch of the object and query popularity distributions. Such a system would identify transiently popular terms and proactively seek to locate matching files for these queries." } @INPROCEEDINGS{Acze0808:Separation, AUTHOR="Kristof Aczel and Istvan Vajk", TITLE="Separation of periodic and aperiodic sound components by employing frequency estimation", BOOKTITLE="European Conference on Signal Processing 2008", ADDRESS="Lausanne, Switzerland", DAYS=25, MONTH=aug, YEAR=2008, KEYWORDS="periodic, aperiodic, stochastic, deterministic, separation, decomposition", ABSTRACT="Separation of a sound to its two main components, periodic and aperiodic ones, is an area that has gained focus in the past years. Instrument classification, speech recognition and many other systems can benefit from such a representation of the digital sound. Unfortunately the separation of the two components is usually not a straightforward process, regarding that the sinusoidal and the noise-like parts of a waveform are not orthogonal, and can easily overlap in frequency. This article presents an efficient and elegant way of separating the two components. The algorithm operates in frequency domain and does the separation on the grounds of the frequency estimation method proposed by Brown. Being simple to implement, in the same time efficient in the task, it can be employed in many current DSP systems." } @INPROCEEDINGS{Adac0000:Study, AUTHOR="Koichi Adachi and Fumiyuki Adachi and Masao Nakagawa", TITLE="A Study on Channel Capacities of {MC-CDMA} {MIMO} and {OFDM} {MIMO}", BOOKTITLE="11th IEEE International Conference on Communication Systems 2008", ADDRESS="Guangzhou, P.R. China", PAGES="1384-1388", DAYS=19, MONTH=nov, YEAR=2008, KEYWORDS="MIMO, MC-CDMA, OFDM, channel capacity, theoretical study, Jensen’s inequality", ABSTRACT="For the development of future wireless communication systems, an extremely spectrum-efficient transmission technology is required. Orthogonal frequency division multiplexing (OFDM) and multi-carrier code division multiple access (MC-CDMA) have been attracting much attention. The use of multiple-input multiple-output (MIMO) transmission is essential to achieve a very high speed data transmission with the limited bandwidth. In our previous paper, assuming perfect cancellation of inter-code interference (ICI), we have derived a channel capacity expression for MC-CDMA MIMO in a multi-cell environment and confirmed by numerical evaluation that MC-CDMA MIMO provides a slightly higher capacity than OFDM MIMO. In this paper, we theoretically show by using Jensen’s inequality that the channel capacity of MC-CDMA MIMO assuming perfect ICI cancellation (ICIC) is always higher than or equal to that of OFDM MIMO. Furthermore, we compare the channel capacities of MIMO multiplexing and multiple single-input multiple output (SIMO) system." } @INPROCEEDINGS{Adac0803:Bit, AUTHOR="Koichi Adachi and Masao Nakagawa", TITLE="Bit-wise Error Detection Based Iterative Signal Detection for {OFDM} {MIMO} Multiplexing", BOOKTITLE="IEEE Wireless Communications and Networking Conference", ADDRESS="Las Vegas, Nevada, USA", DAYS=31, MONTH=mar, YEAR=2008, KEYWORDS="OFDM MIMO;QRD-M;Iterative signal detection;CRC code", ABSTRACT="Recently, we proposed an iterative modified QR-decomposition and M-algorithm (QRD-M) using decoding results of cyclic redundancy check (CRC) code for OFDM MIMO multiplexing. The symbol-wise CRC decoding results are used in the transmit antenna ranking and in modified M-algorithm. Hereafter we call this iterative QRD-M as symbol-wise iterative modified QRD-M. In this paper, to further improve the transmission performance of OFDM MIMO multiplexing, we replace the use of symbol–wise CRC decoding results by the use of bit-wise CRC decoding results. The symbol replica candidates for the transmitted symbol are re-ordered using the bit-wise CRC decoding results in the modified M-algorithm. Computer simulation shows that an Eb/N0 reduction of about 0.6~0.7 dB can be achieved for average packet error rate (PER)=10-2 compared to the symbol-wise method when 16QAM modulation is used." } @INPROCEEDINGS{Adac0809:Approximate, AUTHOR="Koichi Adachi and Fumiyuki Adachi and Masao Nakagawa", TITLE="Approximate Channel Capacity of {MC-CDMA} {MIMO}", BOOKTITLE="The 11th International Symposium on Wireless Personal Multimedia Communications", ADDRESS="Saariselkä, Lapland, Finland, Finland", DAYS=8, MONTH=sep, YEAR=2008, KEYWORDS="MC-CDMA; MIMO; Channel capacity", ABSTRACT="Much higher rate data transmission (up to 1 Gbps with 100 MHz bandwidth) than 3rd generation systems is required for the future wireless communication systems. Since the channel between the transmitter and the receiver is severely frequency-selective, the single-carrier transmission used in 3rd generation system is degraded owing to severe inter-path interference (IPI). Orthogonal frequency division multiplexing (OFDM) and multi-carrier code division multiple access (MC-CDMA) have been attracting much attention which can improve the spectrum efficiency while mitigating the adverse effect of multipath fading channel. MC-CDMA can achieve the frequency diversity gain through frequency-domain spreading/equalization; however, when code-multiplexing is used to achieve the same transmission rate as OFDM, inter-code interference (ICI) arising from the orthogonality distortion degrades the transmission performance compared to OFDM. Recently, it was shown by computer simulation that the bit error rate (BER) performance of CDMA with ICI cancellation (ICIC) can approach the matched filter bound and can provide almost the same or the better performance than OFDM. A promising technique to increase the transmission rate without expanding the signal bandwidth is multiple-input multiple-output (MIMO) space division multiplexing (SDM) which transmits different data streams from different antennas in parallel using the same bandwidth. Recently, we numerically evaluated the information outage probability of MIMO-SDM in a cellular system and showed that MC-CDMA with perfect ICIC provides larger capacity than OFDM. In this paper, we derive a simple approximate channel capacity formula for MC-CDMA MIMO-SDM assuming perfect ICIC and show that the equivalent number of receive antennas can be increased compared to the actual number of receive antennas. In the derivation of the capacity formula, we use the property that the off diagonal elements of the equivalent channel matrix of MC-CDM MIMO converge to 0 for a sufficiently large spreading factor." } @INPROCEEDINGS{Adam0000:Multielectrode, AUTHOR="Christopher Adams and Jennifer Simonotto and Stephen Eglen and Evelyne Sernagor", TITLE="Multielectrode Array Recordings Of Neural Activity Patterns In The Developing Retina Of The Cone Rod Homeobox Knockout (Crx-/-) Mouse", BOOKTITLE="6th International Meeting on Substrate-Integrated Micro Electrode Arrays", ADDRESS="Reutlingen, Germany", PAGES="53-54", DAYS=8, MONTH=jul, YEAR=2008, KEYWORDS="retina; ganglion cells, retinal waves, oscillations; retinal dystrophy", ABSTRACT="Introduction: The Crx-/- mouse is a model for retinal dystrophy. Crx-/- photoreceptors lack outer segments from the onset, resulting in complete absence of vision through the photoreceptor/bipolar/ganglion cell pathway from birth. However, all other retinal layers appear intact at birth and start degenerating from one month postnatal, when wiring of visual connections have matured. The degeneration process lasts 3-4 months, ultimately resulting in a retina lacking outer nuclear and plexiform layers whilst the inner retina remains mostly intact, with retinal ganglion cells (RGCs) still sending impulses to the visual centres of the brain via the optic nerve. As immature retinal neural activity, both in the form of spontaneous waves and early visual experience, is important for the development of visual connections, the Crx retina offers an interesting scenario to study early neural activity patterns in the absence of visual experience during the critical period for establishing visual connections. Methods: We have used a 60 channel microelectrode array (MEA, 30 m electrode diameter, 200m separation) (Multi Channel Systems MCS GmbH) to record firing patterns from the RGC layer of Crx-/- and wild-type (wt) retinas during the first postnatal month, before the onset of degeneration. Signals were acquired at 25 kHz without filtering. In addition to spontaneous activity, retinas were also stimulated with diffuse blue light (480 nm wavelength) to evaluate RGC intrinsic photosensitivity, a phenomenon normally encountered in ~3\% of all murine RGCs (projecting to the circadian clock in the hypothalamus). Spikes were amplitude threshold-detected using MC\_Rack to calculate total firing rates on each electrode. To evaluate global activity and propagation patterns, we have computed firing rates for each electrode as well as correlation indices as a function of distance between electrodes. To estimate local field responses we have also measured all intrinsic signal frequencies. Results: Spontaneous waves of activity normally sweep across the RGC layer in wt mouse until postnatal day 14 (P14), after which they break down and disappear by P20. In the Crx-/- retina, propagating waves (Figure 1) disappear earlier, around P10, switching to strong random bursting. Slow oscillations (4-15Hz) (Figure 2), mediated by glutamatergic connections and intrinsic membrane properties, become conspicuous at P14, increasing in power over time. We were able to record such oscillations up to 2 months postnatal, the oldest age studied (and well into the period of degeneration). We also found that correlation indices were 3 times higher in the Crx-/- retina than in wt for all ages investigated (Figure 3). Finally, we found a striking increase in responsiveness to blue light in Crx-/- retinas, with 12-93\% of all electrodes on the array showing a significant response when compared with <4\% in wt. Conclusions: These results demonstrate that the retina is capable of developing compensatory mechanisms to counteract visual experience impairment during the critical wiring period of visual connections. This study is part of the CARMEN consortium Work Package 6 investigating small neural networks dynamics. We thank the whole CARMEN consortium for their support (EPSRC - EP/E002331/1)" } @INPROCEEDINGS{Adam0804:Hardware, AUTHOR="Oluwayomi Adamo", TITLE="{Hardware-Efficient} Encryption Encoder and Decoder Unit", BOOKTITLE="International Symposium of Consumer Electronics 2008", ADDRESS="Vilamoura, Algarve, Portugal", DAYS=14, MONTH=apr, YEAR=2008, ABSTRACT="The widespread distribution and retrieval of multimedia data over wireless networks creates the need for secure transmission of data over the network. However, one of the main problems with the secure transmission of digital data over wireless networks is that the bit errors that occur during transmission need to typically be resolved before decryption could begin. Due to the limited resource such as power and size of wireless devices, hardware-efficient implementations are desired. This paper presents a joint hardware efficient design for both encryption and channel coders that is optimized for low-resource requirements. We implemented the Rijndael AES algorithm and convolutional encoder for the encryption and encoder sub-unit respectively. In order to decode the received digital data, Viterbi decoder is used which has been known to be suited for convolutional codes. Our design has an 11\% percent reduction in the number of hardware resource for the encoding subunit through the block of XORs. The low-resource usage is achieved through resource sharing between the AES encryption sub-unit and encoder sub-unit. Majority of hardware reduction was achieved in AddRoundKey and the encoder sub-unit. The architectures were modeled, simulated and synthesized in Xilinx ISE." } @INPROCEEDINGS{Adam0805:Distributed, AUTHOR="Davide Adami and Christian Callegari and Stefano Giordano and Michele Pagano", TITLE="Distributed and Centralized Path Computation Algorithms: Implementation in {NS2} and Performance Comparison", BOOKTITLE="ICC'08 - Communications QoS, Reliability, and Performance Modeling Symposium", ADDRESS="Beijing, China, P.R. China", DAYS=19, MONTH=may, YEAR=2008, ABSTRACT="Originally conceived as a fast forwarding technique, MPLS provides support for Traffic Engineering and network resilience. Constrained-based path computation is a key building block for Traffic Engineering in MPLS networks, since it allows to set-up LSPs along paths that satisfy QoS constraints. This paper deals with on-line and off-line path computation algorithms and, more in detail, introduces and compares the performance of three novel off-line path computation algorithms which aim at improving the performance of their standard version by means of some heuristics. All these algorithms have been developed in NS2 as an extension of OSPF-TE\ns and integrated with RSVP-TE\ns." } @INPROCEEDINGS{Adam0805:NS2, AUTHOR="Davide Adami and Christian Callegari and Stefano Giordano and Michele Pagano", TITLE="A New {NS2} Simulation Module for Bandwidth Constraints Models in {DS-TE} Networks", BOOKTITLE="13th International Workshop on Computer Aided Modeling, Analysis and Design of Communication Links and Networks", ADDRESS="Beijing, China, P.R. China", DAYS=19, MONTH=may, YEAR=2008, KEYWORDS="DS-TE; MAM; Ns2", ABSTRACT="In recent years, network operators rolled out new revenues-generating services by using IP/MPLS networks. MPLS traffic engineering (TE) allows the creation of end-to-end paths with guaranteed bandwidth as well as the optimization of transmission resources, but it does not provide end-to-end QoS to specific traffic flows. DiffServ-aware MPLS-TE (DS-TE) improves the MPLS-TE model by allowing bandwidth reservations to be performed on a per-class basis. In particular, the Bandwidth Constraints (BCs) model is a building block of the DS-TE architecture, since it establishes how bandwidth is allocated to different traffic classes. This paper deals with the development of a new software module for the simulation of DS-TE networks and BCs models within the Network Simulator 2 (NS2) environment. The results of some simulations are reported to show the operational working of the developed modules and the benefits coming from the use of the DS-Te architecture." } @INPROCEEDINGS{Adam0805:Soil, AUTHOR="Francesco Adamo and Filippo Attivissimo and Laura Fabbiano and Nicola Giaquinto and Maurizio Spadavecchia", TITLE="Soil moisture assessment by means of {MEMS} tri-axial accelerometers", BOOKTITLE="International Instrumentation and Measurement Technology Conference", ADDRESS="Victoria, Vancouver Island, British Columbia, Canada", DAYS=12, MONTH=may, YEAR=2008, KEYWORDS="elastic wave propagation; seismic velocities; soil moisture; moisture measurement", ABSTRACT="The main purpose of the present work is to design and build a seismic sensor prototype for the measurement of the degree of saturation in unconsolidated granular mediums. In this paper major emphasis is given to the description of the custom-built hardware and of the measurement method." } @INPROCEEDINGS{Adam0806:TerraSAR, AUTHOR="Nico Adam and Nestor Yague-Martinez and Richard Bamler", TITLE="{TerraSAR-X} High Resolution {SAR-Interferometry}", BOOKTITLE="7th European Conference on Synthetic Aperture Radar", ADDRESS="Friedrichshafen, Graf-Zeppelin-Haus, Germany", DAYS=2, MONTH=jun, YEAR=2008, ABSTRACT="TerraSAR-X is in orbit since June 15th, 2007 and collecting data. Thousands of images have been acquired for evaluation during the comissioning phase that will last until end of 2007. In order to proof the phase quality of the overall system a number of interferometric pairs and even small stacks of repeated InSAR data have been scheduled during this phase. Our paper gives a representative overview of our evaluation results. After proofing the technical quality of sensor and data processing system we focus on the new potentials of high resolution SAR interferometry. Using spotlight mode the pixel size is reduced to 1 meter allowing to distinguish and monitor different parts of buildings. We show the information content of spotlight SAR images in urban areas and assess interferograms with different temporal and spatial baselines w.r.t. coherence and phase stability. Our current results are encouraging us to predict that spotlight interferometry will be a hot topic in the next years with many practical applications." } @INPROCEEDINGS{Adam0807:Reliability, AUTHOR="Gero Adamek", TITLE="Reliability as an Interdomain Service", BOOKTITLE="Future Internet Seminar", ADDRESS="Karlsruhe, Germany", DAYS=23, MONTH=jul, YEAR=2008, ABSTRACT="Netzwerkausfälle passieren Tag-täglich. In Fehlersituationen müssen Ausfälle kompensiert werden, ohne Datenübertragungen zu behindern. Natürlich sollten Maßnahmen für die Verfügbarkeitserhöhung möglichst kostenarm und effektiv sein. Dazu wird Reliability as an Interdomain Service (REIN) eingeführt. Mit REIN ist es möglich, effizient Engpässe im Internet zu verhindern. Für die Optimierung des Datenflusses werden ”Interdomain Bypass“ Pfade eingeführt. Durch teilweises Umleiten des Verkehrs über die ”Interdomain Bypass“ Pfade (Umleitungspfade über benachbarte Netze) können die eigenen Verbindungspfade (”Intradomain Links“) entlastet werden. Der aufkommende Datenverkehr eines Netzwerks soll möglichst optimal und Kosten senkend auf die vorhandenen (eigenen und benachbarten) Links verteilt werden." } @INPROCEEDINGS{Adam0809:Adaptive, AUTHOR="Helmut Adam and Christian Bettstetter and Sidi-Mohammed Senouci", TITLE="Adaptive Relay Selection in Cooperative Wireless Networks", BOOKTITLE="IEEE PIMRC 2008 Mobile and Wireless Networks Track", ADDRESS="Cannes, France", DAYS=15, MONTH=sep, YEAR=2008, KEYWORDS="Cooperative networking, relaying, cooperative diversity, selection protocols, energy efficiency", ABSTRACT="The concept of cooperative relaying promises gains in robustness and energy-efficiency in wireless networks. Although protocols for cooperative relay selection were proposed recently, their analysis was made without consideration of the energy required for receiving. Such an analysis is unfair, as relaying requires more receptions than direct source-destination transmission. We consider this lack of analysis and propose two refinements of cooperative relaying. Using “relay selection on demand,” relays are only selected if required by the destination. Using “early retreat,” each potential relay assesses the channel state and decides whether to participate in the relay selection process or not. Simulation results show that these enhancements reduce the overall energy consumption significantly." } @INPROCEEDINGS{Adam0809:Monitoring, AUTHOR="Dan Adam and Itai Winkler", TITLE="Monitoring of Hyperthermia Therapy by Ultrasound Imaging", BOOKTITLE="8th International Symposium on Therapeutic Ultrasound", ADDRESS="Minneapolis, Minnesota, USA", DAYS=10, MONTH=sep, YEAR=2008, KEYWORDS="ultrasound, ablation, hyperthermia, microbubbles, signal processing", ABSTRACT="Thermal therapy of tumors is used worldwide as a minimally invasive technique that treats malignant lesions while causing minimal damage to surrounding tissue. Its success depends on real-time monitoring of tissue damage, causing high temperatures (50-80C) at the target tissue, without destruction of surrounding healthy tissue. This study investigated the possibilities of monitoring thermal damage. Strong heating causes cavitation. Bubbles, driven into nonlinear oscillation by an incident sound field, produce signals that contain harmonics of the transmitted frequency. The data analysis performed here was mainly of the sub-harmonic frequencies within the ultrasound response. In vivo and in vitro experiments were performed to monitor these signals during RF therapeutic procedures. Real-time monitoring by a modified commercial Ultrasound Imaging system and post-processing of raw ultrasound echoes were performed, and compared to thermocouples temperature measurements and post treatment visualization of the heated area. The echo amplitude changes at the sub-harmonic frequency correlated with temperature elevations, but depended on the distance from the heating source and the duration of heating, suggesting generation of microbubbles during the heating phases and correlation to blood circulation in the treated area. Specifically, when the blood flow is disrupted, a steep increase in the subharmonic amplitude, due to bubble accumulation was observed, signifying the target being treated. The subharmonic amplitude later decreases, when the tissue becomes ablated and no liquids reach this zone. This signifies the termination of the therapy at that location. The results obtained demonstrate the feasibility of non-invasive control of targeted thermal therapy." } @INPROCEEDINGS{Adam0809:Solving, AUTHOR="William {Adams, Jr.}", TITLE="Solving the U {S.} Air Force’s {ATS} Proliferation Problem {–} the {VDATS} Solution", BOOKTITLE="IEEE AUTOTESTCON 2008", ADDRESS="Salt Lake City, UT, USA", DAYS=8, MONTH=sep, YEAR=2008, KEYWORDS="VDATS; USAF ATS Proliferation", ABSTRACT={The Versatile Automated Depot Test Station (VDATS) is a major component in solving the U.S. Air Force’s Automatic Test System (ATS) proliferation concerns. VDATS addresses the proliferation issue by providing the capability to replace an estimated 260 depot-level test systems that assume 150 different configurations, as well as a large number of intermediate-level test systems. The Department of Defense (DoD) has invested billions of dollars in aging and increasingly obsolete ATS used to troubleshoot and diagnose components of military aircraft and weapon systems. The issues of increased downtimes, test system obsolescence, and non-portable Test Program Sets (TPS) further contributes to the DoD’s continued reporting of spare parts shortages and the increasing impacts that ATS obsolescence has on the readiness of military aircraft and weapon systems. The VDATS provides a viable approach to resolving these issues. VDATS has an extensible designed-in expansion capability intended to support present and future Air Force workloads by providing an organically-developed ATS platform with a modular, open-systems architecture that is Flexible, Capable, Tailorable, and Sustainable. VDATS makes it technically feasible to now realize the laudable 1994 DoD policy goal stated in: Military Readiness: DOD Needs to Better Manage Automatic Test Equipment Modernization,{"} GAO-03-451, March 2003. VDATS meets this stated DoD policy goal of producing an ATS capable of supporting multiple weapon systems, aircraft, and eventually being interoperable between DoD services. In 2007 the Air Force’s VDATS was officially designated as a DoD Standard Family of Testers, supporting the 2005 ATS Master Plan requirement meant to reduce ATS proliferation and life-cycle operations and support costs. This paper briefly examines the present-day issues and how the U.S. Air Force is resolving these with the VDATS program. It also explains the strategy to preserve present-day and near-future TPS re-host investments, while enhancing system capabilities to meet the Air Force’s depot and intermediate-level ATS requirements for the foreseeable future.} } @INPROCEEDINGS{Adam0810:Integrated, AUTHOR="Dionisis Adamopoulos", TITLE="An Integrated Development Approach for Composing Web Services", BOOKTITLE="4th Distributed Frameworks for Multimedia Applications", ADDRESS="Penang, Malaysia", DAYS=21, MONTH=oct, YEAR=2008, KEYWORDS="Web services; Web service engineering; Internet middleware; service grids", ABSTRACT="Web services are emerging technologies that can be considered as the result of the continuous improvement of Internet services due to the tremendous increase in demand that is being placed on them. They are rapidly evolving and are expected to change the paradigms of both software development and use, by promoting software reusability over the Internet, by facilitating the wrapping of underlying computing models with XML, and by providing diverse and sophisticated functionality fast and flexibly in the form of composite service offerings. In this paper, the different facets of Web services are identified and a flexible approach to engineering complex Web services is adopted in the form of a proposed framework for the development of Web services. After the examination of its main constituent parts, it is argued that its full potential and that of Web service engineering in general, is realized through the gradual formation of a rich service grid offering value-added supporting functionality and therefore the main desirable properties of such a service grid are highlighted. Finally, the paper outlines a validation approach for the proposed framework and assembles important pointers for future work and concluding remarks." } @INPROCEEDINGS{Adam0810:Throughput, AUTHOR="Athanassios Adamis and Konstantinos Maliatsos and Philip Constantinou", TITLE="Throughput Analysis of Overlay {CSMA/CA} for Secondary Networks", BOOKTITLE="IEEE International Conference on Wireless and Mobile Computing, Networking and Communications", ADDRESS="Avignon, France", DAYS=12, MONTH=oct, YEAR=2008, KEYWORDS="DCF; Overlay Access; Secondary Networks; MAC", ABSTRACT="Overlay Access has recently appeared as a promising solution that improves licensed spectrum utilization, by allowing secondary networks to exploit portions of spectrum when they are not used by licensed networks. Moreover wireless local area networks, with the IEEE 802.11 standard as their major representative, have widely spread as a very successful broadband wireless access technology. In this work we present an analytical model for the saturation throughput calculation of the Distributed Coordination Function, the core of IEEE 802.11, in the overlay-intermittent operation mode for Cognitive Radios forming Secondary Networks." } @INPROCEEDINGS{Adam0811:Interferometry, AUTHOR="Nico Adam and Michael Eineder and Nestor Yague-Martinez", TITLE="Interferometry with {TerraSAR-X}", BOOKTITLE="CEOS SAR Workshop on Calibration and Validation", ADDRESS="Oberpfaffenhofen, Germany", DAYS=27, MONTH=nov, YEAR=2008, KEYWORDS="Spotlight SAR Interferometry; TerraSAR-X", ABSTRACT="The German SAR sensor TerraSAR-X provides for the first time civil high resolution space-borne radar data which are also suitable for interferometric applications. The resolution is 0.6 m in slant range and 1.1 m in azimuth in the high resolution spotlight mode. This significant resolution improvement and the short radar wavelength of about 3.1 cm compared to the previous used space-borne SAR sensors result in a change of the characteristics of the single SLC scenes and finally of the interferometric properties. DLR’s operational InSAR processing system GENESIS has been adapted to cope with the new signal characteristic and the various acquisition modes of the sensor. Interferometric applications could be demonstrated already in a very early stage of the TerraSAR-X mission. This paper describes the updated interferometric algorithms and the new interferometric characteristic is reported with examples." } @INPROCEEDINGS{Adco0807:Directions, AUTHOR="John Adcock and Matthew Cooper and Jeremy Pickens", TITLE="New Directions In Video Search", BOOKTITLE="ACM International Conference on Image and Video Retrieval 2008", ADDRESS="Niagara Falls, Canada", DAYS=7, MONTH=jul, YEAR=2008, KEYWORDS="Multimedia information retrieval, interactive video search,", ABSTRACT="We have developed an interactive video search system that allows the searcher to rapidly assess query results and easily pivot o those results to form new queries. The system is intended to maximize the use of the discriminative power of the human searcher. This is accomplished by providing a hierarchical segmentation, streamlined interface, and redun- dant visual cues throughout. The typical search scenario includes a single searcher with the ability to search with text and content-based queries. In this paper, we evaluate new variations on our basic search system. In particular we test the system using only visual content-based search capabilities, and using paired searchers in a realtime col- laboration. We present analysis and conclusions from these experiments." } @INPROCEEDINGS{Adda0805:Efficient, AUTHOR="Tommaso Addabbo and Ada Fort and Marco Mugnaini and Santina Rocchi and Valerio Vignoli", TITLE="On the Efficient Digital Implementation of Nonlinear Congruential Generators derived from the Rényi Chaotic Map", BOOKTITLE="International Instrumentation and Measurement Technology Conference", ADDRESS="Victoria, Vancouver Island, British Columbia, Canada", DAYS=12, MONTH=may, YEAR=2008, KEYWORDS="pseudo random number generation, digital circuits", ABSTRACT="The generation of random numbers is required in several applications, including Montecarlo simulations, testing of digital circuits, noise generation, telecommunication systems, and cryptography. In this paper we discuss a technique to obtain efficient digital hardware implementations of a class of pseudo random number generators derived from the Rényi chaotic map." } @INPROCEEDINGS{Addi0808:Non, AUTHOR="William Addison and Malcolm MacLeod", TITLE="{Non-Stationary} Bayesian Direction of Arrival Estimation with Drifting Sensor Locations", BOOKTITLE="European Conference on Signal Processing 2008", ADDRESS="Lausanne, Switzerland", DAYS=25, MONTH=aug, YEAR=2008, KEYWORDS="Bayesian; Non-stationary; Direction of arrival", ABSTRACT="We describe a new tracking algorithm for the direction of arrival estimation problem where both the locations of the sensors in the array and the directions of arrival are non-stationary. The approach taken is Bayesian. The algorithm assumes that the filtering distribution is approximately Gaussian and maintains the mean and covariance of this approximation by fitting a quadratic surface to the log posterior around the location where the log posterior is maximized. In the case where the sensor locations are stationary, the algorithm is shown to have similar performance to particle filter based algorithms but at a reduced computational cost. In the case where the sensor locations are non-stationary particle filtering is unsuccessful and the new algorithm performs significantly better than currently existing algorithms." } @INPROCEEDINGS{Adel0000:Bandwidth, AUTHOR="Olufemi Adeluyi", TITLE="Bandwidth Allocation Whitening and Performance {Fore-Knowledge} for {QoS} Guarantees in {WiMAX} Sytems", BOOKTITLE="The First IEEE International Workshop on Generation C Wireless Networks", ADDRESS="Austin, Texas, USA", DAYS=7, MONTH=dec, YEAR=2008, KEYWORDS="wimax, bandwidth-allocation, performance-fore-knowledge, QoS, y-sim, co-design", ABSTRACT="IEEE 802.16 networks, also known as Wireless Interoperability for Microwave Access (WiMAX) networks, hold a lot of potential for providing a significantly improved user experience on wireless networks. This enhanced quality of experience is tightly coupled to the Quality of Service (QoS) guarantees provided for in WiMAX networks. This paper presents a new, so called White, approach for distributing the bandwidth resource in a fair and simple manner. This approach is used in tandem with our Performance-Fore-Knowledge (PFK) approach. PFK is a new approach that simulates all possible scenarios in advance, optimizes the hardware-software co-design generated mapping sets through the use of fair y-sim and then stores these best values in a look-up-table for eventual use during live scenarios. Simulation has been carried out using of fair y-sim tool and Qualnet 4.5 Developer. Some results suggest that we can reduce the latency and increase the efficiency of the process by a factor of 10.Combining our Bandwidth Whitening, PFK and fairy-sim optimization approaches give impressive result, significantly reduce runtime complexity and latency, while ensuring QoS guarantees in IEEE 802.16 networks." } @INPROCEEDINGS{Adey0800:Analysis, AUTHOR="Olalekan Adeyinka", TITLE="Analysis of problems associated with {IPSec} {VPN} Technology", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, KEYWORDS="Internet Protocol Security (IPSec); Vitual Private Network (VPN) ; Encapsulation Security Payload (ESP); Authentication Header (AH); Internet Key Exchange (IKE)", ABSTRACT="The original goal of Internet Protocol Security (IPSec) is to enable the protection of all types of Internet protocol (IP) communications by protecting multiple peers at the network layer, in both the IPv4 and IPv6 environments. IPSec is a standard for securing internet communication and a widely deployed mechanism for implementing Virtual Private Networks (VPNs). Most organisations deploy IPSec VPNs that provide enterprise-level secure remote access by protecting the IP packet exchanged between remote networks or host and an IPSec gateway located at the edge of a private network.. This paper investigates the security issues of IPSec VPN technology with respect to remote access communication." } @INPROCEEDINGS{Adey0804:Achieving, AUTHOR="Michael Adeyeye and Neco Ventura", TITLE="Achieving Web Session Hand-off using {SIP}", BOOKTITLE="International Symposium of Consumer Electronics 2008", ADDRESS="Vilamoura, Algarve, Portugal", DAYS=14, MONTH=apr, YEAR=2008, ABSTRACT="The aim of this research work is to achieve session hand-off and content sharing during web browsing using Session Initiation Protocol (SIP). First, web browsers will be extended by integrating a SIP stack into them. Second, a SIP Application Server (SIP AS) which co-ordinates Hypertext Transfer Protocol (HTTP) Session Mobility will be implemented. There are two SIP Session Mobility types namely Third-party Call Control and Session Hand-off. They can be mapped into content sharing and session transfer between two web browsers also referred to as User Agent Clients (UACs). Though the research work requires implementing session hand-off and content sharing between two UACs, the process flow of session hand-off will only be described in this paper." } @INPROCEEDINGS{Adia0806:Evaluation, AUTHOR="Riski Adianto and Pean-Yue Ben Jar", TITLE="Evaluation of New Fracture Behavior of {High-Density} Polyethylene Using the Essential Work of Fracture Concept", BOOKTITLE="Canadian Society for Mechanical Engineers Forum 2008", ADDRESS="Ottawa, Ontario, Canada", DAYS=5, MONTH=jun, YEAR=2008, KEYWORDS="Polymers; Fracture Mechanics", ABSTRACT="The plane stress and transition fracture toughness of a customized grade of high-density polyethylene (HDPE), provided by NOVA Chemicals, was investigated using the conventional and energy-partition modified essential work of fracture (EWF) method. It was observed in the experiment that this HDPE exhibited three unique fracture mechanisms during the fracture process, which were plastic yielding of the ligament, material separation, and globalized necking of the ligament followed by its growth in the loading direction. For fracture in the transition mode, another mechanism was observed, which was the splitting of the ligament volume during the neck propagation. While the application of these EWF methods still produced a linear trend resulting in acquisition of the fracture toughness value, their assumptions are not sufficient in capturing all of the mechanisms occurred in this study, which would cast doubt into the value of the fracture toughness obtained. The classical EWF method only considers the first two fracture mechanisms described above, which are the plastic yielding and surface formation, while the modified EWF formulation was based on HDPE that did not split. Thus, a new energy formulation based on the EWF concept is deemed necessary for analyzing this specific case of fracture behavior of HDPE." } @INPROCEEDINGS{Adib0807:Optimality, AUTHOR="Mehdi Adibi and Vahid {TabaTaba Vakili}", TITLE="Optimality of Multichannel Beamforming for Spatially Correlated {Multiple-Antenna} Rayleigh Fading Channels with Channel Covariance Information at Transmitter", BOOKTITLE="Fifth IEEE Sensor Array and Multichannel Signal Processing Workshop", ADDRESS="Darmstadt, Germany", PAGES="28-32", DAYS=21, MONTH=jul, YEAR=2008, KEYWORDS="Ergodic capacity, capacity-achieving transmit covariance, correlated MISO Rayleigh fading channel, multiple input single output, multichannel beamforming", ABSTRACT="In this paper, we obtain a closed form necessary and sufficient condition under which $r$-rank multichannel beamforming achieves the capacity of a single user spatially correlated Rayleigh fading channel employing multiple transmit antennas and a single receive antenna when the transmitted only knows the channel distribution. Moreover, a set of $r$ independent closed form equation is derived that gives the $r$ non-zero eigenvalues of transmit covariance associated to transmit power along each mode." } @INPROCEEDINGS{Adla0810:One, AUTHOR="Gautam Adlakha", TITLE="One Unified Address Book", BOOKTITLE="3rd European IEEE Conference on Smart Sensing and Context", ADDRESS="Zurich, Switzerland", DAYS=29, MONTH=oct, YEAR=2008, KEYWORDS="Mobile communication, mobile applications", ABSTRACT="As a result of advancement in communication technology, users today have a vast variety of options in the way they want to communicate with their friends \& family. E-Mail clients, Instant Messengers, VOIP Clients, Push To Communicate services, etc are some of the examples of the communication options available today a the disposal of the customers. With the increasing number of options available, it becomes messy at times to manage ones contacts among different applications. This calls for a need to have a unified system which takes care of synchronizing contacts and relieves the user from the burden of contact management among various address book applications. We propose 1UAB (1Unified Address Book) as an integrated platform that synchronizes with the native address database of the phone to bring together the functions of presence detection, XDM, local address book, SMS, MMS, Push-To-Talk, Push-To-Share, E-Mail, Instant Messaging (IM) and other “Push-to-Communicate” services into a single user experience. 1UAB also aims at making the address book dynamic where in new future applications could simply plus in and make use of the address book functionality." } @INPROCEEDINGS{Adle0805:Detection, AUTHOR="Andy Adler and Yednek Asfaw", TITLE="Detection of unreliable measurements in multi-sensor devices", BOOKTITLE="IEEE International Workshop on Medical Measurements and Applications", ADDRESS="Ottawa, Ontario, Canada", DAYS=9, MONTH=may, YEAR=2008, KEYWORDS="Data errors; sensors; reconstruction algorithms", ABSTRACT="Abstract Multi-sensor monitoring devices that use skin surface or implanted sensors are susceptible to changes in temperature, sweat, and movement, such that the measured data cannot be used. This paper presents an automatic approach to detect such erroneous sensors. It is based on the assumption that valid measurements are related by a reconstruction model, while measurements from erroneous sensors are unrelated. The method estimates the data at each sensor based on the measurements from all other sensors, and compares it to the measurements. The sensor-data match is tested using ANOVA to detect the presence of an erroneous sensor. The method was tested on simulated and experimental data of Electrical Impedance Tomography (EIT) and ECG data which showed consistent identification of erroneous electrodes." } @INPROCEEDINGS{Adme0808:Iris, AUTHOR="Manuel Admella and Jordi Batlle and Lorena Albiol and Carlos Belmonte", TITLE="Iris Communication System Design Study {–} Phase {A:} {ICOS} Project", BOOKTITLE="Fourth Advanced Satellite Mobile Systems Conference", ADDRESS="Bologna, Italy", DAYS=26, MONTH=aug, YEAR=2008, KEYWORDS="Satellite; Communications; Aeronatics; ATM; SESAR; ATC; AOC", ABSTRACT="The ESA, in coordination with the Eurocontrol, has initiated the Iris program to standardise a satellite-based communication system for the provisioning of Air-Ground communications in accordance to the future ATM concept, defined in the SESAR programme. As a part of the Iris programme, the ICOS project is being carried out under the frame of the ESA contract number 21364/08/NL/CPL entitled “Iris communication system design study – Phase A” by an industrial consortia leaded by Indra Espacio. The consortium is composed by Indra Espacio, Thales Alenia Space France and Thales Alenia Space Italy with high expertise in satellite communications developments, and Indra ATM, Airtel, ARINC, Rockwell Collins and SELEX with demonstrated expertise in aeronautical and terrestrial communications developments. The purpose of the ICOS project is to define and assess, with a financial and commercial perspective, a satellite-based communication standard to cope with the future ATM needs, allowing seamless operation with terrestrial standards and compatible with mandatory ICAO recommendations. This study should demonstrate the capacity of the satellite communication technology to fulfil the stringent ATC/AOC services performance defined within the SESAR framework for different domains, granting its competitiveness in front of other terrestrial solutions. The study should also allow undertaking future dissemination and standardisation activities with the purpose to be adopted the satellite based communications solution at ICAO level, and validated worldwide. The current systems used for air traffic management are terrestrially based analogue systems. In most cases, they are provided on a State-by-State basis and full efficiency is inhibited by the imposition of State boundaries. This often means that duplication is provided, not for operational purposes, but because of the perceived need for each State to provide the full menu of services and facilities. Due to the European air traffic management systems are saturated, the need of increasing the data traffic exchange in front of voice traffic and the increasing needs sharing information between the stakeholders, the communication technologies must evolve from an analogue to digital system. In the future, the data services will be the primary means, whilst voice services will become as a secondary and backup means. Then, special attention must be paid to security, safety and quality of service management across the whole communication network. In this context, the Future Radio System (FRS) infrastructure will consist of a mix of access technologies, each with its own communication elements at the aircraft side (antennas, base-band equipments, etc) and its own ground infrastructure (base stations, etc). The satellite network, as it will just be one of a number of communication means, will have to be well integrated into the FRS and capable to adopt system-wide solutions and global interoperability. In order to meet with the high stringent requirements of the ATC and AOC services (availability, integrity, ...), the future terrestrial communication technologies and the satellite based ones can provide complementarities services, reducing the spectrum usage by the terrestrial system for less critical communications. But the satellite technologies can also be an alternative to provide high performance communications in those domains where the terrestrial technologies are less competitive. The main advantages the satellite-based communications technology can offer is its inherent capability for broadcasting and the possibility to provide worldwide coverage, especially those oceanic and remote regions with very simple ground infrastructure. The Iris communication system network topology will be of multi-star type being its main constituents a space segment elements constituted by one or several satellites, several fixed ground segment elements, located in the satellite network centre and several mobile user segment elements, named AES (Aircraft Earth Station), located at the satellite network edges. Even though during the beginning of life a centralised network architecture is foreseen, the objective is to evolve to a distributed, easily deployable, flexible and high scalable architecture to reach the worldwide coverage. The ground segment comprises three network elements: the Network Management Centre (NMC), the Network Control Centre (NCC) and the Ground Earth Station (GES). The NMC is the network entity responsible for performing the overall management of the satellite communications system elements, defining frequency plans, establishing service policies and logging alarms and monitor information from the whole network entities (NCC, GES and AES) adopting an unified management mechanism inside the Pan-European Network (PEN). The NCC is in charge of performing network control functions, which involve the generation of the network signalling information and the control fulfilment of service polices defined by the NMC. Finally, the GES is the network entity responsible for providing communication between the air traffic control centre (ATCC) and airline operational centre (AOC) and the aircrafts (AES) via satellite. For providing access to remote ATC/AOC, the GES will also interface with the terrestrial network. In this paper, the ICOS project major outcomes will be included, related to the definition of the satellite communications system architecture and protocols that best fits with the major number of ATC/AOC service constraints stated in COCR document. Moreover, following Eurocontrol recommendations of keeping lowers not only the technological risk level but the cost of the system, trade-offs results to assess the proposed architecture will be presented, as well as, protocol simulation results. This simulation will be carried out to demonstrate in a very preliminary stage the capacity of the satellite communications system to fulfil the required performances of selected ATC/AOC services. Finally, a preliminary development plan including all satellite communications system deployment activities necessary to ensure compatibility with the SESAR master plan needs will be provided." } @INPROCEEDINGS{Adri0805:M3R, AUTHOR="Odile Adrian", TITLE="{M3R} {AESA} Technology for Extended Air Defence", BOOKTITLE="2008 IEEE Radar Conference", ADDRESS="Rome, Italy", PAGES="1641-1646", DAYS=26, MONTH=may, YEAR=2008, ABSTRACT="This paper focus on the M3R Active Electronically Steered Antenna (AESA) System and will describe how this AESA is a step towards a fully digitized antenna with a receiver and an A/D-converter behind every antenna element and a full digital beam forming without using analogue sub arrays. First, it will be explained why Extended Air Defence (that is Air and Missile Defence) requires a multi-function, multi-beam radar technology; then M3R radar will be described and the M3R innovative antenna concept implemented in the M3R radar will be presented; The antenna system will be detailed showing the large contribution of the M3R programme to the Thales Building Block Product Policy. The final part shows how M3R antenna architecture is a step towards fully digital radar and multi-static operating mode." } @INPROCEEDINGS{Adve0803:Sum, AUTHOR="Raviraj Adve and Hassen Karaa", TITLE="{Sum-MSE} Based User Selection in {MIMO-OFDM} Systems with Linear Precoding", BOOKTITLE="IEEE Wireless Communications and Networking Conference", ADDRESS="Las Vegas, Nevada, USA", DAYS=31, MONTH=mar, YEAR=2008, KEYWORDS="MIMO-OFDM, user selection, multiuser communications, linear precoding", ABSTRACT="This paper develops a sum mean squared error (SMSE)-based user selection scheme for the downlink in multiuser multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems using linear precoding. We propose a suboptimal user selection algorithm based on an existing multiuser MIMO algorithm, that jointly optimizes the power allocation and the transmit and receive filters. We further develop a simplified version of the proposed algorithm and present a simple and efficient method to reduce the computational load of user selection in MIMO-OFDM systems by exploiting the correlation between adjacent OFDM subcarriers. The simulations show that the proposed user selection algorithm exhibits a near optimal performance and that the computational reduction methods cause minimal performance loss." } @INPROCEEDINGS{Adve0805:Orthogonal, AUTHOR="Raviraj Adve and Earnest Lock", TITLE="Orthogonal Frequency Division Multiplexing in Distributed Radar Apertures", BOOKTITLE="2008 IEEE Radar Conference", ADDRESS="Rome, Italy", PAGES="1892-1897", DAYS=26, MONTH=may, YEAR=2008, ABSTRACT="In previous work, frequency diversity has been shown to be an effective means of exploiting distributed radar apertures. Frequency diversity allows for each transmission to be isolated and processed independently of other frequencies. This paper presents an efficient implementation of a frequency diverse distributed radars, based on orthogonal frequency division multiplexing (OFDM), a concept borrowed from wireless communications. OFDM allows for frequency diversity to be implemented using only a single modulator/demodulator with the transformation, using a Fast Fourier Transform (FFT) to move between time and frequency domains as required. The resulting system is significantly simpler, but, as we will show, OFDM places a stringent constraint on the allowed sampling rate." } @INPROCEEDINGS{Aelt0808:Removal, AUTHOR="Jan Aelterman and Bart Goossens and Aleksandra Pizurica and Wilfried Philips", TITLE="Removal of correlated Rician noise in Magnetic Resonance Imaging", BOOKTITLE="European Conference on Signal Processing 2008", ADDRESS="Lausanne, Switzerland", DAYS=25, MONTH=aug, YEAR=2008, KEYWORDS="MRI; correlated noise; Rician noise; bias correction; denoising", ABSTRACT="We propose a new method for Magnetic Resonance Imaging (MRI) restoration. Because MR magnitude images are corrupted by Rician distributed noise, these images suffer from a contrast-reducing signal-dependent bias. Also the noise is often assumed to be white, however a widely used acquisition technique to decrease the acquisition time gives rise to correlated noise. In this paper, we propose and motivate a two-step denoising procedure, where bias is removed from the squared magnitude image and denoising itself is then performed on the square root of this image in the wavelet domain. This denoising step takes into account noise correlation when distinguishing significant wavelet coefficients from insignificant ones. The estimated statistics of these two classes of wavelet coefficients are employed within a Bayesian estimator. The results show that the proposed technique is more efficient at removing correlated noise than existing MRI denoising techniques. The presented bias removal technique is shown to visibly improve contrast as well as to provide a large increase in PSNR." } @INPROCEEDINGS{Afga0811:Information, AUTHOR="Mostafa Afgani and Sinan Sinanovic and Harald Haas", TITLE="Information Theoretic Approach to Signal Feature Detection for Cognitive Radio", BOOKTITLE="IEEE Globecom 2008 Symposium on Selected Areas in Communications", ADDRESS="New Orleans, LA, USA", DAYS=30, MONTH=nov, YEAR=2008, ABSTRACT="Cognitive radio (CR) systems need to be able to adjust the transceiver characteristics in response to stimuli received from the radio environment. Therefore, monitoring the wireless signal in real-time for stimuli such as unexpected changes due to sporadic interference in radio frequency band of operation is at the core of such systems. In this paper, a method of detecting anomalies in a periodic signal by means of statistical analysis of its envelope is described. The proposed scheme makes use of the Kullback-Leibler divergence between probability distributions drawn from analogous segments of the periodic signal to detect anomalous events. Experiments conducted on real wireless signals suggest that the method described is simple, robust and effective for the analysis of periodic signals." } @INPROCEEDINGS{Afif0000:Small, AUTHOR="Nabil Afifi and Kah Chung", TITLE="Small World Wireless Mesh Networks", BOOKTITLE="Fifth International Conference on Innovations in Information Technology", ADDRESS="Al Ain, UAE", DAYS=16, MONTH=dec, YEAR=2008, KEYWORDS="wireless mesh networks; small world; network planing", ABSTRACT="In this paper, the performance of a wireless mesh network (WMN) is improved by introducing a number of long links at strategic locations, based on the small world network concept, to shorten transmission delay. A Genetic Algorithm (GA) is used to determine the minimum number of long links and their locations such that the maximum number of hops of a given WMN with n nodes is minimized. In the optimization process, practical implementation aspects are considered. These include the radio interference likely to be introduced by the long links, and the possibility of traffic congestion at these links. It is envisaged that a long link will be equipped with a higher power transmitter and directional antenna." } @INPROCEEDINGS{Afla0800:Approach, AUTHOR="Pouya Aflaki and Renato Negra and Abbas Mohammadi and Fadhel Ghannouchi", TITLE="A New Approach to Design a Frequency Synthesizer Using Direct Digital Synthesis Technique", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, KEYWORDS="DDS; frequency multiplier; matching network", ABSTRACT="In this paper a new method to generate a high resolution Ka-band frequency synthesizer is presented. Using a DDS (Direct Digital Synthesizer) as a central oscillator followed by a chain of precisely designed multipliers, a very high resolution and fast switching time Ka-band synthesizer with acceptable phase noise is achieved. The output power of Ka-band synthesizer is around -5 dBm all over 5 GHz bandwidth. To implement the design, a DDS having approximately 0.5 Hz resolution and proper phase noise around -145dBc/Hz is used. The 330-400 MHz output frequency of the DDS is increased to the desired 24-29 GHz band." } @INPROCEEDINGS{Afon0809:Protecting, AUTHOR="Joao Afonso and Pedro Veiga", TITLE="Protecting the {DNS} Infrastructure of a Top Level Domain: {Real-Time} monitoring with Network Sensors", BOOKTITLE="4th IEEE International Workshop on Wireless and Sensor Networks Security (IEEE WSNS 2008)", ADDRESS="Atlanta, Georgia, USA", DAYS=29, MONTH=sep, YEAR=2008, KEYWORDS="DNS, security, sensors, real time firewall", ABSTRACT="In this paper we propose a solution to strengthen the security of Domain Name System (DNS) servers associated with one or more Top Level Domains (TLD). The proposed solution has been developed and tested at FCCN, the TLD manager for the .PT domain. Through the implementation of network probes that monitor the network in real-time, we are able to dynamically prevent, detect or limit the scope of attempted intrusions or other types of attacks to the DNS service. The platform relies heavily on cross-correlation allowing data from a particular sensor to be shared with the others. Administration tasks such as setting up alarms or performing statistical analysis are made through a web-based interface." } @INPROCEEDINGS{Afra0809:Hive, AUTHOR="Amir Afrah and Gregor Miller and Donovan Parks and Martin Matthias Finke and Sidney Fels", TITLE="Hive: A Distributed System for Vision Processing", BOOKTITLE="Second ACM/IEEE International Conference on Distributed Smart Cameras", ADDRESS="Stanford University, Palo Alto, CA, USA", DAYS=7, MONTH=sep, YEAR=2008, KEYWORDS="Computer Vision, Distributed Systems, Middleware, Architecture", ABSTRACT="We have built a novel vision processing system architecture called Hive. Hive fills a gap in the vision middleware by providing mechanisms for simple setup and configuration of distributed vision computation. Hive facilitates communication between independent cross-platform modules via an extensible protocol, allowing these distributed modules to form a vision processing pipeline. A plug-in interface allows general software to be represented as Hive modules: e.g. drivers for hardware devices such as cameras or implementations of particular vision algorithms. The modules are set up as a peer-to-peer network which allows for automated data transfer, callbacks and synchronization. We describe the architecture, communication protocol, plug-in interface and control system for the modules. A distributed face tracking system demonstrates the simplicity and flexibility for creating complex distributed vision applications using Hive." } @INPROCEEDINGS{Afsh0810:Tight, AUTHOR="Armita Afsharinejad and Abolfazl {Toroghi Haghighat}", TITLE="A tight upper bound approximation of loss ratio in high-speed networks based on self-similar traffic", BOOKTITLE="The 14th Asia-Pacific Conference on Communications", ADDRESS="Tokyo, Japan", DAYS=14, MONTH=oct, YEAR=2008, KEYWORDS="high-speed networks, Loss ratio, linear approximation, QoS, Self-Similar traffic, tight upper bound", ABSTRACT="High-speed communication network technologies such as MPLS, ATM, DiffServ, etc can support multiple classes of traffic with different quality of service (QoS) requirements and diverse traffic characteristics. A main QoS requirement is the packet/cell loss ratio (CLR/PLR) .We needs a real-time expression for calculating the loss ratio in these networks where statistical multiplexing is an important factor. In this paper, according to the fact that the real data traffic in high-speed networks shows a self-similar (fractal) behavior, we first, present a PLR simulation based on self-similar traffic. The simulation is done at the packet level that provides very accurate results with the buffer size as a variant. Second, we have found a tight linear PLR approximation that can be calculated in real-time. We have studied application of these bounds in non-homogeneous as well as homogeneous cases." } @INPROCEEDINGS{Afza0803:RSRP, AUTHOR="Syed Rehan Afzal", TITLE="{RSRP:} A Robust Secure Routing Protocol for Mobile Ad hoc Networks", BOOKTITLE="IEEE Wireless Communications and Networking Conference", ADDRESS="Las Vegas, Nevada, USA", DAYS=31, MONTH=mar, YEAR=2008, KEYWORDS="Ad hoc network routing; security; networking", ABSTRACT="Routing scenario in ad hoc networks is different from infrastructure-based wireless networks; since in ad hoc networks each node acts as a router and is responsible for managing topological information and ensuring correct route learning. Although a number of secure routing protocols have been proposed so far, all of them have certain advantages and disadvantages. Hence, security in ad hoc networks is still a contentious area. In this paper we first explore the security problems and attacks in existing routing protocols and then we present the design and analysis of a new secure on-demand routing protocol, called RSRP which confiscates the problems mentioned in the existing protocols. Moreover, unlike Ariadne, RSRP uses a very efficient broadcast authentication mechanism which does not require any clock synchronization and facilitates instant authentication." } @INPROCEEDINGS{Agab0000:Vitro, AUTHOR="Oshiorenoya Agabi and Stefan Weigel and Hansruedi {Früh} and Ruedi Stoop and Arie Bruinink", TITLE="In vitro model for the peripheral nervous system", BOOKTITLE="6th International Meeting on Substrate-Integrated Micro Electrode Arrays", ADDRESS="Reutlingen, Germany", PAGES="47-47", DAYS=8, MONTH=jul, YEAR=2008, KEYWORDS="Bursting, Spinal Cord, Motor Neurons, DRG, Surface Functionalization, Collagen, AFM, Myofibrils", ABSTRACT="Presently, only a single part of the peripheral nervous system (PNS), e.g. motoneurons or DRG is used for investigating in vitro the effects of drugs and chemicals on electrical activity of the PNS. For questions for which a more complex system is necessary in vivo models are currently used. However, the investigation of the PNS in vivo results in reactions from variables which are directly under study and may interfere with the PNS in undesired ways. The aim of the present study is to develop a truly in vitro peripheral nervous system model on the one hand for drug development and toxicological questions and on the other hand to resolve the regimes of communication from the spine to the peripheral nervous system (PNS). The model should be characterised by being easily accessible to electrical, chemical manipulation and physical modelling. We have developed a co-culture system composed of all parts of the reflective arc: myofibrils, spinal cord neurons including motor neurons and DRG cells, all being kept on a micro electrode array (MEA) chip. The MEA surface is functionalized to support contractile cells (myofibrils - skeletal muscle cells) and neural cells (Motor Neurons and dorsal root ganglia (DRG) neurons) also ensuring that recording and stimulation is not precluded. We show the formation of “Neuromuscular Junctions” in the cultures on this chip and the correlation of activity between the different cell species. The functionality of the neuromuscular junction is further evaluated by blocking the acetylcholine receptors (AChR) known to be present on the myofibrils using Tubocurarine. The blockage of this signal pathway is found to be 99\% effective thereby proving the functionality of the neuromuscular junction. Neurons in this culture exhibit bursting activity. The myofibrils also show spontaneous spiking behaviour. We show that while the muscle cells are capable of higher frequencies the neurons do not drive the myofibrils to such frequencies spontaneously. The highest frequencies of the myofibrils occur when the neurons burst." } @INPROCEEDINGS{Agar0000:Leveraging, AUTHOR="Surya Agarwal", TITLE="Leveraging Technology for Growth of Businesses : Indian Expereinces", BOOKTITLE="International Conference on Management of Technology 2008", ADDRESS="Dubai, UAE", DAYS=6, MONTH=apr, YEAR=2008, ABSTRACT="Innovation, R\&D and technology are among the non-price factors, driving competitiveness and growth of businesses in knowledge based economies, according to current economic theories. Therefore, capacities to generate and use innovations and technologies at national and firm levels are important for sustainable growth of businesses. It is hypothesized that the firms in India are generally developing businesses more through business innovations and acquiring mainly foreign technologies, rather than generating technologies significantly through their own efforts. The manufacturing firms need to strengthen their innovations and technological capabilities in most sectors for sustainable growth of their businesses beyond this stage of development. This model of development seems to have been successful so far, as the Indian economy is growing fast and expected to continue to grow in near future at 8 to 9\%. GDP has crossed US $ 1 trillion while exports have been more than US $ 120 billion, being 0.8 per cent of world exports compared to 0.5\% a few years back. The share of technology based exports has also been increasing. The sustainability of this growth rate could however be a matter of concern if capacities to generate new commercialisable technological innovations and technologies are not adequately generated in the country involving industrial sector for technology based businesses at higher levels. Exports and export capabilities are generally reflections of technological capabilities, competitiveness and business growth. The paper summarises the findings of research surveys including field studies for 375 technology based firms/organizations regarding their technology related export performance, and R\&D or technological capabilities during 2003-04 and 2004-05, and analysis of similar time series data for the period 2000-01 to 2004-05. Also, research surveys were carried out for exportable R\&D services available in national R\&D laboratories in the Council of Scientific \& Industrial Research (CSIR) and Indian Council of Medical Research (ICMR), besides a limited survey of about 125 foreign R\&D centres in India. These studies indicated availability of internationally Competitive R\&D Capacities in several areas but weak linkages of industry with academics and national innovation systems, and very limited participation towards enhancing manufacturing competitiveness and exports though technology related exports have grown speedily. Export behaviour of firms having foreign direct investments did not indicate any definite direct relationships and varied across the sectors, though overall technological and managerial capabilities as well as exports have been positively influenced by FDI in-flows in industry. The foreign R\&D centres (~ 300) seemed to have positively impacted the businesses of the parent corporations and the strengthening of national innovation capacities in areas of their operations though their interactions with Indian firms and organizations appeared to be limited. The research studies have further indicated that technology exports of India are at 5 per cent of manufactured exports compared to 27 per cent in China and 58 per cent in Malaysia. Also, technology intensive exports as a percentage of merchandise exports in India increased from 9.74 per cent in 1997-98 to 14.77\% in 2000-01 and to 21.86 per cent in 2003-04 and 20.89 in 2004-05. Medium technology products dominated the exports and increased by 164.44 per cent during 200-01 to 04-05, while high technology products showed an increase of 73.08 per cent and low technology products showed an increase of 52.89 per cent only during the same period. Firm level technological capacities strengthened through absorption and upgradation of acquired foreign technologies and internal business innovations seemed to have positively influenced the competitiveness and business growth of Indian firms. The national R\&D expenditures have been hovering around less than one per cent of GDP, out of which about 80\% is spent by the government and the rest 20\% by industry. The R\&D expenditures have been considerably increased in several sectors over the last five years though the nature of R\&D has been more of applied and incremental. The research survey is estimated to have captured over 70 per cent of the value of non-computer software national technology intensive exports. The research studies tend to show increasing realization to leverage technology and innovation for business growth at firm levels as reflected in the growth of exports of technology based products and sales. However, to sustain this growth and move to higher value chain, the capacity to generate new technologies and innovations in select sectors, need to be enhanced through increased R\&D expenditures, a more conducive policy environment and more effective supporting structures. The government has taken several initiatives to enhance manufacturing competitiveness including enhancing technological capacities at firm levels. Based on the views and suggestions of firms, recommendations have been made to improve the firm level capabilities to better leverage technologies for their business growth in emerging knowledge economy, as the present model may not be sustainable for long." } @INPROCEEDINGS{Agar0804:Financial, AUTHOR="Virat Agarwal and Lurng-Kuo Liu and David Bader", TITLE="Financial Modeling on the Cell Broadband Engine", BOOKTITLE="22nd IEEE International Parallel \& Distributed Processing Symposium", ADDRESS="Miami, Florida, USA", DAYS=14, MONTH=apr, YEAR=2008, ABSTRACT="High performance computing is critical for financial markets where analysts seek to accelerate complex optimizations such as pricing engines to maintain a competitive edge. In this paper we investigate the performance of financial workloads on the Sony-Toshiba-IBM Cell Broadband Engine, a heterogeneous multicore chip architected for intensive gaming applications and high performance computing. The Cell processor consists of a traditional microprocessor (called the PPE) that controls eight SIMD co-processing units called synergistic processor elements (SPEs). We use Monte Carlo techniques to design efficient parallel algorithms for European Option (EO) and Collateralized Debt Obligation (CDO) pricing. To achieve high performance, we design, analyze and optimize different high performance pseudo and quasi random number generators as well as normalization techniques, while maintaining high accuracy. Our Cell-optimized EO pricing achieves a speedup of 1.51 over NVIDIA GeForce 8800 (using CUDA), a speedup of over 2 in comparison to using RapidMind SDK for Cell and a speedup of 1.26 as compared to using RapidMind SDK for GPU (NVIDIA GeForce 8800). We also present the design of an efficient parallel CDO pricing algorithm. This algorithm contains several stages that are popular scientific kernels, proven to demonstrate high performance on the Cell/B.E. Our detailed analysis and performance results suggest that the IBM Cell/B.E. is well suited for financial workloads, and Monte Carlo simulation provides high scalability among the various SPEs." } @INPROCEEDINGS{Agar0804:System, AUTHOR="Ankur Agarwal and Hari Kalva and Cyril-Daniel Iskander and Ravi Shankar", TITLE="{System-Level} Modeling of a {NoC-Based} {H.264} Decoder", BOOKTITLE="2nd Annual IEEE Systems Conference", ADDRESS="Montreal, Quebec, Canada", DAYS=9, MONTH=apr, YEAR=2008, KEYWORDS="network-on-chip; NoC; MLDesigner; H.264; concurrency", ABSTRACT="Networks-on-chip (NOC) are expected to play a key role in future embedded systems. A NOC-based system has the potential to support concurrent processing, in both software and hardware. This can however lead to concurrency issues. We present a multiprocessor system modeling and performance evaluation approach that addresses concurrency. We illustrate our methodology by mapping a H.264 decoder onto a 4×3 mesh-based NOC architecture. We show latency, area, and power consumption results for this NOC architecture abstracted from its FPGA implementation." } @INPROCEEDINGS{Agar0804:System, AUTHOR="Ankur Agarwal and Cyril-Daniel Iskander and Ravi Shankar and Georgiana Hamza-Lup", TITLE="System Level Modeling Environment: {MLDesigner}", BOOKTITLE="2nd Annual IEEE Systems Conference", ADDRESS="Montreal, Quebec, Canada", DAYS=9, MONTH=apr, YEAR=2008, KEYWORDS="System Modeling, MLDesigner, Models of Computation, Top Down Design Methodology, Bottom Up Design Methodology", ABSTRACT="– System modeling has the potential to enhance system design productivity by providing a platform for system performance evaluations. This model must be designed at an abstract level, hiding system details. However, it must represent any subsystem or its components at any level of specification details as needed. In order to model such a system, we will need to combine various models-of-computation (MOC). MOCs provide a framework to model various algorithms and activities, while accounting for and exploiting concurrency and synchronization aspects. Along with supporting various MOCs, a modeling environment should also support a well developed library. In this paper, we have explored and compared various system modeling environments. MLDesigner is one such modeling environment that supports a well developed library and integrates various MOCs. We discuss the process of system modeling with MLDesigner. We further present an abstract model of a Network-on-Chip (NoC) in MLDesigner and show latency results for various customizable parameters for this model." } @INPROCEEDINGS{Agar0805:Multi, AUTHOR="Manish Agarwal and Dongning Guo and Mike Honig", TITLE="{Multi-Carrier} Transmission with Limited Feedback: Power Loading over {Sub-Channel} Groups", BOOKTITLE="ICC'08 - Communication Theory Symposium", ADDRESS="Beijing, China, P.R. China", DAYS=19, MONTH=may, YEAR=2008, ABSTRACT="Feedback of channel state information (CSI) enables a multi-carrier transmitter to optimize the power allocation across sub-channels. We consider a single user feedback scheme in which the entire set of sub-channels is evenly divided into smaller groups of sub-channels, and the receiver requests the use of a particular group if the gain of every sub-channel in the group is above a threshold. The transmit power is then uniformly spread across the requested sub-channel groups. The amount of feedback is therefore controlled by the group size and the threshold. For this scheme, we characterize how the channel capacity scales with the number of sub-channels $N$ as a function of the feedback rate. We then consider transmission over a block fading channel, assuming that each coherence block contains both feedback and data transmission. We optimize the fraction of feedback overhead as a function of the number of feedback bits per channel use and coherence time. Numerical results show that the asymptotic (large-$N$) analysis accurately predicts the behavior of finite-size systems of interest." } @INPROCEEDINGS{Agar0808:Multi, AUTHOR="Prakhar Agarwal and Vikas Saxena", TITLE="Multi-tier Virtual Machine Architecture: {VM-on-VM} (n,n-1) Implementation", BOOKTITLE="International Conference on Contemporary Computing", ADDRESS="Noida, India", DAYS=7, MONTH=aug, YEAR=2008, KEYWORDS="Virtual Machine,VM,Hypervisor,Virtual Machine Monitor,Virtualization", ABSTRACT="The maintenance of Virtual Machine (VM) and inter-VM communication is still a challenge in virtual machines development. This paper proposes a scheme called “VM-on-VM”, which creates multiple layers of VMs hosting the operating systems (OS) and allows them to share conventional hardware in an innovative fashion. The concept of reverse-hierarchy has been devised to demonstrate the proposed scheme" } @INPROCEEDINGS{Agar0812:Case, AUTHOR="Sachin Agarwal", TITLE="A Case Study of Large Scale {P2P} Video Multicast", BOOKTITLE="The 1st International Conference on IP Multimedia Subsystems Architecture and Applications", ADDRESS="Bangalore, India", DAYS=6, MONTH=dec, YEAR=2008, ABSTRACT="The availability of several P2P video multicast solutions has enabled scalable video multicast on the Internet by using the uplink bandwidth of broadband users in order to stream video content to other users. We present several network and quality-of-service characteristics of a large scale P2P video multicast system, recently deployed in Japan, comprising of about 120,000 users. Our findings highlight several network provisioning issues that accentuate the difference between P2P video multicast and traditional IP multicast from a quality-of-service perspective. In particular, we show how commercial grade P2P video multicast may require bandwidth augmenting server-farms in order to serve peers and avoid the effects of high peer churn, a finding that counters the common perception that commercial P2P video multicast can be a free video distribution platform. Our results show that P2P video multicast systems suffer from video quality issues, further differentiating the service quality of P2P video multicast and QoS-enabled IP multicast. Our analysis indicates that a substantial fraction of peers are geographically ditributed, indicating that traffic localization algorithms for P2P video multicast that use IP prefix-matching may not be efficient, leading to added congestion in the network core." } @INPROCEEDINGS{Agar0812:Impact, AUTHOR="Parul Agarwal and Brijesh Yadav", TITLE="Impact of New Highly Secure Scheme on Wireless Network {802.11} Performance", BOOKTITLE="2008 4th International Conference on Information and Automation for Sustainability", ADDRESS="Galle Face Hotel, Sri Lanka", DAYS=12, MONTH=dec, YEAR=2008, ABSTRACT="Wireless local area networks (WLAN) are beginning to play a much larger role in corporate network environments and are already very popular for home networking applications. This increase in accessibility has created large security holes for hackers and thieves to abuse, that is finally being addressed by stronger security protocols and these security protocols include Wired Equivalent Privacy (WEP), Wi-Fi Protected Access (WPA) and 802.11i (WPA2). In this paper, we investigate the performance of wireless local area networks (WLANs) and security protocols available for WLANs. These existing security protocols have certain vulnerabilities and often hamper network performance as maintain poor trade-off between security and overhead on network performance. Here we propose our security protocol Slot Based Security Scheme (SBSS) in wireless local area network. Our proposed security protocol SBSS drastically increases the security and incurs almost same overhead on network performance as other existing security protocols in WLANs. We also develop our simulator in c++ to examine the impacts of these existing security protocols and our proposed protocol SBSS in WLANs on network performance that proves that our proposed scheme SBSS is much more efficient than existing security protocols in WLANs as SBSS maintains good trade-off between security and its associated overhead incurred on network performance. We have simulated these security schemes in c++ with certain parameters. We have concluded that when the number of nodes is less in the network, the security features do not affect the network performance very much. The simulation results described for the throughput and simulation time for large number of nodes show the clear pattern about the efficiency of our proposed security scheme over existing security mechanisms for wireless networks. By using not only one but four algorithms to encrypt and decrypt, any hacker or intruder needs to devise a mean to guess the exact slots configurations for each node in the network. The time factor of SBSS does not depend only on the key but also depends on the combinations of the keys along with the possible combinations of the slots." } @INPROCEEDINGS{Agar0812:Intrusion, AUTHOR="Parul Agarwal and Brijesh Yadav", TITLE="Intrusion Detection Scheme for Securing Cluster Based Routing Protocol in Mobile Ad hoc Networks", BOOKTITLE="2008 4th International Conference on Information and Automation for Sustainability", ADDRESS="Galle Face Hotel, Sri Lanka", DAYS=12, MONTH=dec, YEAR=2008, ABSTRACT="A mobile ad hoc network (MANET) is an autonomous, infrastructureless system of mobile nodes connected by wireless links. The mobile nodes are free to move randomly and organize themselves arbitrarily. MANET nodes are typically distinguished by their limited power, processing, and memory resources as well as high degree of mobility. Due to the open medium, dynamically changing network topology, cooperative algorithms, lack of centralized monitoring and management point, and lack of a clear line of defense, MANETs are highly vulnerable to attacks. Intrusion Detection Systems (IDSs), serving as the second line of defense for information systems, are indispensable for MANETs with high security requirements. In this paper, we present an intrusion detection scheme for securing cluster based routing protocol against byzantine type attack. We carry out comparative analysis to evaluate the effectiveness our scheme to achieve desirable performance and efficiency and to meet the security requirement of MANETs." } @ARTICLE{Agar0812:Low, AUTHOR="Rajiv Agarwal and Zhu Han and Rath Vannithamby and John Cioffi", TITLE="Low Complexity Resource Allocation with Opportunistic Feedback over Downlink {OFDMA} Networks", JOURNAL="IEEE JSAC Special Issue on Exploiting Limited Feedback in Tomorrows Wireless Communication Networks", DAYS=1, MONTH=dec, YEAR=2008, ABSTRACT="Downlink OFDMA optimization is a non-convex NP-hard problem that requires extensive feedback for channel information. In this paper, two constant-complexity limited-feedback algorithms are proposed to achieve near-optimal performance. First, using opportunistic feedback, the proposed schemes are shown to reduce feedback overhead by requiring only users likely to be allocated resources to feed back. There are differences between the two proposed schemes for implementation of the feedback protocol. One scheme requires less feedback but is contention-based, while the other scheme is sequential and thus avoids possible collisions leading to slightly higher performance, but needs more feedback. Second, complexity is reduced for resource allocation by solving the optimizationproblem in a distributed manner, rather than centrally at the base station. As shown both analytically and through numerical results, these distributed algorithms reduce the required feedback significantly, and achieve constant computational complexity with little performance loss compared to the optimal solution." } @INPROCEEDINGS{Agba0811:CHANNEL, AUTHOR="Basile Landaabalo Agba and Francois Gagnon and Ammar Kouki", TITLE="{CHANNEL} {CAPACITY} {AND} {SECOND} {ORDER} {STATISTICS} {IN} {TACTICAL} {MOBILE} {AD} {HOC} {NETWORKS}", BOOKTITLE="IEEE Globecom 2008 Ad Hoc, Sensor and Mesh Networking Symposium", ADDRESS="New Orleans, LA, USA", DAYS=30, MONTH=nov, YEAR=2008, KEYWORDS="channnel capacity; second order statistics, ad hoc networks, performances", ABSTRACT="The channel capacity and the channel statistics are both important performance metrics to consider for appropriate design of wireless systems. In tactical mobile ad hoc networks environment, the capacity and the second order statistics are investigated based on an optimized physical layer simulation tool which includes tactical scenarios generator and propagation modeler. The possible link data rate is stemmed from the average channel capacity analysis between all pair of nodes. And based on the minimum data rate requirement for typical services (web, audio and video streaming, VoIP, videoconference…), connectivity graphs are constructed. Moreover, Level Cross Rate (LCR) and Average Duration of Fade (ADF) are simulated as function of double mobility degree and the results show how the double mobility affects the second order channel statistics and the error probability." } @INPROCEEDINGS{Agee0805:Synchronization, AUTHOR="Anton Ageev and David Macii and Dario Petri", TITLE="Synchronization Uncertainty Contributions in Wireless Sensor Networks", BOOKTITLE="International Instrumentation and Measurement Technology Conference", ADDRESS="Victoria, Vancouver Island, British Columbia, Canada", DAYS=12, MONTH=may, YEAR=2008, KEYWORDS="Wireless Sensor Networks, time synchronization, time measurement, measurement uncertainty", ABSTRACT="This paper deals with a detailed analysis of the uncertainty sources affecting the inter-node time synchronization in Wireless Sensor Networks (WSNs). This analysis relies on several experimental results performed on commercial nodes and is used to model the uncertainty contributions associated to both local time measurements and time transfers between WSN nodes. The obtained models represent the first step to create a simulation framework aimed at comparing the performance of different synchronization protocols on a common reference platform." } @INPROCEEDINGS{Agee0809:Adaptive, AUTHOR="Anton Ageev and David Macii and Alessandra Flammini", TITLE="Towards an Adaptive Synchronization Policy for Wireless Sensor Networks", BOOKTITLE="International Symposium on Precision Clock Synchronization for Measurement, Control, and Communication", ADDRESS="Ann Arbor, Michigan, USA", DAYS=22, MONTH=sep, YEAR=2008, KEYWORDS="Synchronization, Wireless Sensor Networks (WSNs), Time measurement, Calibration.", ABSTRACT="Time synchronization in wireless sensor networks (WSNs) is essential to coordinate the activities distributed among different nodes. In recent years many protocols have been proposed to achieve high-accuracy synchronization. However, up to now only few researchers focused their attention on the issue of trading the number of periodic synchronization events for the target accuracy. In fact, the synchronization requirements of low-cost WSNs often are not particularly strict and strongly depend on the intended application. In this paper, we propose an algorithm aimed at changing the number of synchronization events as a function of the probability of finding the various WSN nodes within given tolerance boundaries. Some experimental results to validate the proposed algorithm are reported. This algorithm is expected to pave the way to novel synchronization protocols for WSNs, which should provide better flexibility and power efficiency than existing ones." } @INPROCEEDINGS{Ager0808:Robust, AUTHOR="Matthew Ager and Zoran Cvetkovic and Peter Sollich and Bin Yu", TITLE="Towards robust phoneme classification: Augmentation of {PLP} models with acoustic waveforms", BOOKTITLE="European Conference on Signal Processing 2008", ADDRESS="Lausanne, Switzerland", DAYS=25, MONTH=aug, YEAR=2008, KEYWORDS="Speech Recognition; Robustness; Generative Classification; Acoustic Waveforms; PLP", ABSTRACT="The robustness of classification of phoneme segments using generative classifiers is investigated for the PLP and acoustic waveform speech representations in the presence of white Gaussian noise. We show a method to combine the strengths of both representations, specifically the excellent classification accuracy of PLP in quiet conditions with the additional robustness of acoustic waveform classifiers. This is achieved using a convex combination of their respective log-likelihoods. Issues of noise modelling and time-invariance of acoustic waveforms are also addressed with initial solutions shown. The resulting combined classifier has greater accuracy than PLP alone and is significantly more robust to the presence of additive noise during testing." } @INPROCEEDINGS{Agga0804:Improving, AUTHOR="Vinay Aggarwal and Obi Akonjang and Anja Feldmann", TITLE="Improving User and {ISP} Experience through {ISP-aided} {P2P} Locality", BOOKTITLE="11th IEEE Global Internet Symposium 2008", ADDRESS="Phoenix, AZ, USA", DAYS=15, MONTH=apr, YEAR=2008, KEYWORDS="ISP-P2P collaboration; topology; user behaviour; performance improvement", ABSTRACT="Despite recent improvements, P2P systems are still plagued by fundamental issues such as overlay/underlay topological and routing mismatch, which affects their performance and causes traffic strains on the ISPs. In this work, we aim to improve overall system performance for ISPs as well as P2P systems by means of traffic localization through improved collaboration between ISPs and P2P systems. More specifically, we study the effects of different ISP/P2P topologies as well as a broad range of influential user behavior characteristics, namely content availability, churn, and query patterns, on end-user and ISP experience. We show that ISP-aided P2P locality benefits both P2P users and ISPs, measured in terms of improved content download times, increased network locality of query responses and desired content, and overall reduction in P2P traffic. The benefits hold across different topologies under a broad range of user behavior scenarios." } @INPROCEEDINGS{Agga0809:Protocol, AUTHOR="Vineet Aggarwal", TITLE="Protocol Aware Test Systems with {FPGA} Hardware", BOOKTITLE="IEEE AUTOTESTCON 2008", ADDRESS="Salt Lake City, UT, USA", DAYS=8, MONTH=sep, YEAR=2008, KEYWORDS="Protocol, FPGA, Digital,", ABSTRACT="In a recent conference paper, the call was made by Andrew Evans of Broadcom to ATE vendors to “make a broad paradigm shift in ATE architecture that will enable true system level testing as part of the production test flow and methodology.” Coined “protocol aware,” this system level testing involves greater intelligence on the part of the ATE to understand protocols and provide a better simulation or emulation of the native environment around the device-under-test (DUT). Pure test vector coverage can sometimes lead to a false sense of security and potentially dangerous effects. While this might be a difficult short-term transition for existing testing infrastructures, the capability to embed protocol intelligence in hardware already exists in COTS technology and could be used to modify existing architectures. Field programmable gate array (FPGA) technology has evolved over the last 20 years from prototyping platform for application specific integrated circuits (ASICs), to a valuable reconfigurable embedded platform with widespread adoption in many areas. Test and measurement can exploit this technology to create hardware that has this native protocol awareness while preserving the benefits of being integrated into Off-the-shelf hardware. The paper will discuss the topic of protocol aware testing and how to achieve aspects of it with COTS FPGA hardware. It will explore important hardware architectures that are well suited for this concepts which include FPGA-based boards with a standard interfaces like PCI, PCIe, PXI or PXIe, surrounding circuitry for memory storage and clock generation, and front end electronics that are either fixed for specialized input or open to development for custom purposes. Protocol aware ATE is an important step to increase the intelligence of the next generation test system, resulting in meaningful test coverage, DUTs with more realistic testing environments, Increased productivity through abstraction, and reduced overhead of custom electronics and software development." } @INPROCEEDINGS{Agga0811:Effect, AUTHOR="Chetan Aggarwal and H Mangalvedekar and Harish Chaudhari", TITLE="Effect of Fault Location on Optimal Coordination of Directional over Current Relay", BOOKTITLE="IEEE Region 10 Conference", ADDRESS="Hyderabad, Andhra Pradesh, India", DAYS=18, MONTH=nov, YEAR=2008, KEYWORDS="Power system protection; Optimal relay coordination; Over current relay; LLL LLG LG fault coordination.", ABSTRACT="The objective of optimal relay coordination in interconnected power system is to achieve selectivity without sacrificing sensitivity \& fast fault clearance time. This paper presents the effect of fault location on the flow of current direction \& optimal coordination of directional over current relay. In this coordination problem Time Dial Setting (TDS) \& Pick up Current Setting (Ip) of all relays considered as optimal parameter \& it will provide coordination for all kind of fault (LLL, LLG, LG). The problem is solved using optimization toolbox of MatLab for continuous value of TDS \& Ip" } @ARTICLE{Agga0812:Performance, AUTHOR="Vaneet Aggarwal and Ashutosh Sabharwal", TITLE="Performance of Multiple Access Channels with Asymmetric Feedback", JOURNAL="IEEE JSAC Special Issue on Exploiting Limited Feedback in Tomorrows Wireless Communication Networks", DAYS=1, MONTH=dec, YEAR=2008, ABSTRACT="Channel state feedback at the transmitter is extensively used to increase the reliability of wireless transmissions. In multiuser systems, the downlink capacity to different users is often different due to the near-far effect.We capture this asymmetry by introducing an asymmetric feedback model where different users get different amount of feedback from the base station. First, we derive the outage probability for the optimum maximum-likelihood receiver which forms an upper bound on the diversity-multiplexing performance for all receivers. This is accompanied by the conditions under which these bounds can be achieved. Gaussian random coding bounds are presented, which are not only asymptotically tight, but also reach quite close to the optimum with moderate block lengths. Second, we analyze the performance of two popular suboptimal receivers: the spatial decorrelator and successive interference cancellation receiver. As a special case, when there is no asymmetry, the performance matches feedback-based single-user performance in many scenarios which may be of independent interest." } @INPROCEEDINGS{Aggo0805:Implementation, AUTHOR="George Aggouras and Vassilis Paliouras", TITLE="On the implementation of bus-based architectures", BOOKTITLE="International Symposium on Wireless Pervasive Computing 2008", ADDRESS="Santorini, Greece", PAGES="642-645", DAYS=7, MONTH=may, YEAR=2008, KEYWORDS="LDPC decoding, message passing", ABSTRACT="Three families of architectures for LDPC decoding are presented in this paper, focusing on reducing the interconnection complexity dominant in an LDPC decoder. The proposed architectures explore tradeoffs between the interconnection complexity, delay, and decoding performance. A graph based technique is introduced that allows the formation of groups of calculations, of minimal inter-group communication, subsequently mapped onto processor units." } @INPROCEEDINGS{Aggr0806:Application, AUTHOR="George Aggrey and Ran Tao", TITLE="Application of the {FRFT} to distortion analysis in Transmultiplexers", BOOKTITLE="24th Queen's Biennial Symposium on Communications", ADDRESS="Kingston, Ontario, Canada, Canada", DAYS=23, MONTH=jun, YEAR=2008, KEYWORDS="Tramsmultiplexer; Fractional Fourier transform; nonstationary signals; Filter banks; Amplitude distortion; Phase distortion", ABSTRACT="In this paper, a fractional Fourier transform based technique for the elimination of amplitude and phase distortions in the transmultiplexer (TMUX) is presented. The core elements of the TMUX, the synthesis and analysis filter banks cause amplitude and phase changes due to the filtering operations in the filter banks thereby altering the perfect reconstruction property. This study investigates a new approach to transmultiplexer design in the processing of the nonstationary signals." } @INPROCEEDINGS{Agha0000:Nonlinear, AUTHOR="Seyyed Amir Aghaei", TITLE="A Nonlinear Dynamic Model of Female Labor Supply Model: Case of Iran", BOOKTITLE="10th International Conference on Computer Modelling \& Simulation", ADDRESS="Cambridge, United Kingdom", DAYS=1, MONTH=apr, YEAR=2008, KEYWORDS="Mathematical Modeling, Dynamic Models, System Dynamics, Nonlinear Models, Female Labor Supply, Labor Market Dynamics", ABSTRACT="In developing countries, one of the most essential economic problems is the high unemployment rate along with the low economic growth. Unfortunately their female unemployment rate is higher than average unemployment rates. In order to analyze the situation and then take it under control, a mathematical model for both sides of female labor market is required. In this paper, an analytical dynamical model is developed for the Iranian female labor supply. The lifecycle theory is used to divide it into three age groups. Then the static theory is used as a basis to construct each model analytically. It has been presented that some criteria such as the education level, marriage and history of unemployment rate can strongly affect the labor supply as well as the rate of real wage and real non-labor income has both the substitution and income effects. Moreover, a reservation wage is estimated for each model." } @INPROCEEDINGS{Aghd0805:ET, AUTHOR="Hadi S. Aghdasi", TITLE="{ET-MAC:} An {Energy-Efficient} and High Throughput {MAC} Protocol for Wireless Sensor Networks", BOOKTITLE="Sixth Annual Conference on Communication Networks and Services Research", ADDRESS="Halifax, Nova Scotia, Canada", DAYS=5, MONTH=may, YEAR=2008, ABSTRACT="The efficient use of energy in wireless sensor networks is a critical issue as the sensor nodes typically operate with limited power sources. Most consumption energy of the sensor nodes is used for communication parts. MAC protocols directly control the communications in network; therefore, in this paper we design an innovative contention-based MAC protocol for wireless sensor networks to provide long network lifetime. Our MAC protocol embeds some extra information in long wake up preamble frame and it also uses collision avoidance signaling and handshaking. These ideas help wireless nodes to stay at sleep mode as much as possible. This protocol avoids major energy waste causes, such as idle listening, collision and overhearing, without compromising other network performance measures like latency. Our simulation results and analyses show that with dynamic traffic load, ET-MAC protocol achieves significant improvement in energy-efficiency and throughput, over well known MAC protocols like B-MAC." } @INPROCEEDINGS{Agir0000:Continuous, AUTHOR="Handan Agirman-Tosun and Ali Akansu", TITLE="Continuous Phase Modulation for {Multi-Level} Spreading Codes in {CDMA} Communications", BOOKTITLE="IEEE Sarnoff Symposium 2008", ADDRESS="Princeton , NJ, USA", DAYS=28, MONTH=apr, YEAR=2008, ABSTRACT="Continuous Phase Modulation has been favorably considered for use in DS-CDMA communications due to its constant envelope and spectral efficiency over other competing signaling techniques. On the other hand, more recently proposed multi-level orthogonal spreading code families offer better inter- and intra-code correlation properties than the conventional binary code families like Gold and Walsh. This paper evaluates BER performance of a system employing CPM technique for signaling and multi-level orthogonal spreading codes for DS-CDMA communications. It is shown that CPM-DS-CDMA system employing multi-level spreading codes significantly outperform binary spreading codes under the same test conditions." } @INPROCEEDINGS{Agra0000:Robust, AUTHOR="Himanshu Agrawal and Andrew Jennings and Mark Gregory", TITLE="Robust Traffic Engineering", BOOKTITLE="Second IEEE International Conference on Advanced Networks and Telecommunication Systems (ANTS)", ADDRESS="Mumbai (Bombay), India", DAYS=15, MONTH=dec, YEAR=2008, KEYWORDS="Keywords- Robust Routing, Traffic demand matrix, Traffic Engineering.", ABSTRACT="Abstract-Phenomenal growth of Internet applications in recent years have made it difficult to forecast traffic patterns. Daily Internet traffic pattern shows that network is vulnerable to malicious attacks, flash crowds and denial of service attacks (DDoS). Based on the observation for an IP network, it has been pointed out by [10] that 50\% of the failures last for < 1 minute and 80\% of failures last for < 10 minute. In this paper we present a Robust Routing Technique (RRT) that captures both captures normal routing conditions as well as transient failures. Our preliminary results are compared with OSPF-TE. We are aiming further to improving RRT by combining the best of offline and dynamic traffic engineering approaches." } @INPROCEEDINGS{Agra0804:Supporting, AUTHOR="Gagan Agrawal", TITLE="Supporting {Fault-Tolerance} in Streaming Grid Applications", BOOKTITLE="22nd IEEE International Parallel \& Distributed Processing Symposium", ADDRESS="Miami, Florida, USA", DAYS=14, MONTH=apr, YEAR=2008, ABSTRACT="This paper considers the problem of supporting and efficiently implementing fault-tolerance for tightly-coupled and pipelined applications, especially streaming applications, in a grid environment. We provide an alternative to basic checkpointing and use the notion of {\em Light-weight Summary Structure}(LSS) to enable efficient failure-recovery. The idea behind LSS is that at certain points during the execution of a processing stage, the state of the program can be summarized by a small amount of memory. This allows us to store copies of LSS for enabling failure-recovery, which causes low overhead fault-tolerance. Our work can be viewed as an optimization and adaptation of the idea of application-level checkpointing to a different execution environment, and for a different class of applications. Our implementation and evaluation of LSS based failure-recovery has been in the context of the GATES (Grid-based AdapTive Execution on Streams) middleware. An observation we use for providing very low overhead support for fault-tolerance is that algo rithms analyzing data streams are only allowed to take a single pass over data, which means they only perform approximate processing. Therefore, we believe that in supporting fault-tolerant execution for these applications, it is acceptable to not analyze a small number of packets of data during failure-recovery. We show how we perform failure-recovery and also demonstrate how we could use additional buffers to limit data loss during t he recovery procedure. We also present an efficient algorithm for allocating a new computation resource for failure-recovery at runtime. We have extensively evaluated our implementation using three stream data processing applications, and shown that the use of LSS al lows effective and low-overhead failure-recovery." } @INPROCEEDINGS{Agra0805:ECG, AUTHOR="Foteini Agrafioti and Dimitrios Hatzinakos", TITLE="{ECG} Based Recognition Using Second Order Statistics", BOOKTITLE="Sixth Annual Conference on Communication Networks and Services Research", ADDRESS="Halifax, Nova Scotia, Canada", DAYS=5, MONTH=may, YEAR=2008, ABSTRACT="This paper investigates the applicability of Electrocardiogram (ECG) signals for human recognition. Current approaches apply feature extraction on a fiducial points basis. In this paper we demonstrate an autocorrelation based feature extraction approach, in conjunction with the Discrete Cosine Transform or Linear Discriminant Analysis. As an optimization, we introduce a Template Matching technique that substantially improves the classification performance while also acting as an intruder detector. The experimental results show considerably high recognition rates, rendering identification applications based on ECG very promising." } @INPROCEEDINGS{Agra0811:Performance, AUTHOR="Dharma Agrawal", TITLE="Design and Performance Issues in Wireless Mesh Networks", BOOKTITLE="IEEE Globecom 2008 Tutorials", ADDRESS="New Orleans, LA, USA", DAYS=30, MONTH=nov, YEAR=2008, KEYWORDS="Mesh Networks; Mesh outers; Internet Gateways; Routing; Performance; Security", ABSTRACT="Mesh networks have become increasingly important because they can be easily implemented without much infrastructure and can support adequate bandwidth with a flexible multi-hop wireless communication among their routers serving the clients. This tutorial provides an overview of the Wireless Mesh Networks (WMNs) and identifies various associated characteristics. The very first problem faced in the WMN design is how many mesh routers (MRs) to be deployed and where should they be placed. Another related question is how many MRs ought to be used as the Internet Gate Ways (IGWs) and where they should be located. Other issues such as route determination, channel allocation, load-balancing, etc. have to be considered carefully to have a clear understanding of the WMN technology. Issues such as selfishness and its impact on the performance will be discussed. Useful research directions will also be clearly identified. Future widespread deployment of the WMN seems quite promising, even though security and scalability questions still remain real bottlenecks." } @INPROCEEDINGS{Agra0811:System, AUTHOR="Smriti Agrawal and Rama Yadav and Ranvijay Singh", TITLE="System Level Energy Aware Fault Tolerance Approach for Real Time System", BOOKTITLE="IEEE Region 10 Conference", ADDRESS="Hyderabad, Andhra Pradesh, India", DAYS=18, MONTH=nov, YEAR=2008, KEYWORDS="Checkpointing; Critical Speed; Dynamic Voltage Scaling; Dynamic Power Down; Scheduling; Hard Real Time System", ABSTRACT="This paper investigates an integrated approach to dynamic power management with fault tolerance in real time system. The system is composed of DVS processor (frequency dependent) and peripheral devices (frequency independent) with a better survival possibility in harsh environmental conditions. The fault tolerance is achieved via checkpointing and energy minimization is done by dynamic voltage scaling and dynamic power down techniques. We estimated a critical speed which effectively balanced the fault tolerance requirement of a system and the energy consumed by the associated frequency dependent and independent devices. The simulations results and examples illustrate that our proposed approach provides better tolerance to faults where existing approaches fail to survive and still consume lesser energy." } @INPROCEEDINGS{Agra0811:Wavelet, AUTHOR="Navneet Agrawal and K Venugopalan", TITLE="Wavelet Packets Based {SAR} Image Compression and Sub-band Coding", BOOKTITLE="CEOS SAR Workshop on Calibration and Validation", ADDRESS="Oberpfaffenhofen, Germany", DAYS=27, MONTH=nov, YEAR=2008, KEYWORDS="Wavelets, Sub-band , Synthetic Aperture Radar(SAR)", ABSTRACT="Standard wavelet transforms are not very efficient for raw SAR data compression so we provide a formalism leading to the derivation of a 2-D optimal wavelet which minimizes the transform coefficients correlation.The wavelet decomposition produces signal components whose spectra consists of consecutive octave bands, the wavelet packet decomposition provides a finer spectral resolution" } @INPROCEEDINGS{Agra0812:Methodology, AUTHOR="Prashant Agrawal and Pavankumar V and Ashwin Muppalla and Srinivasa Stg and Ajit Pal", TITLE="Methodology for Thermal Aware Topologies and Partitioning with Better Lateral Spreading", BOOKTITLE="20th International Conference on Microelectronics (ICM) 2008", ADDRESS="Sharjah, UAE, UAE", PAGES="171-174", DAYS=14, MONTH=dec, YEAR=2008, KEYWORDS="Floorplanning, Thermal Gradient, Proliferation Designs, Thermal Design Power", ABSTRACT="Exponentially increasing power densities in current day designs due to aggressive technology scaling has resulted in temperature being one of the primary design constraint along with others like timing, area and power. Lot of design techniques are being adopted during physical design stage to minimize the power, apart from the architectural techniques like throttling for dynamic thermal management. In this work we propose a practical methodology for better thermal management by floorplan modifications, based on thermal hotspots obtained through dynamic simulations without disturbing the logical connectivity information. This methodology definitely warrants the benefits which can be readily realized by doing this analysis early in the design cycle. This can also improve the placement of the thermal sensors and boast additional performance which can be extracted by their delayed triggering, considering the lateral spreading due to better floorplanning." } @INPROCEEDINGS{Agre0805:Estimation, AUTHOR="Dusan Agrez", TITLE="Estimation of the Component Parameters for the Evaluation of the Power Quality Disturbances in the Frequency Domain", BOOKTITLE="International Instrumentation and Measurement Technology Conference", ADDRESS="Victoria, Vancouver Island, British Columbia, Canada", DAYS=12, MONTH=may, YEAR=2008, KEYWORDS="measurement on power systems; power quality disturbances; frequency; amplitude; phase; harmonic distortion; estimation in the frequency domain" } @INPROCEEDINGS{Ague0803:Accurate, AUTHOR="Ramon Aguero and Marta Garcia and Luis {Muñoz}", TITLE="On the accurate simulation of {TCP} behavior over error-prone wireless links with memory", BOOKTITLE="IEEE Wireless Communications and Networking Conference", ADDRESS="Las Vegas, Nevada, USA", DAYS=31, MONTH=mar, YEAR=2008, KEYWORDS="performance; throughput; simulation; TCP; wireless links; simulation; channel model", ABSTRACT="In this paper we show how traditional indoor channel models do not accurately reflect the real behavior exhibited by TCP when operated over error-prone wireless links, especially due to the large variability which is empirically observed. In contrast with them, we use a novel channel model, based on an auto-regressive filtering scheme, and which we have integrated into the \emph{Network Simulator} framework, to better capture the real behavior of wireless links. We shall see that the memory characteristic of the channel, with a clear influence over retransmissions and inactivity times that the TCP transmitter suffers from, highlights as it most distinctive aspect. The idea is to provide a realistic modeling of wireless channels, so as to overcome the deficiencies which characterize other more traditional approaches." } @INPROCEEDINGS{Ague0803:Outage, AUTHOR="Ramon Aguero and Johnny Choque and Luis {Muñoz}", TITLE="On the outage probability for multi-hop communications over array network deployments", BOOKTITLE="IEEE Wireless Communications and Networking Conference", ADDRESS="Las Vegas, Nevada, USA", DAYS=31, MONTH=mar, YEAR=2008, KEYWORDS="outage; mesh;", ABSTRACT="This paper discusses the benefits that mesh and \emph{multi-hop} networking may bring about over traditional network deployments. An optimal distribution of access elements, following a grid structure is assumed, and the paper analyzes the coverage extension which could be achieved, by means of forwarding stations, assuming different number of hops per route, as well as different end user (and relaying nodes) densities. The paper follows a two-fold approach, since it presents both an analytical as well as a simulation-based analysis." } @INPROCEEDINGS{Agui0807:Multicast, AUTHOR="Alberto Aguilar and Raime Bustos and Kia Makki and Raimund Ege", TITLE="{Multicast-P2P} Content Distribution in {Large-Scale} Enterprise Networks", BOOKTITLE="13th IEEE Symposium on Computers and Communications", ADDRESS="Marrakech, Morocco", DAYS=6, MONTH=jul, YEAR=2008, KEYWORDS="Multicast, P2P, BitTorrent", ABSTRACT="Multicast has been used as a one-to-many approach to deliver information; it is based on the idea that if one package of data should be transmitted to several recipients, the information should be sent by the origin just one time. In this paper, we propose the use of overlay multicast to distribute content and to make distribution more efficient,we combine it with a P2P approach. Our research includes a token-based algorithm to construct multicast trees based on information provided by a tracker and a comparison with current BitTorrent implementations. We focus on environments such as large-scale enterprise networks." } @INPROCEEDINGS{Agui0809:Two, AUTHOR="Teck Aguilar and Hossam Afifi", TITLE="{Two-Hops} Clustering Algorithm With a Composed Metric for Wireless Sensor Networks", BOOKTITLE="The 11th International Symposium on Wireless Personal Multimedia Communications", ADDRESS="Saariselkä, Lapland, Finland, Finland", DAYS=8, MONTH=sep, YEAR=2008, KEYWORDS="Sensor networks, clustering", ABSTRACT="In Wireless Sensor Networks, the nodes are provided of some constrained resources like processing capabilities, limited transmission range and energy. So a critical aspect of this kind of networks is its lifetime. Clustering sensor nodes is a good technique to efficiently manage the resources. In this paper, we describe a new two-hops clustering algorithm where each node requires only a combination of local information at two-hops to generate the clustering in the network. 2HopCH is a distributed and localized algorithm that partitions the network into a set of clusters. In our methodology we select the cluster head according to a metric that uses the energy, the node degrees and the density in a 2-hops environment." } @INPROCEEDINGS{Agui0811:Optical, AUTHOR="Luis Aguirre-Torres", TITLE="Optical Burst Switching in Packet {WDM} Transport Networks", BOOKTITLE="IEEE Globecom 2008 Design and Developers Forum", ADDRESS="New Orleans, LA, USA", DAYS=30, MONTH=nov, YEAR=2008, KEYWORDS="Packet WDM, Optical burst switching, all optical", ABSTRACT="During the past decade, significant progress has been made in the area of optical burst switching (OBS) technology with the goal of packetizing optical networks. Commercially available products leveraging OBS technology have recently become available. These products allow operators to significantly lower the cost of deploying Ethernet optical networks, improve bandwidth utilization and increase service flexibility. The proliferation of Ethernet, in combination with the availability of OBS technology, has opened the door for network operators to achieve substantial economic benefits by incorporating OBS into the Ethernet transport network. Ethernet frames can now be transported as optical bursts using a color-based wavelength addressing scheme, without requiring optical buffering or dynamic wavelength routing at the optical layer. OBS enables multiple benefits, among them the ability to further optimize the use of network resources by creating a shared transmission media, for the first time enabling the virtualization of the optical layer. This is achieved through the sharing of optical burst transponders, which is unique in its ability to allow multiple endpoints to communicate using a single transponder. This is accomplished as each OBS transponder is dynamically re-tuned to different wavelengths in just nanoseconds for the transmission of optical burst packets containing Ethernet frames. At intermediate nodes, only passive optical filters are required to direct all bursts of a given wavelength to a specific destination. The benefits of optical burst switching technology are not limited to the optical layer. Combining Ethernet with OBS enables not only the virtualization of the optical layer, but it also greatly simplifies operations by making it possible to manage, monitor and provision the network as a single distributed Ethernet switch, where the optical layer functions as a high-speed backplane over which Ethernet switching interfaces communicate at wire-speed. Any to any communication among Ethernet ports is made possible by employing a multiple-wavelength, color-based addressing scheme. This presentation provides an overview of optical burst switching technology in Ethernet transport networks, emphasizing its technical and economic benefits, and elaborating on those aspects related to traffic management, color-based addressing and bandwidth management. It also provides an example of how this technology can be used to minimize operational complexity and associated costs in real network scenarios." } @INPROCEEDINGS{Agus0807:Resource, AUTHOR="Adrian Agustin and Josep Vidal", TITLE="Resource optimization in decode-and-forward half-duplex multiple relay-assisted channel", BOOKTITLE="The Ninth IEEE International Workshop on Signal Processing Advances in Wireless Communications", ADDRESS="Recife, Brazil", PAGES="436-440", DAYS=5, MONTH=jul, YEAR=2008, KEYWORDS="Relays, cooperative systems, radio spectrum management", ABSTRACT="The half-duplex multiple relay-assisted channel is investigated, where the relays work under decode-and-forward (DF) in time/frequency orthogonal resources. Achievable rates are optimized with respect to the transmitted powers and with respect to the fraction of time/bandwidth allocated to the relay-receive and the relay-transmit phases. Different transmission strategies associated to different complexities at the receivers are considered. For each case we take into account either the synchronous or asynchronous transmission of the terminals, depending on the availability of channel state information (CSI) in transmission from all links. We find that all the cases can be formulated as a unique convex problem, and we compare the achievable rates thus obtained. We finally derive under which conditions the use of two DF relays brings significant gains over the use of one." } @INPROCEEDINGS{Aham0000:Half, AUTHOR="Syed Ahamed", TITLE="{Half-Width} Pulse Simulations for Plastic Fiber Optics", BOOKTITLE="Fifth International Conference on Innovations in Information Technology", ADDRESS="Al Ain, UAE", DAYS=16, MONTH=dec, YEAR=2008, KEYWORDS="Simulations, Plastic Fiber Optic Systems, PMMA Distance Limits", ABSTRACT="The current applications of plastic fibers include data distribution in aircraft and automobiles. They can also be deployed for a variety of small local area networks. Plastic fiber systems are an order of magnitude less expensive than silica fiber optic systems and are more robust. The applications in other traditional data communication systems remain a distinct possibility. We present signal to noise ratio for optical rates up to 2.5 Gb/s and for link lengths up to 500 m, even though the signal level becomes too low for most of the PIN diodes. Applications in a high-rise office buildings and premises distribution architectures are investigated. As in most data transmission systems, the quality of components affects the performance dramatically. The simulations are focused for the Polymethyl Methacrylate (PMMA) plastic fiber to offer a window and envision other applications for this new breed of optical fibers." } @INPROCEEDINGS{Aham0000:Implementing, AUTHOR="Shaik Ahamed", TITLE="Implementing a High Dynamic Range Adaptive Decision Feedback Equalizer On a Low Cost Fixed Point Processor", BOOKTITLE="National Conference on Communications 2008", ADDRESS="IIT Bombay, Mumbai., India", DAYS=1, MONTH=feb, YEAR=2008, ABSTRACT="A scheme for efficient finite precision realization of the adaptive decision feedback equalizer using block floating point (BFP) arithmetic is presented. The scheme adopts separate BFP formats for the feed forward and the feedback filter weights and works out separate update relations for their respective mantissas and exponents. Care is taken to prevent overflow in all computations by using a dynamic scaling of the data and a carefully chosen upper bound for the step size $\mu$. Since no block processing of the feedback input is possible, an efficient scheme is presented for block formatting the data stored in the feedback filter memory, at each time index. The proposed scheme mostly employs simple fixed point operations and achieves considerable speed up over its floating point counterpart." } @INPROCEEDINGS{Aham0000:Knowledge, AUTHOR="Syed Ahamed", TITLE="Knowledge, Opportunities and Information Ethics", BOOKTITLE="Fifth International Conference on Innovations in Information Technology", ADDRESS="Al Ain, UAE", DAYS=16, MONTH=dec, YEAR=2008, KEYWORDS="Knowledge Management, Flow of Information, Information Ethics", ABSTRACT="High-speed Internet provides unprecedented opportunities in the information domain. The wealth of information in the web-based knowledge banks brings about innumerable business prospects. This relentless rush for knowledge lowers the information ethics. The rewards had brought a stream of successful dot-com corporations in the 1990s. The dangers have also brought bankruptcy for most of these corporations. The plunderers are the knowledgeable and skilled few and the victims are the ignorant who are not able to see through the games that Internet exploiters can play. The boom and bust of the dot-com opportunists is grim reminder of how knowledge cycle has taken the ignorant few to the depth of despair. In this paper, we suggest that intelligent knowledge processing software should curtail the abuse of the IP networks, much as the network security programs that block the spread of spam and viruses." } @INPROCEEDINGS{Ahar0801:SnapNShare, AUTHOR="Nadav Aharony", TITLE="{SnapN'Share} - Peerwise Content Distribution for Mobile Platforms - Demo Proposal", BOOKTITLE="CCNC'2008 Demonstration Proposals", ADDRESS="Las Vegas, USA", DAYS=12, MONTH=jan, YEAR=2008, ABSTRACT="Using mobile wireless pocket devices, users generate and seamlessly share content with different groups and communities that they belong to, such as: friends, family, co-workers, or the general public. A user would simply walk into a meeting or pass by a fellow group member and automatically receive new and relevant files and content. SnapN'Share is the first sample application of a new platform implementing an ad-hoc, wireless, peer-to-peer information system that bypasses the need for any centralized servers, coordination, or administration. It combines knowledge and awareness of the user's social relationships with the communication protocols and network services. The platform could be extended and customize to support many other types of applications and needs. We intend to show a working prototype of the system, running on mobile devices." } @INPROCEEDINGS{Ahle0801:Oh, AUTHOR="Dirk Ahlers and Susanne Boll", TITLE="Oh Web image, where art thou?", BOOKTITLE="The Fourteenth International Multimedia Modeling Conference", ADDRESS="Kyoto, Japan", DAYS=9, MONTH=jan, YEAR=2008, ABSTRACT="The role of location for images has been discussed in many research papers in recent years. Considering the Web, many questions about location can not be reliably answered for Web images as they typically do not explicitly reveal their relationship to an actual geographic position. In this paper, we present a geospatial Web image search engine that allows finding images that are only implicitly related to a geographic position. Exploiting location information on common Web pages, we combine context and content analysis to assign a location to embedded images. Thus, a large number of potentially geographically-related Web images are unlocked for commercially relevant spatial Web image search." } @INPROCEEDINGS{Ahlg0000:Considerations, AUTHOR="Bengt Ahlgren and Matteo D'Ambrosio and Christian Dannewitz and Marco Marchisio and Ian Marsh and Börje Ohlman and Kostas Pentikousis and René Rembarz and Ove Strandberg", TITLE="Design Considerations for a Network of Information", BOOKTITLE="First Workshop on Re-Architecting the Internet", ADDRESS="Madrid, Spain", DAYS=9, MONTH=dec, YEAR=2008, KEYWORDS="Network of Information; information-centric networking", ABSTRACT="The existing Internet ecosystem is a result of decades of evolution. It has managed to scale well beyond the original aspirations. Evolution, though, highlighted a certain degree of inadequacies that is well documented. In this position paper we present the design considerations for a re-architected global networking architecture which delivers dissemination and non-dissemination objects only to consenting recipients, reducing unwanted traffic, linking information producers with consumers independently of the hosts involved, and connects the digital with the physical world. We consider issues ranging from the proposed object identifier/locator split to security and trust as we transition towards a Network of Information and relate our work with the emerging paradigm of publish/subscribe architectures. We introduce the fundamental components of a Network of Information, i.e., name resolution, routing, storage, and search, and close this paper with a discussion about future work." } @INPROCEEDINGS{Ahma0000:3Dimension, AUTHOR="Baharak Ahmadipoor and Sami Saei and Mehdi Sarram", TITLE="3Dimension {GPS} Free Positioning In Mobile Ad Hoc Networks", BOOKTITLE="Mosharaka International Conference on Communications, Networking and Information Technology", ADDRESS="Amman, Jordan", DAYS=5, MONTH=dec, YEAR=2008, KEYWORDS="Ad Hoc, Routing, Geographical position", ABSTRACT="Mobile ad hoc wireless networks contain nodes that communicate without any topological structure. Even though it has found popularity in its application, the mobility of nodes is one of the main challenges. This is due to the fact that the links between the nodes may break at any time and consequently affects the entire network performance. In this article a distributed way for detecting the location of nodes in three dimensions has been proposed, which it is more agreeable with the real world situations. In this approach the nodes distances are determined by several methods such as signal strength, Angle of arrival (AOA), time of arrival (TOA) and time difference of arrival (TDOA). In this work a geometrical method is utilized to determine the relative position of nodes leading to efficient routing process." } @INPROCEEDINGS{Ahma0000:Minimum, AUTHOR="Muhammad Ishtiaq Ahmad", TITLE="Minimum Variance Beamforming using Polarization Sensitive Array", BOOKTITLE="11th IEEE International Conference on Communication Systems 2008", ADDRESS="Guangzhou, P.R. China", PAGES="489-492", DAYS=19, MONTH=nov, YEAR=2008, KEYWORDS="Array signal processing; polarization; linear arrays.", ABSTRACT="In this paper we study an accurate interference rejection capability of a minimum-variance polarization sensitive (MVPS) beamformer using a uniform linear array of crossed dipoles. The interference cancellation is done in the spatio-polarized domain since MVPS beamformer search in both the direction of arrival and polarization domains. Also, MVPS beamformer has the capability of handling more signals than the scalar array having the same number of sensors in a single beam. We have also analyzed that there will be no beam when the desired and interference EM signals are same in nature." } @INPROCEEDINGS{Ahma0000:Multi, AUTHOR="Baharak Ahmadipoor and Sami Saei and Mehdi Sarram and M. Hassan Shirali-Shahreza", TITLE="{Multi-Layer} {QoS} Interface Guided Routing In Mobile Ad Hoc Networks", BOOKTITLE="The First IEEE International Workshop on Generation C Wireless Networks", ADDRESS="Austin, Texas, USA", DAYS=7, MONTH=dec, YEAR=2008, KEYWORDS="Multi-Layer QoS, Ad Hoc Networks, Mobile Communication", ABSTRACT="Mobile Ad Hoc Networks (MANETs) consist of wireless hosts that communicate with each other in the absence of a fixed infrastructure. They have potential applications in disaster relief, conference, and battlefield environments, and have received significant attention in recent years. In a MANET, a message sent by a node reaches all its neighboring nodes that are located at distances up to the transmission radius. Because of the limited transmission radius, the routes between nodes are normally created through several hops in such multi-hop wireless networks. Host mobility can cause frequent unpredictable topology changes. Researchers do some works on QoS routing in MANETs. But the QoS routing algorithms for wired networks cannot be applied directly to Ad Hoc networks. First, the performance of most wired routing algorithms relies on the availability of precise state information. However, the dynamic nature of an Ad Hoc network makes the available state information inherently imprecise. Second, nodes may join, leave, and rejoin an Ad Hoc network at any time and any location; existing links may disappear, and new links may be formed as the nodes move. Hence, the established paths can be broken at any time. In this paper we define a QoS routing method. We define an extra QoS interface for each layer of OSI model to provide better “hand shake”. Our approach is easy to accomplish and can be implemented on existing systems while providing improved QoS management and performance. Furthermore, the proposed holistic approach is novel as it considers the different factors that contribute to QoS at the different layers in contrast to traditional QoS routing protocols which work primarily on ensuring that the QoS requirements are satisfied at a specific level." } @INPROCEEDINGS{Ahma0000:Policy, AUTHOR="Baharak Ahmadipoor and Sami Saei and Mehdi Sarram and M. Hassan Shirali-Shahreza", TITLE="Policy Based Security In Mobile Ad Hoc Networks", BOOKTITLE="Mosharaka International Conference on Communications, Networking and Information Technology", ADDRESS="Amman, Jordan", DAYS=5, MONTH=dec, YEAR=2008, KEYWORDS="Mobile Ad Hoc Network, Policy, Security", ABSTRACT="Mobile Ad Hoc Networks (MANETs) consist of wireless hosts that communicate with each other in the absence of a fixed infrastructure. They have potential applications in disaster relief, conference, and battlefield environments, and have received significant attention in recent years. In a MANET, a message sent by a node reaches all its neighboring nodes that are located at distances up to the transmission radius. Because of the limited transmission radius, the routes between nodes are normally created through several hops in such multi-hop wireless networks. Host mobility can cause frequent unpredictable topology changes. Research on securing ad hoc networks has concentrated on secure routing, intrusion detection and key management. Although these techniques will deliver the message securely to the destination or authenticate nodes, all sources have the same access rights to resources at the destination. Given the increasing sophistication of computers, cell phones, PDAs etc., that form ad hoc networks, as well as the increasing complexity of the services such networks provide, there is a need for an additional level of security for resource protection. In this paper we propose a distributed policy based architecture for mobile ad hoc networks, the implementation of the policy is also presented. Simulations indicate that the routing overheads associated with the proposed system make this a feasible approach for enhancing the security of mobile ad hoc networks." } @INPROCEEDINGS{Ahma0000:Proactive, AUTHOR="Iftekhar Ahmad", TITLE="A Proactive Forward Error Control Scheme for Mobile {WiMAX} Communication", BOOKTITLE="11th IEEE International Conference on Communication Systems 2008", ADDRESS="Guangzhou, P.R. China", PAGES="1647-1651", DAYS=19, MONTH=nov, YEAR=2008, KEYWORDS="WiMAX communication; vehicular speed; throughput, bit error rate, error control", ABSTRACT="The IEEE 802.16 standard, also known as WiMAX, has emerged as an exciting wireless communication technology to offer high throughput and support high bandwidth demanding applications. WiMAX however, has yet to prove its effectiveness when the end terminals are not static and free to move at vehicular speeds. Recent studies suggest that while WiMAX (802.16e) is capable to deliver a data rate up to 75 Mb/s for fixed wireless communications, data rate decreases drastically for mobile wireless communications, often providing a data rate less than 1 Mb/s when the mobile nodes travel at vehicular speeds. High bit error rate caused by multipath fading at high vehicular speeds, is a key reason for low throughput at high speeds. Standard error control mechanism like transmission control protocol (TCP) has limited and often detrimental impacts on overall throughput because of the excessive retransmission overheads. Forward error correction (FEC) mechanism that eliminates the need for retransmission is more suitable in this environment. Adaptive FEC schemes that adjust the size of FEC code (i.e., extra bits) according to received packer error rate at the receiver end is an enhancement over standard FEC scheme that uses fixed code size. Existing adaptive FEC schemes work in a reactive fashion as they adjust code size only when packet errors experienced at the receiver end are reported back to the sender. Existing adaptive schemes, therefore, have limited efficiency when the end terminal moves at vehicular speeds because some packets are already lost before the sender is notified and the code size is adjusted. Frequent feedback packets also reduce the actual data transmission capacity in an already tight scenario at high vehicular speeds. In this paper, we propose a proactive FEC scheme that adjusts the FEC code size based on the estimated bit error rate at various vehicular speeds. We propose a mathematical model to estimate the bit error rate in WiMAX communication. We then propose a FEC scheme to proactively compute the FEC code size. We simulated the proposed scheme for a centralized video surveillance system in a public train where the train is the mobile node and sends real-time video data to the base stations. The results show that the proposed scheme achieves significantly higher throughput and lower jitter compared to existing schemes." } @INPROCEEDINGS{Ahma0000:Query, AUTHOR="Mnir Ahmad and Muhammad Abdul Qadir and Abdul Rind", TITLE="Query Matching Algorithm over Relational Databases with Semantic Cache", BOOKTITLE="Mosharaka International Conference on Communications, Networking and Information Technology", ADDRESS="Amman, Jordan", DAYS=5, MONTH=dec, YEAR=2008, KEYWORDS="Query Matching", ABSTRACT="Data access latency can be reduced for databases by using caching. Semantic caching enhances the performance of normal caching by locally answering the partially overlapped queries. Efficient query processing and cache management are major challenges for semantic caching. Semantic caching demands efficient, correct and complete algorithms to process incoming queries. One of the challenges is efficient query matching for semantic cache. So to make the query processing efficient there is a need to make the process of query matching accurate and effective. In this paper, we have proposed an algorithm for query matching with hierarchal content matching scheme. Comparison of proposed algorithm with existing algorithm is provided. On the basis of comparison and runtime complexity we have concluded that proposed query matching algorithm has small runtime complexity for matching contents of queries with stored semantic. As well as proposed algorithm is capable to stop the useless processing as was done in the previous algorithms." } @INPROCEEDINGS{Ahma0800:Receive, AUTHOR="Javad Ahmadi-Shokouh and S. Hamidreza Jamali and Safieddin Safavi-Naeini", TITLE="Receive Soft Antenna Selection for {Spatial-Multiplexing} {MIMO} Systems in {Interference-Dominated} Channels", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, KEYWORDS="MIMO systems, Fading Channels, Information Theory, Array Signal Processing, Antenna Selection,", ABSTRACT="In this paper, we find the optimum Soft Antenna Selection (SAS) whichmaximizes themutual information for theMultiple- Input Multiple-Output (MIMO) spatialmultiplexing transmission in an interference-limited channel. In this optimization problem, a 2-Dimensional (2D) directive interference model is used. We first find an optimal solution for SAS without applying any constraint on it and then propose a sub-optimal solution for the case when a phase-shift-only Passive Linear Network (PLN) is used used to implement the SAS method. Moreover, we compare the performance of the SAS method against a full-complexity MIMO system in the presence of above modeled interference through a simulation study." } @INPROCEEDINGS{Ahma0800:Switch, AUTHOR="Javad Ahmadi-Shokouh and S. Hamidreza Jamali and Safieddin Safavi-Naeini and Gholamreza Rafi", TITLE="Switch Loss and Antenna Directivity Effects on {MIMO} Antenna Selection", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, KEYWORDS="MIMO systems, Fading Channels, Array Signal Processing, Antenna Selection, Passive Beamforming, Diversity Methods", ABSTRACT="In this paper, we study the effect of antenna directivity on Multi-Input-Multi-Output (MIMO) antenna selection. A 4 orthogonal pattern antenna array platform at the receiver side associated with an antenna selection mechanism is used in this study. The performance of the proposed method is evaluated for two cases where the antenna selection switches are located either after or before Low Noise Amplifiers (LNA), on a MIMO system under the diversity transmission. The results show how the antenna directivity and switch loss can affect the overall MIMO system performance." } @INPROCEEDINGS{Ahma0805:Approach, AUTHOR="Mahmood Ahmadi", TITLE="An Approach for Optimal Bandwidth Allocation in Packet Processing Systems", BOOKTITLE="Sixth Annual Conference on Communication Networks and Services Research", ADDRESS="Halifax, Nova Scotia, Canada", DAYS=5, MONTH=may, YEAR=2008, ABSTRACT="The increasing demand for more bandwidth and the increased application variety fuel the need for high performance network processors. Typically, a network processor consists of a parallel processor core with a number of memory interfaces and special co-processors. Recently, distributed architectures are being utilized in the design of network processors. In such environments, a challenging problem is to allocate optimal bandwidth between different network processors (NPs) to achieve more performance. In this paper, the formulation and solution of an optimal bandwidth allocation strategy using queuing network for NP-based architectures at system level is proposed. The solution allocates optimal bandwidth between network processors in grid-oriented environment. It derives a new formula based on optimal capacity allocation concept in queuing network. The simulation results show that the proposed strategy is able to enhance response time in NP-based architecture when compared to a same NP-based architectures without optimal bandwidth allocation." } @INPROCEEDINGS{Ahma0806:Effects, AUTHOR="Roozbeh Ahmadi and Muthukumaran Packirisamy and Javad Dargahi", TITLE="Effects of {Squeezed-Film} Damping on Dynamic Vibration Response in {Micro-Cantilever} Structures", BOOKTITLE="Canadian Society for Mechanical Engineers Forum 2008", ADDRESS="Ottawa, Ontario, Canada", DAYS=5, MONTH=jun, YEAR=2008, KEYWORDS="Squeeze Film Damping, Free and Forced Vibrations, Micro-cantilever, MEMS, Fluid-Structure Interaction, Finite Element Analysis", ABSTRACT="Considering the squeezed-film air damping effect on the moving parts of Micro-Electro-Mechanical-Systems (MEMS) is crucial in many applications, especially where gap damping properties are important in fluid-structure interactions. For example, gap damping parameters are very important in MEMS devices, in which a micro-cantilever bends with high frequency while there is a thin air film between the substrate and micro-cantilever. As a result, squeeze film air damping could be a critical aspect of many MEMS sensors, and actuators. This paper presents the numerical analysis of squeezed-film air damping effect on vibrations of micro-cantilevers. Using COMSOL package, the finite element analysis (FEM) has been employed for two-dimensional (2D) modeling of the fluid-structure interaction by using weak formulations of the Reynolds equation which is coupled to the lower surface of micro-cantilever where there is a thin air layer between that lower surface and substrate. The effects of different parameters such as air gap thickness, cantilever’s dimensions, ambient pressure, and fluid’s viscosity on squeeze film damping phenomena are presented." } @INPROCEEDINGS{Ahma0806:Performance, AUTHOR="Rizwan Ahmad and Fu-Chun Zheng and Micheal Drieberg and Sverrir Olafsson", TITLE="Performance Evaluation of Enhanced {Relay-Enabled} Distributed Coordination Function", BOOKTITLE="14th European Wireless Conference 2008", ADDRESS="Prague, Czech Republic", DAYS=22, MONTH=jun, YEAR=2008, ABSTRACT="In this paper we evaluate the performance of our earlier proposed Enhanced relay-enabled Distributed Coordination Function (ErDCF) for wireless ad hoc networks. The idea of ErDCF is to use high data rate nodes to work as relays for the low data rate nodes. ErDCF achieves higher throughput and reduced energy consumption compared to IEEE 802.11 Distributed Coordination Function (DCF). This is a result of: 1) using relay which helps to increase the throughput and lower overall blocking time of nodes due to faster dual hop transmission, 2) using dynamic preamble (i.e. using short preamble for the relay transmission) which further increases the throughput and lower overall blocking time and also by 3) reducing unnecessary overhearing (by other nodes not involved in transmission). We evaluate the throughput and energy performance of the ErDCF with different rate combinations. ErDCF (11,11) (i.e. R1=R2=11 Mbps) yields a throughput improvement of 92.9\% (at the packet length of 1000 bytes) and an energy saving of 72.2\% at 50 nodes." } @INPROCEEDINGS{Ahma0809:Intelligent, AUTHOR="Syed Zubair Ahmad and Muhammad Abdul Qadir and Muhammad Saeed Akbar", TITLE="Intelligent Resource Management Through Reliable Transport of Mobility Related Services for Vertical Handovers", BOOKTITLE="The 11th International Symposium on Wireless Personal Multimedia Communications", ADDRESS="Saariselkä, Lapland, Finland, Finland", DAYS=8, MONTH=sep, YEAR=2008, KEYWORDS="Mobility Services, Transport Service; Resource Management; Seamless Mobility; Quality of service", ABSTRACT="Multi-mode hand-held devices are forecasted as major source of connectivity in rapidly evolving heterogeneous wireless network environment. In such environment, efficient utilization of both radio and computing resources is a complex problem and requires comprehensive design for optimum performance and service provisioning. Load-balancing in heterogeneous wireless networks, is one important aspect that can maximize quality of service provisions under varying load of multimode devices. In this paper, a light-weight protocol for transport of mobility related services has been presented to exchange dynamically changing link and computing resource conditions and achieve optimized vertical handover, in favor of a network that possesses sufficient resources to service a specific ongoing session. Simulation results show significant improvement in QoS compliance and performance optimization as compared to other handover strategies. These results provide sufficient support for use of such services to achieve better mobility management in heterogeneous wireless networks." } @INPROCEEDINGS{Ahma0809:Study, AUTHOR="Ahmad Ahmad and Aroua Biri and Hossam Afifi", TITLE="Study of a new physical layer encryption concept", BOOKTITLE="4th IEEE International Workshop on Wireless and Sensor Networks Security (IEEE WSNS 2008)", ADDRESS="Atlanta, Georgia, USA", DAYS=29, MONTH=sep, YEAR=2008, KEYWORDS="AES, Error coding, OFB mode, Physical layer security, wireless networks", ABSTRACT="Physical layer encryption is taking a significant importance in securing wireless networks. In this paper, an efficient physical layer encryption is proposed. It relies on the implementation of OFB mode just after the error coding process. The significant advantage of this implementation is that it hides the entire MAC frame. In order to reduce the overhead power consumption at the receiver, an identification mechanism is presented. This security solution is valuable in terms of location privacy and attack prevention. The provided results in this paper prove that this solution does not have any influence on the encoder/decoder functionalities." } @INPROCEEDINGS{Ahma0809:TDMA, AUTHOR="Zeeshan Ahmad and Aitor {del Coso} and Christian Ibars", TITLE="{TDMA} Network Design using {Decode-and-Forward} Relays with Finite Set Modulation", BOOKTITLE="IEEE PIMRC 2008 Fundamentals \& PHY Track", ADDRESS="Cannes, France", DAYS=15, MONTH=sep, YEAR=2008, KEYWORDS="Relaying, decode-and-forward, TDMA", ABSTRACT="This paper studies the uplink channel of a time division multiple access (TDMA) cellular network assisted by wireless relays. Aiming at increasing the network´s transmission rate, we optimally place multiple decode-and-forward (D\\&F) relays within every cell. In the first part of the contribution, we consider the relays transmitting Gaussian codewords. Results show that there is almost 39\\% gain in the transmission rate of each cell with respect to no relaying. Inthe second part, we analyze the performance impact of finite set modulation at user and relays (\textit{i.e.} M-PAM) . With such a modulation, the gain is slightly decreased to 27\\%. Finally, we show that D\\&F relaying provides large gains in the transmission rate at the edge of the cell, with similar performance for Gaussian and M-PAM modulation." } @INPROCEEDINGS{Ahma0810:Real, AUTHOR="Syed Zubair Ahmad", TITLE="{Real-Time,} Distributed, {QoS} Provisioned Resource Management Scheme for Multimedia Applications in Heterogeneous Wireless Networks", BOOKTITLE="4th ACM International Workshop on QoS and Security for Wireless and Mobile Networks", ADDRESS="Vancouver, British Columbia, Canada", DAYS=27, MONTH=oct, YEAR=2008, KEYWORDS="Resource management; Mobility services; Vertical handover; load-balancing; Transport of Mobility Services", ABSTRACT="Quality of Service provisioning in heterogeneous wireless network environment is a complex process and requires comprehensive management strategy to find workable solution. Call-drop during handover, and Call-block due to non-availability of resources at call-admission, account for two important parameters that require critical-composition to achieve real-time QoS provisions for mobile sessions. In this paper we present a virtual configuration based resource management scheme that uses low overhead transport service to exchange resource availability at collocated networks, to maintain predictive resource list for optimal resource utilization. In the presence of reliable statistical information of call duration, much higher resource utilization is achieved through resource virtualization. Results show that much higher call admission rates are achieved by aggregating virtual resource allocation and load balancing approach." } @INPROCEEDINGS{Ahma0811:Carrier, AUTHOR="Mohammad Taghi Ahmadi and Ismail Saad and Razali-utm-email Ismail and Vijay Arora", TITLE="Carrier Velocity in Carbon Nano Tube Field Effect Transistor", BOOKTITLE="2008 IEEE International Conference on Semiconductor Electronics", ADDRESS="Johor Bahru, Malaysia", DAYS=25, MONTH=nov, YEAR=2008, KEYWORDS="Carrier Transport,Carbon Nanotube ,CNTFET,One dimensional device", ABSTRACT="The fact that there are no dangling bond states at the surface of CNT allows for a wide choice of gate insulators .There fore the CNT are being considered as viable candidates for high-speed applications. The mobility and saturation velocity are the two important parameters that control the charge transport in a conducting MOSFET channel. It is shown that the high mobility does not always lead to higher carrier velocity. The ultimate drift velocity in Carbon Nanotube due to the high electric-field streaming are based on the asymmetrical distribution function that converts randomness in zerofield to streamlined one in a very high electric field. The limitation drift velocity is found to be appropriate thermal velocity for nondegenerate regime, increasing with the temperature, but independent of carrier concentration. However, the limitation drift velocity is the Fermi velocity for degenerate regime increasing with carrier concentration but independent of the temperature." } @INPROCEEDINGS{Ahma0811:Congestion, AUTHOR="Mohammad Ahmad and Damla Turgut", TITLE="Congestion avoidance and fairness in wireless sensor networks", BOOKTITLE="IEEE Globecom 2008 Ad Hoc, Sensor and Mesh Networking Symposium", ADDRESS="New Orleans, LA, USA", DAYS=30, MONTH=nov, YEAR=2008, ABSTRACT="Designing a sensor network congestion algorithm is a challenging task due to the application specific nature of these networks. The frequency of event sensing is a deciding factor in the occurrence of congestion. Numerous sensors, simultaneously transmitting data, increase the probability of packet drops due to congestion close to the base station(s). In this paper, we propose a novel distributed congestion avoidance algorithm which uses the ratio of the number of downstream and upstream nodes along with available queue sizes of the downstream nodes to detect incipient congestion. Monitoring queue sizes of candidate downstream nodes helps ensure effective load balancing and fairness in our avoidance algorithm. Through simulation studies we observe a greater packet delivery ratio and higher network lifetime in comparison with other prevalent mechanisms." } @INPROCEEDINGS{Ahma0811:Memory, AUTHOR="Mahmood Ahmadi and Stephan Wong", TITLE="A Memory-optimized Bloom Filter using An Additional Hashing Function", BOOKTITLE="IEEE Globecom 2008 Next Generation Networks, Protocols, and Services Symposium", ADDRESS="New Orleans, LA, USA", DAYS=30, MONTH=nov, YEAR=2008, KEYWORDS="Bloom filter, network processor, packet processing, universal hashing function", ABSTRACT="A Bloom filter is a simple space-efficient randomized data structure for representing a set in order to support membership queries. In recent years, Bloom filters have increased in popularity in database and networking applications. In this paper, we introduce a new approach to optimize memory utilization for regular Bloom filters that we call Bloom filter with an additional hashing function (BFAH). The regular Bloom filter stores items from a set k times at locations pointed by addressed that are the result of the k hashing functions. The additional hashing function is utilized to select only one out of the k generated addresses. Consequently, it is no longer needed to store the k-1 redundant copies. In addition, we present the insert and search operations for both the regular and the counting Bloom filter and we present the delete operation for the counting Bloom filter. We implemented our approach in a software packet classifier based on tuple space search with the H3 class of universal hashing functions. Our results show that our approach is able to reduce the number of collisions when compared to a regular Bloom filter." } @INPROCEEDINGS{Ahma0811:Modelling, AUTHOR="Mohammad Taghi Ahmadi and Javad Karamdel and Razali-utm-email Ismail", TITLE="Modelling of the {Current-Voltage} Characteristics of a Carbon Nano Tube Field Effect Transistor", BOOKTITLE="2008 IEEE International Conference on Semiconductor Electronics", ADDRESS="Johor Bahru, Malaysia", DAYS=25, MONTH=nov, YEAR=2008, KEYWORDS="CNTFET,carbon nanotube,CNTFET modelling,CNTFET I-V characteristic", ABSTRACT="Abstract- Working on carbon nanotube field effect transistors (CNTFETs) involving the skill to treat electronic devices at the molecular scale. Nanotubes are being considered as the best candidates for highspeed applications. The charge transport in CNTs is controlled by mobility and saturation velocity. It has also been shown that the high mobility does not always lead to higher carrier velocity. In the high electric field, velocity vectors are changed from randomness to streamline. Velocity approach is applied to the modelling of the current-voltage characteristic of a carbon nanotube field effect transistor. According to the simulation results, in the absence of the quantum capacitance, the short channel effects are arising. However it is foreseeable that if the quantum capacitance takes into consideration, this effect can be improved." } @INPROCEEDINGS{Ahma0811:TIME, AUTHOR="Handie Ahmataku and Ling Hock", TITLE="{TIME} {AND} {COST} {REDUCTION} {FOR} {45} {NOTCH} {ORIENTED} {<100>} {SILICON} {SUBSTRATE} {SAMPLE} {PREPARATION}", BOOKTITLE="2008 IEEE International Conference on Semiconductor Electronics", ADDRESS="Johor Bahru, Malaysia", DAYS=25, MONTH=nov, YEAR=2008, ABSTRACT="Common method for sample preparation on 45 degree notch oriented <100> silicon substrate requires cleaving followed by polishing technique. To prevent surface damage during polishing, top layer capping using epoxy cover-glass is required. A faster technique named as ‘Superman’ method involves only cleaving has been proposed." } @INPROCEEDINGS{Ahma0812:Classification, AUTHOR="Norashikin Ahmad and Damminda Alahakoon and Rowena Chau", TITLE="Classification of Protein Sequences using the Growing {Self-Organizing} Map", BOOKTITLE="2008 4th International Conference on Information and Automation for Sustainability", ADDRESS="Galle Face Hotel, Sri Lanka", DAYS=12, MONTH=dec, YEAR=2008, KEYWORDS="protein sequence; self-organizing map;clustering; classification; neural networks", ABSTRACT="Protein sequence analysis is an important task in bioinformatics. The classification of protein sequences into groups is beneficial for further analysis of the structures and roles of a particular group of protein in biological process. It also allows an unknown or newly found sequence to be identified by comparing it with protein groups that have already been studied. Artificial neural networks have been widely used in solving problems in many areas including protein sequence classification. The unsupervised neural networks such as Self-Organizing Map (SOM) has some advantages over the supervised methods as it does not require examples in its learning process. SOM also can construct a non-linear projection of complex and high-dimensional input signal into a low dimensional map which at the same time provides the visualization of the cluster grouping. In this paper, we present the use of Growing Self-Organizing Map (GSOM), an extended version of the Self-Organizing Map (SOM) in classifying protein sequences. Unlike SOM which has a fixed structure, GSOM provides the ability to grow nodes to better represent the discovered patterns. With spread factor (SF) parameter, the growth or spread of the map can be controlled thus giving an analyst a flexibility to analyze the resulting clusters at different granularities. This study focuses on two aspects; analysis of the effect of spread factor parameter in the GSOM to the node growth and the identification of grouping and subgrouping under different level of abstractions by using the spread factor. In this paper, we have shown that GSOM is capable of discovering knowledge in protein sequences. The results of the study indicate that GSOM can be used to classify protein sequences and identify the grouping as well as subgrouping from the protein sequences. The formation of groups under different level of abstractions can be achieved by changing the spread factor value. GSOM also require less processing time and provides better visualization of the data which make it a valuable tool in biological data analysis." } @INPROCEEDINGS{Ahma0812:Improved, AUTHOR="Iftekhar Ahmad", TITLE="An Improved {FEC} Scheme for Mobile Wireless Communication at Vehicular Speeds", BOOKTITLE="Australasian Telecommunication Networks and Applications Conference 2008", ADDRESS="Adelaide, South Australia, Australia", DAYS=7, MONTH=dec, YEAR=2008, KEYWORDS="Mobile communication, vehicular speeds, throughput", ABSTRACT="WiMAX has emerged as a promising wireless communication technology with potential to deliver high throughput and guaranteed quality of service to the end applications. Recent studies suggest that while WiMAX (802.16e) is capable of delivering a data rate of up to 75 Mbps for fixed wireless communications, data rate decreases drastically for mobile wireless communications, often providing a data rate less than 1 Mb/s when the mobile nodes travel at vehicular speeds. High bit error rate caused at high vehicular speeds is the key reason for low throughput. In noisy mobile communication environments, standard error control mechanisms like the transmission control protocol (TCP) has limited and often detrimental impacts on the overall throughput because of the excessive retransmission overheads. To address this issue, WiMAX standard incorporates forward error correction (FEC) mechanism that eliminates the need for retransmissions. In FEC, extra parity bits are added to the original message to recover the corrupted information. Adaptive FEC that adjusts the size of extra parity bits in response to packet retransmission requests is an enhancement over standard FEC that uses fixed block of party bits. Existing adaptive FEC schemes, however, have limited efficiency when the end terminal moves at vehicular speeds. In this paper, we propose a new FEC scheme that estimates and adjusts the size of extra parity bits to suit the chancel conditions. We apply the concept of interval based data sampling to address the dynamic nature of communication environments at high vehicular speeds. We simulate the proposed scheme for a centralized live video surveillance system in a public train where the train is the mobile node and sends real-time video data to the base stations on train platforms. The results show that the proposed scheme achieves significantly higher throughput and lower jitter compared to other standard schemes." } @INPROCEEDINGS{Ahma0812:Intelligent, AUTHOR="Iftekhar Ahmad", TITLE="An Intelligent Model to Control Preemption Rate of Instantaneous Request Calls in Networks with {Book-Ahead} Reservation", BOOKTITLE="Australasian Telecommunication Networks and Applications Conference 2008", ADDRESS="Adelaide, South Australia, Australia", DAYS=7, MONTH=dec, YEAR=2008, KEYWORDS="Quality of Service, preemption, resource reservation", ABSTRACT="Resource sharing between Book-Ahead (BA) and Instantaneous Request (IR) reservation often results in high preemption rate of on-going IR calls. High IR call preemption rate causes interruption to service continuity which is considered as detrimental in a QoS-enabled network. A number of call admission control models have been proposed in literature to reduce the preemption rate of on-going IR calls. Many of these models use a tuning parameter to achieve certain level of preemption rate. This paper presents an Artificial Neural Network (ANN) model to dynamically control the preemption rate of on-going calls in a QoS-enabled network. The model maps network traffic parameters and desired level of preemption rate into appropriate tuning parameter. Once trained, this model can be used to automatically estimate the tuning parameter value necessary to achieve the desired level of preemption rate. Simulation results show that the preemption rate attained by the model closely matches with the target rate." } @INPROCEEDINGS{Ahme0000:Bio, AUTHOR="Muna Ahmed", TITLE="Bio Inspired Intrusion Prevention and Self-healing Architecture for", BOOKTITLE="Fifth International Conference on Innovations in Information Technology", ADDRESS="Al Ain, UAE", DAYS=16, MONTH=dec, YEAR=2008, KEYWORDS="immune system; intrusion prevention; self-healing; networking security", ABSTRACT="Inspired by the immune system and multi agent system, architecture of dynamic protection immune multi-agent and self-healing system for network intrusion prevention is proposed. This paper describes the architecture of hybrid intrusion detection and prevention system (IPS) combines with a self-healing model that incorporates an artificial immune intrusion prevention system for network security. Our architecture based upon data inspired by the natural immune human system. The IPS analyzes the anomalous activities to trigger the self-healing system. The detection of the damage caused by attacks is used to start the self - healing system (SH). This system is automaton and enhances the fault repair and system recovery." } @INPROCEEDINGS{Ahme0000:Capacity, AUTHOR="Zahoor Ahmed and Jean Pierre Cances", TITLE="The Capacity of Gaussian ‘Light’ Relay Channel", BOOKTITLE="IWCMC 2008 Next Generation Mobile Networks Symposium", ADDRESS="Chania Crete Island, Greece, Greece", DAYS=6, MONTH=aug, YEAR=2008, ABSTRACT="In this paper, we derive the capacity of Gaussian degraded ‘light’ relay channel, which possesses the most practical limitation and properties of half duplex time division multiplexing. The achievability is proved by using superposition encoding and successive decoding techniques. The converse is derived using the min-cut max -flow theorem for networks with light nodes. Our work of capacity analysis shows that even with light radios, the cooperative coding is beneficial and has a capacity advantage over direct transmission" } @INPROCEEDINGS{Ahme0000:Extended, AUTHOR="Pervez Ahmed", TITLE="Extended Visual Object based Intelligent Visual Programming Environment", BOOKTITLE="2008 4th International Conference on Information and Automation for Sustainability", ADDRESS="Galle Face Hotel, Sri Lanka", DAYS=12, MONTH=dec, YEAR=2008, KEYWORDS="Visual Programming; Visual Programming Environment; Programming By Demonstration", ABSTRACT="The programming language and software development environment both affect the programmer’s productivity. Studies suggest the use of Visual Programming Languages (VPL) for preparing better and productive programmers, and it has been observed that Visual Programming Environment (VPE) that supports VPL further improves the productivity. Therefore, VPEs that support VPL are being built for software development for dedicated applications as well as for general purpose software development. The VPEs are well suited for dedicated applications development in Machine Vision, Geographical Information Systems, and distributed computing but their applicability is also explored for the general purpose software development. The research work presented in this paper focuses on the design aspects of a general purpose Visual Programming Environment (VPE). The VPE that we have designed supports: scalability and extensibility; execution persistence; straightforward implementation; and system integration at varying levels. The scalability and extensibility helps in managing the requirement volatility because it allows augmentation of new functionalities. The execution persistence guaranties that the system should not crash in algorithmic development stage. The straightforward implementation makes programmers more productive as it may reduce debugging and testing complexities and time. The system integration at varying levels may allow creation of different versions of the software to meet the changing hardware and software requirements. To meet requirements mentioned above, we employ three paradigms in our design. These paradigms are: the Programming by Demonstration (PBD), Object-Oriented Programming (OOP), and the Visual Object-Oriented Programming (VOOP). We call our visual programming environment: A Visual Object Oriented Programming Environment (VOOPE). The environment supports a programming approach in which a program is created using Extended Visual Objects (EVOs)─the objects having visual forms and dynamic behaviors. The environment allows creation of EVOs and modification of its behavior to adapt the changing software requirements. To further improve the versatility of the environment, we introduce a new concept of Extended Visual Object (EVO). An EVO is a visual object that has visual form and dynamic behavior. The dynamic behavior allows EVOs to learn the requirement changes dynamically and adapt with the changes accordingly. Hence EVOs easily fulfill the scalability and extensibility requirements. The Programming-by-Demonstration (PBD) allows capturing the visual manifestation of concepts associated with the software requirements, and in PBD environment programs are created interactively by demonstrating the concepts, thereby it allows straightforward implementation. Moreover, the PBD allows visualization of concepts while capturing them, therefore PBD ensure execution persistence. In VOOPE, a software creation process involves arranging the EVOs in a specified order visually and interactively, therefore software can be created by integrating the subsystems at varying levels of software construction hierarchy." } @INPROCEEDINGS{Ahme0000:Improving, AUTHOR="Ashraf Ahmed", TITLE="Improving Availability and Maintaining Consistency of Data in Large Scale Mobile Environments", BOOKTITLE="Fifth International Conference on Innovations in Information Technology", ADDRESS="Al Ain, UAE", DAYS=16, MONTH=dec, YEAR=2008, KEYWORDS="mobile database; optimistic replication; pessimistic replication; evenual consistency", ABSTRACT="An important challenge to database researchers in mobile computing environment is to provide a data replication solution that maintains the consistency and improves the availability of replicated data. This paper addresses this problem for large scale mobile environments. Our solution represents a new binary hybrid replication strategy, in terms of its components and approach. The new strategy encompasses two components: replication architecture to provide a solid infrastructure for improving data availability and replication method to transfer data updates in a manner that achieves the consistency of data. The new strategy is a hybrid of both pessimistic and optimistic replication approaches in order to exploit the features of each in regard to supporting higher data availability and lower rate of inconsistencies as well as supporting the mobility of users." } @INPROCEEDINGS{Ahme0000:Method, AUTHOR="Omar Ahmed and Rami Qahwaji and Tufan Colak and Thierry {Dudok de Wit} and Stan Ipson", TITLE="A New Method for Processing Solar Images to Calculate the Magnetic Energies Associated with Active Regions", BOOKTITLE="Fifth International Multi-conference on Systems, Signals, and Devices", ADDRESS="Amman, Jordan", DAYS=20, MONTH=jul, YEAR=2008, KEYWORDS="Ising model; sunspots; active regions; MDI magnetogram images", ABSTRACT="In this paper, a new method is applied to calculate the magnetic energies of active regions and sunspots in satellites images. Digital images from the Solar \& Heliospheric Observatory (SOHO) satellite are used in this study. The magnetic energies are calculated using the Ising model, which has been modified for our application. The new algorithm is integrated with our existing ASAP system (Automate Solar Activity Prediction). Extensive testing was carried out and the promising results are obtained that will aid in enhancing the accuracy of our automated real-time solar prediction system are presented." } @INPROCEEDINGS{Ahme0000:Quantitative, AUTHOR="Mohammad Salim Ahmed and Ehab Al-Shaer and Latifur Khan", TITLE="A Novel Quantitative Approach For Measuring Network Security", BOOKTITLE="The 27th IEEE International Conference on Computer Communications", ADDRESS="Phoenix, Arizona, USA", DAYS=13, MONTH=apr, YEAR=2008, KEYWORDS="Network risk evaluation; Vulnerability analysis; Attack propagation;", ABSTRACT="Evaluation of network security is an essential step in securing any network. This evaluation can help security professionals in making optimal decisions about how to design security countermeasures, to choose between alternative security architectures, and to systematically modify security configurations in order to improve security. However, the security of a network depends on a number of dynamically changing factors such as emergence of new vulnerabilities and threats, policy structure and network traffic. Identifying, quantifying and validating security metrics is a major challenge in this area. In this paper, we propose a novel security metric framework that identifies and quantifies objectively the most significant security risk factors, which includes existing vulnerabilities, historical trend of vulnerability of the remotely accessible services, prediction of potential vulnerabilities for any general network service and their estimated severity and finally policy resistance to attack propagation within the network. We then describe our rigorous validation experiments using real-life vulnerability data of the past 6 years from National Vulnerability Database (NVD) to show the high accuracy and confidence of the proposed metrics. Some previous works have considered vulnerabilities using code analysis. However, as far as we know, this is the first work to study and analyze these metrics for network security evaluation using publicly available vulnerability information and security policy configuration." } @INPROCEEDINGS{Ahme0000:Reducing, AUTHOR="Saleem Ahmed", TITLE="Reducing Sidelobes in Orthogonal Frequency Division Multiplexing Based Overlay Systems", BOOKTITLE="IFIP Wireless Days", ADDRESS="Dubai, UAE", DAYS=24, MONTH=nov, YEAR=2008, ABSTRACT="In this paper, we consider out-of-band radiations caused by high sidelobes in orthogonal frequency division multiplexing (OFDM) system. Suppression of sidelobes in OFDM system allows higher spectral efficiency and less interference with existing legacy systems in OFDM based overlay system. We combine different sidelobe suppression techniques to suppress the sidelobes in OFDM system. In this paper, the multiple-choice sequence (MCS) is combined with both cancellation carriers (CC) and subcarrier weighting (SW) techniques. Multiple-choice sequence (MCS) is applied prior to cancellation carriers or subcarrier weighting techniques. Simulation results show that combining MCS with CC and SW techniques the sidelobes in OFDM can be significantly reduced, which allow a successful co-existance between a OFDM overlay system and an existing legacy system." } @INPROCEEDINGS{Ahme0000:Study, AUTHOR="Ahsan Ahmed and Atef Fahim and Hani Naguib", TITLE="A Study Of The Mechanical Adhesion Of {Foam-Metal} Joints", BOOKTITLE="Canadian Society for Mechanical Engineers Forum 2008", ADDRESS="Ottawa, Ontario, Canada", DAYS=5, MONTH=jun, YEAR=2008, KEYWORDS="Adhesion, Foams, Joints, ANSYS, Contacts", ABSTRACT="The design of metal-polymer foam adhesion and load transfer characteristics is carried out in this research work. The metal inserts are used as the load transfer component, while the foam is used as the structural element of the system. The inserts are imbedded in the foam during the foaming process. Flexural testing was conducted on different metal foam configurations to establish the typical interaction trends. The stress-strain response and the mode of failure of the structure were documented. Rectangular, circular, and triangular (taper/wedge like) inserts were used. Results show that simple taper inserts imbedded in foam slabs perform better than the other shapes. FEA analyses of the interaction under different loads were carried out. The modeling results coincided with the experimental ones hence validating the model." } @INPROCEEDINGS{Ahme0004:Finite, AUTHOR="Nadeem Ahmed", TITLE="Finite Element Modelling and Simulation of Gun Dynamics using {‘ANSYS’}", BOOKTITLE="10th International Conference on Computer Modelling \& Simulation", ADDRESS="Cambridge, United Kingdom", DAYS=1, MONTH=apr, YEAR=2008, KEYWORDS="Finite Element, Modelling and Simulation, Gun Dynamics, ANSYS", ABSTRACT="The dynamic response of the gun during the firing cycle and the relative motion of the projectile with respect to the barrel has a significant effect on the accuracy and consistency of the gun as well as the shot launch conditions. Computer modelling techniques can be used to simulate motion of the gun during the firing cycle. A three dimensional finite element model of a large calibre gun was developed using ANSYS commercial software and its motion during the firing cycle was simulated to study and predict the effects of various design factors on the dynamic response of the gun. Physical contact conditions of the gun system components have been modelled using contact technology in ANSYS. Results are compared with general responses of the gun system obtained through available docummented sources. Effectiveness of the software for accurate modelling of gun dynamics is discussed." } @INPROCEEDINGS{Ahme0800:Beampattern, AUTHOR="Mohammed Ahmed and Sergiy Vorobyov", TITLE="Beampattern random behavior in wireless sensor networks with Gaussian distributed sensor nodes", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, KEYWORDS="Random arrays; cooperative systems; array signal processing; phased arrays.", ABSTRACT="Collaborative beamforming (CB) has been introduced in wireless sensor networks (WSNs) to increase the transmission range of sensor nodes. CB improves the power efficiency of the transmission. However, the CB beampattern is random in the sidelobe region. Therefore, it is important to characterize the power level in the sidelobe region to predict the interference to neighboring sensor node clusters. In this paper, we assume that sensor nodes in a cluster of WSN are Gaussian distributed and study the random behavior of the beampattern. To characterize the beampattern in the sidelobe region, we first model the array factor as a complex random variable and find the corresponding mean and variance. The distribution function of beampattern level and the outage probability of sidelobes is derived and compared with the corresponding characteristics resulting from uniform distributed sensor nodes." } @INPROCEEDINGS{Ahme0800:Data, AUTHOR="Ejaz Ahmed", TITLE="Data Loading and Mapping using Staging {DBMS} in the Grid", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, KEYWORDS="Data Integration; Global Schema; Staging DBMS; Staging Schema; grid;", ABSTRACT="Abstract—With the proliferation of international standards for grid-enabled databases, the need for data loading and data mapping in a large integrated environment of heterogeneous databases highlights issues of consistency and integrity. We discuss methods for providing semi-autonomous data integration by focusing on efficient data loading design and effective mapping strategies. In order to upload and integrate data from various small to large size data repositories, an intermediate staging facility is employed to temporarily store data before it is validated to ensure accurate and useful integration into the target data source. We propose a mechanism that semi-automates the integration process that includes not only new data, but legacy data as well. We expand the notation of a database management system (DBMS) to include the management of the data transfer or data transformation processes. The DBMS now must perform the task of data mapping in the form of value correspondences by using a staging schema or staging DBMS mapping procedure." } @INPROCEEDINGS{Ahme0800:Power, AUTHOR="Rehan Ahmed and Faheem Sheikh and Shahid Masud", TITLE="Power Aware Design of Superscalar Architecture for High Performance {DSP} Operations", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, KEYWORDS="power optimization; superscalar architecture; real-time digital signal processing; simplescalr; wattch", ABSTRACT="In this paper a methodology for architectural level power optimization of a superscalar processor is proposed. The optimization is targeted at high performance real-time DSP operations. Sample Rate Conversion operation in Software Defined Radios has been taken as an exemplar operation. Various superscalar configurations have been obtained through a systematic procedure. SimpleScalar architecture modeling tool has been used for simulation along with its power estimation extension - Wattch. Overall performance gain of more than 100 percent has been achieved while meeting all operating constraints." } @INPROCEEDINGS{Ahme0803:Iterative, AUTHOR="Sohail Ahmed and Robert Maunder and Lie-Liang Yang and Lajos Hanzo", TITLE="Iterative Detection of {Three-Stage} Concatenated {FFH-MFSK}", BOOKTITLE="IEEE Wireless Communications and Networking Conference", ADDRESS="Las Vegas, Nevada, USA", DAYS=31, MONTH=mar, YEAR=2008, KEYWORDS="Fast frequency hopping; Iterative Decoding; Irregular codes; variable length coding; Three-Stage Concatenation", ABSTRACT="Serially concatenated and iteratively decoded Irregular Variable Length Coding (IrVLC) combined with precoded Fast Frequency Hopping (FFH) M-ary Frequency Shift Keying (MFSK) is considered. We employ EXtrinsic Information Transfer (EXIT) charts to investigate the 3-stage concatenation of the FFH-MFSK demodulator, the rate-1 decoder and the outer IrVLC decoder. The proposed joint source and channel coding scheme is capable of operating at low Signal-to-Noise Ratio (SNR) in Rayleigh fading channels contaminated by Partial Band Noise Jamming (PBNJ). The IrVLC scheme is comprised of a number of component Variable Length Coding (VLC) codebooks employing different coding rates for encoding particular fractions of the input source symbol stream. These fractions may be chosen with the aid of EXIT charts in order to shape the inverted EXIT curve of the IrVLC codec so that it can be matched with the EXIT curve of the inner decoder. We demonstrate that using the proposed scheme an infinitesimally low bit error ratio may be achieved at low SNR values." } @INPROCEEDINGS{Ahme0805:Model, AUTHOR="Dewan Ahmed and Shervin Shirmohammadi", TITLE="Model and Measurement of State Dissemination in {MMOGs}", BOOKTITLE="International Instrumentation and Measurement Technology Conference", ADDRESS="Victoria, Vancouver Island, British Columbia, Canada", DAYS=12, MONTH=may, YEAR=2008, KEYWORDS="Massively Multiuser Online Gaming; state sharing; communications modeling and measurements", ABSTRACT="NOTE: This is a STUDENT paper (graduate) Massively Multiuser Online Game (MMOG) has become an active research area in the last couple of years especially to integrate players to perform the routing task with the intention of keeping the game deployment cost to a minimum. This paper proposes a novel state dissemination model for MMOG in the context of a hybrid P2P architecture by exploiting the idle periods of the participating players. The proposed approach performs such a task more efficiently than other traditional approaches with the identical environmental setup, for both homogeneous and heterogeneous environments. The performance of this technique is compared with popular multi-tree dissemination methods, and validates the superiority of our proposed model." } @INPROCEEDINGS{Ahme0805:Performance, AUTHOR="Irfan Ahmed and Mugen Peng and Wenbo Wang", TITLE="Performance Analysis of an {ARQ} Initialized Cooperative Communication Protocol", BOOKTITLE="Cooperative Communications and Networking, Theory, Practice, and Applications", ADDRESS="Beijing, China, P.R. China", DAYS=18, MONTH=may, YEAR=2008, ABSTRACT="We develop and analyze an ARQ (Automatic Repeat reQuest) initialized transmit diversity protocol for cooperative communications. Medium access control (MAC) layer packet retransmission limit (similar to aShortRetryLimit or aLongRetryLimit [802.11-1997]) has been used as an actuator for transmit cooperative diversity initialization. We take the channel state information (CSI) as a function of retransmission tries. Relays close to the source node are chosen for the transmit cooperation. Closed form expressions are obtained for symbol error rate (SER), outage capacity and outage probability for the proposed scheme in shadowed fading channels. This cooperative scheme achieves lower signal-to-noise ratio (SNR) values for desired symbol error rate, stumpy outage probability and high bandwidth efficiency as compared to the preceding ARQ based cooperative protocols. Finally, the results of computer simulations are included to demonstrate the efficacy of the proposed scheme and to verify the accuracy of analytical expressions." } @INPROCEEDINGS{Ahme0806:Performance, AUTHOR="Hassan Ahmed and Hossam Hassanein", TITLE="A Performance Study of Roaming in Wireless Local Area Networks Based on {IEEE} 802.11r", BOOKTITLE="24th Queen's Biennial Symposium on Communications", ADDRESS="Kingston, Ontario, Canada, Canada", DAYS=23, MONTH=jun, YEAR=2008, KEYWORDS="Fast Basic Service Set Transition; Roaming.", ABSTRACT="The wide deployment of IEEE 802.11 based wireless local area networks (WLANs), and increased interest in multimedia applications support in WLANs, have lead to the need to support real-time applications even when devices are roaming across WLAN access points (APs). This has lead to the development of the IEEE 802.11r fast roaming mechanism, in which a connection to a candidate AP is established before the loss of connectivity with the current one. In this paper, we study the performance of the IEEE 802.11r and its viability for real-time applications. Our simulation results demonstrate the flexibility of the IEEE 802.11r and the effectiveness of its roaming procedure. Also, a noticeable reduction in roaming time and delays at APs is shown to be achievable, which guarantees the required quality of service level of Voice over IP over WLAN (VoWLAN) applications." } @INPROCEEDINGS{Ahme0807:Microcell, AUTHOR="Dewan Ahmed and Shervin Shirmohammadi", TITLE="A Microcell Oriented Load Balancing Model for Collaborative Virtual Environments", BOOKTITLE="Conference on Virtual Environments, Human-Computer Interfaces and Measurement Systems", ADDRESS="Istanbul, Turkey", DAYS=14, MONTH=jul, YEAR=2008, KEYWORDS="Hotspot; Area of interest; MMOG; Load Balancing", ABSTRACT="In this paper, we present a microcell oriented load balancing mechanism in the context of hybrid MMOG (massively multiplayer online game) architecture. The objective of the proposed approach is to define a fair load balancing method for peer-to-peer MMOGs and virtual environments that minimizes peer-to-peer distortions in the overlays." } @INPROCEEDINGS{Ahme0808:Decaying, AUTHOR="Javed Ahmed and Muhammad Jafri", TITLE="Decaying Extension Based Phase Correlation for Robust Object Localization in Full Search Space", BOOKTITLE="European Conference on Signal Processing 2008", ADDRESS="Lausanne, Switzerland", DAYS=25, MONTH=aug, YEAR=2008, KEYWORDS="decaying extension, phase correlation, object localization", ABSTRACT="Phase correlation is an efficient tool for precisely localizing an object of interest in an image. However, its performance is severely deteriorated, if: (1) the images contain significant mismatch between the intensity levels of the pixels at the opposite boundaries, (2) the object in the search image is slightly rotated or scaled, or (3) the search image is significantly noisy or blurred. Some of these problems have been addressed by previous techniques, but at the cost of an spatial constraint that the object is fairly inside some central region in the search space. Therefore, we propose an efficient and effective preprocessing technique, that extends the search image and the template with new pixels having smoothly decaying values. It is demonstrated that the proposed method outperforms two recent techniques in localizing an object of interest in real images, especially when the object lies away from the central region in the search space." } @INPROCEEDINGS{Ahme0809:Cryptographic, AUTHOR="Zahoor Ahmed and Jean-Pierre Cances", TITLE="Cryptographic Spread Spectrum Relay Communication", BOOKTITLE="International Workshop on Wireless and Mobile Security", ADDRESS="Cardiff, United Kingdom", DAYS=16, MONTH=sep, YEAR=2008, KEYWORDS="spread spectrum;cryptography;relay network", ABSTRACT="Spread spectrum (SS) is a technique of secure communication, which increases resistance to natural interference and jamming, and prevent detection. If a cryptographically secure pseudo random sequence is used, the communication becomes more secure. Generally some short pseudo-random sequences are used in Spread spectrum. In this paper we present a technique of signal hiding where we use non secret communication and a secret Spread spectrum communication. We present a class of relay channel with orthogonal components for transmission of our proposed SS communication" } @INPROCEEDINGS{Ahme0809:Performance, AUTHOR="Nadeem Ahmed and Mark Rutten and Travis Bessell and Alex Dong and Salil Kanhere and Neil Gordon and Sanjay Jha", TITLE="Performance Evaluation of a Wireless Sensor Network Based Tracking System", BOOKTITLE="The Fifth IEEE International Conference on Mobile Ad-hoc and Sensor Systems", ADDRESS="Atlanta, GA, USA", DAYS=29, MONTH=sep, YEAR=2008, KEYWORDS="Detection and Tracking;Particle Filter;Simulations;Experiments", ABSTRACT="In this paper, we present a comprehensive analysis of the performance of a wireless sensor network based target tracking system using the Particle Filter. In particular, we evaluate the effect of various network design parameters such as the number of nodes, number of generated particles, and sampling interval on the tracking accuracy and computation time of the tracking system. Based on our analysis, we also present recommendations on suitable values for the relevant network design parameters, which provide a reasonable trade-off between accuracy and computational expense for this problem. In addition, we also analyze the theoretical Cramer-Rao bound as the benchmark for the best possible tracking performance. We demonstrate that the results for our simulations closely match the theoretical bounds. We also present initial results from experiments comprising of a 25 node wireless sensor network. Initial experimental results are promising and show that the PF based estimtion is suitable for detection and tracking using inexpensive wireless sensor network devices." } @INPROCEEDINGS{Ahme0809:Simple, AUTHOR="Khondker Ahmed", TITLE="a simple {ESR} mesurement technique for capacitor using {DC-DC} booster", BOOKTITLE="IEEE AUTOTESTCON 2008", ADDRESS="Salt Lake City, UT, USA", DAYS=8, MONTH=sep, YEAR=2008, KEYWORDS="esr; capacitor; stability; booster", ABSTRACT="This paper proposes a simple technique to measure the equivalent series resistance (ESR) of a capacitor. This method uses a switching DC-DC boost regulator to measure the ESR. This method is very simple in technique and consumes very little time." } @INPROCEEDINGS{Ahme0810:Auxiliary, AUTHOR="Dewan Ahmed and Shervin Shirmohammadi", TITLE="An Auxiliary Area of Interest Management for Synchronization and Load Regulation in Zonal {P2P} {MMOGs}", BOOKTITLE="International Workshop on Haptic Audio-Visual Environments and Games", ADDRESS="Ottawa, Ontario, Canada", DAYS=18, MONTH=oct, YEAR=2008, KEYWORDS="Area of Interest; Load; Hotspot; MMOG; P2P; Synchronization; Zone crossing", ABSTRACT="For better gaming experience, this paper proposes an auxiliary area of interest management (AoIM) in zonal MMOGs that works in P2P manner. The concept, named Synchronized AoIM (S- AoIM), ensures synchronization to the system. The S-AoIM runs along with the general/primary area of interest management (G-AoIM) that provides most of the game services. The benefits are two-fold. First, the necessary data required for seamless zone crossing, a usual phenomenon in zonal MMOGs, is readily available from S-AoIM. Second, the anticipated model can also be tuned as a means against hotspot or excess load. Thus, the overall design supports synchronization and regulates load of zonal MMOGs." } @INPROCEEDINGS{Ahme0811:Analytical, AUTHOR="Imtiaz Ahmed and Shankhanaad Mallick", TITLE="Analytical Performance Evaluation of an {OFDM} System in the Presence of Carrier Frequency Offset, Phase Noise and Timing Jitter", BOOKTITLE="IEEE Region 10 Conference", ADDRESS="Hyderabad, Andhra Pradesh, India", DAYS=18, MONTH=nov, YEAR=2008, KEYWORDS="OFDM, Carrier Frequency Offset, Phase Noise, Timing Jitter, ICI, SINR, BER", ABSTRACT="This paper proposes an analytical performance evaluation of an Orthogonal Frequency Division Multiplexing (OFDM) under the combined influence of Carrier Frequency Offset (CFO), phase noise and timing jitter. An exact closed form expression for the Signal-to-Interference-Noise Ratio (SINR) is derived and the combined effects of these synchronization impairments are exhibited by expressing the OFDM system performance as a function of its critical parameters. Analysis show that OFDM is more sensitive to phase noise than CFO and timing jitter and the performance degradation also depends on the system parameters." } @INPROCEEDINGS{Ahme0811:IMPLEMENTATION, AUTHOR="Khondker Ahmed and Mustafa Ryadh and Mohammad {Moakhkhrul Islam}", TITLE="{IMPLEMENTATION} {OF} {PSEUDO-QUADRATIC} {SLOPE} {COMPENSATION} {CIRCUIT} {FOR} {PWM} {PEAK} {CURRENT} {MODE} {BOOST} {REGULATOR}", BOOKTITLE="2008 IEEE International Conference on Semiconductor Electronics", ADDRESS="Johor Bahru, Malaysia", DAYS=25, MONTH=nov, YEAR=2008, KEYWORDS="pseudo quadratic slope compensation, stability, switching boost regulator", ABSTRACT="Current Mode PWM boost regulator is considered as an important integrated circuit for many low power mobile applications. Although current mode design offers many advantages over voltage mode design, one of the major problems of the design scheme is the inherent sensitivity to current disturbance while operating at a duty cycle greater than 50\% [1]. The current disturbance which grows cycle by cycle if not compensated and makes the IC unstable. The compensation, commonly known as slope compensation, is theoretically expected to be non-linear with respect to duty cycle. This paper presents a circuit implementation to fulfill the demand of the non-linear slope compensation to improve stability in a switching current mode boost converter. The circuit is implemented by regular threshold voltage NMOS and PMOS and standard on-chip pF range capacitor biased by a PTAT current. Using the quadratic nature of the drain current of a MOS device in saturation the circuit generates a compensating slope signal on a cycle by cycle basis and this compensating slope signal is added with the current sense signal to compensate the disturbance that might arise. The quadratic slope generating current is added to a fixed current signal and the summed up current is then used to charge an on-chip capacitor. The capacitor is discharged at the end of each cycle and starts charging up by the dc-shifted quadratic current at the beginning of each cycle. The reason for adding a fixed current to the quadratic one is to provide a fixed amount of slope compensation at lower duty cycle. Without the additional fixed current compensation at lower duty cycle when the quadratic slope generating current might be too low to provide minimum amount of compensation at lower duty cycle and the chip might go unstable. The slope compensation which is added by the fixed current provides a shield against noise at lower duty and remains the chip in stable region. The instability due to poor compensation at lower duty is shown in Fig.1(a) and instability due to poor compensation at higher duty is shown in Fig.1(b). Another important reason is to compensate the loss for base current in lateral PNP based differential gain stage which takes the slope signal as input. The base current effect can also be nullified by using a CMOS differential gain stage. A current mode boost regulator is fabricated with the proposed slope compensation circuit in 0.5µm technology. The slope compensation signal is tested and measured. Moreover, the complete stability analysis is done on board level with the fabricated chip. The booster is found to be stable from duty cycle as low as 15\% to as high as 85\%. Corresponding oscilloscope snaps are shown in Fig.2(a) and Fig.2(b). The wide stable operating range is a significant evidence of better performance of the pseudo quadratic slope compensation circuit. Reference: [1] “Current Mode Control” Technical Paper 05, Venable Industries Inc." } @INPROCEEDINGS{Ahme0811:Simulation, AUTHOR="Abdelaziz Ahmed and John Dennis and Mohamad Naufal {Mohamad Saad}", TITLE="Design and Simulation of a High Temperature {MEMS} Micro-hotplate for Application in Trace Gas Detection", BOOKTITLE="2008 IEEE International Conference on Semiconductor Electronics", ADDRESS="Johor Bahru, Malaysia", DAYS=25, MONTH=nov, YEAR=2008, KEYWORDS="Micro-hotplate, MEMS, CoventorWare, Microsenor, Trace Gas detection", ABSTRACT="Extended Abstract: The micro-hotplate (MHP) is a basic MEMS (Micro Electromechanical Systems) structure used as building block for metal oxide gas sensors as well as other applications. These micro-hotplates significantly reduce the power consumption required to operate at elevated temperatures (200oC – 500oC) in order to enable the thin film sensors detect various types of trace gases in the ambient environment. A micromachined sensor with a micro-hotplate that can withstand higher temperatures in the range of 500oC – 800oC would make it possible to utilize an important range of solid state materials that require these elevated temperatures to perform efficiently as the sensing layer of the MHP. In order to operate at these elevated temperatures, there is need to carefully select the dielectric membrane layer, heater materials and a plate for uniform temperature distribution on the membrane. In this paper the effect of varying the thickness of the silicon nitride (Si3N4) membrane of the MHP on the temperature and displacement of the membrane and on the power consumption of the MHP at elevated temperatures is simulated and evaluated using CoventoreWare FEM software. CoventorWare is one of the most comprehensive suites of MEMS design and simulation tools in the industry. It acts as a design environment that reduces design risk, speeds time-to-market and lowers development costs. Electro-thermo-mechanical solver (MemMech) module in the CoventorWare is used to simulate the temperature and displacement of the MEMS micro-hotplate. This solver computes the electrical potential field, thermal, and displacement distributions resulting from an applied voltage through a resistive heater. The micromachined MHP structure is designed on single side p-type [100] silicon wafer as the substrate with a thickness of 300 µm and 400 µm x 400 µm area. SiO2 layer of 0.5 µm thickness is deposited on the silicon substrate followed by silicon nitride (Si3N4) layer. A portion of the Si3N4 layer is then isolation using negative photoresist etching to form a membrane of 100 µm x 100 µm area supported by four microbridges of 113 µm length and width of 20 µm. Several Si3N4 layes of various thicknesses from 0.3 µm to 3 µm are deposition on the SiO2 layer in order to investigate the effect of thickness on the thermal, electrical and mechanical properties of the support membrane of the MHP. A 0.5 µm thick SiO2 layer is deposited on the Si3N4 layer followed by a platinum metal layer with a thickness 0.2 µm, length of 800 µm and width of 5.0 µm that forms a meandering heating element. SiO2 with 0.8 µm thickness is next deposited as planner fill on top of the platinum heating element followed by a silicon carbide (SiC) layer of thickness 0.2 µm that acts as a heat distributor to maintain uniform temperature on the membrane. Finally, SiO2 of 0.5 µm thickness is deposited on the SiC layer. KOH anisotropic etching of the back-side of the Si wafer is then carried out as a post processing step to isolate the membrane area that will be heated by the Pt resistor from the Si substrate and thus reduce heat dissipation to the substrate. The SiO2 layer below the Si3N4 membrane is also removed. The actual fabrication process is defined in the Process Editor (PE) in the Designer part of the software. Materials, thickness of the layers and masks polarity were also defined in PE. Material properties were defined globally in Material Property Database (MPD). Based upon this process, mask layouts were made in Layout Editor (LE). 3D models were then built based on the mask layout, process sequences, and layer thicknesses using Preprocessor. Tetrahedron mesh is applied to the solid model. Si, Si3N4 and SiO2 layers are meshed with a 80 µm element size. A fine 5 µm element size mesh is however used for the platinum heater and SiC layer in order to obtain accurate FEM simulation results at these layers where the heating takes place. After meshing in preprocessor, the device was analyzed in Analyzer. Full 3D geometrical models were generated with exact dimensions of the micro-hotplates for all the designs. Simulation results indicate that when 1.0 V is applied between the terminals of the platinum heater, increasing the thickness of the supporting membrane (Si3N4) from 0.3 µm to 3 µm results in an exponential decrease in temperature of the MHP from 1227°C to 297°C while the displacemnt changes from 7.7 µm to 0.85 µm. Therefore in order to maintain the operating temperature at a nominal value of 727°C it is required to increase the applied voltage from 0.77 V to 1.7 V while the thickness of the membrane is increased from 0.3 µm to 3 µm. Thus the power consumption of the MHP increases from 7.1 mW to about 34.4 mW as the membrane thickness is increased, while the mechanical displacement of the membrane remains constant at about 5.8 µm. Another interesting observation is that as the thickness of the membrane is increased from 0.3 µm to 3 µm the temperature on the Si substarate increases linearly from about 72°C to 250°C. These observations indicate that it is possible to manipulate the thickness of the MHP membrane to optimize the power consumption while reducing the mechanical deflection of the membrane to tolerable limits and thus prevent mechanical failure of the membrane. It is also demonstrated that when the MHP is designed with a SiC heat distributor inserted above the SiO2 layer on top of the heater, the uniformity of the temperature on the membrane is improved as compared to a membrane without SiC." } @INPROCEEDINGS{Ahme0812:Cluster, AUTHOR="Ghufran Ahmed and Noor Khan and Zubair Khalid and Rodica Ramer", TITLE="Cluster Head Selection Using Decision Trees for Wireless Sensor Networks", BOOKTITLE="2008 Fourth International Conference on Intelligent Sensors, Sensor Nertworks and Information Processing", ADDRESS="Sydney, Australia", DAYS=15, MONTH=dec, YEAR=2008, KEYWORDS="Wireless Sensor Network; Network clustering", ABSTRACT="Wireless Sensor Network (WSN) is the hot research topic in the civil as well as military applications. Researchers are working in this area to boost it up according to the current needs and requirements. An efficient way to enhance the lifetime of the WSN is to partition the network into distinct clusters with a high-energy node called gateway as cluster-head. In this paper we present the cluster head selection scheme based on four major factors. We are using decision tree algorithm to select the best node as a cluster head. Simulation results show that the performance of this scheme is better than the cluster head selection using both the AHP (Analytical Hierarchy Process) and the LEACH (Low Energy Adaptive Clustering Hierarchy)." } @INPROCEEDINGS{Ahme0812:CSOLAP, AUTHOR="Taher Ahmed", TITLE="{CSOLAP} (Continuous Spatial {On-Line} Analytical Processing)", BOOKTITLE="Fifth International Conference on Innovations in Information Technology", ADDRESS="Al Ain, UAE", DAYS=16, MONTH=dec, YEAR=2008, KEYWORDS="CSOLAP;GIS; Multidimensional Models, SOLAP", ABSTRACT="Decision support systems are usually based on multidimensional structures. Dimensions are the axes of analysis and form a space where a fact is located by a set of coordinates at the intersections of members of dimensions. Conventional multidimensional structures deal with discrete facts linked to discrete dimensions. However, when dealing with natural continuous phenomena the discrete representation is not adequate. There is a need to integrate spatiotemporal continuity within multidimensional structures to enable analysis and exploration of continuous data. There is a multitude of research issues that lead to the integration of spatiotemporal continuity in multidimensional structures. In this paper, we discuss some of these issues, present briefly a multidimensional model for continuous field data. We also define new aggregation operations. This work is validated by a prototype." } @INPROCEEDINGS{Ahme0812:Online, AUTHOR="Nabeel Ahmed and Usman Ismail and Srinivasan Keshav and Konstantina Papagiannaki", TITLE="Online Estimation of {RF} Interference", BOOKTITLE="Fourth Conference on emerging Networking EXperiments and Technologies", ADDRESS="Madrid, Spain", DAYS=9, MONTH=dec, YEAR=2008, KEYWORDS="interference; modeling; measurement", ABSTRACT="Increased AP density in enterprise WLANs leads to increased RF interference and decreasing performance. An important step towards mitigating interference is to construct precise RF maps in the form of a conflict graph. Prior work on conflict graph construction, mostly using bandwidth tests, suffers from two problems: a) It is limited to static settings and cannot support mobility, and b) It incurs significant measurement overhead and must be performed offline (i.e. overnight). An alternative to bandwidth tests is ``micro-probing'' that can operate on millisecond-level time scales. Micro-probing rapidly constructs the conflict graph even while the network is in use, i.e. online. While interesting in principle, micro-probing has only been evaluated in simulation. In this work, we empirically study micro-probing on a 40-node wireless testbed. In doing so, we do not only show that micro-probing is in fact practically realizable, but also present key insights that drive the design choices for our implementation. We benchmark micro-probing against bandwidth tests and find that micro-probing is just as accurate, at only a fraction of the cost. Finally, we argue that a successful implementation of micro-probing opens up the possibility for further innovations in realtime WLAN adaptation and optimization." } @INPROCEEDINGS{Ahmi0806:Elliptical, AUTHOR="Narges Ahmidi and Abbas Ali {lotfi Neyestanak} and Robin Dawes", TITLE="Elliptical Array Antenna design based on Particle Swarm Method using Fuzzy Decision Rules", BOOKTITLE="24th Queen's Biennial Symposium on Communications", ADDRESS="Kingston, Ontario, Canada, Canada", DAYS=23, MONTH=jun, YEAR=2008, KEYWORDS="Elliptical Array Antenna, Particle Swarm, Fuzzy Decision Rules", ABSTRACT="In this paper an optimized elliptical array antenna is presented. The side lobe level and directivity of the array is optimized using particle swarm based on fuzzy decision-making. In the implemented fuzzy system, inputs are parameters like population, and outputs are parameters such as some coefficient to produce the next generation. A fuzzy inference system is used for the control of the parameters of the particle swarm. Simulation results show the high quality of particle swarm optimization based on fuzzy logic. Amplitudes of the elliptical array antenna have been optimized with the novel design approach presented herein. This array can be used in a smart antenna in MIMO wireless communications systems." } @INPROCEEDINGS{Ahn0801:Energy, AUTHOR="Sanghyun Ahn and Yujin Lim and Hyun Yu", TITLE="{Energy-Efficient} Flooding Mechanisms for the Wireless Sensor Networks", BOOKTITLE="The International Conference on Information Networking", ADDRESS="Busan, Korea", DAYS=23, MONTH=jan, YEAR=2008, KEYWORDS="wireless sensor network; flooding; overlay structure", ABSTRACT="Most of the data transmissions in the sensor network are based on flooding. The original flooding causes the implosion and the overlap problems, so flooding may result in the reduced network lifetime of the sensor network with limited resources. Therefore, in order to reduce the overhead by flooding, we propose the flooding overlay structure (FOS) which adopts the concept of the overlay network so that the overhead caused by flooding can be reduced. We propose two types of FOS mechanisms, the centralized FOS (CFOS) and the distributed FOS (DFOS). CFOS is for the static sensor network in which the sink can select forwarding nodes more effectively. And DFOS is proposed for the more dynamic sensor network environment. To provide the network connectivity in DFOS, the concept of the notice delay is introduced. We have carried out simulations for our FOS mechanisms and the original flooding, and shown that our FOS mechanisms outperform the original flooding in many performance aspects." } @INPROCEEDINGS{Ahn0801:High, AUTHOR="Chang-Jun Ahn", TITLE="High Time Resolution Carrier Interferometry for {MIMO/OFDM}", BOOKTITLE="2008 IEEE Consumer Communications and Networking Conference - Network Access and Communications", ADDRESS="Las Vegas, USA", DAYS=10, MONTH=jan, YEAR=2008, ABSTRACT="In MIMO systems, channel estimation is important to distinguish transmit signals from multiple transmit antennas. When MIMO systems are introduced in cellular systems, we have to measure the received power from all the connectable base station (BS), as well as to identify all the channel state information (CSI) for the combination of transmitter and receiver antenna elements. One of the most typical channel estimation schemes for MIMO in a cellular system is to employ a code division multiplexing (CDM) based scheme in which a unique spreading code is assigned to identify both BS and MS antenna elements. However, by increasing the number of transmit antenna elements, a large spreading code and pilot symbols are required to estimate an accurate CSI. To reduce this problem, in this paper, we propose a high time resolution carrier interferometry (HTRCI) for MIMO/OFDM to achieve an accurate CSI without increasing the number of pilot symbols." } @INPROCEEDINGS{Ahn0803:Efficient, AUTHOR="Soobeen Ahn and Moonseong Kim and Hyunseung Choo", TITLE="Efficient Algorithm for Reducing Delay Variation on Delay-bounded Multicast Trees in Heterogeneous Networks", BOOKTITLE="IEEE Wireless Communications and Networking Conference", ADDRESS="Las Vegas, Nevada, USA", DAYS=31, MONTH=mar, YEAR=2008, KEYWORDS="Multicast communication; Delay variation; End-to-end delay; Heterogeneous network; Delay- and delay Variation Bounded Multicast Tree (DVBMT) problem", ABSTRACT="This paper investigates the construction of a multicast tree satisfying Quality of Service (QoS) real-time group communication in a heterogeneous network comprising multiple Mobile Ad-hoc NETworks (MANETs) attached to the backbone Internet. The main objective of our work is to optimize the Delay- and delay Variation Bounded Multicast Tree (DVBMT) problem, which has been proved to be NP-complete. This problem has to satisfy the minimum delay variation and the end-to-end delay within an upper bound. The well-known algorithms solved this problem are the DVMA, the DDVCA, the Cheng's algorithm, and so on. In this paper, we propose an algorithm that outperforms other algorithms in terms of the multicast delay variation in the realistic network environment. The enhancement increases to approximately 3.7\%~32.9\% in terms of that. The time complexity of the proposed algorithm is O(mn^2), which is comparable to that of DDVCA." } @INPROCEEDINGS{Ahn0804:AMC, AUTHOR="Seok-Ki Ahn and Young Uk Do and Kyeong Cheol Yang", TITLE="{AMC} with Irregular Modulation", BOOKTITLE="The 18th Joint Conference on Communications and Information (Korea Domestic Conference)", ADDRESS="Jeju Island, Korea", DAYS=23, MONTH=apr, YEAR=2008, KEYWORDS="adaptive modulation and coding; low-density parity-check codes; irregular modulation", ABSTRACT="Irregular modulation may use different modulations within one block of coded bits. In this paper, we propose a hardware efficient AMC scheme based on LDPC codes with irregular modulation. We analyze the BICM capacity of irregular modulation to select rates of LDPC codes for supporting AMC. We optimize a bit-to-symbol mapping with respect to noise threshold at each transmission rate. Simulation results show that proposed AMC scheme has compatible performance compared with a fully optimized AMC scheme." } @INPROCEEDINGS{Ahn0804:Implementation, AUTHOR="Sanghyun Ahn and Jae-Hwoon Lee and Hyun Yu and InJoon Park and Chang min Lee and Beom jae Lee", TITLE="Design and Implementation of Address autoconfiguration mechanism in Mobile Ad Hoc Network", BOOKTITLE="The 18th Joint Conference on Communications and Information (Korea Domestic Conference)", ADDRESS="Jeju Island, Korea", DAYS=23, MONTH=apr, YEAR=2008, KEYWORDS="MANET,MANET Auto-configuration", ABSTRACT="무선 Ad Hoc 네트워크(MANET)는 이동 노드로 구성된 독립적인 네트워크로서 노드의 이동성을 보장하며 유선망과 기지국이 필요 없는 무선 네트워크이다. 과거에는 이러한 MANET의 이동 노드는 인터넷 등 기간망과 연결하기 위해 독립적인 하나의 global IP 주소만 가지면 됐었지만 최근에 MANET 구조가 수정됨에 따라 MANET 인터페이스에 할당할 주소뿐 만 아니라 호스트들에게 할당하기 위한 주소 공간도 필요하게 되었다. 이에 따라 하나의 MANET 노드는 MANET 인터페이스 주소와 prefix를 자동으로 생성하여 다른 노드들과 충돌이 생기지 않도록 하는 기법이 필요하다. 따라서 본 논문에서는 새로운 MANET 구조에 적합한 주소 자동 설정 기법 제안 하고, 제안된 기법을 구현하여 검증하고자 한다." } @INPROCEEDINGS{Ahn0804:OFDMA, AUTHOR="Sungbo Ahn", TITLE="{OFDMA} {기반} Relay {시스템에서} Relay {의} Capability {에} {따른} {VoIP} {성능} {분석}", BOOKTITLE="The 18th Joint Conference on Communications and Information (Korea Domestic Conference)", ADDRESS="Jeju Island, Korea", DAYS=23, MONTH=apr, YEAR=2008, KEYWORDS="relay;multi-hop;capability;VoIP", ABSTRACT="본 논문에서는 OFDMA 기반 relay 시스템에서 사용자에게 VoIP 서비스를 제공할 경우, Relay Station (RS)의 capability에 따른 용량 성능 차이를 분석하였다. Relay 시스템은 스케줄링을 수행하는 주체에 따라 mid-capability relay 시스템과 high-capability relay 시스템으로 구분할 수 있다. High-capability relay 시스템의 경우, Base Station (BS) 뿐만 아니라 RS도 직접 스케줄링을 수행한다. 그러나 mid-capability relay 시스템의 경우, 각 RS로부터 단말들의 수신 SINR, 발생 traffic양 등의 정보를 BS에서 수집하여 BS 단독으로 스케줄링을 수행한다. 이로 인해 정보 수집에 대한 control 오버헤드는 커지지만, BS가 모든 단말에 대한 정보를 알고 있으므로 효율적인 자원 할당 및 스케줄링이 가능하다. 모의 실험을 통해 VoIP traffic 환경에서 RS의 capability에 따른 평균 packet delay, good packet ratio, cell goodput을 도출하였다. 선정한 VoIP 성능 지표에 대해서, mid-capability relay 시스템이 high-capability relay 시스템에 비해 성능이 우수함을 확인하였다." } @INPROCEEDINGS{Ahn0805:Parallel, AUTHOR="Chang-Jun Ahn", TITLE="Parallel Detection Algorithm Using Multiple {QR} Decompositions with Permuted Channel Matrix for {SDM/OFDM}", BOOKTITLE="International Symposium on Wireless Pervasive Computing 2008", ADDRESS="Santorini, Greece", PAGES="101-105", DAYS=7, MONTH=may, YEAR=2008, KEYWORDS="MIMO, SDM, MLD, OFDM, QR decomposition", ABSTRACT="SDM/OFDM systems transmit different data using the same frequency, so it is necessary to separate simultaneously received signals in the receiver. Previous studies have shown that maximum likelihood detection (MLD) provides the best BER performance. However, the complexity of MLD exponentially increases with the constellation size and the number of transmit antenna branches. Therefore, it is impractical to use a full MLD without reducing its computational complexity, because it would be prohibitively large for implementation. Recently, the use of QRD-M has been proposed for reducing the system complexity, while maintaining the performance of the system. However, the QRD-M performance depends on the number of surviving symbol replica candidates. When QRD-M is used with a small number of surviving symbol replica candidates, the performance declines, but when there is a large number of surviving symbol replica candidates and the transmitter antenna branches, QRD-M requires a large memory to maintain their branch metrics, and long latency time is also required. To reduce these problems, in this paper, we propose a parallel detection algorithm using multiple QR decompositions with permuted channel matrices for SDM/OFDM systems." } @INPROCEEDINGS{Ahn0809:Proportional, AUTHOR="Woo-Geun Ahn and Hyung-Myung Kim", TITLE="Proportional Fair Scheduling in Relay Enhanced Cellular {OFDMA} Systems", BOOKTITLE="IEEE PIMRC 2008 Mobile and Wireless Networks Track", ADDRESS="Cannes, France", DAYS=15, MONTH=sep, YEAR=2008, KEYWORDS="Proportional Fair Scheduling;Relay;routing;OFDMA", ABSTRACT="We propose an efficient proportional fair scheduling algorithm for multi-user OFDMA systmes employing fixed relays. We formulate an PF metric maximization problem for relay enhanced OFMDA cellular systems. We propose a two-step algorithm consisted of user grouping and resource allocation steps. The simulation results show that the proposed algorithm works near-optimally in PF sense." } @INPROCEEDINGS{Ahn0810:Efficient, AUTHOR="Woojin Ahn and Young Kim", TITLE="An Efficient {Resource-Allocation} Scheme Using Subcarrier Sharing in {MIMO/OFDM} Multi-cell Environment", BOOKTITLE="The 14th Asia-Pacific Conference on Communications", ADDRESS="Tokyo, Japan", DAYS=14, MONTH=oct, YEAR=2008, KEYWORDS="Resource Allocation, Spatial Separability, Subcarrier Sharing", ABSTRACT="The development of intelligent resource-management algorithms has been recently identified as a key technology for exploiting potential system diversity and improving power-spectral efficiency in wireless communication systems, as well as high-performance physical-layer techniques to provide high throughput, efficient resource use, and aggressive multiple access. In this paper, we propose an adaptive subcarrier allocation algorithm in multi-cell point of view using subcarrier sharing. The objective of this paper is to: 1) exploit the inherent system diversities in the frequency, space, and user domains; 2) minimize the overall transmit power; and 3) improve the fairness among users in power aspect. Numerical results shows that tremendous power gain and improvement of the fairness among users is achieved, compared with inherent system." } @INPROCEEDINGS{Ahn0810:Study, AUTHOR="Jinsoo Ahn and Wooshik Kim", TITLE="A Study of {ISO/IEEE11073} Platform Based on Power Line Communication", BOOKTITLE="The 14th Asia-Pacific Conference on Communications", ADDRESS="Tokyo, Japan", DAYS=14, MONTH=oct, YEAR=2008, KEYWORDS="IEEE 11073, PLC, healthcare", ABSTRACT="IEEE 11703 defines the standard for effective network system construction for communication between the host computer and medical equipments under the clinical environment. Advancement in communication systems promotes installation of new networks at hospitals. The objective of this thesis is to research on a scheme to graft the IEEE 11703-based power line communication (PLC), which has numerous advantages such as ease of installation, accessibility, and low cost. Furthermore, use of PLC will be a step closer to POC. If PLC is used in constructing the network, problems such as frequency interference with expensive ultramodern medical equipment within a hospital, and out of signal range problems for wireless can be resolved." } @INPROCEEDINGS{Ahre0801:Iterative, AUTHOR="Andreas Ahrens and Volker Kuehn and Tobias Weber", TITLE="Iterative Detection for Spatial Multiplexing with Adaptive Power Allocation", BOOKTITLE="7th International ITG Conference on Source and Channel Coding", ADDRESS="Ulm, Germany", DAYS=14, MONTH=jan, YEAR=2008, ABSTRACT="In this contribution, bit and transmit power allocation are analyzed for spatial division multiplexing schemes with iterative detection. Existing bit loading and transmit power allocation techniques are often optimized for maintaining both a fixed power and a fixed target bit-error rate while attempting to maximize the overall data-rate. However, delay-critical real-time interactive applications, such as voice or video transmission, may require a fixed data rate. In addition to bit- and power loading we invoke channel coding and identify the most beneficial number of signalling levels that minimize the bit-error rate under the constraint of a given data throughput. The performance is analyzed by both simulations as well as EXIT charts. The results demonstrate that adaptive power allocation combined with an appropriate choice of a modulation scheme for each MIMO layer is highly effective in uncoded scenarios whereas in coded systems, a uniform distribution of the transmit power seems to be the best choice." } @INPROCEEDINGS{Ahre0802:Modulation, AUTHOR="Andreas Ahrens and Volker Kuehn", TITLE="{Modulation-Mode} and Power Assignment for {MIMO-BICM} Schemes", BOOKTITLE="International ITG Workshop on Smart Antennas 2008", ADDRESS="Darmstadt, Germany", DAYS=26, MONTH=feb, YEAR=2008 } @INPROCEEDINGS{Ahuj0000:Benefits, AUTHOR="Sandeep Ahuja and Abishek Gopalan and Srinivasan Ramasubramanian", TITLE="Benefits of {Inter-Flow} Bandwidth Sharing in Broadband Wireless Infrastructure Networks", BOOKTITLE="Second IEEE International Conference on Advanced Networks and Telecommunication Systems (ANTS)", ADDRESS="Mumbai (Bombay), India", DAYS=15, MONTH=dec, YEAR=2008, KEYWORDS="wireless infrastructure networks, channel discontinuity constraint, channel continuity constraint", ABSTRACT="Broadband wireless infrastructure networks are increasingly becoming common in metro areas. To improve spatial bandwidth usage, the nodes in such networks employ directional transmissions over multiple orthogonal channels. In this paper, we study the benefits of sharing link bandwidth across multiple flows. Every connection is assumed to require a bandwidth that is half of the link bandwidth. We model the routing and channel assignment problem in two different ways to account for the presence and absence of inter-flow bandwidth sharing. Through simulations, we demonstrate that supporting inter-flow bandwidth sharing through simple time-sharing mechanism results in improved network throughput." } @INPROCEEDINGS{Ahuj0804:SRLG, AUTHOR="Satyajeet Ahuja and Srinivasan Ramasubramanian and Marwan Krunz", TITLE="{SRLG} Failure Localization in {All-Optical} Networks Using Monitoring Cycles and Paths", BOOKTITLE="The 27th IEEE International Conference on Computer Communications", ADDRESS="Phoenix, Arizona, USA", DAYS=13, MONTH=apr, YEAR=2008, KEYWORDS="all-optical networks, algorithms, fault detection, fault localization, monitoring, graph theory", ABSTRACT="We introduce the concepts of monitoring paths (MPs) and monitoring cycles (MCs) for unique localization of shared risk linked group (SRLG) failures in all-optical networks. An SRLG failure is a failure of multiple links due to a failure of a common resource. MCs (MPs) start and end at same (distinct) monitoring location(s). They are constructed such that any SRLG failure results in the failure of a unique combination of paths and cycles. We derive necessary and sufficient conditions on the set of MCs and MPs needed for localizing an SRLG failure in an arbitrary graph. When a single monitoring location is employed, we show that a network must be (k+2)-edge connected for localizing all SRLG failures with up to k links. For networks that are less than (k+2)-edge connected, we derive necessary and sufficient condition on the placement of monitoring locations for unique localization of any SRLG failure of up to k links. We use these conditions to develop an O(k L) algorithm for the placement of monitoring locations in a network with L links. We show a graph transformation technique that converts the problem of identifying MCs and MPs with multiple monitoring locations to a problem of identifying MCs with single monitoring location. We provide an integer linear program and a heuristic to identify MCs for networks with one monitoring location. Through extensive simulations, we demonstrate the effectiveness of the proposed monitoring technique." } @INPROCEEDINGS{Ahuj0809:Analyzing, AUTHOR="Sandeep Ahuja and Srinivasan Ramasubramanian", TITLE="Analyzing Channel Assignment with Rearrangement in Wireless Networks with Directional Antennas", BOOKTITLE="16th IEEE Workshop on Local and Metropolitan Area Networks", ADDRESS="Cluj-Napoca, Transylvania, Romania", DAYS=3, MONTH=sep, YEAR=2008, ABSTRACT="In this paper, we analyze the blocking performance of channel assignment scheme in a multi-channel wireless line network. We assume that the already existing calls in the network may be rearranged on different channels to accommodate an incoming call. The analysis is limited to single-hop calls with different transmission ranges. Through extensive simulations, we demonstrate that the developed analytical model closely approximates the values obtained through simulation." } @ARTICLE{Ai0812:Optimality, AUTHOR="Xin Ai and Vikram Srinivasan and Chen Khong Tham", TITLE="Optimality and Complexity of Pure Nash equilibria in the Coverage Game", JOURNAL="IEEE JSAC Special Issue on Game Theory in Communication Systems", DAYS=1, MONTH=dec, YEAR=2008, ABSTRACT={In this paper, we investigate the coverage problem in wireless sensor networks using a game theory method. We assume that nodes are randomly scattered in a sensor field and the goal is to partition these nodes into K sets. At any given time, nodes belonging to only one of these sets actively sense the field. A key challenge is to achieve this partition in a distributed manner with purely local information and yet provide near optimal coverage. We appropriately formulate this coverage problem as a coverage game and prove that the optimal solution is a pure Nash equilibrium. Then, we design synchronous and asynchronous algorithms, which converge to pure Nash equilibria. Moreover, we analyze the optimality and complexity of pure Nash equilibria in the coverage game. We prove that, the ratio between the optimal coverage and the worst case Nash equilibrium coverage, is upper bounded by 2-1/(m+1) (m is the maximum number of nodes, which cover any point, in the Nash equilibrium solution). We prove that finding pure Nash equilibria in the general coverage game is PLS-complete, i.e. ``as hard as that of finding a local optimum in any local search problem with efficient computable neighbors{"}. Finally, via extensive simulations, we show that, the Nash equilibria coverage performance is very close to the optimal coverage and the convergence speed is sublinear. Even under the noisy environment, our algorithms can still converge to the pure Nash equilibria.} } @INPROCEEDINGS{Aiac0000:Load, AUTHOR="Hervé Aiache and Vania Conan and Laure Lebrun and Stephane Rousseau", TITLE="A load dependent metric for balancing Internet traffic in Wireless Mesh Networks", BOOKTITLE="Second IEEE International Workshop on Enabling Technologies and Standards for Wireless Mesh Networking", ADDRESS="Atlanta, Georgia, USA", DAYS=29, MONTH=sep, YEAR=2008, KEYWORDS="Wiress Mesh Network, load-aware Routing Metric, Performance evaluation", ABSTRACT="In Wireless Mesh Networks (WMNs) traffic is routed from mobile clients through a multihop wireless backbone to and from Internet Gateways (IGWs). Because of their limited number, IGWs become the major traffic bottlenecks. The purpose of this work is to explore the benefits of introducing load-dependent routing metrics to increase WMN capacity and performance. We use weighted shortest path routing and introduce LAETT a weight metric that captures both traffic load and link quality. We compare the scheme to ETT and MIC, two load independent metrics, and show in simulation its benefits for various network and traffic configurations." } @INPROCEEDINGS{Aiac0805:Reed, AUTHOR="Hervé Aiache and Cedric Tavernier and Corinne SIEUX", TITLE="{Reed-Solomon} Codes and {Multi-Path} Strategies to Improve Privacy Performance over Ad Hoc Networks", BOOKTITLE="International Symposium on Wireless Pervasive Computing 2008", ADDRESS="Santorini, Greece", PAGES="430-435", DAYS=7, MONTH=may, YEAR=2008, KEYWORDS="Privacy, Anonymity, Confidentiality, Ad hoc networks, Reed-Solomon codes, Multi-path routing", ABSTRACT="This paper presents a privacy protection scheme, suitable for devices limited in CPU and/or in memory capabilities, which not only ensures anonymity and confidentiality but has also a limited impact on end-to-end network performance. Such an approach for anonymous communications, inspired by network coding techniques, benefits from recent improvements in list decoding algorithms for Reed-Solomon codes, and takes advantage of multi-path routing capabilities. The combination of these techniques is adapted for constrained and pervasive environments, such as wireless ad hoc networks, as it decreases the processing complexity of the cryptographic/decoding operations and as it ensures better tolerance to packet losses (due to mobility or to bad quality of the radio channel)." } @INPROCEEDINGS{Aiac0805:XIAN, AUTHOR="Hervé Aiache and Vania Conan and Jeremie Leguay", TITLE="{XIAN} Automated Management and {Nano-Protocol} to Design {Cross-Layer} Metrics for Ad hoc Networking", BOOKTITLE="IFIP/TC6 NETWORKING 2008", ADDRESS="Singapore, Singapore", DAYS=5, MONTH=may, YEAR=2008, ABSTRACT="In the highly dynamic and unpredictable environment of MANETs, cross-layer design is receiving growing interest but lacks experimental validation tools. This paper presents XIAN (Cross-layer Interface for wireless Ad hoc Networks), a generic framework for experimenting cross-layer designs in Linux testbeds with 802.11 wireless cards using the MadWifi driver. XIAN can be used as a service by other layers or system components to access MAC/PHY configuration and performance information. It provides experimenters with an open framework to create automatically complex metrics from both local and neighbour node measurements. The defined and implemented software architecture introduces the XIAN Nano-protocol and its automated management. We exemplify their benefits through the implementation of the well-known ETX (Expected Transmission count) metric and we provide results from real experimentations." } @INPROCEEDINGS{Aiel0000:Statistical, AUTHOR="Maurizio Aiello", TITLE="Statistical anomaly detection on real e-mail traffic", BOOKTITLE="International Workshop on Computational Intelligence in Security for Information Systems - 2008", ADDRESS="Genoa, Italy", DAYS=23, MONTH=oct, YEAR=2008, KEYWORDS="behavioural analysis; intrusion detection systems;Anomaly Detection Techniques; indirect worm; real e-mail traffic", ABSTRACT="There are many recent studies and proposal in Anomaly Detection Techniques, especially in worm and virus detection. In this field it does matter to answer few important questions like at which ISO/OSI layer data analysis is done and which approach is used. Furthermore these works suffer of scarcity of real data due to lack of network resources or privacy problem: almost every work in this sector uses synthetic ( e.g. DARPA) or pre-made set of data. Our study is based on layer-seven quantities (number of e-mail sent in a chosen period): we analyzed quantitatively our network e-mail traffic (4 SMTP servers, 10 class C networks) and applied our method on gathered data to detect indirect worm infection (worms which use e-mail to spread infection). The method is a threshold method and, in our dataset, it identified various worm activities. In this document we show our data analysis and results in order to stimulate new approaches and debates in Anomaly Intrusion Detection Techniques." } @INPROCEEDINGS{Aija0000:Architecture, AUTHOR="Fahad Aijaz and Seyed Adeli", TITLE="Architecture for Consuming {Long-Lived} Mobile Web Services over Multiple Transport Protocols", BOOKTITLE="The Second International Conference on New Technologies, Mobility and Security", ADDRESS="Tangier, Morocco", DAYS=5, MONTH=nov, YEAR=2008, ABSTRACT="With the increasing storage capacity, processing power and battery capabilities, mobile devices are now able to providing services instead of just being service consumers. These services deployed on mobile devices are termed as Mobile Web Services (Mob-WS). This paper introduces a middleware for time independent Mob-WS that avoids the overheads of long durational synchronous communication. Details of communication architecture and interaction among the middleware components is presented and discussed. Due to the transport neutral nature of SOAP, the middleware provides miltiple transport protocol bindings and hence, the Bluetooth binding for SOAP has been developed and briefly presented. Finally, some preliminary performance evaluation results are shown followed by conclusion." } @INPROCEEDINGS{Aija0000:Mean, AUTHOR="Fahad Aijaz", TITLE="Mean Delay Gain Evaluation of Synchronous Mobile Web Services using Signal Flow Graphs", BOOKTITLE="Fifth International Conference on Innovations in Information Technology", ADDRESS="Al Ain, UAE", DAYS=16, MONTH=dec, YEAR=2008, KEYWORDS="Mobile Web Services; In-Network; Sensor; Wireless Networks; SOAP; XML; Asynchronous; Synchronous; Computations;", ABSTRACT="Demand of Mobile Web Services (Mob-WS) architectures is catching pace with the increasing requirements of pervasive and mobile computing applications. Performance of such architectures remain an open question due to limited capabilities of mobile nodes. In this paper, we analyze a generic synchronous Mob-WS architecture in terms of mean delay gain using the feedback theory of Signal Flow Graphs (SFG). The synchronous process models are analytically derived based on the requirements and dependencies within the architecture. Finally, a generic recursive model to evaluate in-architecture mean delay gain for unique or multiple process interaction paths is presented and verified." } @INPROCEEDINGS{Ains0806:Polarimetric, AUTHOR="Thomas Ainsworth and John Kelly and Jong-Sen Lee", TITLE="Polarimetric Analysis of Dual Polarimetric {SAR} Imagery", BOOKTITLE="7th European Conference on Synthetic Aperture Radar", ADDRESS="Friedrichshafen, Graf-Zeppelin-Haus, Germany", DAYS=2, MONTH=jun, YEAR=2008, ABSTRACT="Analysis of dual polarimetric SAR imagery has taken on new importance with the recent launches of the POL-SAR and TERRASAR-X polarimetric SAR systems, and the soon to be launched RADARSAT-2 polarimetric SAR. While these space borne polarimetric SARs can provide full polarimetric imagery, a majority of the col-lected imagery will be restricted to dual polarimetric imaging modes. Here we develop polarimetric analysis methods specific to the dual-pol imagery modes typically available from the new space borne SAR systems, i.e. (HH, VH), (VV, HV) and (VV, HH). We employ available quad-pol imagery as the baseline for all compari-sons. From the full quad-pol data we extract the data corresponding to each individual dual-pol imaging modes. We pay particular attention to the information content of each dual-pol imaging mode, comparing them against the quad-pol imaging results. Another point of comparison will be the hybrid dual-pol modes, e.g. when one transmits a circular polarization and coherently receives H and V linear polarizations. These dual polarimetric analysis methods may aid the interpretation and application of dual polarimetric SAR imagery." } @INPROCEEDINGS{Aira0811:Participatory, AUTHOR="Demetrios Airantzis and Alice Angus and Giles Lane and Karen Martin and George Roussos and Jenson Taylor", TITLE="Participatory Sensing for Urban Communities", BOOKTITLE="International Workshop on Urban, Community, and Social Applications of Networked Sensing Systems", ADDRESS="Raleigh, NC, USA", DAYS=4, MONTH=nov, YEAR=2008, KEYWORDS="participation, environmental sensing, community art, prototyping", ABSTRACT="Social Tapestries views participatory sensing as the principal supporting technology to enable grass-roots groups and communities to track and act on information about their local environment. In this article, we report on our experiences with a low-cost open source hardware and software platform, which we specifically developed for this task. We describe how we employed this platform to support community workshops and art, and highlight the lessons learnt through our involvement with urban communities in London, UK. We conclude by identifying the main ingredients for the development of a successful strategy for the use of this and other similar platforms in supporting environmental sustainability through sustainable communities." } @INPROCEEDINGS{Aïs0807:Blind, AUTHOR="Abdeldjalil {Aïssa-El-Bey} and Karim Abed-Meraim", TITLE="Blind {SIMO} Channel Identification Using a Sparsity Criterion", BOOKTITLE="The Ninth IEEE International Workshop on Signal Processing Advances in Wireless Communications", ADDRESS="Recife, Brazil", PAGES="271-275", DAYS=5, MONTH=jul, YEAR=2008, ABSTRACT="In this paper, we are interested in blind identification of single-input multiple-output (SIMO) systems. Using the sparsity property of impulse response, we propose an iterative method which minimizes a cost function based on the lp norm. This norm is considered as a good sparsity measure. The simulations show that the proposed method outperforms existing techniques in terms of estimation error and robustness to channel order overestimation." } @INPROCEEDINGS{Aïs0808:Blind, AUTHOR="Abdeldjalil {Aïssa-El-Bey} and Karim Abed-Meraim", TITLE="Blind Identification of Sparse {SIMO} Channel using Maximum A Posteriori Approach", BOOKTITLE="European Conference on Signal Processing 2008", ADDRESS="Lausanne, Switzerland", DAYS=25, MONTH=aug, YEAR=2008, ABSTRACT="In this paper, we are interested in blind identification of sparse single-input multiple-output (SIMO) systems. A maximum a posteriori approach is considered using generalized Laplacian distribution for the channel coefficients. This leads to a cost function given by the deterministic maximum likelihood (ML) criterion penalized by `a sparsity measure' term expressed by the $\ell\_p$ norm of the channel coefficient vector. A simple but efficient optimization algorithm using gradient technique with optimal step-size is proposed. The simulations show that the proposed method outperforms the ML technique in terms of estimation error and is robust against channel order overestimation errors." } @INPROCEEDINGS{Aiss0805:Effect, AUTHOR="Sonia Aissa and Jian Qi", TITLE="On the Effect of Power Amplifier Nonlinearity on {MIMO} {MRC} Systems", BOOKTITLE="ICC'08 - Wireless Communications Symposium", ADDRESS="Beijing, China, P.R. China", DAYS=19, MONTH=may, YEAR=2008, ABSTRACT="Nonlinearity of high-power amplifier (HPA) plays a crucial factor in the performance of multiple-input multiple-output (MIMO) wireless communications systems. In this paper, we investigate the performance of MIMO maximal ratio combining (MRC) systems in the presence of nonlinear HPA with a transfer function characterized via a polynomial of arbitrary degree. The impact of HPA nonlinearity on the performance of the MIMO MRC systems in uncorrelated Rayleigh fading channels is assessed in terms of their average symbol error probability (SEP), outage probability and ergodic capacity, for which new expressions are derived. Numerical results are provided to illustrate the effects of several system parameters such as the order and coefficients of the power amplifier model, the numbers of transmit and receive antennas, and the order of quadrature amplitude modulation (QAM). In particular, it is shown that the HPA nonlinearity results in significant performance degradation in the high-SNR region, and that the first two nonlinearity coefficients have the most degrading effect on the MIMO MRC system performance." } @INPROCEEDINGS{Aiss0811:Oriented, AUTHOR="Mohamed Aissani and Abdelhamid Mellouk", TITLE="Oriented Void Avoidance Scheme for {Real-Time} Routing Protocols in Wireless Sensor Networks", BOOKTITLE="IEEE Globecom 2008 Ad Hoc, Sensor and Mesh Networking Symposium", ADDRESS="New Orleans, LA, USA", DAYS=30, MONTH=nov, YEAR=2008, KEYWORDS="Communication voids, Real-time routing, Sensor networks, Avoiding voids", ABSTRACT="To avoid the negative impact of void areas on real-time routing efficiency, we propose a new oriented avoid avoidance scheme for sensor networks. To choose the forwarding region (clockwise or anticlockwise) around the void, proposed scheme is oriented by the destination location with respect to the void. Our scheme uses graph theory to discover the void and geometric formulas to obtain the forwarding region of a source node near the void. This node reduces its forwarding candidate set according to its already obtained forwarding region. Proposed approach is simple to implement, economic and could incorporate various other optimisations studies." } @INPROCEEDINGS{Aiss0811:Void, AUTHOR="Mohamed Aissani and Abdelhamid Mellouk and Nadjib Badache", TITLE="Void Avoiding in Advance {Real-Time} Routing in Wireless Sensor Networks", BOOKTITLE="IEEE Globecom 2008 Communications Software and Services Symposium", ADDRESS="New Orleans, LA, USA", DAYS=30, MONTH=nov, YEAR=2008, KEYWORDS="Minimum local problem, Real-time routing, Sensor networks, Bypassing holes, Avoiding voids", ABSTRACT="Communication voids have negative impact on real-time routing protocols in sensor networks. To decrease both routing distance and energy consumption in large-scale sensor networks, we propose a novel real-time routing mechanism to make data packets avoid meeting voids in advance. Our mechanism discovers a void, calculates its center-point and then geocasts coordinates of this center-point to all nodes proportionally closer to the void. These coordinates are then used by a sender node in trigonometric formulas to obtain its oriented forwarding region to start countering the void in advance. For that, the sender node selects its forwarding neighbors according to its already obtained forwarding region. Proposed mechanism is fairly simple to implement and saves the sensor network resources." } @INPROCEEDINGS{AitI0803:Joint, AUTHOR="Tarik Ait-Idir and Houda Chafnaji and Samir Saoudi", TITLE="Joint Hybrid {ARQ} and Iterative {Space-Time} Equalization for Coded Transmission over {MIMO-ISI} Channel", BOOKTITLE="IEEE Wireless Communications and Networking Conference", ADDRESS="Las Vegas, Nevada, USA", DAYS=31, MONTH=mar, YEAR=2008, KEYWORDS="Hybrid ARQ, MIMO-ISI, Integrated Equalization, Iterative space-time processing, iterative channel estimation", ABSTRACT="This paper focuses on the problem of efficient packet combining techniques for coded systems with hybrid automatic repeat request (ARQ) operating over frequency selective fading multiple input multiple output (MIMO) channel. We introduce a receiver scheme where space-time soft equalization is integrated into the packet combiner. This allows for creating at each transmission an additional set of virtual receive antennas, increasing thereby the diversity order of the system. We also propose a second packet combining scheme where equalization is carried out separately for each transmission. Block error rate (BLER) performance is investigated via computer simulations for both perfect and imprecise channel state information (CSI) at the receiver side for demonstrating the potential of integrated soft equalization-based packet combining for transmission over multipath MIMO channels." } @INPROCEEDINGS{Aiti0809:Turbo, AUTHOR="Tarik Ait-Idir and Samir Saoudi", TITLE="Turbo Packet Combining for {MIMO-ISI} Channels with {Co-Channel} Interference", BOOKTITLE="IEEE PIMRC 2008 Fundamentals \& PHY Track", ADDRESS="Cannes, France", DAYS=15, MONTH=sep, YEAR=2008, KEYWORDS="ARQ, MIMO-ISI, turbo equalization", ABSTRACT="This work focuses on signal-level packet combining techniques for coded transmission over co-channel interference (CCI)-limited multiple input multiple output (MIMO) channels with intersymbol interference (ISI). A turbo packet combining algorithm that jointly equalizes multiple transmissions using the concept of virtual antennas is proposed. Block error rate (BLER) performance is investigated to show the great potential of the introduced technique for many scenarios." } @INPROCEEDINGS{AitK0000:Using, AUTHOR="Mounir {Ait Kerroum} and Ahmed Hammouch and Driss Aboutajdine and Bellaachia Abdelghani", TITLE="Using The Maximum Mutual Information Criterion To Textural Feature Selection For Satellite Image Classification", BOOKTITLE="13th IEEE Symposium on Computers and Communications", ADDRESS="Marrakech, Morocco", DAYS=6, MONTH=jul, YEAR=2008, KEYWORDS="Textural Feature Selection, Mutual Information,Cooccurrence Matrix, Support Vectors Machine, Satellite Image Classification, PCA, LDA.", ABSTRACT="This paper presents and evaluates the use of the maximum mutual information criterion to textural feature selection for satellite image classification. Our approach is based on a recent work of Mutual Information Feature Selector Algorithm. The effectiveness of the proposed approach is evaluated on real data. In fact, the textural features are extracted using the cooccurrence matrix from two forest zones of SPOT HRV(XS) image in the region of Rabat, Morocco. The experimental tests of this study prove that the proposed approach gives a better performance for satellite image classification than classical methods such as Principal Components Analysis (PCA) and Linear Discriminant Analysis (LDA). The classifier used in this work is the Support Vectors Machine (SVM)." } @INPROCEEDINGS{Aits0000:Gradient, AUTHOR="Nadjib {Ait Saadi} and Nadjib Achir and Khaled Boussetta", TITLE="A Gradient Approach for Differentiated Wireless Sensor Network Deployment", BOOKTITLE="IFIP Wireless Days", ADDRESS="Dubai, UAE", DAYS=24, MONTH=nov, YEAR=2008, KEYWORDS="Wireless Sensor Network, Differentiated Deployment in WSN, Potential Field, Virtual Forces, 0/1 Optimization.", ABSTRACT="In this paper, we are focused on deployment problem in Wireless Sensor Network (WSN). This problem is considered in the case where the monitored area is characterized by a geographical irregularity of the sensed events. In this case, each point of the deployment area requires a specific minimum guarantee in event detection probability. Our resulting differentiated WSN deployment problem is formulated as A Binary Linear Programming problem. Then, we firstly provide, in this paper, an exact resolution of this problem using the Branch \& Bound approach. Unfortunately, due to the the large solution state space and the exponential computational complexity, the exact methods can be applied only in the case of small scale problem. To overcome the computational complexity of an optimal resolution, we propose a new scalable deployment strategy based on Potential Field and Virtual Force, namely Gradient Differentiated Deployment Algorithm (GDDA). This strategy is able to take into consideration the required detection probability threshold of each point in a large scale area while minimizing the number of deployed sensors. We compared our proposal strategy to several others strategies proposed in the literature and the obtained results show that GDDA guarantees the better performances." } @INPROCEEDINGS{Aits0801:Tabu, AUTHOR="Nadjib {Ait Saadi} and Nadjib Achir and Khaled Boussetta and Guy Pujolle", TITLE="A Tabu Search Approach for Differentiated Sensor Network Deployment", BOOKTITLE="2008 IEEE Consumer Communications and Networking Conference - Wireless Routing and Transport", ADDRESS="Las Vegas, USA", DAYS=10, MONTH=jan, YEAR=2008, ABSTRACT="In this paper, we address the Wireless Sensor Network (WSN) deployment issue. Compared to similar works, we relaxe some assumptions that were generally considered in the literature. Precisely, instead of the classical binary detection model, we consider a distance-related probabilistic one. Moreover, we assume that the observed area is characterized by the geographical irregularity of the sensed events. Our resulting differentiated WSN deployment problem is formulated as a Multi-Objectives Optimization one. To overcome the computational complexity of an exact resolution, we propose an original pseudo-random approach based on the Tabu Search heuristic. Our proposal is able to take into consideration the required detection probability threshold of each point in the monitored area while minimizing the number of deployed sensors. Performances evaluations show that our proposal achieves a much better satisfaction rate than several other approaches proposed in the literature." } @INPROCEEDINGS{Ajag0805:FPGA, AUTHOR="Samson Ajagunmo and Aleksandar Jeremic", TITLE="An {FPGA} Platform for {Real-Time} Simulation of Tissue Deformation", BOOKTITLE="IEEE Canadian Conference on Electrical and Computer Engineering 2008 (CCECE'08)", ADDRESS="Niagara Falls, Ontario, Canada", DAYS=4, MONTH=may, YEAR=2008, KEYWORDS="tissue deformation; reconfigurable architecture; hardware computing", ABSTRACT="The simulation of soft tissue deformations has many practical uses in the medical field such as diagnosing medical conditions, training medical professionals and surgical planning. While there are many good computational models that are used in these simulations, carrying out the simulations is time consuming especially for large systems. In order to improve the performance of these simulators, field-programmable-gate-arrays (FPGA) based accelerators for carrying out Matrix-by-Vector multiplications (MVM), the core operation required for simulation, have been proposed recently. A better approach, yet, is to implement a full accelerator for carrying out all operations required for simulation on FPGA. In this paper we propose an FPGA accelerator tested for simulating soft-tissue deformation using finite-difference approximation of elastodynamics equations based on conjugate-gradient inversion of sparse matrices. The resource and timing requirements show that this approach can achieve speeds capable of carrying out real-time simulation." } @INPROCEEDINGS{Ajib0801:Multichannel, AUTHOR="Wessam Ajib", TITLE="New Multichannel {MAC} Protocol for Ad Hoc Networks", BOOKTITLE="The International Conference on Information Networking", ADDRESS="Busan, Korea", DAYS=23, MONTH=jan, YEAR=2008, KEYWORDS="CDMA; Medium access control; multichannel protocols; ad hoc networks", ABSTRACT="Since wireless ad hoc networks require a distributed multiple access protocol, the medium access control (MAC) layer can be seen as the bottleneck for the throughput in wireless 802.11-based ad hoc networks. In this paper, we develop a new MAC protocol for multichannel operation in wireless ad hoc networks. The proposed protocol is based on the code division multiple access (CDMA) technique where each spreading code represents one channel. However, the proposed MAC protocol is not limited to CDMA systems. It can be applicable within frequency division multiple access (FDMA) systems (with one radio transceiver) or multi radio systems. We show through computer simulations that our proposition of multichannel MAC protocol significantly improves the communication performance in wireless ad hoc networks." } @INPROCEEDINGS{Ajlo0807:Landmine, AUTHOR="Aseel Ajlouni", TITLE="Landmine Detection with {IR} Sensors Using Karhunen Loeve Transformation and Watershed Segmentation", BOOKTITLE="Fifth International Multi-conference on Systems, Signals, and Devices", ADDRESS="Amman, Jordan", DAYS=20, MONTH=jul, YEAR=2008, KEYWORDS="Landmine Detection, KLT, Watershed Segmentation, IR sensors.", ABSTRACT="In this paper, we present our idea of using the Karhunen Loeve Transformation (KLT) and Watershed Segmentation to detect landmine objects from Infrared images. On doing this, we proposed a simplified process for reducing the computation in the Karhunen Loeve Transformation using a smaller number of images than traditional methods do. We effectively used the Marker Based Watershed Segmentation to detect the mines with high performance detection rate. We tested our proposed method on three different mine fields with two different soil types. Our proposed method consists of four stages: feature extraction, enhancement, object segmentation, and object recognition. The results are promising." } @INPROCEEDINGS{Akag0812:Development, AUTHOR="Tetsuya Akagi and Shujiro Dohta and Shin-ichi Katayama", TITLE="Development of Small-sized Flexible Pneumatic Valve Using Vibration Motor and Its Application for Wearable Actuator", BOOKTITLE="15th International Conference on Mechatronics and Machine Vision in Practice, 2008", ADDRESS="Massey University,Auckland, New Zealand", PAGES="470-475", DAYS=2, MONTH=dec, YEAR=2008, KEYWORDS="small-sized valve, valve uisng vibration motor, wearable actuator", ABSTRACT="Recently, due to the ageing in Japanese society and the decreasing birthrate, an important problem of providing nursing care for the elderly has occurred. As a result, it is necessary to develop wearable systems to aid in nursing care. To realize the system, we require not only wearable soft actuators, but also compact and flexible control valve that can drive the soft actuator such as a pneumatic artificial muscle. The purpose of our study is to develop a flexible, lightweight and compact control valve which can be safe enough to be attached to the human body. In this study, we proposed and tested a new type of control valve. The valve consists of a vibration motor and a check valve that is made of a steel ball and an orifice in flexible tube. The operating principle of the valve is as follows. The valve is normally closed as a function of check valve. When the vibration is applied, the inner ball in the check valve moves and the valve opens. By giving continuous vibration, the valve can keep open. As a result, we find that the valve can control the relatively larger flow rate for their weight and size. As an application of the tested valve, we propose the control device of wearable actuator such as a McKibben artificial muscle." } @INPROCEEDINGS{Akas0810:Wavelength, AUTHOR="Youichi Akasaka and Inwoong Kim and Andrew Lee and Matthew Davy and Takao Naito", TITLE="Wavelength and Temporal Dependency of Polarization Mode Dispersion based on {150,000} Continuous Measurements over Buried Field Fiber in Indiana", BOOKTITLE="The 14th Asia-Pacific Conference on Communications", ADDRESS="Tokyo, Japan", DAYS=14, MONTH=oct, YEAR=2008, KEYWORDS="Field fiber measurements, Polarization mode dispersion, Temporal dependency, Wavelength dependency", ABSTRACT="A detailed analysis of more than 70 million PMD data points (490 wavelengths x ~150000 continuous measurements) on 160 km of buried field fiber was executed. Both of DGD and SOPMD show wavelength dependency and temporal dependency over measurement periods. Discrepancy between measured JPDF and calculated JPDF suggested necessity of a re-visit to the calculation model based on a sequence of randomly birefringent sections." } @INPROCEEDINGS{Akba0000:Comparative, AUTHOR="Muhammad Ali Akbar and Zeeshan Tariq and Muddassar Farooq", TITLE="A Comparative Study of Anomaly Detection Algorithms for Detection of {SIP} Flooding in {IMS}", BOOKTITLE="International Conference on Internet Multimedia Services Architecture and Applications", ADDRESS="Bangalore, India", DAYS=10, MONTH=dec, YEAR=2008, ABSTRACT="The IP Multimedia Subsystem (IMS) framework uses Session Initiation Protocol (SIP) for signaling and control of sessions. In this paper, we first demonstrate that SIP flooding attacks on IMS can result in denial of service to the legitimate users. Afterwards, we report our comparative study of three well-known anomaly detection algorithms, Adaptive threshold, Cumulative sum, and Hellinger distance) for detection of flood attacks in IMS. We evaluate the accuracy of the algorithms using a comprehensive traffic dataset that consists of varying benign and malicious traffic patterns." } @INPROCEEDINGS{Akba0000:Mobility, AUTHOR="Muhammad Saeed Akbar and Syed Zubair Ahmad and Muhammad Abdul Qadir", TITLE="Mobility Aware Transmission Control Protocol {(MA-TCP)}", BOOKTITLE="The Fourth International Conference on Mobile Computing and Ubiquitous Networking", ADDRESS="Miraikan, Tokyo, Japan", DAYS=11, MONTH=jun, YEAR=2008, KEYWORDS="MA-TCP; Wireless Network; Mobility; Hand off; CWND", ABSTRACT="The Transmission Control Protocol (TCP) is a reliable end to end protocol which obtains the major share of the internet traffic over wired networks. The random and unpredictable behavior of the wireless network is major cause for performance degradation of the TCP. A number of attempts have been made to improve the performance of the TCP in wireless environment where random loss, Mobility and burst loss are common. We propose a new TCP variant MA-TCP which can distinguish between the losses due the host mobility and congestion. The key component of the MA-TCP is to handle the hand off condition and keep the performance up to the mark. This article presents the architecture of the MA-TCP and describes the simulation results of NS 2. The result shows that MA-TCP provides the 10.25\% to 53.75\% improvement in through put over other TCP variants in unpredictable and heterogeneous wireless networks." } @INPROCEEDINGS{Akba0811:Machine, AUTHOR="Rehan Akbani and Turgay Korkmaz and Gottumukkala Raju", TITLE="A Machine Learning Based Reputation System for Defending Against Malicious Node Behavior", BOOKTITLE="IEEE Globecom 2008 Computer and Communications Network Security Symposium", ADDRESS="New Orleans, LA, USA", DAYS=30, MONTH=nov, YEAR=2008, KEYWORDS="Machine Learning; Peer-to-Peer; Reputation Systems; Support Vector Machines", ABSTRACT="Reputation Systems (RS) are designed to detect malicious nodes in a network and thwart their attacks, such as the spreading of viruses or worms, or attacking known vulnerabilities. They do this by collecting information about past transactions of a node and utilizing that to predict its future behavior. Traditionally, RSs have been designed by manually devising specific models or equations that use the historical data to defend against certain types of attacks. In this paper, we propose a Machine Learning based RS that automates the process of devising the RS model and defends against many patterns of attacks. We discuss the merits of this approach and propose using Support Vector Machines as the basis of the RS. We delineated the factors associated with building the SVM based RS and then proposed and evaluated our technique. We compared the performance of our RS with another RS found in the literature, called TrustGuard, and showed that our RS significantly outperforms TrustGuard. Our RS correctly distinguishes between good and malicious nodes with high accuracy, even when the proportion of malicious nodes in the network is very high." } @INPROCEEDINGS{Akde0810:Ontology, AUTHOR="Umut Akdemir and Pavan Turaga and Rama Chellappa", TITLE="An Ontology based Approach for Activity Recognition from Video", BOOKTITLE="ACM Multimedia 2008 Short Papers-Content Track", ADDRESS="Vancouver, Canada", DAYS=27, MONTH=oct, YEAR=2008, KEYWORDS="Activity Ontologies; Visual Surveillance; Human Activity Recognition", ABSTRACT="Representation and recognition of human activities is an important problem for video surveillance and security applications. Considering the wide variety of settings in which surveillance systems are being deployed, it is necessary to create a common knowledge-base or ontology of human activities. Most current attempts at ontology design in computer vision for human activities have been empirical in nature. In this paper, we present a more systematic approach to address the problem of designing ontologies for visual activity recognition. We draw on general ontology design principles and adapt them to the specific domain of human activity ontologies. Then, we discuss qualitative evaluation principles and provide several examples from existing ontologies and how they can be improved upon. Finally, we demonstrate quantitatively in terms of recognition performance, the efficacy and validity of our approach for bank and airport tarmac surveillance domains." } @INPROCEEDINGS{Akei0811:Direct, AUTHOR="Ehad Akeila and Zoran Salcic and Akshya Swain", TITLE="Direct Gravity Estimation and Compensation in Strapdown {INS} Applications", BOOKTITLE="3rd International Conference on Sensing Technology", ADDRESS="Tainan, Taiwan", PAGES="244-249", DAYS=30, MONTH=nov, YEAR=2008, KEYWORDS="accelerometer, gravity, Gyro-Based INS, Gyro-Free INS", ABSTRACT="This paper proposes a novel algorithm for estimating the gravity and compensating its effects on acceleration measurements in Inertial Navigation System (INS) based applications. Gravity is a critical factor and its effects are usually included in the measurements obtained from accelerometers. This results in a need to eliminate gravity effects from the measurements in order to accurately determine the true acceleration of a moving object. In the present study, a new method has been proposed to estimate the gravity using the measurements from the existing INS sensors without employing any additional sensors. This significantly reduces the complexity of INS based system design. Two different types of models have been developed based on the proposed gravity compensation method to be used in Gyro based and Gyro-free INS applications. The performance of both these models is illustrated by simulations and experiments. Results of simulations demonstrate that by including the proposed gravity compensation model, the errors in the acceleration measurements reduces significantly" } @INPROCEEDINGS{Akei0811:Implementation, AUTHOR="Ehad Akeila and Zoran Salcic and Akshya Swain", TITLE="Implementation, Calibration and Testing of {GFINS} Models Based on {Six-Accelerometer} Cube", BOOKTITLE="IEEE Region 10 Conference", ADDRESS="Hyderabad, Andhra Pradesh, India", DAYS=18, MONTH=nov, YEAR=2008, KEYWORDS="Gyroscope free inertial navigation system ; accelerometers", ABSTRACT="Gyro-Free Inertial Navigation Systems (GFINS) models have been developed in the past to remove gyroscopes and rely only on accelerometers in computing the motions of objects. However, most of the research done in this area focused on analyzing the models using simulated data. The work presented in this paper is concerned with the implementation and testing of a GFINS hardware prototype based on the six-accelerometer cubic arrangement. The system has been calibrated in three stages; sensors calibration, compensation for sensors misalignments and overall system calibration. The system was used to validate different types of models which describe the outputs of the accelerometers in the GFINS cube. The performance of the GFINS prototype has been studied by testing the system both under rotational and linear motions. Results obtained from the sensors of the prototype have convincingly demonstrated that gravity factor should be included while modeling the outputs of the accelerometers. Testing results of the prototype under rotational and linear motions show that the system can accurately measure accelerations. However, when displacements are computed by integrating the accelerations, any initial small error gets accumulated over time." } @INPROCEEDINGS{Akem0807:Empirical, AUTHOR="Yuji Akematsu and Masatsugu Tsuji", TITLE="An Empirical Analysis of Reduction of Medical Expenditures by eHealth System: Further Results", BOOKTITLE="IEEE 10th International Conference on e-Health Networking, Application \& Services", ADDRESS="Singapore, Singapore", DAYS=7, MONTH=jul, YEAR=2008, KEYWORDS="eHealth system; lifestyle-related illness; Receipt of National Health Insurance; OLS", ABSTRACT="This paper aims to examine reduction of medical expenditures by utilizing the system of Nishi-aizu Town, Fuikushima Prefecture. The town office has been implementing it since 1994 and keeps receipts on medical expenditures of its approximately 4,000 residents paid by National Health Insurance for 5 years from 2002 to 2006. We select (i) users; and (ii) non-users of the eHealth system, and by comparing their medical expenditures, we examine: (i) difference in medical expenditures between two groups; and (ii) negative correlation between medical expenditures and the length of usage of the eHealth system. We find that total medical expenditures of users are larger than those of non-users, whereas by restricting to lifestyle-related illnesses such as high blood pressure, cerebral infarction, strokes, and diabetes, medical expenditures of users are found to be smaller than those of non-users. Users’ average annual expenditures per person related to lifestyle-related illnesses is smaller than that of non-users by 15,302 yen (US$133.06), which is about 20.7\% of average expenditures of non-users. If users utilize the system one more year, then the above expenditures would decrease about 13,719 yen (US$119.30) per year, which is about 18.7\% of the average expenditures. In addition, we show (iii) the elasticity of reduction of medical expenditures with respect to the length of utilizing the system increases according to years of its use, and also verify (iv) medical expenditures of those who have diseases would be reduced larger than that of people who do not have disease. Finally, we calculate (v) exact amount reimbursement from the National Medical Insurance to this system." } @INPROCEEDINGS{Akha0000:National, AUTHOR="Amir Nasser Akhavan and Asghar {Jebalbarezi Sarbijan}", TITLE="National Innovation {System(NIS)} in Developing Countries : The Case of Iran", BOOKTITLE="International Conference on Management of Technology 2008", ADDRESS="Dubai, UAE", DAYS=6, MONTH=apr, YEAR=2008, ABSTRACT="While the study on NIS concept as a whole is still at the early stages, the study on NIS in developing countries is at an even more primitive stages. Main focuses of studies on NIS in developing countries were on countries that have intensive technological learning and, hence, successfully catching up with developed countries. This paper, using Iran as a case study, aims at understanding the NIS in developing countries that are less successful in techological catching up.It proposes, the development level of NIS in Iran does not link to its economic structural development levels. This paper argues that studies of NIS in countries less successful in technological catching up like Iran should focus not only on how innovation related activities start and improve over time, but also more importantly, on factors contributing to the long-running perpetuation of weak and fragmented NIS, especially those preventing intensive technological learning to take place. Enhancement of tembedded autonomy of government bureaucracies is policy recommendation." } @INPROCEEDINGS{Akha0000:Research, AUTHOR="Amir Nasser Akhavan and Nooshin Jabbari", TITLE="Research Carried out on Product \& Production Development : Challenges for Iranian Manufacturing Industry", BOOKTITLE="Internation