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Computer Engineering Commons

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2009

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Articles 121 - 150 of 545

Full-Text Articles in Computer Engineering

An Electrooculogram-Based Binary Saccade Sequence Classification (Bssc) Technique For Augmentative Communication And Control, Johnalan Keegan, Ted Burke, James Condron Sep 2009

An Electrooculogram-Based Binary Saccade Sequence Classification (Bssc) Technique For Augmentative Communication And Control, Johnalan Keegan, Ted Burke, James Condron

Conference Papers

In the field of assistive technology, the electroocu-logram (EOG) can be used as a channel of communication and the basis of a man-machine interface. For many people with severe motor disabilities, simple actions such as changing the TV channel require assistance. This paper describes a method of detecting saccadic eye movements and the use of a saccade sequence classification algorithm to facilitate communication and control. Saccades are fast eye movements that occurs when a person's gaze jumps from one fixation point to another. The classification is based on pre-defined sequences of saccades, guided by a static visual template (e.g. a …


Defining A Framework For Knowledge Sharing In A Dynamic Sales Oriented Organisation, Joern Hussock Sep 2009

Defining A Framework For Knowledge Sharing In A Dynamic Sales Oriented Organisation, Joern Hussock

Dissertations

The analysts of Datamonitor describe the knowledge management and collaboration as 2009 trends to watch. Why is collaboration and KM so important? It can be managed for unstructured business processes through sharing knowledge, best practices and experience on the business process context, soliciting feedback on problem resolution, seeking support from colleagues or communicating with other partner and customer communities. The challenge for organisations, especially for sales oriented teams is finding a way of structured managing and supporting the combination of the benefits based on the exchange of information in already existing unstructured activities in collaborative environments. This research aims to …


Exploiting Set-Level Non-Uniformity Of Capacity Demand To Enhance Cmp Cooperative Caching, Dongyuan Zhan, Hong Jiang, Sharad C. Seth Sep 2009

Exploiting Set-Level Non-Uniformity Of Capacity Demand To Enhance Cmp Cooperative Caching, Dongyuan Zhan, Hong Jiang, Sharad C. Seth

School of Computing: Technical Reports

As the Memory Wall remains a bottleneck for Chip Multiprocessors (CMP), the effective management of CMP last level caches becomes of paramount importance in minimizing expensive off-chip memory accesses. For the CMPs with private last level caches, Cooperative Caching (CC) has been proposed to enable capacity sharing among private caches by spilling an evicted block from one cache to another. But this eviction-driven CC does not necessarily promote cache performance since it implicitly favors the applications full of block evictions regardless of their real capacity demand. The recent Dynamic Spill-Receive (DSR) paradigm improves cooperative caching by prioritizing applications with higher …


Polarization Diversity For Indoor Wireless Communications, Tadeusz Wysocki, Jason Uher, Beata J. Wysocki Sep 2009

Polarization Diversity For Indoor Wireless Communications, Tadeusz Wysocki, Jason Uher, Beata J. Wysocki

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

As the demand for high wireless data rates in indoor environments grows, we must find new ways to increase the performance of wireless links in multi-path fading. One common way to do this is to add diversity in the form of spatial or temporal diversity through the application of space-time block codes (STBCs). Recently, a method for combining STBCs with polarization diversity has been presented that allows for modeling the changes in polarization with quaternion numbers, introducing space-time-polarization block codes (STPBCs). This presentation shows some results from an initial investigation into the quality of cross polarized channels as compared to …


On The Issue Of Decoupled Decoding Of Codes Derived From Quaternion Orthogonal Designs, Tadeusz Wysocki, Beata Wysocki, Sarah Spence Adams Sep 2009

On The Issue Of Decoupled Decoding Of Codes Derived From Quaternion Orthogonal Designs, Tadeusz Wysocki, Beata Wysocki, Sarah Spence Adams

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Quaternion orthogonal designs (QODs) have been previously introduced as a basis for orthogonal space-time polarization block codes (OSTPBCs). This note will serve to correct statements concerning the optimality of a decoupled maximum-likelihood (ML) decoding algorithm. It will be shown that when compared to coupled decoding, the decoupled decoding is only optimal in certain cases. This raises several open problems concerning the decoding of OSTPBCs.


Effect Of Sample Timing On Ls Channel Estimation, Jason Uher, Tadeusz Wysocki, Beata Wysocki Sep 2009

Effect Of Sample Timing On Ls Channel Estimation, Jason Uher, Tadeusz Wysocki, Beata Wysocki

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

As block coding and intelligent receiver combining in multi-antenna systems moves from the theoretical into the physical domain, it is necessary to apply robust analysis to the problems encountered with the development of real radio systems that are often overlooked during theoretical development of methods and processes. One such problem is the lack of synchronization between the transmitter and receiver sampling clocks. This text attempts to analyze the significance of poorly correcting for differences in the transmit and receive sample clocks by simulating the BER of an Alamouti space-time coded system under a variety of sample rates and clock offsets. …


Program Of The 3rd International Conference On Signal Processing And Communication Systems, Omaha, Nebraska, 28-30 September 2009 Sep 2009

Program Of The 3rd International Conference On Signal Processing And Communication Systems, Omaha, Nebraska, 28-30 September 2009

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

10 sessions; 2 poster sessions.
Schedule and Table of Contents.


Pre-Filtering Of Self-Encoded Spread Spectrum In Dense Multipath Channels, Won Mee Jang, Lim Nguyen Sep 2009

Pre-Filtering Of Self-Encoded Spread Spectrum In Dense Multipath Channels, Won Mee Jang, Lim Nguyen

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

We present pre-filtering methods of self-encoded spread spectrum (SESS) in dense multipath channels. SESS eliminates the need for traditional transmit and receive pseudo noise (PN) code generators. In this paper, we propose multipath management of SESS in dense multipath urban environments. We propose a transmitter pre-filtering method that retains only good paths that contribute to the data decision positively at the receiver, and eliminates undesirable paths. The proposed technique significantly improves the system performance while increasing the transmit power moderately.


Ergodic Capacity Of Cooperative Networks Using Adaptive Transmission And Selection Combining, Bao Q. Vo-Nguyen, Trung Q. Duong, Nguyen N. Tran Sep 2009

Ergodic Capacity Of Cooperative Networks Using Adaptive Transmission And Selection Combining, Bao Q. Vo-Nguyen, Trung Q. Duong, Nguyen N. Tran

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Closed-form expressions for ergodic capacity of repetition-based cooperative networks under adaptive transmission with selection combining are derived. According to the changing channel conditions, the source adapts its rate and/or power level while the relays simply amplify and then forward the received signals. Specifically, three different adaptive techniques are investigated under the assumption of independent Rayleigh fading channels: optimal simultaneous power and rate adaptation (OPRA), constant power with optimal rate adaptation (OPA) and channel inversion with fixed rate (TIFR). Among them, for an arbitrary number of relays, TIFR gives the worst channel capacity; OPRA gives the best channel capacity and ORA …


Synthesis, Interdiction, And Protection Of Layered Networks, Kevin T. Kennedy Sep 2009

Synthesis, Interdiction, And Protection Of Layered Networks, Kevin T. Kennedy

Theses and Dissertations

This research developed the foundation, theory, and framework for a set of analysis techniques to assist decision makers in analyzing questions regarding the synthesis, interdiction, and protection of infrastructure networks. This includes extension of traditional network interdiction to directly model nodal interdiction; new techniques to identify potential targets in social networks based on extensions of shortest path network interdiction; extension of traditional network interdiction to include layered network formulations; and develops models/techniques to design robust layered networks while considering trade-offs with cost. These approaches identify the maximum protection/disruption possible across layered networks with limited resources, find the most robust layered …


Binary Usenet Application, Alexander J. Patterson Sep 2009

Binary Usenet Application, Alexander J. Patterson

Masters Projects

ANZBC software was written as a prototype to download small‐encoded files form Usenet servers. This software allows anything from a text document to a HD movie to be downloaded and decoded into a single file. Often this is a single file that is split into multiple small files and then compressed.


Admission Control For Differentiated Services In Future Generation Cdma Networks, Hwee-Pink Tan, Rudesindo Núñez-Queija, Adriana F. Gabor, Onno J. Boxma Sep 2009

Admission Control For Differentiated Services In Future Generation Cdma Networks, Hwee-Pink Tan, Rudesindo Núñez-Queija, Adriana F. Gabor, Onno J. Boxma

Research Collection School Of Computing and Information Systems

Future Generation CDMA wireless systems, e.g., 3G, can simultaneously accommodate flow transmissions of users with widely heterogeneous applications. As radio resources are limited, we propose an admission control rule that protects users with stringent transmission bit-rate requirements (“streaming traffic”) while offering sufficient capacity over longer time intervals to delay-tolerant users (“elastic traffic”). While our strategy may not satisfy classical notions of fairness, we aim to reduce congestion and increase overall throughput of elastic users. Using time-scale decomposition, we develop approximations to evaluate the performance of our differentiated admission control strategy to support integrated services with transmission bit-rate requirements in a …


Bit Error Rates For Ultrafast Apd Based Optical Receivers: Exact And Large Deviation Based Asymptotic Approaches, Peng Sun, Majeed M. Hayat, Abhik K. Das Sep 2009

Bit Error Rates For Ultrafast Apd Based Optical Receivers: Exact And Large Deviation Based Asymptotic Approaches, Peng Sun, Majeed M. Hayat, Abhik K. Das

Electrical and Computer Engineering Faculty Research and Publications

Exact analysis as well as asymptotic analysis, based on large-deviation theory (LDT), are developed to compute the bit-error rate (BER) for ultrafast avalanche-photodiode (APD) based optical receivers assuming on-off keying and direct detection. The effects of intersymbol interference (ISI), resulting from the APD's stochastic avalanche buildup time, as well as the APD's dead space are both included in the analysis. ISI becomes a limiting factor as the transmission rate approaches the detector's bandwidth, in which case the bit duration becomes comparable to APD's avalanche buildup time. Further, the effect of dead space becomes significant in high-speed APDs that employ thin …


Learning Without Default: A Study Of One-Class Classification And The Low-Default Portfolio Problem, Kenneth Kennedy, Brian Mac Namee, Sarah Jane Delany Aug 2009

Learning Without Default: A Study Of One-Class Classification And The Low-Default Portfolio Problem, Kenneth Kennedy, Brian Mac Namee, Sarah Jane Delany

Conference papers

This paper asks at what level of class imbalance one-class classifiers outperform two-class classifiers in credit scoring problems in which class imbalance, referred to as the low-default portfolio problem, is a serious issue. The question is answered by comparing the performance of a variety of one-class and two-class classifiers on a selection of credit scoring datasets as the class imbalance is manipulated. We also include random oversampling as this is one of the most common approaches to addressing class imbalance. This study analyses the suitability and performance of recognised two-class classifiers and one-class classifiers. Based on our study we conclude …


Wireless Networks: Spert: A Stateless Protocol For Energy-Sensitive Real-Time Routing For Wireless Sensor Network, Sohail Jabbar, Abid Ali Minhas, Raja Adeel Akhtar Aug 2009

Wireless Networks: Spert: A Stateless Protocol For Energy-Sensitive Real-Time Routing For Wireless Sensor Network, Sohail Jabbar, Abid Ali Minhas, Raja Adeel Akhtar

International Conference on Information and Communication Technologies

Putting constraints on performance of a system in the temporal domain, some times turns right into wrong and update into outdate. These are the scenarios where apposite value of time inveterate in the reality. But such timing precision not only requires tightly scheduled performance constraints but also requires optimal design and operation of all system components. Any malfunctioning at any relevant aspect may causes a serious disaster and even loss of human lives. Managing and interacting with such real-time system becomes much intricate when the resources are limited as in wireless sensor nodes. A wireless sensor node is typically comprises …


Wireless Networks: Automated Frequency Distribution, Management & Assignment (Afdma) In Ieee 802.16, Khurram Shehzad, A. Ali, F. Rasool, R. M. Hashmi, A. Zubair, R. L. Ali Aug 2009

Wireless Networks: Automated Frequency Distribution, Management & Assignment (Afdma) In Ieee 802.16, Khurram Shehzad, A. Ali, F. Rasool, R. M. Hashmi, A. Zubair, R. L. Ali

International Conference on Information and Communication Technologies

Frequency is amongst the most exclusive and most costly resources in wireless communication networks, especially, while considering the demands of broadband wireless access (BWA). In BWA, the management of frequency distribution and its effective utilization is of utmost importance. This research explores possible ways to ensure the most effective allocation of bandwidth resources and their best possible utilization on need basis. The model for static frequency allocation has been optimized and the dynamic frequency management has been calculated while dividing the users in different user classes on the basis of their needs and requirements. The effect of ping-pong handovers has …


Networks - Ii: Formal Modeling Of Trust In Semantic Grid Registry, Saba Mahmood, Saman Iftikhar, Hafiz Farooq Ahmad, Farah Mahmood Aug 2009

Networks - Ii: Formal Modeling Of Trust In Semantic Grid Registry, Saba Mahmood, Saman Iftikhar, Hafiz Farooq Ahmad, Farah Mahmood

International Conference on Information and Communication Technologies

In this paper we have analyzed and developed a formal specification of a trust model in semantic grid registry. This paper formalizes the basic requirements of a trust model in case of semantic grid registry. We have described the flow of operations of our system through links and processes in the system architecture. The system is formally modeled in pi-calculus. Finally we transformed the specification to pi- ADL and generated code using Archware tool. We have already developed a semantic grid registry.


Application Of Ict - I: Power Optimization Of Relay Channels, F Ahmed, Z Howard Aug 2009

Application Of Ict - I: Power Optimization Of Relay Channels, F Ahmed, Z Howard

International Conference on Information and Communication Technologies

Relaying in wireless communication can improve power and quality of service. Multiple nodes share channel resources to achieve optimized power. We consider a model with fixed source, destination and relay nodes. Our model finds the optimal values for power transmission for direct and relayed transmitting nodes. In our problem we compare amplify and forward and decode and forward transmission protocols. Unlike other researchers who use constant achievable rates as objective function and power as constraint, we use the strategy of minimizing relay and source power with achievable and target rates as constraints. We simulate various scenarios and our results indicate …


Application Of Ict - I: A Framework For Finding Minimal Test Vectors For Stuck-At-Faults, Azam Beg, S.K. Hasnain Aug 2009

Application Of Ict - I: A Framework For Finding Minimal Test Vectors For Stuck-At-Faults, Azam Beg, S.K. Hasnain

International Conference on Information and Communication Technologies

This paper presents a framework that utilizes Boolean difference theory to find test vectors for stuck-at-fault detection. The framework reads in structural-style Verilog models, and automatically injects single stuck-at-faults (either stuck-at-zero or stuck-at-one) into the models. The simulations are then performed to find minimal sets of test vectors. Using this setup, we conducted experiments on more than 4000 different circuits. The results show that an appreciable savings in test time and effort can be achieved using the method. The same setup can also be used for didactic purposes, specifically for digital design and test courses.


Application Of Ict - I: Using Point-To-Point 1550nm Laser For Outdoor Mobility, Roshan A. Shaikh, Abdul Basit Aug 2009

Application Of Ict - I: Using Point-To-Point 1550nm Laser For Outdoor Mobility, Roshan A. Shaikh, Abdul Basit

International Conference on Information and Communication Technologies

Significant implementation challenges exist in wireless backbone connectivity. Typical optical wireless communication topologies are evaluated. A fresh approach using 1550nm Wavelength laser to design protocol and topology for point-to-point outdoor connectivity is carried out. Matlab simulation results support the 1550nm laser as a good choice for outdoor connectivity for optical wireless communication. New design and topology for an optical wireless communication system is suggested with special consideration of security and recommendation for the optimal use of such a technology is suggested.


Networks - I: Networks-On-Chip: Challenges, Trends And Mechanisms For Enhancements, Omer Tayan Aug 2009

Networks - I: Networks-On-Chip: Challenges, Trends And Mechanisms For Enhancements, Omer Tayan

International Conference on Information and Communication Technologies

The rate of increase of silicon capacity in integrated circuits (IC) will enable system integration of several billion transistors to reside on a single chip in the near future. Future system-on-chip (SoC) systems must therefore integrate up to several hundreds of cores within a single chip, and SoC designs will employ on-chip communication networks (NoCs) as a result. This paper discusses the problems with many current SoC systems, surveys the challenges and trends facing future SoC designs and proposes a mechanism for enhancing NoC strategies of the future by enhancing memory management and utilization techniques within an NoC.


Networks - I: An Instantiation Of Way Point Routing For Mobile Ad Hoc Networks, Waseem M. Arain, Sayeed Ghani Aug 2009

Networks - I: An Instantiation Of Way Point Routing For Mobile Ad Hoc Networks, Waseem M. Arain, Sayeed Ghani

International Conference on Information and Communication Technologies

Mobile ad hoc networks are increasingly finding their existence in the marketplace heading to a new paradigm of pervasive computing. However there are many areas open to research in the field. Due to node mobility resulting in an ever-changing network topology, conventional routing methods cannot be applied in MANETS. Therefore, this is one of the core areas of research. Researchers are challenged to design protocols that can potentially scale to anything from thousand to tens of thousands of nodes and to reduce the route discovery latency. In this paper a different instantiation of way point routing (WPR) model is proposed, …


Networks - I: A Comparative Analysis Of Dccp Variants (Ccid2, Ccid3), Tcp And Udp For Mpeg4 Video Applications, Muhammad Ajmal Azad, Rashid Mahmood, Tahir Mehmood Aug 2009

Networks - I: A Comparative Analysis Of Dccp Variants (Ccid2, Ccid3), Tcp And Udp For Mpeg4 Video Applications, Muhammad Ajmal Azad, Rashid Mahmood, Tahir Mehmood

International Conference on Information and Communication Technologies

New emerging technologies like Multimedia applications require timely delivery of information as compared to reliability. The most widely used protocols over transport layer are Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). Both of these have some drawbacks while using in real time applications. TCP increases delay in transfer of data but achieving reliable transfer of data while UDP does not provide any acknowledgment, hence it overcomes the problem of delay but lacking congestion control mechanism. To provide congestion control over transport layer using UDP, Datagram Congestion Control Protocol (DCCP) has been designed to provide timely delivery of data …


Artificial Intelligence – I: A Two-Step Approach For Improving Efficiency Of Feedforward Multilayer Perceptrons Network, Shoukat Ullah, Zakia Hussain Aug 2009

Artificial Intelligence – I: A Two-Step Approach For Improving Efficiency Of Feedforward Multilayer Perceptrons Network, Shoukat Ullah, Zakia Hussain

International Conference on Information and Communication Technologies

An artificial neural network has got greater importance in the field of data mining. Although it may have complex structure, long training time, and uneasily understandable representation of results, neural network has high accuracy and is preferable in data mining. This research paper is aimed to improve efficiency and to provide accurate results on the basis of same behaviour data. To achieve these objectives, an algorithm is proposed that uses two data mining techniques, that is, attribute selection method and cluster analysis. The algorithm works by applying attribute selection method to eliminate irrelevant attributes, so that input dimensionality is reduced …


Selection Of Switching Sites In All-Optical Nework Topology Design, Shivashis Saha, Eric D. Manley, Jitender S. Deogun Aug 2009

Selection Of Switching Sites In All-Optical Nework Topology Design, Shivashis Saha, Eric D. Manley, Jitender S. Deogun

School of Computing: Technical Reports

In this paper, we consider the problem of topology design for optical networks. We investigate the problem of selecting switching sites to minimize total cost of the optical network. The cost of an optical network can be expressed as a sum of three main factors: the site cost, the link cost, and the switch cost. To the best of our knowledge, this problem has not been studied in its general form as investigated in this paper. We present a mixed integer quadratic programming (MIQP) formulation of the problem to find the optimal value of the total network cost. We also …


Design Of An All-Optical Wdm Lightpath Concentrator, Shivashis Saha, Jitender S. Deogun Aug 2009

Design Of An All-Optical Wdm Lightpath Concentrator, Shivashis Saha, Jitender S. Deogun

School of Computing: Technical Reports

A design of a nonblocking, all-optical lightpath concentrator using WOC and WDM crossbar switches is presented. The proposed concentrator is highly scalable, cost-efficient, and can switch signals in both space and wavelength domains without requiring a separate wavelength conversion stage.


Microsoft Silverlight Photography Framework: Comparing Component Based Designs In Adobe Flex And Microsoft Silverlight, David Roossien Aug 2009

Microsoft Silverlight Photography Framework: Comparing Component Based Designs In Adobe Flex And Microsoft Silverlight, David Roossien

Masters Projects

Flex and Silverlight provide large Application Programming Interfaces (API’s). Applications can be designed using a variety of architectures. The purpose of this paper is not to perform a complete comparison between Flex and Silverlight. To do such a comparison would require massive amounts of time and research. The purpose of this paper is to describe the design and implementation of the Silverlight photography framework project. Along the way this paper compares the Silverlight project to the Adobe Flex project and discusses the goals of each product. During the comparison many important similarities and differences between Silverlight and Flex technologies are …


Symmetry Between True, False, And Uncertain: An Explanation, Eulalia Szmidt, Vladik Kreinovich Aug 2009

Symmetry Between True, False, And Uncertain: An Explanation, Eulalia Szmidt, Vladik Kreinovich

Departmental Technical Reports (CS)

In intuitionistic fuzzy sets, there is a natural symmetry between degrees of truth and falsity. As a result, for such sets, natural similarity measures are symmetric relative to an exchange of true and false values. It has been recently shown that among such measures, the most intuitively reasonable are the ones which are also symmetric relative to an arbitrary permutation of degrees of truth, falsity, and uncertainty. This intuitive reasonableness leads to a conjecture that such permutations are not simply mathematical constructions, that these permutations also have some intuitive sense. In this paper, we show that each such permutation can …


From Interval Computations To Constraint-Related Set Computations: Towards Faster Estimation Of Statistics And Odes Under Interval And P-Box Uncertainty, Vladik Kreinovich Aug 2009

From Interval Computations To Constraint-Related Set Computations: Towards Faster Estimation Of Statistics And Odes Under Interval And P-Box Uncertainty, Vladik Kreinovich

Departmental Technical Reports (CS)

No abstract provided.


Scene-Based Nonuniformity Correction With Reduced Ghosting Using A Gated Lms Algorithm, Russell C. Hardie, Frank Orion Baxley, Brandon J. Brys, Patrick C. Hytla Aug 2009

Scene-Based Nonuniformity Correction With Reduced Ghosting Using A Gated Lms Algorithm, Russell C. Hardie, Frank Orion Baxley, Brandon J. Brys, Patrick C. Hytla

Electrical and Computer Engineering Faculty Publications

In this paper, we present a scene-based nouniformity correction (NUC) method using a modified adaptive least mean square (LMS) algorithm with a novel gating operation on the updates. The gating is designed to significantly reduce ghosting artifacts produced by many scene-based NUC algorithms by halting updates when temporal variation is lacking. We define the algorithm and present a number of experimental results to demonstrate the efficacy of the proposed method in comparison to several previously published methods including other LMS and constant statistics based methods. The experimental results include simulated imagery and a real infrared image sequence. We show that …