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Old Dominion University

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Articles 1711 - 1740 of 1996

Full-Text Articles in Computer Sciences

Protecting The Communication Structure In Sensor Networks, S. Olariu, Q. Xu, M. Eltoweissy, A. Wadaa Jan 2005

Protecting The Communication Structure In Sensor Networks, S. Olariu, Q. Xu, M. Eltoweissy, A. Wadaa

Computer Science Faculty Publications

In the near future wireless sensor networks will be employed in a wide variety of applications establishing ubiquitous networks that will pervade society. The inherent vulnerability of these massively deployed networks to a multitude of threats, including physical tampering with nodes exacerbates concerns about privacy and security. For example, denial of service attacks (DoS) that compromise or disrupt communications or target nodes serving key roles in the network, e.g. sink nodes, can easily undermine the functionality as well as the performance delivered by the network. Particularly vulnerable are the components of the communications or operation infrastructure. Although, by construction, most …


Introduction: Data Communication And Topology Algorithms For Sensor Networks, Stephan Olariu, David Simplot-Ryl, Ivan Stojmenovic Jan 2005

Introduction: Data Communication And Topology Algorithms For Sensor Networks, Stephan Olariu, David Simplot-Ryl, Ivan Stojmenovic

Computer Science Faculty Publications

(First paragraph) We are very proud and honored to have been entrusted to be Guest Editors for this special issue. Papers were sought to comprehensively cover the algorithmic issues in the “hot” area of sensor networking. The concentration was on network layer problems, which can be divided into two groups: data communication problems and topology control problems. We wish to briefly introduce the five papers appearing in this special issue. They cover specific problems such as time division for reduced collision, fault tolerant clustering, self-stabilizing graph optimization algorithms, key pre-distribution for secure communication, and distributed storage based on spanning trees …


Energy-Efficient Self-Organization Protocols For Sensor Networks, Qingwen Xu Jan 2005

Energy-Efficient Self-Organization Protocols For Sensor Networks, Qingwen Xu

Computer Science Theses & Dissertations

A Wireless Sensor Network (WSN, for short) consists of a large number of very small sensor devices deployed in an area of interest for gathering and delivery information. The fundamental goal of a WSN is to produce, over an extended period of time, global information from local data obtained by individual sensors. The WSN technology will have a significant impact on a wide array of applications on the efficiency of many civilian and military applications including combat field surveillance, intrusion detection, disaster management among many others. The basic management problem in the WSN is to balance the utility of the …


Recommender Systems For Multimedia Libraries: An Evaluation Of Different Models For Datamining Usage Data, Raquel Oliveira Araujo Dec 2004

Recommender Systems For Multimedia Libraries: An Evaluation Of Different Models For Datamining Usage Data, Raquel Oliveira Araujo

Computer Science Theses & Dissertations

Many recommender systems exist today to help users deal with the large growth in the amount of information available in the Internet. Most of these recommender systems use collaborative filtering or content-based techniques to present new material that would be of interest to a user. While these methods have proven to be effective, they have not been designed specifically for multimedia collections. In this study we present a new method to find recommendations that is not dependent on traditional Information Retrieval (IR) methods and compare it to algorithms that do rely on traditional IR methods. We evaluated these algorithms using …


Social Engineering In The Age Of Ai, Mohammad A. Saleh Nov 2004

Social Engineering In The Age Of Ai, Mohammad A. Saleh

Cybersecurity Undergraduate Research Showcase

The next great invention is artificial intelligence. AI has grown rapidly over the last 15 years and has brought both advantages and disadvantages to everyday society. One of the most concerning disadvantages highlighted in recent years is the rise of social engineering attacks. Social engineering comes in many different forms, making it difficult to identify at times. With the development of AI, these attacks have become even harder to detect, prevent, and stop. This research essay explores the different types of AI-driven social engineering attacks, how they occur, why they happen, and the impact they have on individuals and organizations.


Bottleneck Analysis Of Cports, Sreekalyana Chakravarthy Kajuluri Oct 2004

Bottleneck Analysis Of Cports, Sreekalyana Chakravarthy Kajuluri

Electrical & Computer Engineering Theses & Dissertations

CPortS is a transportation logistics simulation that models the flow of military cargo through a seaport and the interaction of the cargo with the port resources and infrastructure. It provides information about the seaport's capabilities, how the cargo has been handled, how many days the cargo took to clear a particular port area, and the overall throughput of the seaport. The model is highly data intensive since it models the huge traffic in a real seaport.

Bottlenecks reduce system performance. Systems that are traffic intensive or simulations of systems, which are data intensive, encounter bottlenecks, which reduce their performance. In …


Hierarchical Hybrid Multicast An End System Multicast Algorithm Approach, Guillermo Loaisiga Oct 2004

Hierarchical Hybrid Multicast An End System Multicast Algorithm Approach, Guillermo Loaisiga

Electrical & Computer Engineering Theses & Dissertations

Due to the rapid development in the computer and communication technologies, the Internet is experiencing an increasing demand of high-speed, real-time distributed applications, such as live streaming multimedia, videoconferencing, distributed simulations, and multiparty games. Multicast is an efficient transmission mechanism to support these applications. Historically, IP Multicast (IPM) has provided multicast support with well-known benefits, especially in bandwidth savings. However, it has experienced little deployment due to economic and architectural limitations.

Overlay multicast holds promise for the implementation of large scale Internet multicast services. An overlay network is a virtual topology constructed on top of the Internet infrastructure. This concept …


On Thacker's Biomedia (2004), Nicholas Ruiz Iii Oct 2004

On Thacker's Biomedia (2004), Nicholas Ruiz Iii

Reconstruction: Studies in Contemporary Culture

[First paragraph]

Only we could have done it. The Code (DNA and its analogs, etc.) that we perhaps only narrate, never forgetting all of the fictions that narration portends, today consciously edits the text that evolution has edited unconsciously for eons. Thacker considers how humans -- perhaps little more than interactive Code, manipulate the Code -- with the technology of the Code. No other faction of Code has yet to make such heady ‘gains.’ Where posthumanity was always a literary endeavor, a literary bypass, out of instrumental science and into fictive states, it now is a technical endeavor, encompassing a …


Huffman Approach To Opcode Compression, Jason B. Shreve Oct 2004

Huffman Approach To Opcode Compression, Jason B. Shreve

Electrical & Computer Engineering Theses & Dissertations

Instructions are the building blocks of computer programs. They are composed of opcodes, which uniquely identify each instruction, and the operands or data. In most architectures, the instruction length is a set multiple of the word size. The size and number of operands vary by instruction. Due to programmer usage, program need, or compiler design, opcodes do not occur with a constant distribution. Likely, some opcodes occur very frequently, whereas others occur very infrequently or not at all. If the length of an opcode were representative of its frequency, compression in program size might be achieved.

This thesis is an …


Vector Operations In Superscalar Architectures, Nathan Daniel Flinn Oct 2004

Vector Operations In Superscalar Architectures, Nathan Daniel Flinn

Electrical & Computer Engineering Theses & Dissertations

Vector calculations are very prevalent today. Though the vector-processing computer is quite an old concept, superscalar processors lack hardware support for vector operations. This thesis investigates whether an ordinary superscalar computer architecture can be designed to include hardware support for improved vector operations without drastically changing the existing superscalar design and behavior. A computer architecture design was created and implemented that included the vector multiply (dot product) operation. The design includes a Vector Operations Unit that captures incoming vector operations and generates the necessary set of machine instructions to complete the vector operation internally. It then delivers these instructions to …


An Algorithm For Locating Fundamental Frequency (F0) Markers In Speech, Princy Dikshit Oct 2004

An Algorithm For Locating Fundamental Frequency (F0) Markers In Speech, Princy Dikshit

Electrical & Computer Engineering Theses & Dissertations

Speech has been the principal form of human communication since it began to evolve at least one hundred thousand years ago. Speech is produced by vibrations of the vocal cords. The rate of vibration of the cords is called fundamental frequency (F0) or pitch. The objective of this thesis is to locate pitch period cycles on a cycle-by-cycle basis. The complexity in identifying pitch cycles stems from the highly irregular nature of human speech. Dynamic programming is used to combine two sources of information for pitch period marking. One source of information is the "local" information corresponding to the location …


Qos Provisioning For Multi-Class Traffic In Wireless Networks, Mona El-Kadi Rizvi Jul 2004

Qos Provisioning For Multi-Class Traffic In Wireless Networks, Mona El-Kadi Rizvi

Computer Science Theses & Dissertations

Physical constraints, bandwidth constraints and host mobility all contribute to the difficulty of providing Quality of Service (QoS) guarantees in wireless networks. There is a growing demand for wireless networks to support all the services that are available on wired networks. These diverse services, such as email, instant messaging, web browsing, video conferencing, telephony and paging all place different demands on the network, making QoS provisioning for wireless networks that carry multiple classes of traffic a complex problem. We have developed a set of admission control and resource reservation schemes for QoS provisioning in multi-class wireless networks.

We present three …


Fuzzy Modeling Of Electromagnetic Emissions From Portable Electronic Devices Onboard Commercial Aircraft, Madiha Jamil Jafri Jul 2004

Fuzzy Modeling Of Electromagnetic Emissions From Portable Electronic Devices Onboard Commercial Aircraft, Madiha Jamil Jafri

Electrical & Computer Engineering Theses & Dissertations

The use of Portable Electronic Devices (PEDs) is prohibited during take-off and landing of an aircraft because PEDs may emit signals that can interfere with the aircraft's navigation and communication systems. The electromagnetic interference (EMI) on the aircraft's electronics due to PEDs emissions is examined for Boeing 737 and 747 aircraft. This work, funded by the NASA Graduate Researchers Program, uses Interference Path Loss (IPL) data, collected by researchers from NASA Langley Research Center, Eagles Wings Inc. and United Airlines on several out-of-service United B737 and B747 airplanes.

B737 and B747 IPL data has been analyzed using a graphical analysis …


Interactive Land Use Vrml Application Using Servlet Assist, Suresh Chitithoti Jul 2004

Interactive Land Use Vrml Application Using Servlet Assist, Suresh Chitithoti

Electrical & Computer Engineering Theses & Dissertations

The integration of VRML and Servlet technologies has the potential to revolutionize web-based simulation visualization. The Interactive Land Use VRML Application (ILUVA) uses Java Servlets enabling one to perform urban planning by taking a virtual land area and add buildings, roadways, landscaping, and other features. The Virtual Reality Modeling Language (VRML) is a web-based technology for specifying and delivering interactive three-dimensional visualizations over a browser. The Java Servlet technology offers several powerful capabilities such as user authentication, session management, database connectivity for maintaining several possibly simultaneous user sessions, and dynamically generated VRML. Save and restore capabilities for any applications are …


Probing The Posthuman: Richard Powers' Galatea 2.2 And The Mind-Body Problem, Miranda Campbell Jul 2004

Probing The Posthuman: Richard Powers' Galatea 2.2 And The Mind-Body Problem, Miranda Campbell

Reconstruction: Studies in Contemporary Culture

[Editors' Introduction]

In this paper, Miranda Campbell discusses Richard Powers' novel Galatea 2.2 and argues that this work is situated at the intersection of the posthumanist and humanist discourses. Campbell examines Powers' approach to the mind-body problem, his interrogation of the limits and limitations of posthumanism, and its dissolution of the importance of the body, difference, and agency. In the posthuman setting of the Center for Advanced Science of this novel, scientists integrate the mind into the body through its designation as a mechanically functioning brain. At the Center, the binary of human and machine begins to erode with the …


Parallel Decomposition Procedures For Large-Scale Linear Programming Problems, Yusong Hu Apr 2004

Parallel Decomposition Procedures For Large-Scale Linear Programming Problems, Yusong Hu

Civil & Environmental Engineering Theses & Dissertations

In practice, many large-scale linear programming problems are too large to be solved effectively due to the computer's speed and/or memory limitation, even though today's computers have many more capabilities than before. Algorithms are exploited to solve such large linear programming problems, either in the sequential or parallel computation environment. This study focuses on two parallel algorithms for solving large-scale linear programming problems efficiently.

The first parallel decomposition algorithm discussed in this study is from the theory problems in a special block-angular structure. The theory or the decomposition principle is first examined. Since the subproblems of a linear programming problem …


Generic Performance Evaluation Tool Implementation For An Imaging Fourier Transform Spectrometer, James M. Mengert Apr 2004

Generic Performance Evaluation Tool Implementation For An Imaging Fourier Transform Spectrometer, James M. Mengert

Electrical & Computer Engineering Theses & Dissertations

Evaluation software for analyzing general analytical model applications utilizing MATLAB is presented in this thesis. The focus is to provide an interactive environment for the evaluation of model applications relating to an Imaging Fourier Transform Spectrometer. The Generic Performance Evaluation Tool (GPET) was developed by researchers at Old Dominion University and NASA-Langley Research Center and was a NASA-Langley Research Center sponsored project. GPET is capable of producing a multitude of object-oriented input data for any number of individual model applications. The tool is also capable of creating user-defined input interfaces for the purpose of viewing and/or editing input object data, …


Speaker Normalization For Improved Automatic Speech Recognition For Digital Libraries, Wei Wang Apr 2004

Speaker Normalization For Improved Automatic Speech Recognition For Digital Libraries, Wei Wang

Electrical & Computer Engineering Theses & Dissertations

The context of this thesis work is the improvement of automatic speech recognition (ASR) for use with digital libraries. First, commonly used multimedia file formats and codecs are surveyed with the objective of identifying those formats that preserve speech quality while keeping file sizes compact. The main contribution of the work is a new technique for speaker adaptation based on frequency scale modifications. The frequency scale is modified using a minimum mean square error matching of a spectral template for each speaker to a "typical speaker" spectral template. Each spectral template is computed from the average amplitude-normalized spectra of several …


Models, Composability, And Validity, Eric Werner Weisel Apr 2004

Models, Composability, And Validity, Eric Werner Weisel

Computational Modeling & Simulation Engineering Theses & Dissertations

Composability is the capability to select and assemble simulation components in various combinations into simulation systems to satisfy specific user requirements. The defining characteristic of composability is the ability to combine and recombine components into different simulation systems for different purposes. The ability to compose simulation systems from repositories of reusable components has been a highly sought after goal among modeling and simulation developers. The expected benefits of robust, general composability include reduced simulation development cost and time, increased validity and reliability of simulation results, and increased involvement of simulation users in the process. Consequently, composability is an active research …


A Framework For Secure Group Key Management, Sahar Mohamed Ghanem Apr 2004

A Framework For Secure Group Key Management, Sahar Mohamed Ghanem

Computer Science Theses & Dissertations

The need for secure group communication is increasingly evident in a wide variety of governmental, commercial, and Internet communities. Secure group key management is concerned with the methods of issuing and distributing group keys, and the management of those keys over a period of time. To provide perfect secrecy, a central group key manager (GKM) has to perform group rekeying for every join or leave request. Fast rekeying is crucial to an application's performance that has large group size, experiences frequent joins and leaves, or where the GKM is hosted by a group member. Examples of such applications are interactive …


Using Web Services To Integrate Heterogeneous Simulations In A Grid Environment, J. Mark Pullen, Ryan Brunton, Don Brutzman, David Drake, Michael Hieb, Katherine L. Morse, Andreas Tolk Jan 2004

Using Web Services To Integrate Heterogeneous Simulations In A Grid Environment, J. Mark Pullen, Ryan Brunton, Don Brutzman, David Drake, Michael Hieb, Katherine L. Morse, Andreas Tolk

Computational Modeling & Simulation Engineering Faculty Publications

The distributed information technologies collectively known as Web services recently have demonstrated powerful capabilities for scalable interoperation of heterogeneous software across a wide variety of networked platforms. This approach supports a rapid integration cycle and shows promise for ultimately supporting automatic composability of services using discovery via registries. This paper presents a rationale for extending Web services to distributed simulation environments, including the High Level Architecture (HLA), together with a description and examples of the integration methodology used to develop significant prototype implementations. A logical next step is combining the power of Grid computing with Web services to facilitate rapid …


Optimal Design Of Engineering Systems Using Mpi-Enabled Genetic Algorithm, S. D. Rajan, D. T. Nguyen, M. D. Deshpande, L. Harrell Jan 2004

Optimal Design Of Engineering Systems Using Mpi-Enabled Genetic Algorithm, S. D. Rajan, D. T. Nguyen, M. D. Deshpande, L. Harrell

Civil & Environmental Engineering Faculty Publications

The focus of this paper is on the development and implementation of a genetic algorithm (GA)-based software system using message passing interface (MPI) protocol and library. A customized form of simple GA used in previous research [1-4] is parallelized. This MPI-enabled version is used to find the solution to finite element based design optimization problems. Results show that an almost linear speedup is obtained on homogenous hardware cluster and, with proper reworking of the software, on heterogeneous hardware cluster.


Reading Over The Shoulder Of The Future At The Library Of Congress, Samuel Gerald Collins Jan 2004

Reading Over The Shoulder Of The Future At The Library Of Congress, Samuel Gerald Collins

Reconstruction: Studies in Contemporary Culture

[First paragraph]

It is 2003 and I am doing some research at the Library of Congress, the de facto national library for the United States and the largest library in the world. Next to me sit some articles I've printed off of online journals on the Defense Advanced Research Project Agency's Total Information Awareness Project, a plan, still in its formative stage, to throw a panopticon net of surveillance across the United States through a combination of language translation technologies, data search and pattern recognition technologies, and advanced collaborative and decision support tools (DARPA). But I am also doing research …


Resource Harvesting Within The Oai-Pmh Framework, Herbert Van De Sompel, Michael L. Nelson, Carl Lagoze, Simeon Warner Jan 2004

Resource Harvesting Within The Oai-Pmh Framework, Herbert Van De Sompel, Michael L. Nelson, Carl Lagoze, Simeon Warner

Computer Science Faculty Publications

Motivated by preservation and resource discovery, we examine how digital resources, and not just metadata about resources, can be harvested using the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH). We review and critique existing techniques for identifying and gathering digital resources using metadata harvested through the OAI-PMH. We introduce an alternative solution that builds on the introduction of complex object formats that provide a more accurate way to describe digital resources. We argue that the use of complex object formats as OAI-PMH metadata formats results in a reliable and attractive approach for incremental harvesting of resources using the OAI-PMH.


Metadata And Buckets In The Smart Object, Dumb Archive (Soda) Model, Michael L. Nelson, Kurt Maly, Delwin R. Croom Jr., Steven W. Robbins Jan 2004

Metadata And Buckets In The Smart Object, Dumb Archive (Soda) Model, Michael L. Nelson, Kurt Maly, Delwin R. Croom Jr., Steven W. Robbins

Computer Science Faculty Publications

We present the Smart Object, Dumb Archive (SODA) model for digital libraries (DLs), and discuss the role of metadata in SODA. The premise of the SODA model is to "push down" many of the functionalities generally associated with archives into the data objects themselves. Thus the data objects become "smarter", and the archives "dumber". In the SODA model, archives become primarily set managers, and the objects themselves negotiate and handle presentation, enforce terms and conditions, and perform data content management. Buckets are our implementation of smart objects, and da is our reference implementation for dumb archives. We also present our …


Istart: Interactive Strategy Training For Active Reading And Thinking, Danielle S. Mcnamara, Irwin B. Levinstein, Chutima Boonthum Jan 2004

Istart: Interactive Strategy Training For Active Reading And Thinking, Danielle S. Mcnamara, Irwin B. Levinstein, Chutima Boonthum

Computer Science Faculty Publications

Interactive Strategy Training for Active Reading and Thinking (iSTART) is a Web-based application that provides young adolescent to college-age students with high-level reading strategy training to improve comprehension of science texts. iSTART is modeled after an effective, human-delivered intervention called self-explanation reading training (SERT), which trains readers to use active reading strategies to self-explain difficult texts more effectively. To make the training more widely available, the Web-based trainer has been developed. Transforming the training from a human-delivered application to a computer-based one has resulted in a highly interactive trainer that adapts its methods to the performance of the students. The …


Digital Library Services For Three-Dimensional Models, Hesham Anan Jan 2004

Digital Library Services For Three-Dimensional Models, Hesham Anan

Computer Science Theses & Dissertations

With the growth in computing, storage and networking infrastructure, it is becoming increasingly feasible for multimedia professionals—such as graphic designers in commercial, manufacturing, scientific and entertainment areas—to work with 3D digital models of the objects with which they deal in their domain. Unfortunately most of these models exist in individual repositories, and are not accessible to geographically distributed professionals who are in need of them.

Building an efficient digital library system presents a number of challenges. In particular, the following issues need to be addressed: (1) What is the best way of representing 3D models in a digital library, so …


A Longitudinal Metric Study Of Postgresql Software Archeology In Open Source, Terry Franklin Byrum Dec 2003

A Longitudinal Metric Study Of Postgresql Software Archeology In Open Source, Terry Franklin Byrum

Computer Science Theses & Dissertations

Open source software development is credited as the basic fuel powering much of the Internet, especially the Web. While many organizations rely heavily on open source, few studies have focused on the dynamics of development methodology. This document contains the results of a longitudinal metric study of the open source database PostgreSQL representing an 8 year period of community development. This study is software archeology, excavating bits of an Internet community, a cultural group, for understanding. Longitudinally, McCabe's cyclomatic complexity and Halstead's software science change tempo in accordance with PostgreSQL's maturity, though meritocracy practices of open source might suggest greater …


A Computer-Based Articulation Training Aid For Short Words (Cata), Mukund Devarajan Oct 2003

A Computer-Based Articulation Training Aid For Short Words (Cata), Mukund Devarajan

Electrical & Computer Engineering Theses & Dissertations

Several improvements in the vowel articulation training aid (VATA) are described, as well as the efforts to extend the visual feedback system to operate with short words in the form of consonant, vowel and consonant (CVC). The extended version of the visual feedback system is referred to as CATA (Computer-based Articulation Training Aid); the vowel version of the aid (VATA) only operates with ten American English monopthong vowels. Improvements in VATA include the use of a neural network (NN) recognizer method to prune a large database of vowel recordings to eliminate noisy and/or mispronounced tokens. The spectral jitter problem, previously …


Unidirectional Cordic For Efficient Computation Of Trigonometric And Hyperbolic Functions, Satish Ravichandran Oct 2003

Unidirectional Cordic For Efficient Computation Of Trigonometric And Hyperbolic Functions, Satish Ravichandran

Electrical & Computer Engineering Theses & Dissertations

CORDIC (Coordinate Rotation Digital Computer) is an iterative algorithm to compute values of trigonometric, logarithmic and transcendental functions by performing vector rotations, which can be implemented with only shift and add operations in a digital system. CORDIC algorithms are extensively used in the areas of digital signal processing, digital image processing and artificial neural networks. A new technique, named unidirectional CORDIC, for efficient computation of trigonometric and hyperbolic functions is presented in this thesis. In the conventional CORDIC algorithm, the vector rotations are performed in both clockwise and counterclockwise directions, but in the unidirectional CORDIC the vectors are rotated only …