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Old Dominion University

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Articles 1621 - 1650 of 1996

Full-Text Articles in Computer Sciences

Distributed Knowledge Discovery In Large Scale Peer-To-Peer Networks, Sachin Shetty Jul 2007

Distributed Knowledge Discovery In Large Scale Peer-To-Peer Networks, Sachin Shetty

Computational Modeling & Simulation Engineering Theses & Dissertations

Explosive growth in the availability of various kinds of data in distributed locations has resulted in unprecedented opportunity to develop distributed knowledge discovery (DKD) techniques. DKD embraces the growing trend of merging computation with communication by performing distributed data analysis and modeling with minimal communication of data. Most of the current state-of-the-art DKD systems suffer from the lack of scalability, robustness and adaptability due to their dependence on a centralized model for building the knowledge discovery model. Peer-to-Peer networks offer a better scalable and fault-tolerant computing platform for building distributed knowledge discovery models than client-server based platforms. Algorithms and communication …


Investigating Real-Time Sonar Performance Predictions Using Beowulf Clustering, Charles Lane Cartledge Jul 2007

Investigating Real-Time Sonar Performance Predictions Using Beowulf Clustering, Charles Lane Cartledge

Computer Science Theses & Dissertations

Predicting sonar performance, critical to using any sonar to its maximum effectiveness, is computationally intensive and typically the results are based on data from the past and may not be applicable to the current water conditions. This paper discusses how Beowulf clustering techniques were investigated and applied to achieve real-time sonar performance prediction capabilities based on commercially off the shelf (COTS) hardware and software. A sonar system measures ambient noise in real-time. Based on the active sonar range scale, new ambient measurements can be available every 1 to 24 seconds. Traditional sonar performance prediction techniques operated serially and often took …


Dynamic Routing Structure For An Rti Taking An Evolutionary Approach Towards Optimization, Matthew Ryan Davis Jul 2007

Dynamic Routing Structure For An Rti Taking An Evolutionary Approach Towards Optimization, Matthew Ryan Davis

Computational Modeling & Simulation Engineering Theses & Dissertations

The Runtime Infrastructure (RTI) is the common communication framework that High Level Architecture (HLA) simulations incorporate to exchange data. By abstracting the network communication layer from simulation, a common protocol for information exchange is achieved, allowing any RTI- based simulation to exchange data with any other. Such commonality can bring a limitation upon the network infrastructure, enforcing all federates to agree on the same communication policy. While this static network structure is not always the case, an optimal choice would be to adhere to the dynamic properties of a network. Static network configurations deny federates the ability to dynamically avoid …


Factors Affecting Website Reconstruction From The Web Infrastructure, Frank Mccown, Norou Diawara, Michael L. Nelson Jun 2007

Factors Affecting Website Reconstruction From The Web Infrastructure, Frank Mccown, Norou Diawara, Michael L. Nelson

Computer Science Faculty Publications

When a website is suddenly lost without a backup, it may be reconstituted by probing web archives and search engine caches for missing content. In this paper we describe an experiment where we crawled and reconstructed 300 randomly selected websites on a weekly basis for 14 weeks. The reconstructions were performed using our web-repository crawler named Warrick which recovers missing resources from the Web Infrastructure (WI), the collective preservation effort of web archives and search engine caches. We examine several characteristics of the websites over time including birth rate, decay and age of resources. We evaluate the reconstructions when compared …


The Open Archives Initiative, Michael L. Nelson May 2007

The Open Archives Initiative, Michael L. Nelson

Computer Science Presentations

PDF of a powerpoint presentation from the Open Archives Initiative DRIADE ( Digital Repository of Information and Data for Evolution) Workshop, Durham, North Carolina, May 16-17, 2007. Also available on Slideshare.


A Wavelet Based Complementary Approach For Image Enhancement, Ismail Kosum Apr 2007

A Wavelet Based Complementary Approach For Image Enhancement, Ismail Kosum

Electrical & Computer Engineering Theses & Dissertations

Detail in an image means more meaningful information that is very important in many computer vision and pattern recognition applications. The object region visibility in an image plays an important role in obtaining accurate and desired information from the original image. In particular, image processing techniques developed for region segmentation and object classification have better results depending on the visibility in images. There are several enhancement techniques available which are capable of obtaining clear images with balanced lighting and contrast. In this thesis, a completely image dependent approach to enhance the luminance of images under extreme lighting conditions and a …


Long-Range Target Classification In A Cluttered Environment Using Multi-Sensor Image Sequences, Cenk Yaman Apr 2007

Long-Range Target Classification In A Cluttered Environment Using Multi-Sensor Image Sequences, Cenk Yaman

Electrical & Computer Engineering Theses & Dissertations

Accurate identification of unknown contacts is crucial in military intelligence. Automated systems which quickly and accurately determine the identity of a contact could be a benefit in backing up electronic signal identification methods such as Identification Friend and Foe (IFF) systems. Radio Detection and Ranging (RADAR) images are often undesirable in military applications since they reveal the location of the imaging system. So we explore the use of visible and infrared images of which are generally more consistent than RADAR images and for which it is easy to compensate for environmental effects. Recent advances in visible and IR imaging technology …


An Exploratory Study Of Iso 9001:2000 Quality Management Systems Using The Iso/Iec 15504 Architecture, Paul Richard Shimp Apr 2007

An Exploratory Study Of Iso 9001:2000 Quality Management Systems Using The Iso/Iec 15504 Architecture, Paul Richard Shimp

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this paper is to provide an exploratory study on the implementation and issues regarding Quality Management Systems as defined by ISO 9001 :2000 using the architecture of ISO/IEC 15504. The recently published ISO/IEC 15504 series of standards provides a framework to assess processes and determine levels of capability. With the use of this framework, the study will focus on the assessment and identification of problem areas requiring focus for continual improvement within an ISO 9001 :2000 quality management system.

The structure of this paper is as follows: Section 1 provides a background discussion of ISO 9001 :2000. …


A Structured Systemic Framework For Software Development, Kevin Macgregor Adams Apr 2007

A Structured Systemic Framework For Software Development, Kevin Macgregor Adams

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this research was to develop and apply a systems-based framework for the analysis of software development project performance. Software development project performance is measured at the project level; that is, cost, schedule, and product quality that affect the overall project. To date, most performance improvement efforts have been focused on individual processes within the overall software development system. Making improvements to sub-elements, processes, or sub-systems without regard for the overall project is a classic misbehavior entered into by practitioners who fail to use a holistic, systemic approach. Attempts to improve sub-system behavior are at odds with The …


Performance Analysis Of Ieee 802.11b Devices In The Presence Of Interference Aware Scheduling-Adaptive Frequency Hopping Enabled Bluetooth Devices, Deepthi Gopalpet Apr 2007

Performance Analysis Of Ieee 802.11b Devices In The Presence Of Interference Aware Scheduling-Adaptive Frequency Hopping Enabled Bluetooth Devices, Deepthi Gopalpet

Electrical & Computer Engineering Theses & Dissertations

Wireless Local Area networks (WLAN) and Wireless Personal Area Networks (WPAN) provide complimentary services using the same unlicensed radio frequency band of operation. The 802.11b WLAN operates in the 2.4 GHz band and uses a Direct Sequence Spread Spectrum technique. It is designed to cover large areas ranging up to 100 meters in diameter, which may connect hundreds of computers. Bluetooth (BT) WPAN also operates in the same frequency band as the IEEE 802.lib and it uses a Frequency Hopping Spread Spectrum technique. BT is primarily used for communications between notebooks, palm units and other personal computing devices within relatively …


Diagnosing Reading Strategies: Paraphrase Recognition, Chutima Boonthum Apr 2007

Diagnosing Reading Strategies: Paraphrase Recognition, Chutima Boonthum

Computer Science Theses & Dissertations

Paraphrase recognition is a form of natural language processing used in tutoring, question answering, and information retrieval systems. The context of the present work is an automated reading strategy trainer called iSTART (Interactive Strategy Trainer for Active Reading and Thinking). The ability to recognize the use of paraphrase—a complete, partial, or inaccurate paraphrase; with or without extra information—in the student's input is essential if the trainer is to give appropriate feedback. I analyzed the most common patterns of paraphrase and developed a means of representing the semantic structure of sentences. Paraphrases are recognized by transforming sentences into this representation and …


A Resolution Enhancement Technique In Digital Images, Mehmet R. Ormanoglu Apr 2007

A Resolution Enhancement Technique In Digital Images, Mehmet R. Ormanoglu

Electrical & Computer Engineering Theses & Dissertations

Image enhancement is the processing of images to increase their usefulness. The image enhancement methods and objectives vary with the application. When images are enhanced for human viewers, as in television, the objective is mostly to improve perceptual aspects: image quality, intelligibility, or visual appearance. The aim of this research work is to make the processed image better in the visual sense than the unprocessed image. An image can often be enhanced by modifying its contrast or dynamic range, increasing the sharpness of edges, reducing the noise, or reducing the blurring. The most commonly used contrast enhancement technique is histogram …


Filling The Ontology Space For Coalition Battle Management Language, Charles Turnitsa, Curtis Blais, Andreas Tolk Jan 2007

Filling The Ontology Space For Coalition Battle Management Language, Charles Turnitsa, Curtis Blais, Andreas Tolk

Computational Modeling & Simulation Engineering Faculty Publications

The Coalition Battle Management Language is a language for representing and exchanging plans, orders, and reports across live, constructive and robotic forces in multi-service, multi-national and multi-organizational operations. Standardization efforts in the Simulation Interoperability Standards Organization seek to define this language through three parallel activities: (1) specify a sufficient data model to unambiguously define a set of orders using the Joint Command, Control, and Consultation Information Exchange Data Model (JC3IEDM) as a starting point; (2) develop a formal grammar (lexicon and production rules) to formalize the definition of orders, requests, and reports; (3) develop a formal battle management ontology to …


Applying The Levels Of Conceptual Interoperability Model In Support Of Integratability, Interoperability, And Composability For System-Of-Systems Engineering, Andreas Tolk, Saikou Y. Diallo, Charles D. Turnitsa Jan 2007

Applying The Levels Of Conceptual Interoperability Model In Support Of Integratability, Interoperability, And Composability For System-Of-Systems Engineering, Andreas Tolk, Saikou Y. Diallo, Charles D. Turnitsa

Computational Modeling & Simulation Engineering Faculty Publications

The Levels of Conceptual Interoperability Model (LCIM) was developed to cope with the different layers of interoperation of modeling & simulation applications. It introduced technical, syntactic, semantic, pragmatic, dynamic, and conceptual layers of interoperation and showed how they are related to the ideas of integratability, interoperability, and composability. The model was successfully applied in various domains of systems, cybernetics, and informatics.


Freelib: A Self-Sustainable Peer-To-Peer Digital Library Framework For Evolving Communities, Ashraf A. Amrou Jan 2007

Freelib: A Self-Sustainable Peer-To-Peer Digital Library Framework For Evolving Communities, Ashraf A. Amrou

Computer Science Theses & Dissertations

The need for efficient solutions to the problem of disseminating and sharing of data is growing. Digital libraries provide an efficient solution for disseminating and sharing large volumes of data to diverse sets of users. They enable the use of structured and well defined metadata to provide quality search services. Most of the digital libraries built so far follow a centralized model. The centralized model is an efficient model; however, it has some inherent problems. It is not suitable when content contribution is highly distributed over a very large number of participants. It also requires an organizational support to provide …


Using Pareto Fronts To Evaluate Polyp Detection Algorithms For Ct Colonography, Adam Huang, Jiang Li, Ronald M. Summers, Nicholas Petrick, Amy K. Hara Jan 2007

Using Pareto Fronts To Evaluate Polyp Detection Algorithms For Ct Colonography, Adam Huang, Jiang Li, Ronald M. Summers, Nicholas Petrick, Amy K. Hara

Electrical & Computer Engineering Faculty Publications

We evaluate and improve an existing curvature-based region growing algorithm for colonic polyp detection for our CT colonography (CTC) computer-aided detection (CAD) system by using Pareto fronts. The performance of a polyp detection algorithm involves two conflicting objectives, minimizing both false negative (FN) and false positive (FP) detection rates. This problem does not produce a single optimal solution but a set of solutions known as a Pareto front. Any solution in a Pareto front can only outperform other solutions in one of the two competing objectives. Using evolutionary algorithms to find the Pareto fronts for multi-objective optimization problems has been …


Exploration Of Computational Methods For Classification Of Movement Intention During Human Voluntary Movement From Single Trial Eeg, Ou Bai, Peter Lin, Sherry Vorbach, Jiang Li, Steve Furlani, Mark Hallett Jan 2007

Exploration Of Computational Methods For Classification Of Movement Intention During Human Voluntary Movement From Single Trial Eeg, Ou Bai, Peter Lin, Sherry Vorbach, Jiang Li, Steve Furlani, Mark Hallett

Electrical & Computer Engineering Faculty Publications

Objective: To explore effective combinations of computational methods for the prediction of movement intention preceding the production of self-paced right and left hand movements from single trial scalp electroencephalogram (EEG).

Methods: Twelve naïve subjects performed self-paced movements consisting of three key strokes with either hand. EEG was recorded from 128 channels. The exploration was performed offline on single trial EEG data. We proposed that a successful computational procedure for classification would consist of spatial filtering, temporal filtering, feature selection, and pattern classification. A systematic investigation was performed with combinations of spatial filtering using principal component analysis (PCA), independent component analysis …


Validating Pareto Optimal Operation Parameters Of Polyp Detection Algorithms For Ct Colonography, Jiang Li, Adam Huang, Nicholas Petrick, Jianhua Yao, Ronald M. Summers, Maryellen L. Giger (Ed.), Nico Karssemeijer (Ed.) Jan 2007

Validating Pareto Optimal Operation Parameters Of Polyp Detection Algorithms For Ct Colonography, Jiang Li, Adam Huang, Nicholas Petrick, Jianhua Yao, Ronald M. Summers, Maryellen L. Giger (Ed.), Nico Karssemeijer (Ed.)

Electrical & Computer Engineering Faculty Publications

We evaluated a Pareto front-based multi-objective evolutionary algorithm for optimizing our CT colonography (CTC) computer-aided detection (CAD) system. The system identifies colonic polyps based on curvature and volumetric based features, where a set of thresholds for these features was optimized by the evolutionary algorithm. We utilized a two-fold cross-validation (CV) method to test if the optimized thresholds can be generalized to new data sets. We performed the CV method on 133 patients; each patient had a prone and a supine scan. There were 103 colonoscopically confirmed polyps resulting in 188 positive detections in CTC reading from either the prone or …


Optimal Layout Of Multicast Groups Using Network Embedded Multicast Security In Ad Hoc Sensor Networks, Richard R. Brooks, Brijesh Pillai, Michele C. Weigle, Matthew Pirretti Jan 2007

Optimal Layout Of Multicast Groups Using Network Embedded Multicast Security In Ad Hoc Sensor Networks, Richard R. Brooks, Brijesh Pillai, Michele C. Weigle, Matthew Pirretti

Computer Science Faculty Publications

This paper considers the security of sensor network applications. Our approach creates multicast regions that use symmetric key cryptography for communications. Each multicast region contains a single keyserver that is used to perform key management and maintain the integrity of a multicast region. Communications between two multicast regions is performed by nodes that belong to both regions. To ease the network management burden, it is desirable for the networks to self-organize into regions and dynamically select their keyservers. This paper shows how to determine the number of keyservers (k) to use and the size in the number of hops (h) …


Hybrid Training With Binary Search Protocol For Wireless Sensor Networks, Ruzana Ishak, Qingwen Xu, Stephan Olariu, Shaharuddin Salleh Jan 2007

Hybrid Training With Binary Search Protocol For Wireless Sensor Networks, Ruzana Ishak, Qingwen Xu, Stephan Olariu, Shaharuddin Salleh

Computer Science Faculty Publications

Locationing problem in Wireless Sensor Networks(WSN) can be viewed as a general distributed sensor problem. It is with sensors that can discover other nodes or estimate ranges between nodes. that serve as position references. In this paper. we show that sensors acquire coarse-grain location awareness by the training protocol. The training protocol which hybrids the synchronization and training procedure. In this protocol, synchronization and training are combined into one scheme. The sink node sends two beacons in each slot instead of one. In the training, sensor searching for its location using a binary search scheme. Our simulation results shown less …


Istart 2: Improvements For Efficiency And Effectiveness, Irwin B. Levinstein, Chutima Boonthum, Srinivasa P. Pillarisetti, Courtney Bell, Danielle S. Mcnamara Jan 2007

Istart 2: Improvements For Efficiency And Effectiveness, Irwin B. Levinstein, Chutima Boonthum, Srinivasa P. Pillarisetti, Courtney Bell, Danielle S. Mcnamara

Computer Science Faculty Publications

iSTART (interactive strategy training for active reading and thinking) is a Web-based reading strategy trainer that develops students' ability to self-explain difficult text as a means to improving reading comprehension. Its curriculum consists of modules presented interactively by pedagogical agents: an introduction to the basics of using reading strategies in the context of self-explanation, a demonstration of self-explanation, and a practice module in which the trainee generates self-explanations with feedback on the quality of reading strategies contained in the self-explanations. We discuss the objectives that guided the development of the second version of iSTART toward the goals of increased efficiency …


Assessing The Format Of The Presentation Of Text In Developing A Reading Strategy Assessment Tool (R-Sat), Sara Gilliam, Joseph P. Magliano, Keith K. Millis, Irwin Levinstein, Chutima Boonthum Jan 2007

Assessing The Format Of The Presentation Of Text In Developing A Reading Strategy Assessment Tool (R-Sat), Sara Gilliam, Joseph P. Magliano, Keith K. Millis, Irwin Levinstein, Chutima Boonthum

Computer Science Faculty Publications

We are constructing a new computerized test of reading comprehension called the Reading Strategy Assessment Tool (R-SAT). R-SAT elicits and analyzes verbal protocols that readers generate in response to questions as they read texts. We examined whether the amount of information available to the reader when reading and answering questions influenced the extent to which R-SAT accounts for comprehension. We found that R-SAT was most predictive of comprehension when the readers did not have access to the text as they answered questions.


All Minimal Prime Extensions Of Hereditary Classes Of Graphs, Vassilis Giakoumakis, Stephan Olariu Jan 2007

All Minimal Prime Extensions Of Hereditary Classes Of Graphs, Vassilis Giakoumakis, Stephan Olariu

Computer Science Faculty Publications

The substitution composition of two disjoint graphs G1 and G2 is obtained by first removing a vertex x from G2 and then making every vertex in G1 adjacent to all neighbours of x in G2. Let F be a family of graphs defined by a set Z* of forbidden configurations. Giakoumakis [V. Giakoumakis, On the closure of graphs under substitution, Discrete Mathematics 177 (1997) 83–97] proved that F∗, the closure under substitution of F, can be characterized by a set Z∗ of forbidden configurations — the minimal prime extensions of Z. He also …


How Much Preservation Do I Get If I Do Absolutely Nothing? Using The Web Infrastructure For Digital Preservation, Martin Klein, Frank Mccown, Joan A. Smith, Michael Nelson Jan 2007

How Much Preservation Do I Get If I Do Absolutely Nothing? Using The Web Infrastructure For Digital Preservation, Martin Klein, Frank Mccown, Joan A. Smith, Michael Nelson

Computer Science Faculty Publications

To date, most of the focus regarding digital preservation has been on removing copies of the resources to be preserved from the “living web” and placing them in an archive for controlled curation. Once inside an archive, the resources are subject to careful processes of refreshing (making additional copies to new media) and migrating (conversion to new formats and applications). For small numbers of resources of known value, this is a practical and worthwhile approach to digital preservation. However, due to the infrastructure costs (storage, networks, machines) and more importantly the human management costs, this approach is unsuitable for web …


Brass: A Queueing Manager For Warrick, Frank Mccown, Amine Benjelloun, Michael L. Nelson Jan 2007

Brass: A Queueing Manager For Warrick, Frank Mccown, Amine Benjelloun, Michael L. Nelson

Computer Science Faculty Publications

When an individual loses their website and a backup can-not be found, they can download and run Warrick, a web-repository crawler which will recover their lost website by crawling the holdings of the Internet Archive and several search engine caches. Running Warrick locally requires some technical know-how, so we have created an on-line queueing system called Brass which simplifies the task of recovering lost websites. We discuss the technical aspects of recon-structing websites and the implementation of Brass. Our newly developed system allows anyone to recover a lost web-site with a few mouse clicks and allows us to track which …


Crate: A Simple Model For Self-Describing Web Resources, Joan A. Smith, Michael L. Nelson Jan 2007

Crate: A Simple Model For Self-Describing Web Resources, Joan A. Smith, Michael L. Nelson

Computer Science Faculty Publications

If not for the Internet Archive’s efforts to store periodic snapshots of the web, many sites would not have any preservation prospects at all. The barrier to entry is too high for everyday web sites, which may have skilled webmasters managing them, but which lack skilled archivists to preserve them. Digital preservation is not easy. One problem is the complexity of preservation models, which have specific meta-data and structural requirements. Another problem is the time and effort it takes to properly prepare digital resources for preservation in the chosen model. In this paper, we propose a simple preservation model called …


Providing Vanet Security Through Active Position Detection, Gongjun Yan, Gyanesh Choudhary, Michele C. Weigle, Stephan Olariu Jan 2007

Providing Vanet Security Through Active Position Detection, Gongjun Yan, Gyanesh Choudhary, Michele C. Weigle, Stephan Olariu

Computer Science Faculty Publications

Our main contribution is a novel approach to enhancing position security in VANET. We achieve local and global position security by using the on-board radar to detect neighboring vehicles and to confirm their announced coordinates. We compute cosine similarity among data collected by radar and neighbors' reports to filter the forged data from the truthful data. Based on filtered data, we create a history of vehicle movement. By checking the history and computing similarity, we can prevent a large number of Sybil attacks and some combinations of Sybil and position-based attacks.


Neighborhood Defined Feature Selection Strategy For Improved Face Recognition In Different Sensor Modalitie, Satyanadh Gundimada Jan 2007

Neighborhood Defined Feature Selection Strategy For Improved Face Recognition In Different Sensor Modalitie, Satyanadh Gundimada

Electrical & Computer Engineering Theses & Dissertations

A novel feature selection strategy for improved face recognition in images with variations due to illumination conditions, facial expressions, and partial occlusions is presented in this dissertation. A hybrid face recognition system that uses feature maps of phase congruency and modular kernel spaces is developed. Phase congruency provides a measure that is independent of the overall magnitude of a signal, making it invariant to variations in image illumination and contrast. A novel modular kernel spaces approach is developed and implemented on the phase congruency feature maps. Smaller sub-regions from a predefined neighborhood within the phase congruency images of the training …


A Simplified Model For Growth Factor Induced Healing Of Wounds, F. J. Vermolen, E. Van Baaren, J. A. Adam Nov 2006

A Simplified Model For Growth Factor Induced Healing Of Wounds, F. J. Vermolen, E. Van Baaren, J. A. Adam

Mathematics & Statistics Faculty Publications

A mathematical model is developed for the rate of healing of a circular or elliptic wound. In this paper the regeneration, decay and transport of a generic 'growth factor', which induces the healing of the wound, is taken into account. Further, an equation of motion is derived for radial healing of a circular wound. The expressions for the equation of motion and the distribution of the growth factor are related in such a way that no healing occurs if the growth factor concentration at the wound edge is below a threshold value. In this paper we investigate the influence of …


Fault Modeling In Wireless Sensor Networks, Ahmed A. Elmiligui Oct 2006

Fault Modeling In Wireless Sensor Networks, Ahmed A. Elmiligui

Electrical & Computer Engineering Theses & Dissertations

A large amount of research has been done in the area of wireless sensor networks (WSN), but not much work has been done in modeling the fault tolerance and reliability of these networks. In this thesis, the fault tolerance of a WSN to node failures is studied and an analytical reliability model of the network is derived. A valid reliability model of a network could reveal an estimate of the network's performance before it is deployed.

A wireless sensor network was modeled as a k-out-of-n system and a generic fault tolerant framework for the network in terms of node losses …