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1999

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Articles 241 - 270 of 427

Full-Text Articles in Computer Sciences

An Efficient Gps Position Determination Algorithm, Carlos R. Colon Mar 1999

An Efficient Gps Position Determination Algorithm, Carlos R. Colon

Theses and Dissertations

The use of detect, or closed-form solutions of the trilateration equations used to obtain the position fix in GPS receivers is investigated. The paper is concerned with the development of an efficient new position determination algorithm that uses the closed-form solution of the trilateration equations and works in the presence of pseudorange measurement noise and for an arbitrary number of satellites. in addition, an initial position guess is not required and good estimation performance is achieved even under high GDOP conditions. A two step GPS position determination algorithm which 1) entails the solution of a linear regression problem and, 2) …


Structural Emergence And The Collaborative Behavior Of Autonomous Nano-Satellites, Daniel J. Petrovich Mar 1999

Structural Emergence And The Collaborative Behavior Of Autonomous Nano-Satellites, Daniel J. Petrovich

Theses and Dissertations

The collaborative behavior of nano-satellites in a zero-gravity environment is explored, and satellite characteristics are proposed that maximize constellation robustness and minimize manufacturing costs. Behavioral algorithms are proposed to facilitate both swarming and structural formation and are validated using the Structural Emergence Simulator (STEMS) Graphical User Interface (GUl). A payload of multiple satellites is placed in a zero-gravity environment and released to re-configure autonomously into a pre-designed structure. Data transmission between satellites is not permitted during the swarming phase of the structure formation mission. A binary behavior algorithm is invented that produces a direction and magnitude solution to the satellite …


The Practitioner From Within: Revisiting The Virtues, Frances Grodzinsky Mar 1999

The Practitioner From Within: Revisiting The Virtues, Frances Grodzinsky

School of Computer Science & Engineering Faculty Publications

Traditionally the study of computer ethics involves taking students who are not philosophically trained, exposing them to action-guiding theories, presenting them with the codes of ethics of several companies and professional organizations and asking them to make ethical decisions in scenario-based cases. This approach is deliberately action-based and focuses on doing. "What would you do?" is the traditional question we ask our students. While this pedagogical methodology forces them to examine situations and argue from a particular point of view, it does little to influence their character. They see the utilitarian or deontologist as someone other than themselves. There seems …


Prestructuring Neural Networks Via Extended Dependency Analysis With Application To Pattern Classification, George G. Lendaris, Thaddeus T. Shannon, Martin Zwick Mar 1999

Prestructuring Neural Networks Via Extended Dependency Analysis With Application To Pattern Classification, George G. Lendaris, Thaddeus T. Shannon, Martin Zwick

Complex Systems Faculty Publications and Presentations

We consider the problem of matching domain-specific statistical structure to neural-network (NN) architecture. In past work we have considered this problem in the function approximation context; here we consider the pattern classification context. General Systems Methodology tools for finding problem-domain structure suffer exponential scaling of computation with respect to the number of variables considered. Therefore we introduce the use of Extended Dependency Analysis (EDA), which scales only polynomially in the number of variables, for the desired analysis. Based on EDA, we demonstrate a number of NN pre-structuring techniques applicable for building neural classifiers. An example is provided in which EDA …


Can Kiva Accurately Simulate A Gas Turbine Combustor?, John R. Rice Mar 1999

Can Kiva Accurately Simulate A Gas Turbine Combustor?, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.


Visualizing Three-Dimensional Configuration Spaces For Mechanical Design, Elisha Sacks, Charles Pisula, Leo Joskowicz Mar 1999

Visualizing Three-Dimensional Configuration Spaces For Mechanical Design, Elisha Sacks, Charles Pisula, Leo Joskowicz

Department of Computer Science Technical Reports

No abstract provided.


Least Squares Approximation Of Bezier Coefficients Provides Best Degree Reduction In The L 2-Norm, J. Peters, U Reif Mar 1999

Least Squares Approximation Of Bezier Coefficients Provides Best Degree Reduction In The L 2-Norm, J. Peters, U Reif

Department of Computer Science Technical Reports

No abstract provided.


Resource Scheduling In A High-Performance Multimedia Server, Hwee Hwa Pang, Bobby Jose, M. S. Krishnan Mar 1999

Resource Scheduling In A High-Performance Multimedia Server, Hwee Hwa Pang, Bobby Jose, M. S. Krishnan

Research Collection School Of Computing and Information Systems

Supporting continuous media data-such as video and audio-imposes stringent demands on the retrieval performance of a multimedia server. In this paper, we propose and evaluate a set of data placement and retrieval algorithms to exploit the full capacity of the disks in a multimedia server. The data placement algorithm declusters every object over all of the disks in the server-using a time-based declustering unit-with the aim of balancing the disk load. As for runtime retrieval, the quintessence of the algorithm is to give each disk advance notification of the blocks that have to be fetched in the impending time periods, …


Texture Analysis Of Sar Sea Ice Imagery Using Gray Level Co-Occurrence Matrices, Leen-Kiat Soh, Costas Tsatsoulis Mar 1999

Texture Analysis Of Sar Sea Ice Imagery Using Gray Level Co-Occurrence Matrices, Leen-Kiat Soh, Costas Tsatsoulis

School of Computing: Faculty Publications

This paper presents a preliminary study for mapping sea ice patterns (texture) with 100-m ERS-1 synthetic aperture radar (SAR) imagery. We used gray-level co-occurrence matrices (GLCM) to quantitatively evaluate textural parameters and representations and to determine which parameter values and representations are best for mapping sea ice texture. We conducted experiments on the quantization levels of the image and the displacement and orientation values of the GLCM by examining the effects textural descriptors such as entropy have in the representation of different sea ice textures. We showed that a complete gray-level representation of the image is not necessary for texture …


Segmentation Of Satellite Imagery Of Natural Scenes Using Data Mining, Leen-Kiat Soh, Costas Tsatsoulis Mar 1999

Segmentation Of Satellite Imagery Of Natural Scenes Using Data Mining, Leen-Kiat Soh, Costas Tsatsoulis

School of Computing: Faculty Publications

In this paper, we describe a segmentation technique that integrates traditional image processing algorithms with techniques adapted from knowledge discovery in databases (KDD) and data mining to analyze and segment unstructured satellite images of natural scenes. We have divided our segmentation task into three major steps. First, an initial segmentation is achieved using dynamic local thresholding, producing a set of regions. Then, spectral, spatial, and textural features for each region are generated from the thresholded image. Finally, given these features as attributes, an unsupervised machine learning methodology called conceptual clustering is used to cluster the regions found in the image …


A Constructive Induction Approach To Computer Immunology, Kelley J. Cardinale, Hugh M. O'Donnell Mar 1999

A Constructive Induction Approach To Computer Immunology, Kelley J. Cardinale, Hugh M. O'Donnell

Theses and Dissertations

With the increasing birth rate of new viruses and the rise in interconnectivity and interoperability among computers, the burden of detecting and destroying computer viruses is severe. This research integrated four domains: computer virus detection, human immunology, computer immunology and an automated form of machine learning called constructive induction. First, a Computer Health System, based on the public health system, was defined to improve the 'global' approach to computer virus protection. Second, a computer immune model, based on the human immune system, was defined to improve the 'local' approach to virus detection. Third, the detection component of this computer immune …


Target Pose Estimation From Radar Data Using Adaptive Networks, Andrew W. Learn Mar 1999

Target Pose Estimation From Radar Data Using Adaptive Networks, Andrew W. Learn

Theses and Dissertations

his research investigates and extends recent work by J.C. Principe at the University of Florida in target pose estimation using adaptive networks. First, Principe's technique is successfully extended to estimate both azimuth and elevation using SAR images. A network trained and tested using MSTAR data yields mean errors of less than six degrees in azimuth and five degrees in elevation. Second, the technique is applied to high-range resolution radar (HRR) signatures. Ground target (azimuth only) testing yields mean errors of less than 11 degrees for most classes. Air target testing for networks trained and tested on the same aircraft class …


Trade-Off Analysis Of Communications Capabilities Of Inter-Satellite Links, Andrew J. Feltman Mar 1999

Trade-Off Analysis Of Communications Capabilities Of Inter-Satellite Links, Andrew J. Feltman

Theses and Dissertations

This thesis designs, develops, and uses software Graphical User Interfaces (GUIs) to analyze the communications capabilities of Radio Frequency (RF) Inter-Satellite Links (ISLs). The GUIs are geared towards analyzing the proposed ISLs of the Discoverer II program, but are general enough to permit analysis of any free-space RF ISLs. Discoverer II is a demonstration program of low-earth orbiting satellites and is primarily focused on satellite-based sensor technology. This thesis shows RF ISLs can meet the program requirement to broadcast the sensor data back to CONUS in near-real-time. The GUIs operate in real-time and explore trade-offs in the communications capability by …


Gps Signal Offset Detection And Noise Strength Estimation In A Parallel Kalman Filter Algorithm, Barry J. Vanek Mar 1999

Gps Signal Offset Detection And Noise Strength Estimation In A Parallel Kalman Filter Algorithm, Barry J. Vanek

Theses and Dissertations

Measurements from Global Positioning System (GPS) satellites are subject to corruption by signal interference and induced offsets. This thesis presents two independent algorithms to ensure the navigation system remains uncorrupted by these possible GPS failures. The first is a parameter estimation algorithm that estimates the measurement noise variance of each satellite. A redundant measurement differencing (RMD) technique provides direct observability of the differenced white measurement noise samples. The variance of the noise process is estimated and provided to the second algorithm, a parallel Kalman filter structure, which then adapts to changes in the real-world measurement noise strength. The parallel Kalman …


The Window Distribution Of Idealized Tcp Congestion Avoidance With Variable Packet Loss, Archan Misra, Teunis J. Ott Mar 1999

The Window Distribution Of Idealized Tcp Congestion Avoidance With Variable Packet Loss, Archan Misra, Teunis J. Ott

Research Collection School Of Computing and Information Systems

This paper analyzes the stationary behavior of the TCP congestion window performing ideal congestion avoidance when the packet loss probability is not constant, but varies as a function of the window size. By neglecting the detailed window behavior during fast recovery, we are able to derive a Markov process that is then approximated by a continuous-time, continuous state space process. The stationary distribution of this process is analyzed and derived numerically and then extrapolated to obtain the stationary distribution of the TCP window. This numerical analysis enables us to predict the behavior of the TCP congestion window when interacting with …


Research And Implementation Of Integrated Concurrent Software Development Environment Based On Object-Oriented Petri Nets, Jinzhong Niu Feb 1999

Research And Implementation Of Integrated Concurrent Software Development Environment Based On Object-Oriented Petri Nets, Jinzhong Niu

Publications and Research

While network technologies and environments get more and more popular, the demand for concurrent systems becomes stronger and stronger. But the characteristics of concurrency make it difficult to develop them.

This dissertation combines Object-Oriented technology and Petri Nets theory, and put forth OOPN (OO Petri Nets) model to describe concurrent systems. Based on the research of conventional development methods of concurrent software, this article advances a new one, which integrates specification, validation and auto-generating codes. Accordingly, an integrated development environment for concurrent software, i.e., OOPN-IDE, comes into being, which mainly includes the following four tools: the concurrent system modeling tool …


Continuation-Passing Style Versus Direct Style: Choosing An Intermediate Representation For Higher-Order Applicative Languages, Paul Andrew Seale Feb 1999

Continuation-Passing Style Versus Direct Style: Choosing An Intermediate Representation For Higher-Order Applicative Languages, Paul Andrew Seale

Dissertations and Theses

This study analyzes the use of a continuation-passing style (CPS) intermediate representation versus a direct style intermediate representation in the compilation of a higher-order applicative language. The translator used accepts a program written in an ML-like language as input, and outputs a C program acceptable to a standard C compiler. The effects of the translator's simplification and higher-order function removal transformations on the intermediate language are the primary focus of the analysis. The machine code programs generated from both representations are also analyzed.

Initially, the programs under the direct style representation performed better than those that underwent the CPS transformation. …


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 15, Number 2, February 1999, College Of Engineering And Computer Science, Wright State University Feb 1999

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 15, Number 2, February 1999, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.


Structure-Function Relationships In The Pulmonary Arterial Tree, Christopher A. Dawson, Gary S. Krenz, Kelly Lynn Karau, Steven Thomas Haworth, Christopher C. Hanger, John H. Linehan Feb 1999

Structure-Function Relationships In The Pulmonary Arterial Tree, Christopher A. Dawson, Gary S. Krenz, Kelly Lynn Karau, Steven Thomas Haworth, Christopher C. Hanger, John H. Linehan

Mathematics, Statistics and Computer Science Faculty Research and Publications

Knowledge of the relationship between structure and function of the normal pulmonary arterial tree is necessary for understanding normal pulmonary hemodynamics and the functional consequences of the vascular remodeling that accompanies pulmonary vascular diseases. In an effort to provide a means for relating the measurable vascular geometry and vessel mechanics data to the mean pressure-flow relationship and longitudinal pressure profile, we present a mathematical model of the pulmonary arterial tree. The model is based on the observation that the normal pulmonary arterial tree is a bifurcating tree in which the parent-to-daughter diameter ratios at a bifurcation and vessel distensibility are …


Tight Linear Bounds On The Distance Between A Spline And Its B-Spline Control Polygon, David Lutterkort, Jörg Peters Feb 1999

Tight Linear Bounds On The Distance Between A Spline And Its B-Spline Control Polygon, David Lutterkort, Jörg Peters

Department of Computer Science Technical Reports

No abstract provided.


Record Matching To Improve Data Quality, Vassilios S. Verykios, Ahmed K. Elmagarmid, Elias N. Houstis Feb 1999

Record Matching To Improve Data Quality, Vassilios S. Verykios, Ahmed K. Elmagarmid, Elias N. Houstis

Department of Computer Science Technical Reports

No abstract provided.


Gas Turbine Engine Compressor- Combustor Dynamics Simulation Design, Sanford Fleeter, Elias N. Houstis, John R. Rice, Chem Zhou Feb 1999

Gas Turbine Engine Compressor- Combustor Dynamics Simulation Design, Sanford Fleeter, Elias N. Houstis, John R. Rice, Chem Zhou

Department of Computer Science Technical Reports

No abstract provided.


Domain Architecture A Design Framework For System Development And Integration, Vassilka D. Kirova Jan 1999

Domain Architecture A Design Framework For System Development And Integration, Vassilka D. Kirova

Dissertations

The ever growing complexity of software systems has revealed many short-comings in existing software engineering practices and has raised interest in architecture-driven software development. A system's architecture provides a model of the system that suppresses implementation detail, allowing the architects to concentrate on the analysis and decisions that are most critical to structuring the system to satisfy its requirements. Recently, interests of researchers and practi-tioners have shifted from individual system architectures to architectures for classes of software systems which provide more general, reusable solutions to the issues of overall system organization, interoperability, and allocation of services to system components. These …


Parallelization For Image Processing Algorithms Based Chain And Mid-Crack Codes, Wai-Tak Wong Jan 1999

Parallelization For Image Processing Algorithms Based Chain And Mid-Crack Codes, Wai-Tak Wong

Dissertations

Freeman chain code is a widely-used description for a contour image. Another mid-crack code algorithm was proposed as a more precise method for image representation. We have developed a coding algorithm which is suitable to generate either chain code description or mid-crack code description by switching between two different tables. Since there is a strong urge to use parallel processing in image related problems, a parallel coding algorithm is implemented. This algorithm is developed on a pyramid architecture and a N cube architecture. Using link-list data structure and neighbor identification, the algorithm gains efficiency because no sorting or neighborhood pairing …


A Methodology For Component-Based System Integration, Yongming Tang Jan 1999

A Methodology For Component-Based System Integration, Yongming Tang

Dissertations

Component-based software based on software architectures is emerging to be the next generation software development paradigm. The paradigm shifts the development focus from lines-of-codes to coarser-grained components and the interconnections among them. It consists of system architecture design, architecture description, component search and system integration from components to generate a software system.

However, one of the bottlenecks in this paradigm is the integration of the individual components into the overall system. In this dissertation a methodology for component-based system integration is proposed. It is based on an architectural aggregation view, a component model, flowgraphs and cyclomatic complexity. We introduce this …


A Comparative Study Of Sequence Analysis Tools In Computational Biology, Wei-Jen Chuang Jan 1999

A Comparative Study Of Sequence Analysis Tools In Computational Biology, Wei-Jen Chuang

Theses

A biomolecular object, such as a deoxyribonucleic acid (DNA), a ribonucleic acid (RNA) or a protein molecule, is made up of a long chain of subunits. A protein is represented as a sequence made from 20 different amino acids, each represented as a letter. There are a vast number of ways in which similar structural domains can be generated in proteins by different amino acid sequences. By contrast, the structure of DNA, made up of only four different nucleotide building blocks that occur in two pairs, is relatively simple, regular, and predictable.

Biomolecular sequence alignment/string search is the most important …


Iceberg Database System For The Graduate Advisors Of Computer And Information Science Department Of New Jersey Institute Of Technology, Tao Lin Jan 1999

Iceberg Database System For The Graduate Advisors Of Computer And Information Science Department Of New Jersey Institute Of Technology, Tao Lin

Theses

Iceberg system is a departmental database system. It is built for the graduate advisors of the CIS department. It stores the graduate student's information, such as background, bridge requirement and transcript. The graduate advisors can process the student's records using the graphic user interface of Iceberg system.

Iceberg system is an example of the powerful Java language. We use the latest Java technologies to build a flexible system, which is easily extended. The system consists of Iceberg client, Iceberg server and Oracle data source. The Iceberg client is a web-based applet, which can be easily accessed using a browser. The …


Comparison Of Dcom And Corba Distributed Computing, Reginald J. Reynolds Jan 1999

Comparison Of Dcom And Corba Distributed Computing, Reginald J. Reynolds

Theses

The movement of distributed applications from 2-tier to n-tier architectures have enabled systems to be scaled to meet the demands of an ever increasing population of users. Two middleware architectures have come to the forefront: Microsoft's DCOM and the OMG's CORBA. These are not the only possible architectures for n-tier distributed applications, but they are currently the only two which offer a degree of platform independence and the flexibility of using different programming languages for development.

CORBA provides platform independence because it provides a middle layer between the client and the server and services client requests using its internal naming …


Green Manufacturing Of Ammunition Through Knowledge Management With Distributed Access, Ali H. Dogru, Murat M. Tanik, Franz J. Kurfess, Marcus Healey, Leon Jololian Jan 1999

Green Manufacturing Of Ammunition Through Knowledge Management With Distributed Access, Ali H. Dogru, Murat M. Tanik, Franz J. Kurfess, Marcus Healey, Leon Jololian

Computer Science and Software Engineering

This paper describes a distributed software requirements gathering methodology dealing with knowledge management for environmentally safer production and lifecycle aspects of tank ammunition. A requirements elicitation methodology is adapted and implemented as a distributed access tool on the Internet. This tool is used for gathering the requirements related information for a specific ammunition production process. During product development, requirements negotiation is the process where the customer needs are identified. This process is regarded as one of the most important parts of building a system because during this stage it is decided precisely what will be built. The concept has been …


The Xrcl Project: The University Of Arkansas' Entry Into The Aaai 1999 Mobile Robot Competition, Doug S. Blank, Jared H. Hudson, Brian C. Mashburn, Eric A. Roberts Jan 1999

The Xrcl Project: The University Of Arkansas' Entry Into The Aaai 1999 Mobile Robot Competition, Doug S. Blank, Jared H. Hudson, Brian C. Mashburn, Eric A. Roberts

Computer Science Faculty Research and Scholarship

No abstract provided.