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Articles 53251 - 53280 of 58094

Full-Text Articles in Physical Sciences and Mathematics

Towards Performance-Driven System Support For Distributed Computing In Clustered Environments, John Cruz, Kihong Park Oct 1998

Towards Performance-Driven System Support For Distributed Computing In Clustered Environments, John Cruz, Kihong Park

Department of Computer Science Technical Reports

No abstract provided.

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Parallel Algorithms For Maximum Matching In Complements Of Interval Graphs And Related Problems, Marilyn G. Andrews, Mikhail J. Atallah, Danny Z. Chen, D. T. Leo Oct 1998

Parallel Algorithms For Maximum Matching In Complements Of Interval Graphs And Related Problems, Marilyn G. Andrews, Mikhail J. Atallah, Danny Z. Chen, D. T. Leo

Department of Computer Science Technical Reports

No abstract provided.

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On The Collapse Of The Q-Gram Filtration, E. Stuinen, Wojciech Szpankowski Oct 1998

On The Collapse Of The Q-Gram Filtration, E. Stuinen, Wojciech Szpankowski

Department of Computer Science Technical Reports

No abstract provided.

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Validation Of Waimss Incident Duration Estimation Model, Wei Wu, Pushkin Kachroo, Kaan Ozbay Oct 1998

Validation Of Waimss Incident Duration Estimation Model, Wei Wu, Pushkin Kachroo, Kaan Ozbay

Electrical & Computer Engineering Faculty Research

This paper presents an effort to validate the traffic incident duration estimation model of WAIMSS (wide area incident management support system). Duration estimation model of WAIMSS predicts the incident duration based on an estimation tree which was calibrated using incident data collected in Northern Virginia. Due to the limited sample size, a full scale test of the distribution, mean and variance of incident duration was performed only for the root node of the estimation tree, white only mean tests were executed at all other nodes whenever a data subset was available. Further studies were also conducted on the model error …

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Wide-Area Incident Management System On The Internet, Kaan Ozbay, Pushkin Kachroo Oct 1998

Wide-Area Incident Management System On The Internet, Kaan Ozbay, Pushkin Kachroo

Electrical & Computer Engineering Faculty Research

The incident management process consists of four sequential steps-incident detection, response, clearance and recovery. Each of these components comprises of a number of operations and coordinated decision-making between the agencies involved. The provision of computer based support tools for the personnel involved will help develop appropriate strategies and increase efficiency and expediency. Existing systems are developed on various traditional computing platforms. However, with the advent of World Wide Web and Internet based programming tools such as Java, it is now possible to develop platform independent decision support tools for the incident management agencies. Any agency will be able to use …

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Automated Highway Systems, Bruce M. Mcmillin, Kristen L. Sanford Oct 1998

Automated Highway Systems, Bruce M. Mcmillin, Kristen L. Sanford

Computer Science Faculty Research & Creative Works

Intelligent transportation systems (ATS) have received much attention in the transportation community and by the government in the past decade. The technology is an extension of intelligent vehicle highway systems to include transportation modes beyond highways. Major elements of ITS include: advanced traffic management systems; advanced traveller information systems; automated highway systems; the Intelligent Vehicle Initiative; and advanced commercial vehicle systems. ITS initiatives are proposed for both urban and rural areas to increase transportation system capacity by more fully utilizing the existing transportation system and improve transportation system safety. The feasibility of realizing a fully automated highway system is discussed.

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Isophote-Based Interpolation, Bryan S. Morse, Duane Schwartzwald Oct 1998

Isophote-Based Interpolation, Bryan S. Morse, Duane Schwartzwald

Faculty Publications

Standard methods for image interpolation are based on smoothly fitting the image intensity surface. Recent edge-directed interpolation methods add limited geometric information (edge maps) to build more accurate and visually appealing interpolations at key contours in the image. This paper presents a method for geometry-based interpolation that smoothly fits the isophote (intensity level curve) contours at all points in the image rather than just at selected contours. By using level set methods for curve evolution, no explicit extraction or representation of these contours is required (unlike earlier edge-directed methods). The method uses existing interpolation techniques as an initial approximation and …

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Analysis Of The Interpolation Error Between Multiresolution Images, Bryan S. Morse Oct 1998

Analysis Of The Interpolation Error Between Multiresolution Images, Bryan S. Morse

Faculty Publications

Many rendering or image-analysis systems require calculation of versions of an image at lesser resolutions than the original. Because the filtering required to perform such calculations accurately cannot typically be done in real time, many systems use interpolation between images at precalculated resolutions. This discrete sampling of the scale component of multiresolution image spaces is analogous to spatial sampling in discrete images. This paper quantifies and bounds the error that can be introduced during such interpolation as a function of the scale-space sampling rate used. A method is presented that uses the diffusion equation to relate spatial derivatives to scale …

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Variability Analysis Of Discrete Cosine Transform Coefficient (Dctc) Features For Speech Processing, Bingjun Dai Oct 1998

Variability Analysis Of Discrete Cosine Transform Coefficient (Dctc) Features For Speech Processing, Bingjun Dai

Electrical & Computer Engineering Theses & Dissertations

In this research, the variability of Discrete Cosine Transform Coefficient (DCTC) features was investigated. Additionally, a new pitch-synchronous processing method was explored to increase the stability of features and to reduce window effects when compared to the regular method. The noise sources that lead to feature variability were analyzed, and different smoothing methods were tested. It was found that longer frames, frequency warping, time smoothing of the log spectrum, and DCS level time smoothing, all help reduce DCTC variability and increase classification performance. The pitch­ synchronous method was implemented with Matlab. Important processing methods, including pitch period estimation, time­ domain …

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Design And Implementation Of A Maritime Conflict Prediction System, Wee-Keong Ng, Ee Peng Lim, Wen Jing Hsu, Yy Cao Oct 1998

Design And Implementation Of A Maritime Conflict Prediction System, Wee-Keong Ng, Ee Peng Lim, Wen Jing Hsu, Yy Cao

Research Collection School Of Computing and Information Systems

Maritime conflicts have serious impacts on Singapore and the surrounding region both economically and environmentally. This is particularly severe for conflicts such as collisions between large vessels or tankers carrying oil and chemicals. Thus, it is in the interests of the Maritime and Port Authority of Singapore (MPA) to avoid collisions or near-collisions among such vessels navigating through Singapore waters. Existing systems used by MPA predict potential maritime conflicts arising within a short and fixed time horizon. The system produces inconsequential warnings that are often ignored. In this paper, we describe an advanced computerbased system designed to assist in the …

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Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 14, Number 7, September 1998, College Of Engineering And Computer Science, Wright State University Sep 1998

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 14, Number 7, September 1998, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

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Modelowanie Imisji Ozonu W Przyziemnej Warstwie Atmosfery Na Przykładzie Nowego Sącza, Marek Bogacki, Marian Mazur, Robert Oleniacz Sep 1998

Modelowanie Imisji Ozonu W Przyziemnej Warstwie Atmosfery Na Przykładzie Nowego Sącza, Marek Bogacki, Marian Mazur, Robert Oleniacz

Robert Oleniacz

The paper presents the results of research related to the modeling of physicochemical phenomena occurring in the ground-layer of the atmosphere in terms of ozone formation. For this purpose, the box model was used, in which the computational area is defined as a space designated by a steady surface and a variable height. Conducted in Nowy Sącz (Poland) experiment confirmed the possibility of using this type of model to diagnose and possibly forecasting ozone concentrations in any area of ​​calculation. The study also showed that the quality of the results depends mainly on accuracy in preparing of input data, especially …

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The Design And Evaluation Of Distributed Graph-Theoretic Heuristics For Computing Pairwise Interactions Of Moving Entities, Darren R. Law Sep 1998

The Design And Evaluation Of Distributed Graph-Theoretic Heuristics For Computing Pairwise Interactions Of Moving Entities, Darren R. Law

Link Foundation Modeling, Simulation and Training Fellowship Reports

In recent years the focus of training simulations, particularly those in the defense domain, has been on increasing the number of simulated entities. This focus, coupled with the requirement for geographically distributed training sites, has led to increased interest in distributed simulation of the battlefield environment. The large efforts involved in the development of the DIS (Distributed Interactive Simulation) protocol and the HLA (High Level Architecture) have attempted to address these DoD (Department of Defense) requirements in several ways. The cost of con1puting the interactions between pairs of simulated entities frequently dominates system execution time. The difficulty of evaluating these …

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A Wavelet-Based Approach To Dynamic Environments, Glenn A. Martin Sep 1998

A Wavelet-Based Approach To Dynamic Environments, Glenn A. Martin

Link Foundation Modeling, Simulation and Training Fellowship Reports

This paper demonstrates a new approach for terrain representation: multiresolution surfaces based on wavelets and the process of multiresolution analysis. Because they are based on mathematical surfaces, multiresolution surfaces gain the benefits of surfaces (more level of detail control, increased number of possible resolutions, easier updates of a dynamic terrain) that lead to fewer correlation errors both in non-networked and networked simulations. Furthermore, the power of multiple resolutions (at little added cost) reduces network transmission costs and provides a framework for the use of dynamic terrain in shared virtual worlds.

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Software Tools For Solid Freeform Fabrication, Robert Franceschini Sep 1998

Software Tools For Solid Freeform Fabrication, Robert Franceschini

Link Foundation Modeling, Simulation and Training Fellowship Reports

A structured design methodology played a key role in the VLSI (Very Large Scale Integration) revolution. In this methodology, the design is abstracted at different levels (viz. system, function, logic, circuit, and layout) taking into account concerns relevant to a particular level of abstraction. This allows development of CAD tools that can describe, synthesize, and simulate the design at high levels of abstraction independent of the details of the lower levels. In recent years, many researchers have observed that the lessons learned from the "VLSI experience" could be profitably applied to new classes of manufacturing processes called SFF (Solid Freeform …

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Pythia-Ii: A Knowledge/Data Base For Testing And Recommending Scientific Software, Elias N. Houstis, Vassilios S. Verykios, Ann C. Caitlin, Naren Ramakrishnan, John R. Rice Sep 1998

Pythia-Ii: A Knowledge/Data Base For Testing And Recommending Scientific Software, Elias N. Houstis, Vassilios S. Verykios, Ann C. Caitlin, Naren Ramakrishnan, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

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Continuum: A Homotopy- Continuation Solver For Systems Of Algebraic Equations, Cassiano Durand, Christoph M. Hoffmann Sep 1998

Continuum: A Homotopy- Continuation Solver For Systems Of Algebraic Equations, Cassiano Durand, Christoph M. Hoffmann

Department of Computer Science Technical Reports

No abstract provided.

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Average Profile Of The Lempel-Ziv Parsing Scheme For Markovian Source, Philippe Jacquet, Wojciech Szpankowski, Jing Tang Sep 1998

Average Profile Of The Lempel-Ziv Parsing Scheme For Markovian Source, Philippe Jacquet, Wojciech Szpankowski, Jing Tang

Department of Computer Science Technical Reports

No abstract provided.

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Parallel Solution Of Large Sparse Linear Systems By A Balance Scheme Preconditioner, Tz. Ostromsky, Ahmed Sameh, V. Sarin Sep 1998

Parallel Solution Of Large Sparse Linear Systems By A Balance Scheme Preconditioner, Tz. Ostromsky, Ahmed Sameh, V. Sarin

Department of Computer Science Technical Reports

No abstract provided.

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Spatial Contact Analysis Of Fixed- Axes Pairs Using Configuration Spaces, Iddo Drori, Leo Joskowicz, Elisha P. Sacks Sep 1998

Spatial Contact Analysis Of Fixed- Axes Pairs Using Configuration Spaces, Iddo Drori, Leo Joskowicz, Elisha P. Sacks

Department of Computer Science Technical Reports

No abstract provided.

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Minimum Cross-Entropy Approximation For Modeling Of Highly Intertwining Data Sets At Subclass Levels, Qiuming Zhu Sep 1998

Minimum Cross-Entropy Approximation For Modeling Of Highly Intertwining Data Sets At Subclass Levels, Qiuming Zhu

Computer Science Faculty Publications

We study the problem of how to accurately model the data sets that contain a number of highly intertwining sets in terms of their spatial distributions. Applying the Minimum Cross-Entropy minimization technique, the data sets are placed into a minimum number of subclass clusters according to their high intraclass and low interclass similarities. The method leads to a derivation of the probability density functions for the data sets at the subclass levels. These functions then, in combination, serve as an approximation to the underlying functions that describe the statistical features of each data set.

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The Effects Of Three Media Presentation Systems On Maintenance Task Performance, John W. Chastain Sep 1998

The Effects Of Three Media Presentation Systems On Maintenance Task Performance, John W. Chastain

Theses and Dissertations

Wearable computers and Portable Maintenance Aids (PMAs) may soon be the normal way of doing aircraft maintenance in the Air Force. Currently, the Air Force uses the paper form of Technical Orders (TO's) while doing aircraft maintenance. The purpose of this thesis was to compare the effects of three different media presentations of the information used during aircraft maintenance. The three different presentations compared are the current paper form, a Head Mounted Display (HMD), and an auditory mode. An experiment was conducted to determine if there was a significant difference between the systems (in terms of task completion times and …

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Vision-Based Tracking With Dynamic Structure Light, Mark A. Livingston Sep 1998

Vision-Based Tracking With Dynamic Structure Light, Mark A. Livingston

Link Foundation Modeling, Simulation and Training Fellowship Reports

The term virtual reality (VR) has been used in the popular press to describe systems that completely replace the user's view with computer graphics, a view of a synthetic world. Such systems allow building designers to visualize the "completed" building and potential problems in the design before construction. A VR system might allow scientists to view environments as large as galaxies or as small as atoms as if they were human-sized. The primary benefit in these cases would be to interact in more natural ways with objects that, due to their sizes, are usually beyond our reach. In academic literature, …

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Wavelength Conversion In Wdm Networking, Byrav Ramamurthy, Biswanath Mukherjee Sep 1998

Wavelength Conversion In Wdm Networking, Byrav Ramamurthy, Biswanath Mukherjee

School of Computing: Faculty Publications

Wavelength conversion has been proposed for use in wavelength-division multiplexed networks to improve efficiency. This study highlights systems challenges and performance issues which need to be addressed in order to incorporate wavelength conversion effectively. A review/survey of the enabling technologies, design methods, and analytical models used in wavelength-convertible networks is provided.

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Optimizing Amplifier Placements In A Multiwavelength Optical Lan/Man: The Equally Powered-Wavelengths Case, Byrav Ramamurthy, Jason Iness, Biswanath Mukherjee Sep 1998

Optimizing Amplifier Placements In A Multiwavelength Optical Lan/Man: The Equally Powered-Wavelengths Case, Byrav Ramamurthy, Jason Iness, Biswanath Mukherjee

School of Computing: Faculty Publications

Wavelength division multiplexing (WDM) provides the ability to utilize the enormous bandwidth offered by optical networks, using today’s electronics. WDM-based optical networks employing passive-star couplers have been proposed for deployment in local and metropolitan areas. Optical amplification is often required in such networks to compensate for the signal attenuation along the fiber links and the splitting and coupling losses in the network. However, an optical amplifier has constraints on the maximum gain and the maximum output power it can supply; thus optical amplifier placement becomes a challenging problem. A simplifying assumption for analytical tractability requires that all wavelengths, present at …

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Automatic Target Cueing Of Hyperspectral Image Data, Terry A. Wilson Sep 1998

Automatic Target Cueing Of Hyperspectral Image Data, Terry A. Wilson

Theses and Dissertations

Modern imaging sensors produce vast amounts data, overwhelming human analysts. One such sensor is the Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) hyperspectral sensor. The AVIRIS sensor simultaneously collects data in 224 spectral bands that range from 0.4µm to 2.5µm in approximately 10nm increments, producing 224 images, each representing a single spectral band. Autonomous systems are required that can fuse "important" spectral bands and then classify regions of interest if all of this data is to be exploited. This dissertation presents a comprehensive solution that consists of a new physiologically motivated fusion algorithm and a novel Bayes optimal self-architecting classifier …

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Radial Complexity Estimation For Improved Generalization In Artificial Neural Networks, Lemuel R. Myers Jr. Sep 1998

Radial Complexity Estimation For Improved Generalization In Artificial Neural Networks, Lemuel R. Myers Jr.

Theses and Dissertations

When training an artificial neural network (ANN) for classification using backpropagation of error, the weights are usually updated by minimizing the sum-squared error on the training set. As training ensues, overtraining may be observed as the network begins to memorize the training data. This occurs because, as the magnitude of the weight vector, W, grows, the decision boundaries become overly complex in much the same way as a too-high order polynomial approximation can overfit a data set in a regression problem. Since w grows during standard backpropagation, it is important to initialize the weights with consideration to the importance of …

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A Decision Theoretic Approach For Interface Agent Development, Scott M. Brown Sep 1998

A Decision Theoretic Approach For Interface Agent Development, Scott M. Brown

Theses and Dissertations

The complexity of current software applications is overwhelming users. The need exists for intelligent interface agents to address the problem of increasing taskload that is overwhelming the human user. Interface agents could help alleviate user taskload by extracting and analyzing relevant information, and providing information abstractions of that information, and providing timely, beneficial assistance to users. These agents could communicate with the user through the existing user interface and also adapt to user needs and behaviors. Central to providing assistance to a user is the issue of correctly determining the user's intent. This dissertation presents an effective, efficient, and extensible …

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A Feedback-Driven Proportion Allocator For Real-Rate Scheduling, David Steere, Ashvin Goel, Joshua Gruenberg, Dylan Mcnamee, Calton Pu, Jonathan Walpole Sep 1998

A Feedback-Driven Proportion Allocator For Real-Rate Scheduling, David Steere, Ashvin Goel, Joshua Gruenberg, Dylan Mcnamee, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

In this paper we propose changing the decades-old practice of allocating CPU to threads based on priority to a scheme based on proportion and period. Our scheme allocates to each thread a percentage of CPU cycles over a period of time, and uses a feedback-based adaptive scheduler to assign automatically both proportion and period. Applications with known requirements, such as isochronous software devices, can bypass the adaptive scheduler by specifying their desired proportion and/or period. As a result, our scheme provides reservations to applications that need them, and the benefits of proportion and period to those that do not. Adaptive …

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A Resource Allocation Mechanism Based On Cost Function Synthesis In Complex Systems, Carlos C. Amaro Aug 1998

A Resource Allocation Mechanism Based On Cost Function Synthesis In Complex Systems, Carlos C. Amaro

Dissertations

While the management of resources in computer systems can greatly impact the usefulness and integrity of the system, finding an optimal solution to the management problem is unfortunately NP hard. Adding to the complexity, today's 'modern' systems - such as in multimedia, medical, and military systems - may be, and often are, comprised of interacting real and non-real-time components. In addition, these systems can be driven by a host of non-functional objectives – often differing not only in nature, importance, and form, but also in dimensional units and range, and themselves interacting in complex ways. We refer to systems exhibiting …

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