Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Computer Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 52681 - 52710 of 58244

Full-Text Articles in Physical Sciences and Mathematics

Vas (Visual Analysis System): An Information Visualization Engine To Interpret World Wide Web Structure, Tarkan Karadayi May 2000

Vas (Visual Analysis System): An Information Visualization Engine To Interpret World Wide Web Structure, Tarkan Karadayi

Theses and Dissertations - UTB/UTPA

People increasingly encounter problems of interpreting and filtering mass quantities of information. The enormous growth of information systems on the World Wide Web has demonstrated that we need systems to filter, interpret, organize and present information in ways that allow users to use these large quantities of information. People need to be able to extract knowledge from this sometimes meaningful but sometimes useless mass of data in order to make informed decisions. Web users need to have some kind of information about the sort of page they might visit, such as, is it a rarely referenced or often-referenced page? This …


Local Properties Of Query Languages, Guozhu Dong, Leonid Libkin, Limsoon Wong May 2000

Local Properties Of Query Languages, Guozhu Dong, Leonid Libkin, Limsoon Wong

Kno.e.sis Publications

In this paper we study the expressiveness of local queries. By locality we mean — informally — that in order to check if a tuple belongs to the result of a query, one only has to look at a certain predetermined portion of the input. Examples include all relational calculus queries. We start by proving a general result describing outputs of local queries. This result leads to many easy inexpressibility proofs for local queries. We then consider a closely related property, namely, the bounded degree property. It describes the outputs of local queries on structures that locally look “simple.” Every …


A Study Of Disk Performance Optimization., Richard Scott Gray May 2000

A Study Of Disk Performance Optimization., Richard Scott Gray

Electronic Theses and Dissertations

Response time is one of the most important performance measures associated with a typical multi-user system. Response time, in turn, is bounded by the performance of the input/output (I/O) subsystem. Other than the end user and some external peripherals, the slowest component of the I/O subsystem is the disk drive.

One standard strategy for improving I/O subsystem performance uses high-performance hardware like Small Computer Systems Interface (SCSI) drives to improve overall response time. SCSI hardware, unfortunately, is often too expensive to use in low-end multi-user systems. The low-end multi-user systems commonly use inexpensive Integrated Drive Electronics (IDE) disk drives to …


An Infrastructure For A Mobile-Agent System That Provides Personalized Services To Mobile Devices, Debbie O. Chyi May 2000

An Infrastructure For A Mobile-Agent System That Provides Personalized Services To Mobile Devices, Debbie O. Chyi

Dartmouth College Undergraduate Theses

In this paper, we present the design of a mobile-agent system that provides a mobile user with a personalized information retrieval service and we describe the implementation of the infrastructure for such a system. This "Personal Agent System" gathers information from the Internet and uses context-aware mechanisms to manage the information according to a mobile user's needs and preferences. The user's schedule and location are the context indicators in this system. These indicators are critical in ensuring that users obtain only the information they want, receive information in a form that is most useful for viewing on their mobile device, …


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 16, Number 5, May 2000, College Of Engineering And Computer Science, Wright State University May 2000

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 16, Number 5, May 2000, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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


An Adaptive Hybrid Genetic-Annealing Approach For Solving The Map Problem On Belief Networks, Manar Hosny May 2000

An Adaptive Hybrid Genetic-Annealing Approach For Solving The Map Problem On Belief Networks, Manar Hosny

Archived Theses and Dissertations

Genetic algorithms (GAs) and simulated annealing (SA) are two important search methods that have been used successfully in solving difficult problems such as combinatorial optimization problems. Genetic algorithms are capable of wide exploration of the search space, while simulated annealing is capable of fine tuning a good solution. Combining both techniques may result in achieving the benefits of both and improving the quality of the solutions obtained. Several attempts have been made to hybridize GAs and SA. One such attempt was to augment a standard GA with simulated annealing as a genetic operator. SA in that case acted as a …


The Gx-Tree, Amgad Mohamed Abdelkader Al-Sisi May 2000

The Gx-Tree, Amgad Mohamed Abdelkader Al-Sisi

Archived Theses and Dissertations

No abstract provided.


Anytime Algorithms For Maximal Constraint Satisfaction Problems, Noha Kaptan May 2000

Anytime Algorithms For Maximal Constraint Satisfaction Problems, Noha Kaptan

Archived Theses and Dissertations

No abstract provided.


Mpi Collective Operations Over Ip Multicast, Amy Apon, H A. Chen, Y O. Carrasco May 2000

Mpi Collective Operations Over Ip Multicast, Amy Apon, H A. Chen, Y O. Carrasco

Publications

Many common implementations of Message Passing Inter- face (MPI) implement collective operations over point-to-point operations. This work examines IP multicast as a framework for collective operations. IP multicast is not reliable. If a receiver is not ready when a message is sent via IP multicast, the message is lost. Two techniques for ensuring that a message is not lost due to a slow receiving process are examined. The techniques are implemented and compared experimentally over both a shared and a switched Fast Ethernet. The average performance of collective operations is improved as a function of the number of participating processes …


A Simulation Of Auroral Absorption, Eric Michael Greenberg May 2000

A Simulation Of Auroral Absorption, Eric Michael Greenberg

Dartmouth College Undergraduate Theses

HF radio transmissions propagate long distances by reflecting off the ionosphere. At high latitudes radio propagation is strongly affected by the northern lights (aurora borealis), which causes ionization at low altitudes and hence the absorption of radio waves. Models of this process are still in a primitive state. A simulation of radio wave propagation was created in order to test Foppiano and Bradley's empirical model of auroral absorption. The simulation attempts to predict the net absorption of signals at a receiver by simulating a large number of transmitters, even though the exact sources of the signals are unknown. Although the …


3d Outside Cell Interference Factor For An Air-Ground Cdma ‘Cellular’ System, David W. Matolak May 2000

3d Outside Cell Interference Factor For An Air-Ground Cdma ‘Cellular’ System, David W. Matolak

Faculty Publications

We compute the outside-cell interference factor of a code-division multiple-access (CDMA) system for a three-dimensional (3-D) air-to-ground (AG) "cellular-like" network consisting of a set of uniformly distributed ground base stations and airborne mobile users. The CDMA capacity is roughly inversely proportional to the outside-cell interference factor. It is shown that for the nearly free-space propagation environment of these systems, the outside-cell interference factor can be larger than that for terrestrial propagation models (as expected) and depends approximately logarithmically upon both the cell height and cell radius.


Using Raster Sketches For Digital Image Retrieval, James Carswell May 2000

Using Raster Sketches For Digital Image Retrieval, James Carswell

Electronic Theses and Dissertations

This research addresses the problem of content-based image retrieval using queries on image-object shape, completely in the raster domain. It focuses on the particularities of image databases encountered in typical topographic applications and presents the development of an environment for visual information management that enables such queries. The query consists of a user-provided raster sketch of the shape of an imaged object. The objective of the search is to retrieve images that contain an object sufficiently similar to the one specified in the query. The new contribution of this work combines the design of a comprehensive digital image database on-line …


Decision Support Methods In Diabetic Patient Management By Insulin Administration Neural Network Vs. Induction Methods For Knowledge Classification, B. V. Ambrosiadou, S. Vadera, Venky Shankaraman, D. Goulis, G. Gogou May 2000

Decision Support Methods In Diabetic Patient Management By Insulin Administration Neural Network Vs. Induction Methods For Knowledge Classification, B. V. Ambrosiadou, S. Vadera, Venky Shankaraman, D. Goulis, G. Gogou

Research Collection School Of Computing and Information Systems

Diabetes mellitus is now recognised as a major worldwide public health problem. At present, about 100 million people are registered as diabetic patients. Many clinical, social and economic problems occur as a consequence of insulin-dependent diabetes. Treatment attempts to prevent or delay complications by applying ‘optimal’ glycaemic control. Therefore, there is a continuous need for effective monitoring of the patient. Given the popularity of decision tree learning algorithms as well as neural networks for knowledge classification which is further used for decision support, this paper examines their relative merits by applying one algorithm from each family on a medical problem; …


Load Sharing In Distributed Multimedia-On-Demand Systems, Y. C. Tay, Hwee Hwa Pang May 2000

Load Sharing In Distributed Multimedia-On-Demand Systems, Y. C. Tay, Hwee Hwa Pang

Research Collection School Of Computing and Information Systems

Service providers have begun to offer multimedia-on-demand services to residential estates by installing isolated, small-scale multimedia servers at individual estates. Such an arrangement allows the service providers to operate without relying on a highspeed, large-capacity metropolitan area network, which is still not available in many countries. Unfortunately, installing isolated servers can incur very high server costs, as each server requires spare bandwidth to cope with fluctuations in user demand. The authors explore the feasibility of linking up several small multimedia servers to a (limited-capacity) network, and allowing servers with idle retrieval bandwidth to help out servers that are temporarily overloaded; …


Enhancing Partitionable Group Membership Service In Asynchronous Distrib Systems, Marwa Mohamed Mansour May 2000

Enhancing Partitionable Group Membership Service In Asynchronous Distrib Systems, Marwa Mohamed Mansour

Archived Theses and Dissertations

No abstract provided.


Predictive Adaptive Resonance Theory And Knowledge Discovery In Databases, Ah-Hwee Tan, Hui-Shin Vivien Soon May 2000

Predictive Adaptive Resonance Theory And Knowledge Discovery In Databases, Ah-Hwee Tan, Hui-Shin Vivien Soon

Research Collection School Of Computing and Information Systems

This paper investigates the scalability of predictive Adaptive Resonance Theory (ART) networks for knowledge discovery in very large databases. Although predictive ART performs fast and incremental learning, the number of recognition categories or rules that it creates during learning may become substantially large and cause the learning speed to slow down. To tackle this problem, we introduce an on-line algorithm for evaluating and pruning categories during learning. Benchmark experiments on a large scale data set show that on-line pruning has been effective in reducing the number of the recognition categories and the time for convergence. Interestingly, the pruned networks also …


Fuzzy Neural Network Models For Classification, Arun D. Kulkarni, Charles D. Cavanaugh Apr 2000

Fuzzy Neural Network Models For Classification, Arun D. Kulkarni, Charles D. Cavanaugh

Arun Kulkarni

In this paper, we combine neural networks with fuzzy logic techniques. We propose a fuzzy-neural network model for pattern recognition. The model consists of three layers. The first layer is an input layer. The second layer maps input features to the corresponding fuzzy membership values, and the third layer implements the inference engine. The learning process consists of two phases. During the first phase weights between the last two layers are updated using the gradient descent procedure, and during the second phase membership functions are updated or tuned. As an illustration the model is used to classify samples from a …


Computer Vision: Object Recognition, Michael Zalokar '00 Apr 2000

Computer Vision: Object Recognition, Michael Zalokar '00

Honors Projects

One of the growing fields in computer science is that of Artificial Intelligence or AI. Many theories have evolved to make a computer intelligent and so far no one has succeeded (Dreyfus 1992). One of the methods used by the Shelley Project in the past has been to use a back propagation neural network that is the backbone of the GNU Neural Network Visualizer (GNNV). GNNV uses a neural network to try to identify known objects, like faces, in the field of view. A different method, that is the focus of this research, is to identify objects in the image. …


Bounding Interval Rational Bézier Curves With Interval Polynomial Bézier Curves, Thomas W. Sederberg, Falai Chen, Wenping Lou Apr 2000

Bounding Interval Rational Bézier Curves With Interval Polynomial Bézier Curves, Thomas W. Sederberg, Falai Chen, Wenping Lou

Faculty Publications

In this paper, we put forward and study the problem of bounding an interval rational Bézier curve with an interval polynomial Bézier curve. We propose three different methods—Hybrid Method, Perturbation Method and Linear Programming Method to solve this problem. Examples are illustrated to compare the three different methods. The empirical results show that the Perturbation Method and the Linear Programming Method produce much tighter bounds than the Hybrid Method, though they are computationally several times more expensive.


Monitoring Of Distributed Processes With Mobile Agents, Ryan P. Kennedy, Franz J. Kurfess Apr 2000

Monitoring Of Distributed Processes With Mobile Agents, Ryan P. Kennedy, Franz J. Kurfess

Computer Science and Software Engineering

The proliferation of networked and distributed systems presents a need for more tool development with regard to the monitoring and maintenance of distributed processes. The goal of this paper is to present a mechanism used to collect detailed process information from various remote Unix hosts on a network. The interface to this mechanism, a GUI applet, is accessible through a Java enabled browser such as Netscape Navigator. It presents the user with a menu of choices such as which host to view, and what process information to retrieve (I/O-bound processes, numbers of processes, individual/total process usage, etc.). The requested information …


The Next Step, Benjamin Y. Dai, Lynn Thompson, John David N. Dionisio, Hooshang Kangarloo, Ricky K. Taira Apr 2000

The Next Step, Benjamin Y. Dai, Lynn Thompson, John David N. Dionisio, Hooshang Kangarloo, Ricky K. Taira

Computer Science Faculty Works

In traditional radiology practice, reports are typically dictated and then transcribed.? While the free-text reports represent the semantic knowledge interpreted and conveyed by a physician, the information can be hard to access. The advantages of representing medical data in a structured format using standard terminology are clearly recognized. These include the ability to implement a standardized electronic medical record, automatically invoke medical guidelines when appropriate, and conduct outcomes research. Standard structured reports facilitate intelligent indexing, searching, and retrieval of documents from clinical databases. Recent attempts have been made in the industry to enable structured data entry using preformatted templates, but …


Cross Media Promotion Of The Internet In Television Commercials, Steven M. Edwards, Carrie La Ferle Apr 2000

Cross Media Promotion Of The Internet In Television Commercials, Steven M. Edwards, Carrie La Ferle

Temerlin Advertising Institute Research

Increasing presence of internet addresses across traditional media spurred the current study. Specifically, the study examined the cross media promotion of website addresses in television commercials to determine if and when they were being used, and by whom? For comparison purposes, other formsof direct response channels were also measured. A clearer understanding of the practice of promoting web sites in television commercials was garnered by examining website addresses for their size, length, positioning, frequency, product categoy representation, and other important attributes. The findings provide an initial base from which future growth and style of web site advertising in traditional media …


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 16, Number 4, April 2000, College Of Engineering And Computer Science, Wright State University Apr 2000

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 16, Number 4, April 2000, 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.


A Hybrid Finite Element-Finite Difference Method For Thermal Analysis In A Double-Layered Thin Film, Teng Zhu Apr 2000

A Hybrid Finite Element-Finite Difference Method For Thermal Analysis In A Double-Layered Thin Film, Teng Zhu

Doctoral Dissertations

Thin film technology is of vital importance in microtechnology applications. For instance, thin films of metals, of dielectrics such as SiO2, or Si semiconductors are important components of microelectronic devices. The reduction of the device size to the microscale has the advantage of enhancing the switching speed of the device. The reduction, on the other hand, increases the rate of heat generation that leads to a high thermal load on the microdevice. Heat transfer at the microscale with an ultrafast pulsed-laser is also a very important process for thin films. Hence, studying the thermal behavior of thin films or of …


An Empirical Study Of The Effects Of Incorporating Fault Exposure Potential Estimates Into A Test Data Adequacy Criterion, Wei Chen, Gregg Rothermel, Roland H. Untch, Jeffery Von Ronne Apr 2000

An Empirical Study Of The Effects Of Incorporating Fault Exposure Potential Estimates Into A Test Data Adequacy Criterion, Wei Chen, Gregg Rothermel, Roland H. Untch, Jeffery Von Ronne

CSE Technical Reports

Code-coverage-based test data adequacy criteria typically treat all code components as equal. In practice, however, the probably that a test case can expose a fault in a code component varies: some faults are more easily revealed than others. Thus, researchers have suggested that if we could estimate the probability that a fault in a code component will cause a failure, we could use this estimate to determine the number of executions of a component that are required to achieve a certain level of confidence in that component’s correctness. This estimate in turn could be used to improve the fault-detection effectiveness …


On The Validity Of Digital Signatures, Jianying Zhou, Robert H. Deng Apr 2000

On The Validity Of Digital Signatures, Jianying Zhou, Robert H. Deng

Research Collection School Of Computing and Information Systems

An important feature of digital signatures is to serve as non-repudiation evidence. To be eligible as non-repudiation evidence, a digital signature on an electronic document should remain valid until its expiry date which is specified by some non-repudiation policy. As signature keys may be compromised and the validity of signatures may become questionable, additional security mechanisms need to be imposed on digital signatures. This paper examines the mechanisms for maintaining the validity of digital signatures, and provides a guideline on the use of these mechanisms in various context of applications.


Jotmail: A Voicemail Interface That Enables You To See What Was Said, Steve Whittaker, Richard C. Davis, Julia Hirschberg, Urs Muller Apr 2000

Jotmail: A Voicemail Interface That Enables You To See What Was Said, Steve Whittaker, Richard C. Davis, Julia Hirschberg, Urs Muller

Research Collection School Of Computing and Information Systems

Voicemail is a pervasive, but under-researched tool for workplace communication. Despite potential advantages of voicemail over email, current phone-based voicemail UIs are highly problematic for users. We present a novel, Web-based, voicemail interface, Jotmail. The design was based on data from several studies of voicemail tasks and user strategies. The GUI has two main elements: (a) personal annotations that serve as a visual analogue to underlying speech; (b) automatically derived message header information. We evaluated Jotmail in an 8-week field trial, where people used it as their only means for accessing voicemail. Jotmail was successful in supporting most key voicemail …


An Analysis Of The Effectiveness Of A Constructive Induction-Based Virus Detection Prototype, Kevin T. Damp Apr 2000

An Analysis Of The Effectiveness Of A Constructive Induction-Based Virus Detection Prototype, Kevin T. Damp

Theses and Dissertations

Computer viruses remain a tangible threat to systems both within the Department of Defense and throughout the greater international data communications infrastructure on which the DoD increasingly depends. This threat is exacerbated continually, as new viruses are introduced at an alarming rate by the growing collection of connected machines and their operators. Unfortunately, current antivirus solutions are ill-equipped to address these issues in the long term. This thesis documents an investigation into the use of constructive induction, a form of machine learning, as a supplemental antivirus technique theoretically capable of detecting previously unknown viruses through generalized decision-making techniques. A group …


Computational Geometry Column 38, Joseph O'Rourke Apr 2000

Computational Geometry Column 38, Joseph O'Rourke

Computer Science: Faculty Publications

Recent results on curve reconstruction are described.


A Comparative Analysis Of Proposed Mobility Support Schemes For Ip Multicast, Alexander Muller Jr. Apr 2000

A Comparative Analysis Of Proposed Mobility Support Schemes For Ip Multicast, Alexander Muller Jr.

Theses and Dissertations

This thesis introduces a novel mobile multicast transmission mechanism called Minimal Multicast Encapsulation. Additionally, this thesis analyzes the performance of mobility support schemes for IP multicast. Specifically, it compares the performance of combinations of two receive mechanisms and two transmit mechanisms. The receive mechanisms are the Internet Engineering Task Force (IETF) bi-directional tunneling mechanism and the IETF remote subscription mechanism. The transmit mechanisms are the IETF home tunneling mechanism and the Minimal Multicast Encapsulation. The performance analysis consists of examining path efficiencies, packet loss rates, and required mobility agent throughputs for each of the four possible combinations of the aforementioned …