Digital Commons Network^™

An Improved Algorithm For Translating Relational Schemas Into An Object Model, Joseph C. Pearson

Theses and Dissertations

Today's war fighter is inundated with data from numerous Command, Control, Communications and Computers and Intelligence systems. Integration of these systems is desirable, yet integration results in a static solution to a dynamic problem-by the time a global schema can be devised, it is out of date. Automating schema integration will mitigate this problem, but data model disparity must be addressed via translation to a common data model prior to integration. To address this requirement, this thesis presents an improved, relational to object-oriented schema translation algorithm, which is derived from a base algorithm proposed by another research effort. The improved …

Scalable Web Server Clustering Technologies, Trevor Schroeder, Steve Goddard, Byrav Ramamurthy

School of Computing: Faculty Publications

The exponential growth of the Internet, coupled with the increasing popularity of dynamically generated content on the World Wide Web, has created the need for more and faster Web servers capable of serving the over 100 million Internet users. Server clustering has emerged as a promising technique to build scalable Web servers. In this article we examine the seminal work, early products, and a sample of contemporary commercial offerings in the field of transparent Web server clustering. We broadly classify transparent server clustering into three categories.

Sisl: Several Interfaces, Single Logic, Thomas Ball, Christopher P. Colby, Peter Danielsen, Lalita Jategaonkar Jagadeesan, Radhakrishnan Jagadeesan, Konstantin Laufer, Peter Mataga, Kenneth Rehor

Computer Science: Faculty Publications and Other Works

Modern interactive services such as information and e-commerce services are becoming increasingly more flexible in the types of user interfaces they support. These interfaces incorporate automatic speech recognition and natural language understanding, and include graphical user interfaces on the desktop and web-based interfaces using applets and HTML forms. To what extent can the user interface software be decoupled from the service logic software (the code that defines the essential function of a service)? Decoupling of user interface from service logic directly impacts the flexibility of services, or, how easy they are to modify and extend. To explore these issues, we …

Study Of Architecture And Protocols For Reliable Multicasting In Packet Switching Networks, Shiwen Chen

Dissertations

Group multicast protocols have been challenged to provide scalable solutions that meet the following requirements: (i) reliable delivery from different sources to all destinations within a multicast group; (ii) congestion control among multiple asynchronous sources. Although it is mainly a transport layer task, reliable group multicasting depends on routing architectures as well.

This dissertation covers issues of both network and transport layers. Two routing architectures, tree and ring, are surveyed with a comparative study of their routing costs and impact to upper layer performances. Correspondingly, two generic transport protocol models are established for performance study. The tree-based protocol is rate-based …

Genetically Evolved Dynamic Control For Quadruped Walking, Giorgio Grasso

Dissertations

The aim of this dissertation is to show that dynamic control of quadruped locomotion is achievable through the use of genetically evolved central pattern generators. This strategy is tested both in simulation and on a walking robot. The design of the walker has been chosen to be statically unstable, so that during motion less than three supporting feet may be in contact with the ground.

The control strategy adopted is capable of propelling the artificial walker at a forward locomotion speed of ~1.5 Km/h on rugged terrain and provides for stability of motion. The learning of walking, based on simulated …

A Meta-Semantic Language For Smart Component-Adapters, Leon K. Jololian

Dissertations

The issues confronting the software development community today are significantly different from the problems it faced only a decade ago. Advances in software development tools and technologies during the last two decades have greatly enhanced the ability to leverage large amounts of software for creating new applications through the reuse of software libraries and application frameworks. The problems facing organizations today are increasingly focused around systems integration and the creation of information flows.

Software modeling based on the assembly of reusable components to support software development has not been successfully implemented on a wide scale. Several models for reusable software …

Applications Of Agent Architectures To Decision Support In Distributed Simulation And Training Systems, Plamen V. Petrov

Dissertations

This work develops the approach and presents the results of a new model for applying intelligent agents to complex distributed interactive simulation for command and control. In the framework of tactical command, control communications, computers and intelligence (C₄I), software agents provide a novel approach for efficient decision support and distributed interactive mission training. An agent-based architecture for decision support is designed, implemented and is applied in a distributed interactive simulation to significantly enhance the command and control training during simulated exercises. The architecture is based on monitoring, evaluation, and advice agents, which cooperate to provide alternatives to the …

Universal Access In Digital Libraries, Igg Adiwijaya

Theses

Digital libraries are concerned with the creation and management of information sources, the movement of information across global networks and the effective use of this information by a wide range of users. A digital library is a vast collection of obj ects that are of multimedia nature, e.g., text, video, images, and audio. Users wishing to access the digital library objects may possess varying capabilities, preferences, domain expertise, and may use different information appliances. With the phenomenal growth of the Internet, the number of different information appliances will, if not already, increase substantially in the near future. Facilitating access to …

Component-Based Software Engineering, Zhiyuan Wang

Dissertations

To solve the problems coming with the current software development methodologies, component-based software engineering has caught many researchers' attention recently. In component-based software engineering, a software system is considered as a set of software components assembled together instead of as a set of functions from the traditional perspective. Software components can be bought from third party vendors as off-the-shelf components and be assembled together.

Component-based software engineering, though very promising, needs to solve several core issues before it becomes a mature software development strategy. The goal of this dissertation is to establish an infrastructure for component-based software development. The author …

Naming And Sharing Resources Across Administrative Boundaries, Jonathan R. Howell

Dartmouth College Ph.D Dissertations

I tackle the problem of naming and sharing resources across administrative boundaries. Conventional systems manifest the hierarchy of typical administrative structure in the structure of their own mechanism. While natural for communication that follows hierarchical patterns, such systems interfere with naming and sharing that cross administrative boundaries, and therefore cause headaches for both users and administrators. I propose to organize resource naming and security, not around administrative domains, but around the sharing patterns of users.

The dissertation is organized into four main parts. First, I discuss the challenges and tradeoffs involved in naming resources and consider a variety of existing …

Structured Web Databases, Shuang Li

Dissertations and Theses

Recent research has focused on the cooperation of web server and database server software in the deployment of data-intensive web sites. That work has focused either on storing data in a database that can be used to generate the contents of a web site, or on providing interfaces and gateways to enable queries to be invoked from web pages and executed at external database servers.

This thesis describes the implementation of a prototype of the Data Web system that is being implemented at Portland State University. With Data Web, a user can embed in a web page virtual tables that …

Proceedings Of The 2000 Onr Decision-Support Workshop Series: The Human-Computer Partnership In Decision-Support, Collaborative Agent Design Research Center

Collaborative Agent Design (CAD) Research Center

The Decision Support Workshop of May 2-4, 2000 held in San Luis Obispo, Cal., was the second in a series that was started one year earlier as a joint project of the Office of Naval Research and the Collaborative Agent Design Research Center of Cal Poly.

The goal of this series of Workshops is to provide a forum where connections can be established on one hand between developers and proponents of decision support tools, with potential users such as managers of large, complex organizations/systems on the other. Clearly, the military belong to this class of users and it is therefore …

Performance Analysis Of Mobile Agents For Filtering Data Streams On Wireless Networks, David Kotz, Guofei Jiang, Robert Gray, George Cybenko, Ronald A. Peterson

Computer Science Technical Reports

Wireless networks are an ideal environment for mobile agents, because their mobility allows them to move across an unreliable link to reside on a wired host, next to or closer to the resources they need to use. Furthermore, client-specific data transformations can be moved across the wireless link, and run on a wired gateway server, with the goal of reducing bandwidth demands. In this paper we examine the tradeoffs faced when deciding whether to use mobile agents to support a data-filtering application, in which numerous wireless clients filter information from a large data stream arriving across the wired network. We …

Privacy On The Internet : A Study Of Ethical Issues, Jatara C. Brown

Electronic Dissertations and Theses

This paper will explore the ethical issues of privacy as it relates to computer use or more specifically, the Internet. The information for this paper will be gleaned through books on computer ethics and priv acy, Internet web sites as well as through personal experience. This paper will explore the social and legal aspects ofInternet privacy by examining various real-life cases where Internet privacy was perceived to have been breached. In addition, it will showcase the issues of privacy from two sides: from the perspective of ordinary private citizens and from government agencies and marketing companies who feel that they …

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 …

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, …

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 …

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.

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 …

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 …

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.

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; …

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. …

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 …

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.

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 …

An Object-Oriented Algorithmic Laboratory For Ordering Sparse Matrices, Gary Karl Kumfert

Computer Science Theses & Dissertations

We focus on two known NP-hard problems that have applications in sparse matrix computations: the envelope/wavefront reduction problem and the fill reduction problem. Envelope/wavefront reducing orderings have a wide range of applications including profile and frontal solvers, incomplete factorization preconditioning, graph reordering for cache performance, gene sequencing, and spatial databases. Fill reducing orderings are generally limited to—but an inextricable part of—sparse matrix factorization.

Our major contribution to this field is the design of new and improved heuristics for these NP-hard problems and their efficient implementation in a robust, cross-platform, object-oriented software package. In this body of research, we (1) examine …

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 …

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 …

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 …