Engineering Commons^™

The Automated Wingman: An Airborne Companion For Users Of Dis Compatible Flight Simulators, Mark M. Edwards

Theses and Dissertations

A major problem encountered by users of distributed virtual environments is the lack of simulators available to populate these environments. This problem is usually remedied by using computer generated entities. Unfortunately, these entities often lack adequate human behavior and are readily identified as non-human. This violates the realism premise of distributed virtual reality and is a major problem, especially in training situations. This thesis addresses the problem by presenting a computer generated entity called the Automated Wingman. The Automated Wingman is a semi-automated computer generated aircraft simulator that operates under the control of a designated lead simulator and integrates distributed …

An Architecture For Dynamic Meta-Level Process Control For Model-Based Troubleshooting, John E. Friskie

Theses and Dissertations

There are numerous methods used for troubleshooting devices. Each method has certain domains, knowledge requirements, and assumptions required for it to perform well. However, oftentimes no one method by itself is sufficient to completely solve a troubleshooting problem. Therefore, an architecture is required to control the combined use of many problem solving methods. The combination of multiple problem solving methods makes the troubleshooting process more robust in terms of device domains that can be dealt with and quality of diagnoses produced. Troubleshooting has two tasks: diagnosis and problem resolution. This research provides an architecture that allows dynamic method selection during …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 11, Number 9, November 1995, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Aliasing Reduction In Staring Infrared Imagers Utilizing Subpixel Techniques, Joseph C. Gillette, Thomas M. Stadtmiller, Russell C. Hardie

Electrical and Computer Engineering Faculty Publications

We introduce and analyze techniques for the reduction of aliased signal energy in a staring infrared imaging system. A standard staring system uses a fixed two-dimensional detector array that corresponds to a fixed spatial sampling frequency determined by the detector pitch or spacing. Aliasing will occur when sampling a scene containing spatial frequencies exceeding half the sampling frequency. This aliasing can significantly degrade the image quality. The aliasing reduction schemes presented here, referred to as microscanning, exploit subpixel shifts between time frames of an image sequence. These multiple images are used to reconstruct a single frame with reduced aliasing. If …

Customizable Operating Systems, Jonathan Walpole, Crispin Cowan, Andrew P. Black, Jon Inouye, Calton Pu, Shanwei Cen

Computer Science Faculty Publications and Presentations

A customizable operating system is one that can adapt to improve its functionality or performance. The need for customizable and application-specific operating systems has been recognized for many years, but they have yet to appear in the commercial market. This paper explores the notion of operating system customizability and examines the limits of existing approaches. The paper begins by surveying system structuring approaches for the safe and efficient execution of customizable operating systems. Then it discusses the burden that existing approaches impose on application software, and explores techniques for reducing this burden. Finally, support for customizability in the Synthetix project …

Device And Physical Data Independence For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier

Computer Science Faculty Publications and Presentations

Multimedia computing promises access to any type of visual or aural medium on the desktop. But in this networked future, will every type of media be accessible from every terminal device? Current multimedia standards do not allow content that is authored for high-bandwidth workstations to scale down for low-bandwidth applications. The problem is that application requests are commonly interpreted as requests for the highest possible quality and resource overloads are handled by ad hoc methods. We can begin to solve this problem by specifying Quality of Service (QOS) requirements based on functionality rather than on content encoding and device capabilities.

Quality Of Service Specification For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier

Computer Science Faculty Publications and Presentations

The bandwidth limitations of multimedia systems force tradeoffs between presentation data fidelity and real-time performance. For example, digital video is commonly encoded with lossy compression to reduce bandwidth and frames may be skipped during playback to maintain synchronization. These tradeoffs depend on device performance and physical data representations that are hidden by a database system. If a multimedia database is to support digital video and other continuous media data types, we argue that the database should provide a Quality of Service (QOS) interface to allow application control of presentation timing and information loss tradeoffs.

This paper proposes a data model …

Device And Physical Data Independence For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier

Computer Science Faculty Publications and Presentations

Multimedia computing promises access to any type of visual or aural medium on the desktop. But in this networked future, will every type of media be accessible from every terminal device? Current multimedia standards do not allow content that is authored for high-bandwidth workstations to scale down for low-bandwidth applications. The problem is that application requests are commonly interpreted as requests for the highest possible quality and resource overloads are handled by ad hoc methods. We can begin to solve this problem by specifying Quality of Service (QOS) requirements based on functionality rather than on content encoding and device capabilities.

A Computer-Aided Software Engineering (Case) Approach To Business Process Reengineering (Bpr), Faiza I. Khan

Master's Theses - Daytona Beach

This thesis addresses the problem of lack of procedures by which managers can identify business processes that would benefit from reengineering and which could be used to guide the BPR activity to its successful conclusion. The purpose of this study is to analyze various Software Engineering (SE) principles to determine whether they could be used to support Business Process Reengineering (BPR) activities either directly or with some modification, and if so, whether available Computer-Aided Software Engineering (CASE) tools might be applied to BPR in support of managers who wish to implement it. The principles of SE and BPR are discussed …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 11, Number 8, October 1995, 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.

Atomic Broadcast In Heterogeneous Distributed Systems, Osman Zeineldine

Computer Science Theses & Dissertations

Communication services have long been recognized as possessing a dominant effect on both performance and robustness of distributed systems. Distributed applications rely on a multitude of protocols for the support of these services. Of crucial importance are multicast protocols. Reliable multicast protocols enhance the efficiency and robustness of distributed systems. Numerous reliable multicast protocols have been proposed, each differing in the set of assumptions adopted, especially for the communication network. These assumptions make each protocol suitable for a specific environment. The presence of different distributed applications that run on different LANs and single distributed applications that span different LANs mandate …

Safe Stratified Datalog With Integer Order Programs, Peter Revesz

School of Computing: Conference and Workshop Papers

Guaranteeing termination of programs on all valid inputs is important for database applications. Termination cannot be guaranteed in Stratified Datalog with integer (gap)-order programs on generalized databases because they express any Turing-computable function. This paper introduces a restriction of those programs that can express only computable queries. The restricted language has a high expressive power and a non-elementary data complexity.

Teaching Upper Level Computer Science Courses Via Virtual Classroom And Video : Course Reports By Faculty, Computerized Conferencing & Communications Center, Starr Roxanne Hiltz, Julian M. Scher, Michael Bieber, Murray Turoff

Computerized Conferencing and Communications Center Reports

New Jersey Institute of Technology is the grateful recipient of a generous grant from the Alfred P. Sloan Foundation which has enabled it to explore the use of asynchronous learning networks to create and deliver an entire undergraduate degree program in computer and information science. Each of these courses uses some amount of lecture-type material delivered via videotape. These materials are usually available to students in three different ways: by viewing broadcasts on a New Jersey cable station, by renting the set of videotapes, or by viewing in a special room in the library. Videotapes for distance learning are not …

Teaching Lower Level Computer Science Courses Via Virtual Classroom And Video : Course Reports By Faculty, Computerized Conferencing & Communications Center, Starr Roxanne Hiltz, Fadi Deek, Maura Deek, James Geller, Ajaz R. Rana

Computerized Conferencing and Communications Center Reports

New Jersey Institute of Technology is the grateful recipient of a generous grant from the Alfred P. Sloan Foundation which has enabled it to explore the use of asynchronous learning networks to create and deliver an entire undergraduate degree program in computer and information science. Each of these courses uses some amount of lecture-type material delivered via videotape. These materials are usually available to students in three different ways: by viewing broadcasts on a New Jersey cable station, by renting the set of videotapes, or by viewing in a special room in the library. Videotapes for distance learning are not …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 11, Number 7, September 1995, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Linda Jacobson Interview Virtual Reality Evangelist, Loretta L. Lange

SWITCH

In the interview with Linda Jacobson, a Virtual Reality (VR) artist, Jacobson discusses the current and future state of VR technology’s role in the politics of the body, social identity, self, gender, class, and race. This article discusses the fact that barriers to access exist for a more diverse set of artists across race, class, and gender to engage with VR technology and the need to evolve the development platform, so artists can implement their ideas in a low-cost way. The author discusses Jaron Lanier’s ideas about using VR to explore other identities based on a theatrical model where the …

Broadband Dynamic, Holographically Self-Recorded, And Static Hexagonal Scattering Patterns In Photorefractive Knbo3:Fe, Nickolai Kukhtarev, Tatiana V. Kukhtareva, John Caulfield, Partha P. Banerjee, Hsueh-Ling Yu, Lambertus Hesselink

Electrical and Computer Engineering Faculty Publications

We have observed and explained three types of hexagon pattern formation in photo refractive crystal KNb03:Fe. These are:

• Dynamic (laser induced)
• Semipermanent (holographically stored)
• Permanent (induced by a static domain grid) over a wide wavelength range

Transient Wave Mixing And Recording Kinetics In Photorefractive Barium Titanate: A Nonlinear Coupled Mode Approach, Partha P. Banerjee, John M. Jarem

Electrical and Computer Engineering Faculty Publications

By using rigorous coupled-wave diffraction theory along with a time-dependent nonlinear formulation, we analyze two- and multiplewave coupling and the grating kinetics in BaTi03 with different boundary interfaces. Efffects of electrostatic and optical anisotropy have been included in the analysis. Significant mode conversion to higher orders is observed only when the boundary interfaces are highly mismatched.

Guest Editorial: Special Section On Photorefractive Nonlinear Optics, Partha P. Banerjee

Electrical and Computer Engineering Faculty Publications

Hand in hand with experimental work in photorefractives, there is a lot of activity in modeling photorefractive materials and experimental observations in the open literature. This special section contains a paper by Banerjee and Jarem, who use a rigorous coupled wave theory to analyze two- and multiple-wave mixing photorefractive barium titanate, modeled through the Kukhtarev equations.

Preprocessing Of Microcirculatory Images., Mohamed S. Mansour

Electronic Theses and Dissertations

This thesis project consists of the development of a computerized image processing system to preprocess microvascular images of the mouse Latisimus Dorsi Muscle (LDM). This research has been conducted in association with the Division of Plastic and Reconstructive Surgery at the University of Louisville. The input to the system is a set of 35 or more overlapping microscopic fields or sub_images containing segments of the LDM microcirculation, the output is an adjacent single montage encompassing the entire LDM microvasculature. The developed system presents practical solutions to the problems of image registration, overlap resolution, and image segmentation, in addition, the results …

Comparison Of Time-Domain Reflectometry Performance Factors For Several Dielectric Geometries: Theory And Experiments, S. V. Maheshwarla, R. Venkatasubramanian, Robert F. Boehm

Electrical & Computer Engineering Faculty Research

We propose three nontraditional dielectric geometries and present an experimental and theoretical analysis and comparison of time domain reflectometry (TDR) performances for them. The traditional geometry (the probes inserted in material of essentially infinite extent) is compared to three nontraditional geometries where the probes are affixed outside of a core sample, inside of a bore, or flat on the surface of a semi-infinite solid. Our derivation relates the velocity of electromagnetic wave propagation to the complex permittivities and permeabilities of the media and the geometry for the three nontraditional configurations. Experimental results for air, styrofoam, dry sand, wet sand of …

Fault Tolerance In Critical Real-Time Systems, Balaji Tirukarneswaran

Electrical & Computer Engineering Theses & Dissertations

Critical real-time applications require work to be completed before a predefined deadline, else the consequences may be catastrophic. The anticipation of faults in such systems necessitates the need for fault tolerance. Fault tolerance can be achieved in many different ways. A real-time system designer may impose restrictions on any of the system performance measures such as the latency, throughput and number of processors, depending on the type of application. In this work, several different fault tolerant strategies for any given DFG (Data Flow Graph) are discussed. DFG models are developed using the strategies and the resulting worst case performances a.re …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 11, Number 6, June 1995, 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.

Upgrading A Cd-Rom Network For Multimedia Applications, Margaret Sylvia

Faculty Publications

Checking the servers, PCs, and network connections for bottlenecks in serving multimedia across the network are steps that will alleviate speed and connectivity issues for users.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 11, Number 5, May 1995, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Real-Time Communication In The Algorithm To Architecture Mapping Model, Somesh M. Varma

Electrical & Computer Engineering Theses & Dissertations

The objective of this thesis is to analyze schedules of communication resources to obtain deterministic and contention-free communication in the Algorithm To Architecture Mapping Model (ATAMM). In ATAMM, performance must be deterministic to guarantee meeting deadlines. It is difficult to achieve deterministic performance in the presence of contention during communication. This thesis develops new data-flow models to study and analyze different schedules of communication resources to achieve deterministic and contention-free communication. These models are the Synchronous Communication Marked Graph (SCMG) and the Asynchronous Communication Marked Graph (ACMG). The SCMG is based on message passing synchronous communication. It defines schedules for …

Navigation Satellite Selection Using Neural Networks, Daniel J. Simon, Hossny El-Sherief

Electrical and Computer Engineering Faculty Publications

The application of neural networks to optimal satellite subset selection for navigation use is discussed. The methods presented in this paper are general enough to be applicable regardless of how many satellite signals are being processed by the receiver. The optimal satellite subset is chosen by minimizing a quantity known as Geometric Dilution of Precision (GDOP), which is given by the trace of the inverse of the measurement matrix. An artificial neural network learns the functional relationships between the entries of a measurement matrix and the eigenvalues of its inverse, and thus generates GDOP without inverting a matrix. Simulation results …

Mpvm: A Migration Transparent Version Of Pvm, Jeremy Casas, Dan Clark, Ravi Konuru, Steve Otto, Robert Prouty, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Parallel Virtual Machine (PVM) is a widely-used software system that allows a heterogeneous set of parallel and serial UNIX-based computers to be programmed as a single message-passing parallel machine, In this paper, an extension to PVM to support dynamic process migration is presented. Support for migration is important in general-purpose workstation environments since it allows parallel computations to co-exist with other applications, using idle-cycles as they become available and off-loading from workstations when they are no longer free. A description and evaluation of the design and implementation of the prototype Migratable PVM system is presented together with some performance results.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 11, Number 4, April 1995, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Thermal Effects On Y2O3:Eu3+ For Fiber Optic Temperature Sensing, Arnel C. Lavarias

Electrical & Computer Engineering Theses & Dissertations

Fiber optic methods have gained acceptance in the past several years as non­ intrusive optical techniques of measuring environmental variables, particularly under hostile conditions. Fiber optic temperature sensors are required for many applications which have a large operating range. One way to implement this sensor is to introduce rare earth-doped materials into a fiber showing temperature-dependent optical emission characteristics. The thermal effects on optical emission characteristics of Y₂O₃:Eu³⁺ were studied. The thermal broadening and temperature dependence of the lifetime (τ) of the 611.4 nm emission due to the ⁵D₀ ➔ 7F …