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Computer Sciences

1997

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Full-Text Articles in Engineering

Zastosowanie Modelu "Skrzynki" Do Oceny Poziomu Stężeń Zanieczyszczeń Komunikacyjnych W Przyziemnej Warstwie Atmosfery, Marek Bogacki, Marian Mazur, Robert Oleniacz Dec 1997

Zastosowanie Modelu "Skrzynki" Do Oceny Poziomu Stężeń Zanieczyszczeń Komunikacyjnych W Przyziemnej Warstwie Atmosfery, Marek Bogacki, Marian Mazur, Robert Oleniacz

Robert Oleniacz

Road transport is an essential source of nitrogen oxides (NOx), carbon monoxide (CO) and reactive hydrocarbons (RHC) emissions to atmosphere. Quantity and chemical constitution of emitted substances and meteorological conditions determine the level of ozon (O3) concentration forming as a result of photochemical reactions. The method presented in the paper consists in designation of quantity and chemical constitution of substances emitted from mo-bile sources and special mathematical modeling of physical and chemical transformations that take place in the lowest atmospheric layer.

English title: The use of box model to estimate the size of traffic pollutant concentrations in the lowest atmospheric …


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 10, December 1997, College Of Engineering And Computer Science, Wright State University Dec 1997

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 10, December 1997, 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.


Flow And Congestion Control For Internet Streaming Applications, Shanwei Cen, Calton Pu, Jonathan Walpole Dec 1997

Flow And Congestion Control For Internet Streaming Applications, Shanwei Cen, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

The emergence of streaming multimedia players provides users with low latency audio and video content over the Internet. Providing high-quality, best-effort, real-time multimedia content requires adaptive delivery schemes that fairly share the available network bandwidth with reliable data protocols such as TCP. This paper proposes a new flow and congestion control scheme, SCP (Streaming Control Protocol) , for real-time streaming of continuous multimedia data across the Internet. The design of SCP arose from several years of experience in building and using adaptive real-time streaming video players. SCP addresses two issues associated with real-time streaming. First, it uses a congestion control …


Architecture, Design, And Implementation Of A Rapidly Prototyped Virtual Environment For A Military Spaceplane, Scott A. Rothermel Dec 1997

Architecture, Design, And Implementation Of A Rapidly Prototyped Virtual Environment For A Military Spaceplane, Scott A. Rothermel

Theses and Dissertations

The new Global Engagement vision places increased emphasis on the Air Force's ability to control and exploit space. A military spaceplane combining reliable access to space, high operational tempos, and multi-mission capabilities is in conceptual stages of development. Virtual environment technology provides an opportunity to investigate system requirements and unconventional interface paradigms for this unique vehicle. A virtual environment architecture and design based on support for a rapid prototyping development process, separation of concerns, and user interface development is presented. The rapid prototyping process allowed management of changing requirements via an evolutionary approach to implementation. Separation of the activities performed …


Pseudorandom Code Generation For Communication And Navigation System Applications, John F. Brendle Jr. Dec 1997

Pseudorandom Code Generation For Communication And Navigation System Applications, John F. Brendle Jr.

Theses and Dissertations

This research project investigated the design, construction and evaluation of a pseudorandom code generator for communication and navigation system applications. These types of codes include spreading codes, Gold codes, Jet Propulsion Laboratory (JPL) ranging codes, syncopated codes, and nonlinear codes. Such waveforms are typically used in communication and navigation system applications. The code generator uses the Stanford Telecom STEL-1032 Pseudorandom Number (PRN) coder. A coder interface was designed and constructed for manual data entry to the registers of the PRN coder. The code generator is capable of independently clocking and generating all possible codes with lengths up to 4,294,967,295 bits. …


Visualization And Animation Of A Missile/Target Encounter, Jeffrey T. Bush Dec 1997

Visualization And Animation Of A Missile/Target Encounter, Jeffrey T. Bush

Theses and Dissertations

Existing missile/target encounter modeling and simulation systems focus on improving probability of kill models. Little research has been done to visualize these encounters. These systems can be made more useful to the engineers by incorporating current computer graphics technology for visualizing and animating the encounter. Our research has been to develop a graphical simulation package for visualizing both endgame and full fly-out encounters. Endgame visualization includes showing the interaction of a missile, its fuze cone proximity sensors, and its target during the final fraction of a second of the missile/target encounter. Additionally, this system displays dynamic effects such as the …


Modeling And Simulation Support For Parallel Algorithms In A High-Speed Network, Dustin E. Yates Dec 1997

Modeling And Simulation Support For Parallel Algorithms In A High-Speed Network, Dustin E. Yates

Theses and Dissertations

This thesis investigates the ability of a simulation model to compare and contrast parallel processing algorithms in a high-speed network. The model extends existing modeling, analysis, and comparison of parallel algorithms by providing graphics based components that facilitate the measurement of system resources. Simulation components are based on the Myrinet local area network standard. The models provide seven different topologies to contrast the performance of five variations of Fast Fourier Transform (FFT) algorithms. Furthermore, the models were implemented using a commercially developed product that facilitates the testing of additional topologies and the investigation of hardware variations. Accurate comparisons are statistically …


Breast Cancer Mass Detection Using Difference Of Gaussians And Pulse Coupled Neural Networks, Donald A. Cournoyer Dec 1997

Breast Cancer Mass Detection Using Difference Of Gaussians And Pulse Coupled Neural Networks, Donald A. Cournoyer

Theses and Dissertations

CAD, serving as a second reader, has been shown to improve the success of radiologists at detecting breast cancer. This thesis will develop a new algorithm to identify masses in mammograms. The system developed for this thesis will be capable of assisting a radiologist in making decisions.


Applications Of Unsupervised Clustering Algorithms To Aircraft Identification Using High Range Resolution Radar, Dzung Tri Pham Dec 1997

Applications Of Unsupervised Clustering Algorithms To Aircraft Identification Using High Range Resolution Radar, Dzung Tri Pham

Theses and Dissertations

Identification of aircraft from high range resolution (HRR) radar range profiles requires a database of information capturing the variability of the individual range profiles as a function of viewing aspect. This database can be a collection of individual signatures or a collection of average signatures distributed over the region of viewing aspect of interest. An efficient database is one which captures the intrinsic variability of the HRR signatures without either excessive redundancy typical of single-signature databases, or without the loss of information common when averaging arbitrary groups of signatures. The identification of 'natural' clustering of similar HRR signatures provides a …


A Single Chip Low Power Implementation Of An Asynchronous Fft Algorithm For Space Applications, Bruce W. Hunt Dec 1997

A Single Chip Low Power Implementation Of An Asynchronous Fft Algorithm For Space Applications, Bruce W. Hunt

Theses and Dissertations

A fully asynchronous fixed point FFT processor is introduced for low power space applications. The architecture is based on an algorithm developed by Suter and Stevens specifically for a low power implementation. The novelty of this architecture lies in its high localization of components and pipelining with no need to share a global memory. High throughput is attained using large numbers of small, local components working in parallel. A derivation of the algorithm from the discrete Fourier transform is presented followed by a discussion of circuit design parameters specifically, those relevant to space applications. The generic architecture is explained with …


A Modeling And Simulation Approach To Characterize Network Layer Internet Survivability, Leif S. King Dec 1997

A Modeling And Simulation Approach To Characterize Network Layer Internet Survivability, Leif S. King

Theses and Dissertations

The Air Force Core Competency of Information Superiority will be achieved in an age of decreasing AF manpower and corporate expertise. Increased AF reliance on COTS solutions, coupled with nearly ubiquitous points of entry to communication networks, create unique challenges in maintaining the Information Superiority edge. The protection of the internet is part of this equation. The internet supports the daily business traffic of the Air Force. Personnel, finance, and supply data flow through its routers. Controlling an adversary's access to our information systems, either the data, or the hardware and software that control the data and transform it into …


Combining Multi-Attribute Utility And Geographic Information For Boundary Decisions: An Application To Park Planning, Jeffrey Keisler, Ronald Sundell Nov 1997

Combining Multi-Attribute Utility And Geographic Information For Boundary Decisions: An Application To Park Planning, Jeffrey Keisler, Ronald Sundell

Jeffrey Keisler

The quality and value of an area depend primarily on what is found within
its designated boundaries. To determine the value of such areas in terms of boundaries,
we have developed a methodology for integrating multi-attribute utility functions with
spatial analysis so that desirable, or appropriate, boundaries can be determined on the
basis of the goals and objectives for the park. The key to successful evaluation is the
development of measures for what decision makers value, rather than merely using
what is easily measured. In a detailed example for planning of national parks, the
fundamental objectives are conservation and societal …


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 9, November 1997, College Of Engineering And Computer Science, Wright State University Nov 1997

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 9, November 1997, 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.


Simulation Study Of Learning Automata Games In Automated Highway Systems, Cem Unsal, Pushkin Kachroo, John S. Bay Nov 1997

Simulation Study Of Learning Automata Games In Automated Highway Systems, Cem Unsal, Pushkin Kachroo, John S. Bay

Electrical & Computer Engineering Faculty Research

One of the most important issues in Automated Highway System (AHS) deployment is intelligent vehicle control. While the technology to safely maneuver vehicles exists, the problem of making intelligent decisions to improve a single vehicle’s travel time and safety while optimizing the overall traffic flow is still a stumbling block. We propose an artificial intelligence technique called stochastic learning automata to design an intelligent vehicle path controller. Using the information obtained by on-board sensors and local communication modules, two automata are capable of learning the best possible (lateral and longitudinal) actions to avoid collisions. This learning method is capable of …


Searches For Scalar Top And Scalar Bottom Quarks At Lep2, Barate, R.; Et Al., M. Thulasidas Nov 1997

Searches For Scalar Top And Scalar Bottom Quarks At Lep2, Barate, R.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

Searches for scalar top and bottom quarks have been performed with data collected by the ALEPH detector at LEP. The data sample consists of 21.7 pb−1 taken at √ s = 161, 170, and 172 GeV and 5.7 pb−1 taken at √ s = 130 and 136 GeV. No evidence for scalar top quarks or scalar bottom quarks was found in the channels ˜t → cχ, ˜t → bℓν˜, and b˜ → bχ. For the channel ˜t → cχ a limit of 67 GeV/c 2 has been set on the scalar top quark mass, independent of the mixing angle between …


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 8, October 1997, College Of Engineering And Computer Science, Wright State University Oct 1997

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 8, October 1997, 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.


Modeling And Comparison Of Wormhole Routed Mesh And Torus Networks, Ronald I. Greenberg, Lee Guan Oct 1997

Modeling And Comparison Of Wormhole Routed Mesh And Torus Networks, Ronald I. Greenberg, Lee Guan

Computer Science: Faculty Publications and Other Works

2D-mesh and torus networks have often been proposed as the interconnection pattern for parallel computers. In addition, wormhole routing has increasingly been advocated as a method of reducing latency. Most analysis of wormhole routed networks, however, has focused on the torus and the broader class of k-ary n-cubes to which it belongs. This paper presents a performance model for the wormhole routed mesh, and it compares the performance of the mesh and torus based on theoretical and empirical analyses.


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 7, September 1997, College Of Engineering And Computer Science, Wright State University Sep 1997

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 7, September 1997, 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.


A Measurement Of The Qcd Colour Factors And A Limit On The Light Gluino, Barate, R.; Et Al., M. Thulasidas Sep 1997

A Measurement Of The Qcd Colour Factors And A Limit On The Light Gluino, Barate, R.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

Using data collected from 1992 to 1995 with the ALEPH detector at LEP, a measurement of the colour factor ratios CA/CF and TF /CF and the strong coupling constant αs = CFαs(MZ)/(2π) has been performed by fitting theoretical predictions simultaneously to the measured differential two-jet rate and angular distributions in four-jet events. The result is found to be in excellent agreement with QCD, {fx4-1} Fixing CA/CF and TF/CF to the QCD values permits a determination of αs(MZ) and ηf, the number of active flavours. With this measurement the existence of a gluino with mass below 6.3 GeV/c2 is excluded at …


An Improved Analytical Model For Wormhole Routed Networks With Application To Butterfly Fat-Trees, Ronald I. Greenberg, Lee Guan Aug 1997

An Improved Analytical Model For Wormhole Routed Networks With Application To Butterfly Fat-Trees, Ronald I. Greenberg, Lee Guan

Computer Science: Faculty Publications and Other Works

A performance model for wormhole routed interconnection networks is presented and applied to the butterfly fat-tree network. Experimental results agree very closely over a wide range of load rate. Novel aspects of the model, leading to accurate and simple performance predictions, include (1) use of multiple-server queues, and (2) a general method of correcting queuing results based on Poisson arrivals to apply to wormhole routing. These ideas can also be applied to other networks.


Fixpunktsemantik Logischer Programme, Pascal Hitzler Jul 1997

Fixpunktsemantik Logischer Programme, Pascal Hitzler

Computer Science and Engineering Faculty Publications

No abstract provided.


A Synthesized Methodology For Eliciting Expert Judgment For Addressing Uncertainty In Decision Analysis, Richard W. Monroe Jul 1997

A Synthesized Methodology For Eliciting Expert Judgment For Addressing Uncertainty In Decision Analysis, Richard W. Monroe

Engineering Management & Systems Engineering Theses & Dissertations

This dissertation describes the development, refinement, and demonstration of an expert judgment elicitation methodology. The methodology has been developed by synthesizing the literature across several social science and scientific fields. The foremost consideration in the methodology development has been to incorporate elements that are based on reasonable expectations for the human capabilities of the user, the expert in this case.

Many methodologies exist for eliciting assessments for uncertain events. These are frequently elicited in probability form. This methodology differs by incorporating a qualitative element as a beginning step for the elicitation process. The qualitative assessment is a more reasonable way …


Dynamic Load Distribution In Mist, K. Al-Saqabi, R. M. Prouty, Dylan Mcnamee, Steve Otto, Jonathan Walpole Jul 1997

Dynamic Load Distribution In Mist, K. Al-Saqabi, R. M. Prouty, Dylan Mcnamee, Steve Otto, Jonathan Walpole

Computer Science Faculty Publications and Presentations

This paper presents an algorithm for scheduling parallel applications in large-scale, multiuser, heterogeneous distributed systems. The approach is primarily targeted at systems that harvest idle cycles in general-purpose workstation networks, but is also applicable to clustered computer systems and massively parallel processors. The algorithm handles unequal processor capacities, multiple architecture types and dynamic variations in the number of processes and available processors. Scheduling decisions are driven by the desire to minimize turnaround time while maintaining fairness among competing applications. For efficiency, the virtual processors (VPs) of each application are gang scheduled on some subset of the available physical processors.


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 6, June 1997, College Of Engineering And Computer Science, Wright State University Jun 1997

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 6, June 1997, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

Wright State University College of Engineering and Computer Science


A Toolkit For Specializing Production Operating System Code, Crispin Cowan, Dylan Mcnamee, Andrew P. Black, Calton Pu, Jonathan Walpole, Charles Krasic, Perry Wagle, Qian Zhang Jun 1997

A Toolkit For Specializing Production Operating System Code, Crispin Cowan, Dylan Mcnamee, Andrew P. Black, Calton Pu, Jonathan Walpole, Charles Krasic, Perry Wagle, Qian Zhang

Computer Science Faculty Publications and Presentations

Specialization has been recognized as a powerful technique for optimizing operating systems. However, specialization has not been broadly applied beyond the research community because the current techniques, based on manual specialization, are time-consuming and error-prone. This paper describes a specialization toolkit that should help broaden the applicability of specializing operating systems by assisting in the automatic generation of specialized code, and {\em guarding} the specialized code to ensure the specialized system continues to be correct. We demonstrate the effectiveness of the toolkit by describing experiences we have had applying it in real, production environments. We report on our experiences with …


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 5, May 1997, College Of Engineering And Computer Science, Wright State University May 1997

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 5, May 1997, 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.


Single Row Routing: Theoretical And Experimental Performance Evaluation, And New Heuristic Development, David A. Hysom May 1997

Single Row Routing: Theoretical And Experimental Performance Evaluation, And New Heuristic Development, David A. Hysom

Computer Science Theses & Dissertations

The Single Row Routing Problem (SRRP) is an abstraction arising from real-world multilayer routing concerns. While NP-Complete, development of efficient SRRP routing heuristics are of vital concern to VLSI design. Previously, researchers have introduced various heuristics for SRRP; however, a comprehensive examination of SRRP behavior has been lacking.

We are particularly concerned with the street-congestion minimization constraint, which is agreed to be the constraint of greatest interest to industry. Several theorems stating lower bounds on street congestion are known. We show that these bounds are not tight in general, and argue they may be in error by at least 50% …


Predictable File Access Latency For Multimedia, Dan Revel, Crispin Cowan, Dylan Mcnamee, Calton Pu, Jonathan Walpole May 1997

Predictable File Access Latency For Multimedia, Dan Revel, Crispin Cowan, Dylan Mcnamee, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Multimedia applications are sensitive to I/O latency and jitter when accessing data in secondary storage. Transparent adaptive prefetching (TAP) uses software feedback to provide multimedia applications with file system quality of service (QoS) guarantees. We are investigating how QoS requirements can be communicated and how they can be met by adaptive resource management. A preliminary test of adaptive prefetching is presented.


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 4, April 1997, College Of Engineering And Computer Science, Wright State University Apr 1997

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 4, April 1997, 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.


Investigating The Use Of Kalman Filtering Approaches For Dynamic Origin-Destination Trip Table Estimation, Pushkin Kachroo, Kaan Ozbay, Arvind Narayanan Apr 1997

Investigating The Use Of Kalman Filtering Approaches For Dynamic Origin-Destination Trip Table Estimation, Pushkin Kachroo, Kaan Ozbay, Arvind Narayanan

Electrical & Computer Engineering Faculty Research

This paper studies the applicability of Kalman filtering approaches for network wide traveler origin-destination estimation from link traffic volumes. The paper evaluates the modeling assumptions of the Kalman filters and examines the implications of such assumptions.