Digital Commons Network^™

Surface Emitting Semiconductor Lasers And Arrays, Gary A. Evans, Jacob M. Hammer

Electrical Engineering Research

No abstract provided.

Chemical Structural Features Of Pyridine Extracts Of The Argonne Premium Coals Using 13c Nmr Spectroscopy, Thomas H. Fletcher, S Bai, Ronald J. Pugmire, Steven Wood, David M. Grant

Faculty Publications

Soxhlet extractions were performed on the eight Argonne Premium coals using pyridine purged with argon and followed by a novel washing procedure to remove the pyridine. Mass closure (extracts plus residues) on duplicate experiments accounted for 94-96% of the original coal, repeatable to within 2%. Chemical structural features determined from ¹³C NMR analyses of the extracts and residues showed more attachments per aromatic cluster for the residues, indicating a greater degree of covalent bonding in the residue than in the extract. ¹H NMR analysis of the extracts showed a gradual increase in the hydrogen aromaticity with rank, along …

Overview Of Acerc Comprehensive Model Development, Thomas H. Fletcher, Scott C. Hill

Faculty Publications

A major objective of the Advanced Combustion Engineering Research Center (ACERC) is the development of comprehensive combustion models to help in the solution of critical national combustion problems. Computer models incorporate research and technology results from center projects and from external research programs. The synergistic integration of scientific knowledge that is expected from the NSF engineering research centers is demonstrated to a great extent at ACERC by the development of these software tools. The transfer of technology from ACERC to industry is also accomplished in part by the implementation of the models at industrial firms. The effort to develop such …

Intel Nx To Pvm 3.2 Message Passing Conversion Library, Trey Arthur, Michael L. Nelson

Computer Science Faculty Publications

NASA Langley Research Center has developed a library that allows Intel NX message passing codes to be executed under the more popular and widely supported Parallel Virtual Machine (PVM) message passing library. PVM was developed at Oak Ridge National Labs and has become the defacto standard for message passing. This library will allow the many programs that were developed on the Intel iPSC/860 or Intel Paragon in a Single Program Multiple Data (SPMD) design to be ported to the numerous architectures that PVM (version 3.2) supports. Also, the library adds global operations capability to PVM. A familiarity with Intel NX …

A Comparison Of Queueing, Cluster And Distributed Computing Systems, Joseph A. Kaplan, Michael L. Nelson

Computer Science Faculty Publications

Using workstation clusters for distributed computing has become popular with the proliferation of inexpensive, powerful workstations. Workstation clusters offer both a cost effective alternative to batch processing and an easy entry into parallel computing. However, a number of workstations on a network does not constitute a cluster. Cluster management software is necessary to harness the collective computing power. A variety of cluster management and queuing systems are compared: Distributed Queueing Systems (DQS), Condor, Load Leveler, Load Balancer, Load Sharing Facility (LSF - formerly Utopia), Distributed Job Manager (DJM), Computing in Distributed Networked Environments (CODINE), and NQS/Exec. The systems differ in …

Doctoral Program Computing Technology In Education 1993-1994, Nova Southeastern University

College of Engineering and Computing Course Catalogs

No abstract provided.

Pump And Signal Cross Saturation In Cw Dye Lasers, Lee W. Casperson, A. C. Wilson, W. J. Sandle

Electrical and Computer Engineering Faculty Publications and Presentations

It is well known that the signal output intensity from a dye laser oscillator depends directly on the pump intensity. The opposite effect, the dependence of the transmitted pump intensity on the signal intensity, is studied in detail. The theoretical results are compared with experimental data obtained using an argon‐laser‐pumped rhodamine 6G dye laser.

A Water And Heat Management Model For Proton-Exchange-Membrane Fuel Cells, Trung V. Nguyen, Ralph E. White

Faculty Publications

Proper water and heat management are essential for obtaining high-power-density performance at high energy efficiency for proton-exchange-membrane fuel cells. A water and heat management model was developed and used to investigate the effectiveness of various humidification designs. The model accounts for water transport across the membrane by electro-osmosis and diffusion, heat transfer from the solid phase to the gas phase and latent heat associated with water evaporation and condensation in the flow channels. Results from the model showed that at high current densities (> 1 A/cm²) ohmic loss in the membrane accounts for a large fraction of the …

Lightning Arrester Failure And Ferroresonance On A Distribution System, L. J. Bohmann, J. Mcdaniel, Eldon Keith Stanek

Electrical and Computer Engineering Faculty Research & Creative Works

Since 1987 the Upper Peninsula Power Company (UPPCO) has been experiencing a large number of lightning arrester failures on a portion of their distribution system in southern Marquette County, Michigan. It was in the area of the Navy's Extremely Low Frequency (ELF) antenna where the distribution system had been recently reconfigured so that the transformers were connected line-to-line in order to eliminate interference from the antenna. A study was done which determined that the system was susceptible to ferro resonance during single line faults under lightly loaded conditions and that the overvoltage's experienced could be causing the lightning arrester failures. …

Efficient Simulation Of Multicarrier Digital Communication Systems In Nonlinear Channel Environments, Kevin W. Schneider, William H. Tranter

Electrical and Computer Engineering Faculty Research & Creative Works

The effectiveness of computer simulation as a tool for the design and analysis of communication systems is often limited by the long execution times required for many simulations. When simulating multicarrier digital communication systems operating over nonlinear channels, the required high sampling rate contributes significantly to long execution times. A new method that reduces the sampling rate of simulations of such systems is developed. This Partial Sum of Products (ParSOP) method reduces the sampling rate by generating only the intermodulation products that lie in a frequency band of interest. The ParSOP method requires that the bandpass nonlinearity be represented by …

On The Use Of Levy's Method For Symmetrically Laminated Composite Plates, Serge Abrate

Mechanical and Aerospace Engineering Faculty Research & Creative Works

For rectangular plates with two opposite edges simply supported and no bending twisting coupling, Levy's method can yield exact solutions for static deflections, free vibrations and buckling loads. However, three distinct solutions are obtained, depending on the relative magnitude of the plate rigidities, which in turn are functions of material properties, laminate thickness and lay-up. In this communication a stiffness invariant formulation is used to identify those laminates which fall under the three cases defined. © 1993.

Procase: A Prototype Of Intelligent Case-Based Process Planning System With Simulation Environment, Hao Yang, Wen F. Lu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An intelligent case-based process planning system with interactive graphic simulation environment, PROCASE, is developed lo demonstrate an integrated methodology of case-based process planning system. In PROCASE, both the mechanical part features and the machining operations are represented with a frame-based scheme. PROCASE contains a retriever, a modifier, a simulator and a repairer. It distinguishes itself from traditional rule-based process planning systems by representing the process planning knowledge through previous process planning cases instead of production rules. It therefore can overcome some problems in the traditional rule-based expert systems. PROCASE currently resides in IRIS Indigo workstation. With a user-friendly graphic environment, …

A Study Of Dynamic Optimization Techniques: Lessons And Directions In Kernel Design, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

The Synthesis kernel [21,22,23,27,28] showed that dynamic code generation, software feedback, and fine-grain modular kernel organization are useful implementation techniques for improving the performance of operating system kernels. In addition, and perhaps more importantly, we discovered that there are strong interactions between the techniques. Hence, a careful and systematic combination of the techniques can be very powerful even though each one by itself may have serious limitations. By identifying these interactions we illustrate the problems of applying each technique in isolation to existing kernels. We also highlight the important common under-pinnings of the Synthesis experience and present our ideas on …

Faulty Behavior Of Storage Elements And Its Effects On Sequential Circuits, Waleed K. Al-Assadi, Y. K. Malaiya, A. P. Jayasumana

Electrical and Computer Engineering Faculty Research & Creative Works

It is often assumed that the faults in storage elements (SEs) can be modeled as output/input stuck-at faults of the element. They are implicitly considered equivalent to the stuck-at faults in the combinational logic surrounding the SE cells. Transistor-level faults in common SEs are examined here. A more accurate higher level fault model for elementary SEs that better represents the physical failures is presented. It is shown that a minimal (stuck-at) model may be adequate if only modest fault coverage is desired. The enhanced model includes some common fault behaviors of SEs that are not covered by the minimal fault …

Neural Networks In The Former Soviet Union, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Automatic Color Segmentation Algorithms-With Application To Skin Tumor Feature Identification, Scott E. Umbaugh, Randy Hays Moss, William V. Stoecker, G. A. Hance

Electrical and Computer Engineering Faculty Research & Creative Works

Two color-image segmentation methods are described. The first is based on a spherical coordinate transform of original RGB data. The second is based on a mathematically optimal transform, the principal components transform (also known as eigenvector, discrete Karhunen-Loeve, or Hotelling transform). These algorithms are applied to the extraction from skin tumor images of various features such as tumor border, crust, hair scale, shiny areas, and ulcer. The results of this research will be used in the development of a computer vision system that will serve as the visual front-end of a medical expert system to automate visual feature identification for …

Assessment Of Environmental Implications Of Abandoned Oil And Gas Wells, Donald L. Warner, Cary L. Mcconnell

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

A detailed study was made of the potential for abandoned oil and gas wells in the Lower Tuscaloosa sand of Mississippi and Louisiana to act as conduits for movement of saline water from the Lower Tuscaloosa into underground sources of drinking water (USDW's). Finite-difference numerical modeling determined the extent that water might be forced from the Lower Tuscaloosa sand into a USDW as a result of injection into the Lower Tuscaloosa. Within the range of conditions modeled, water from the Lower Tuscaloosa never traveled into a USDW. On the basis of the modeling, we concluded that it is unlikely that …

Cultural Transposition: Exploring Meanings Of And Strategies For Cross-Cultural Transfer Of Organizational Practices, Yongming Tang

Engineering Management & Systems Engineering Theses & Dissertations

The research objective is to study the phenomenon of transferring organizational practices which are conceptualized in one culture to another different culture. The purpose of the study is (1) to understand how cultural values and beliefs are manifested in behavior; (2) to explore how the Western organizational practices are interpreted and assimilated into an organization in an Eastern culture; and (3) to explore strategies for the fit between local cultural orientations and imported organizational practices. A qualitative, interpretive, and reflexive research methodology was developed to conduct this study.

The study was conducted in two phases. The first phase was designed …

Multidimensional Approach To Implementation Of Continuous Process Improvement Utilizing Small Run Analysis In A Shipyard Environment, Paul Ray Hollandsworth

Engineering Management & Systems Engineering Theses & Dissertations

Nationally, both public and private shipyards are experiencing a high rework rate (over 40%) in the fabrication of plug connectors used for electronic systems onboard Navy vessels. The shipyard's survival depends on acquiring the elements necessary to maintain a major industry in a position of continuous improvement that produces a better product than their competitors, at less cost, in a safe manner, and on schedule.

This research addresses the complex problem of how to introduce quality control methodologies within a job shop environment that assists in identifying variables that influence the rework rate of plug fabrication process over a four …

Thermal Analysis Of Spirally Wound Li/Bcx And Li/Socl2 Cells, E. E. Kalu, Ralph E. White

Faculty Publications

A thermal analysis of Li/BCX and high rate Li/SOCl₂ cells is presented. The thermal model developed was used to study the effect of ambient temperature of discharge (0–40°C) on Li/BCX cells discharged at the same rate. The model predictions show that ambient temperature of discharge was critical in thermal management of the cell. For forced convection cooled cells, the model predicted that ambient temperature near room temperature (25°C) was required to achieve the lowest maximum temperature rise in the cell. Inclusion of the effects of reaction products to the model predictions showed that a constant composition assumption may be …

Design And Evaluation Of An Augmentative Communication Aid For Multiply Impaired Individuals, Mark S. Annett

Theses and Dissertations

Individuals with sensory and multiple physical impairments, which may include the loss of the ability to speak, have very specialized communication needs. Based on the belief that the current technology does not fully meet these needs, a prototype communication aid was developed for an individual who is cortically blind, dysphonic, and motor impaired. Furthermore, the communication device has broader applications beyond the present individual.

The prototype system has a direct selection of "Yes" and "No" responses, scanning access to daily phrases, rate enhancement of all scans, prompted encoding for selection of letters, two letter codes for complete sentences, access to …

Large Capacity Missile Carrier (Cmx), C. N. Calvano, J. M. Berner, J. M. Bradley, K. A. Tosiello, D. T. Hooker, C. F. Merrill

Engineering Management & Systems Engineering Faculty Publications

A systems engineering approach to the development of a radically different kind of surface combatant ship is presented, followed by a preliminary design of the ship shown by the analysis to be most effective. The requirement for the project was the development of a ship which would provide a major increase in the missile firepower of a battlegroup. The study conducts an analysis of four warfare scenarios and evaluates the effectiveness of replacing some Aegis ships with the missile carrier (CMX) and examines the relative utility of varying missile loads for the CMX. An alternative is chosen for further development …

Dual Purpose Fuze, Paul Nicholas Worsey

Mining Engineering Faculty Research & Creative Works

A dual purpose fuze for a projectile which can activate a quantity of material selected from a group including high explosive, low explosive, propellant and pyrotechnic compounds. The fuze includes a charge holder having a socket therein facing the quantity of material to be activated. A fuze charge located in the socket has a depression in it so formed as to cause the fuze charge to explode in a jet directed outwardly from the socket of sufficiently high energy to activate a high explosive in a high explosive projectile, the fuze charge being sufficiently small to prevent rupture of containment …

Weapon System Integration For The Afit Virtual Cockpit, William E. Gerhard Jr.

Theses and Dissertations

The Air Force Institute of Technology is continuing research in the Virtual Cockpit. The Virtual Cockpit makes use of high performance graphics workstations, Virtual Environment technology, and Distributed Interactive Simulation network protocols to create a flight simulator based on the capabilities of the McDonnell Douglas F-15E Strike Eagle. The work presented in this thesis focuses on the design and implementation issues for integrating a weapons delivery capability. Weapons simulated include: RADAR and IR guided air- to-air missiles, gravity and precision guided bombs, and a 20mm cannon. Virtual Environment displays used include: color NTSC and monochrome high resolution helmet mounted displays …

Introduction To Intellisim 2.0, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

IntelliSIM is a prototype for a new generation of knowledge-based simulation tool that has been developed by the Systems Simulation Laboratory at Arizona State University. This tool is a computer environment that allows non-simulation trained modelers to predict the performance of a manufacturing system for which the necessary data is available. The system provides predictive data on such items as throughput time, queue levels, equipment utilization, reactions to machine failures, etc. With IntelliSIM, the benefits of discrete-event simulation can be exploited without requiring the high level of expertise necessary to successfully conduct a sound simulation study. The approach offered with …

Long-Term Performance Of Flexible Pavements Located On Cement-Treated Soils, Tommy C. Hopkins, David Q. Hunsucker, Tony L. Beckham

Kentucky Transportation Center Research Report

Long-term performance of flexible pavements located on cement-treated soils and the longevity of soil-cement subgrades are examined at sections of four highway routes. Ages of the soil-cement subgrades range from 6 to 30 years. Field and laboratory studies were conducted at each section. Generally. the soil-cement subgrades were non-plastic and were classified as SM, or sandy silt, according to the Unified Soil Classification System, although the classification of the untreated soil subgrades located below the treated layers ranged from CL (clay) to GC (clayey gravel). Plasticity index of the untreated soils ranged from non-plastic to 44 percent. Generally, the untreated …

An Optoelectronic Implementation Of The Adaptive Resonance Neural Network, Donald C. Wunsch, T. P. Caudell, R. J. Marks, R. A. Falk, C. David Capps

Electrical and Computer Engineering Faculty Research & Creative Works

A solution to the problem of implementation of the adaptive resonance theory (ART) of neural networks that uses an optical correlator which allows the large body of correlator research to be leveraged in the implementation of ART is presented. The implementation takes advantage of the fact that one ART-based architecture, known as ART1, can be broken into several parts, some of which are better to implement in parallel. The control structure of ART, often regarded as its most complex part, is actually not very time consuming and can be done in electronics. The bottom-up and top-down gated pathways, however, are …

Development Of Guidelines And Performance For Asphalt Pavements Containing Rubber -- Review Of State-Of-The-Practice, Kamyar C. Mahboub, Donn E. Hancher

Kentucky Transportation Center Research Report

This interim report provides a summary of key points that are important to successful implementation of the asphalt rubber technology in Kentucky in accordance with ISTEA. Various asphalt rubber technologies are presented in this report along with their advantages and disadvantages. Issues related to structural design and construction are discussed. A variety of environmental issues such as: emissions, leachate and issues related to future recyclability are presented. Finally, criteria are recommended to be used for selection of future asphalt rubber projects in Kentucky.

The Removal Of Lead-Based Paint From Steel Bridges, Theodore Hopwood Ii, Christopher M. Oberst

Kentucky Transportation Center Research Report

The purpose of this study was to assist the Department of Highways in conducting bridge-painting operations involving removal of existing lead-based paint. Pertinent state and Federal regulations affecting generation of hazardous wastes, limiting environmental pollution and protecting public and worker safety were obtained and reviewed.State highway agendas were surveyed relative to how they conducted maintenance bridge painting involving lead-based. paints and comply with applicable regulations. Information from the painting industry related to sale removal of lead-based paints was also reviewed.

Based upon the reviews of applicable regulations, operations of other state highway agencies and painting industry practices, the best demonstrated …

The Use Of A Factory Simulation To Evaluate A Flexible Control Structure For Integrated Manufacturing, Ling Ling Pan

Engineering Management & Systems Engineering Theses & Dissertations

Once a control structure for an integrated manufacturing system is decided upon, manufacturing activities are limited by that structure. A flexible control structure is presented as an approach for accommodating a variety of manufacturing activities, without being limited to a single control structure. A flexible control structure is one that allows multiple types of control structure in the manufacturing process. For example, both hierarchical and non-hierarchical structures may be used in a flexible structure. The properties of a flexible control structure are discussed from the point of view of graph theory.

Control structures for automated manufacturing are difficult to evaluate …