Engineering Commons^™

Radar Cross Section Visualization Using Sample Buffer Progressive Refinement Volume Rendering, Alain L. Jones

Theses and Dissertations

This study developed a prototype for an interactive radar cross section visualization software system. The system, hosted on a Silicon Graphics workstation, is intended to support aircrews, mission planners, aircraft designers, and others who require an understanding of aircraft radar cross section characteristics. The input to the system is a set of radar cross section samples taken at various aspect angles. A pre-processor developed as part of this study transforms the input radar cross section data into a three-dimensional cuberille data volume. This data volume is then visualized using an interactive volume renderer. The interactive volume renderer implements progressive image …

A Virtual Environment For Satellite Modeling And Orbital Analysis In A Distributed Interactive Simulation, Andrea A. Kunz

Theses and Dissertations

In response to the need for a more realistic, interactive, and immersive space simulation system, the Joint National Intelligence Defense Staff JNIDS has sponsored the development of the Satellite Modeler at the Air Force Institute of Technology AFIT. The Satellite Modeler SM is a virtual environment VE application that allows analyst-users to enter a virtual near- Earth space environment and visualize realistic satellite models performing accurate orbital motion. The Satellite Modeler provides manipulation functions that allow a user to interact with multiple satellite models and satellite constellations. The system affords the user multiple vantage points within the environment to view …

Integration And Enhancement Of The Saber Wargame, Karl S. Mathias

Theses and Dissertations

The Saber wargame is a theater-level air/land battle wargame written in Ada that is being developed for the Air Force Wargaming Center at Maxwell AFB, AL. This thesis documents how the user interface and simulation engine were integrated. Integration was accomplished by developing a portable object-oriented database system (OODBMS) interface. The interface was implemented in Ada and tied to an OODBMS also written in Ada. Using the interface, both subsystems were able to work from a consistent database and exchange information. The user interface was enhanced by converting it from the Software Technology for Adaptable Reliable Systems Ada/X Window System …

Developing A Graphical User Interface To Support A Real-Time Digital Signal Processing System, Jeffrey C. Miller

Theses and Dissertations

A graphical software user interface for a VMEbus-based real-time digital signal processing system was designed. Use, requirements were defined and the Rumbaugh object-oriented analysis and design technique was applied to analyze the requirements and produce an object-oriented design. The software design includes a graphical, mouse- and keyboard driven user interface, specialized hardware driver modules, and operating system interfaces. An implementation plan was also developed to map the design into the C programming language using existing system code, automatically generated code, and newly written code. Based on the implementation plan, a limited software system prototype w successfully developed and demonstrated. The …

Pavement Drainage And Pavement Shoulder Joint Evaluation Numerical Analysis Of Infiltration And Drainage In Pavement Systems, Reynaldo David. Espinoza, Philippe L. Bourdeau, Thomas D. White

JTRP Technical Reports

The continuing loss of pavement performance observed in the U.S. transportation infrastructure system raises the issue of the subdrainage design. Experience with the Indiana highways indicates that the lack of adequa the sub-drainage is probably a major cause of pavement distress. In order to provide highway engineers with a methodology to analyze the water migration and drainage into pavement systems a new numerical model has been developed. The numerical scheme is a finite difference formulation of the equations of water flow in unsaturated porous media. The resulting system of equations used is nonlinear and state-of-the-art numerical techniques have been used …

Development Of Guidelines And Performance For Asphalt Concrete Containing Recycled Rubber, Kamyar C. Mahboub, Donn E. Hancher

Kentucky Transportation Center Research Report

The primary objective of this study was to investigate the feasibility of implementation of the crumb rubber technology in Kentucky. The impetus for this study was provided by the lntermodal Surface Transportation Efficiency Act of 1991 (ISTEA).

This study included an overview of existing literature on the subject from an implementation point of view for Kentucky's conditions. Upon completion of this phase of the study, guidelines were developed by the KTC research team and were submitted to the Transportation Cabinet for field implementation of the crumb rubber modifier (CAM) technology in Kentucky. From the ease of implementation point of view, …

Evaluation Of Electronic Truck Monitoring, Jerry G. Pigman, Joseph D. Crabtree

Kentucky Transportation Center Research Report

Automatic vehicle identification (AVI) and weigh-in-motion (WIM) equipment were installed at the northbound weigh/enforcement station on 1-65 in Simpson County, Kentucky. The objectives were to determine the reliability and accuracy of the equipment and to determine the benefits/costs for the trucking industry and enforcement agencies.

The test site for evaluation of the equipment became operational in July 1991 and the evaluation continued through June 1993. AVI equipment was provided by Amtech Corporation and WIM equipment by International Road Dynamics. Participating motor carriers were United Parcel Service and Averitt Express, with a total of 114 trucks equipped with transponders. The system …

Performance Of The Crash Cushion Attenuating Terminal (Cat) In Traffic Accidents, Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

The objective of this study was to report the results of the continued monitoring of the performance of the Crash Cushion Attenuating Terminal (CAT) in traffic accidents.

The documented performance of the CAT system in traffic accidents justifies additional use. A recommended location would be at median piers and bridge abutments in narrow medians. While accidents involving this system should continue to be evaluated, this evaluation results in the conclusion that the CAT system could be classified as operational.

The performance of the CAT system indicates a couple of areas which should be addressed. For installations in a raised median, …

Primary Coolant Flow Characteristics As It Exits The Palisades Reactor, Gregory Alan Baustian

Masters Theses

During fuel cycles 9 and 10 at the Palisades Nuclear Power Plant, new phenomena have been observed using the resistance temperature devices installed in the reactor coolant piping. Oscillations in the temperature readings have been observed leading to the assumptions that there is temperature stratification of the coolant in the reactor hot-legs and that the coolant rotates as it leaves the reactor. In addition, oscillations in the bulk coolant flow within the two hot legs have been postulated. This report outlines work performed using computational fluid dynamics modelling which predict the observed and assumed flow characteristics of the Palisades reactor …

Megabit Dram Trench Depth Characterization Using Two Dimensional Diffraction Analysis With Multivariate Statistics, Ziad Ramez Hatab

Electrical and Computer Engineering ETDs

Advances in memory IC technology for dynamic random access memory (DRAM) devices, have been achieved by increasing the number of memory cells occupying a certain chip area, consequently increasing memory size. Current methods of implementation include vertical topography which relies on reducing cell's thickness, while increasing its depth in order to maintain the same capacitance of stored electrical charges. As the memory size on DRAM devices continuously rises, memory cells have to reach deeper levels, thus making the process of measuring depth even harder. This creates a particularly heavy burden on microelectronics manufacturing to research new techniques capable of accurately …

Bs News

Building Services Engineering

No abstract provided.

Dynamic Response Of A Compressor Research Facility, Janet W. Grondin

Theses and Dissertations

The response of the Wright Laboratory Compressor Research Facility to a small amplitude, acoustic, sinusoidal disturbance was investigated. The fluid transmission line equations for laminar, one-dimensional flow in a circular duct were solved and verified through a laboratory experiment using a scale model of the facility. The resonant frequencies of the facility were determined for a variety of flow conditions. Techniques for analytically modeling end impedance and flow straightening elements were also studied. The fundamental frequency of the facility was determined to be between 5.5 and 6.5 Hz depending on the flow conditions and geometry configurations specified.

Rendering Of Three-Dimensional Data Sets Derived From Finite-Difference And Spectral Methods, Paul A. Schubert

Theses and Dissertations

The timely visualization of three-dimensional data sets and the advantages of using a spectral method solution versus a finite-difference method solution in rendering isosurfaces is described. The Beam-Warming numerical algorithm, which uses implicit-approximate-factorization, is used to generate the steady-state solutions for a model diffusion-convection problem. The Chebyshev collocation operator is used to evaluate the right-hand side of the Beam-Warming algorithm for the spectral solution. Comparing the model problem results with the exact solution, the spectral series solution is truncated to the same degree of accuracy as the finite-difference for comparison of rendering times. The rendering algorithm employs octrees to efficiently …

Design And Construction Of The Aerobot Robotic Manipulator (Arm), William L. Cochran

Theses and Dissertations

This thesis designed, constructed, and tested a robotic arm for the Aerobot Aerial Robot. The main purpose of the ARM is to enable the Aerobot to retrieve objects for use in an annual robotics competition. Design of the ARM involved synthesizing the characteristics of simplicity, weight, strength, and size. The result was a three-degree-of-freedom manipulator that uses electric motors, cable linkages, and telescoping tubes to access a work space below the Aerobot. Forward and inverse kinematics were investigated to enable automation of the ARM. Data was collected from infrared sensors to validate the model. Manipulation of the ARM is presently …

Automating Satellite Range Scheduling, S. Michael Schalck

Theses and Dissertations

The objective of this study was to develop a computer based satellite range scheduling SRS algorithm to create a 24 hour satellite support schedule. The algorithms goal was to schedule as many satellite support requests as possible. An iterative heuristic approach was used to schedule satellite support requests in three successive sub problems. The first sub problem involves scheduling low altitude satellite support requests using a mixed integer programming approach. The next two sub problems each involve scheduling 12 hour blocks of medium and high altitude satellite support requests, again using a mixed integer programming approach. Fourteen 24 hour schedules …

Modeling And Simulation Of Bipolar Transistor At Low Temperature, Swarupa Madhav Nerurkar

Dissertations and Theses

The BICMOS technology which integrates the CMOS technology with bipolar technology has drawn considerable attention as an attractive VLSI technology because of the high speed performance and low power consumption of the BICMOS. However, continued down scaling of CMOS devices has caused increased concerns with problems such as latch up, hot carriers and short channel effect. Most of the above mentioned problems can be avoided by operating the CMOS at liquid-nitrogen temperature(LNT). At low-temperatures, the CMOS exhibits lower sub threshold leakage, higher carrier mobility (which yields improved speed performance), and a steeper logarithmic currentvoltage slope. On the other hand, the …

Simple High-Quality Lossy Image Coding Scheme, Shaolin Bi, Khalid Sayood

Department of Electrical and Computer Engineering: Faculty Publications

A simple yet efficient image data compression method is presented. This method is based on coding only those segments of the image that are perceptually significant to the reconstruction of the image. Sequences of image pixels whose gray-level differences from the pixels of the previous row exceed two prespecified thresholds are considered significant. These pixels are coded using a differential pulse code modulation scheme that uses a 15-level recursively indexed nonuniform quantizer for the first pixel in a segment and a 7-level recursively indexed nonuniform quantizer for all other pixels in the segment. The quantizer outputs are Huffman coded. Simulation …

Constructed Wetlands As An Innovative, Cost-Effective Solution For Wastewater Treatment In Small Communities, Christy Womack Vines

Honors Capstone Projects and Theses

No abstract provided.

Ionic Charge Dependence Of The Zero Degree Binary Encounter Peak For Partially Stripped Heavy Ions, W. Wolff, H. E. Wolff, J. L. Shinpaugh, Jee-Ching Wang, Ronald E. Olson, D. Fainstein, S. Lencinas, U. Bechthold, R. Herrmann, H. Schmidt-Bocking

Chemical and Biochemical Engineering Faculty Research & Creative Works

We report on the measurements of double differential cross sections, at zero degree, for the production of secondary electrons from the collision of 0, 6 MeV amu^-1 Cu⁵⁺, I⁷⁺, Au¹¹⁺, U¹³⁺, Cu¹⁹⁺, t²³⁺ and Au²⁹⁺ projectiles with H₂ and He. The shapes and positions of the observed binary encounter electron peaks are compared with continuum distorted wave-eikonal initial state (CDW-EIS), impulse approximation and classical trajectory Monte Carlo calculations, as well as with predictions from an adiabatic resonant tunnelling model recently proposed by Fainstein and co-workers. The …

Pattern Recognition And Erp Waveform Analysis Using Wavelet Transform, Hong Qi

Dissertations and Theses

Wavelet transform provides an alternative to the classical Short-Time Fourier Transform (STFT). In contrast to the STFT, which uses a single analysis window, the Wavelet Transform uses shorter windows at higher frequencies and longer windows at lower frequencies. For some particular wavelet functions, the local maxima of the wavelet transform correspond to the sharp variation points of the signal. As an application, wavelet transform is introduced to the character recognition. Local maximum of wavelet transform is used as a local feature to describe character boundary. The wavelet method performs well in the presence of noise. The maximum of wavelet transform …

High Power Edge-Emitting Light Emitting Diodes At 1.5Μ With Extremely Low Back Facet Feedback, J. E. Fouquet, G. R. Trott, W. V. Sorin, M. J. Ludowise, D. M. Braun, Dennis J. Derickson

Electrical Engineering

This paper describes novel semiconductor sources for optical low coherence reflectometry (OLCR), a measurement technique for characterizing device and fiber reflections with high sensitivity and high spatial resolution. Lasers and conventional superluminescent LEDs are not suitable for OLCR because strong reflections from the back facets mask weak reflection signals from the device or fiber under test. Even standard edge emitting LEDs (EELEDs) show significant reflections, which have limited the dynamic range of previous measurements. Low source output powers have also limited sensitivity. In order to obtain high power while minimizing internal reflections, a high single pass gain device is required. …

Explanation Of Timing Jitter Mechanisms In Multisegment Mode-Locked Semiconductor Lasers, Dennis J. Derickson

Electrical Engineering

Multisegment mode-locked semiconductor lasers offer a simple, high performance solution for short pulse generation. Six mode-locking techniques used in multisegment mode-locked semiconductor lasers are shown. This paper concentrates on a theoretical explanation of the timing jitter mechanisms in these lasers with supporting experimental measurements. The analysis covers passive, hybrid, and active mode-locking techniques for both monolithic and external cavity devices. Timing jitter is a very important system consideration for most applications of mode-locked lasers.

Obscured Object Detection Via Bayesian Target Modeling Techniques, Rufus H. Cofer

Electrical Engineering and Computer Science Faculty Publications

Underground objects are by nature often severely obscured although the general character of the intervening random media may be reasonably understood. The task of detecting these underground objects also implies that their exact location and or orientation is not known. To partially counter these difficulties, one may; however, be given a model of the target of interest, e.g. a particular tank type, a water pipe, etc. To set up a quality framework for solution of the above problem, this paper utilizes the paradigm of Bayesian decision theory that promises minimum error detection given that certain probability density functions can be …

Rate Equations For The Phonon Peak In Resonant-Tunneling Structures, Roger Lake, Gerhard Klimeck, J. P. Anantram, Supriyo Datta

Birck and NCN Publications

The ratio of the phonon peak current to the main peak current in double-barrier resonant-tunneling structures is significantly enhanced by barrier asymmetry. Previously, using the Keldysh formalism, we derived analytical expressions, valid in the zero-temperature, high-bias regime, which explained this eftect. We now provide analytical expressions valid for finite temperature and bias obtained from (i) an intuitive derivation using a rate equation approach and (ii) a more general derivation using the Keldysh formalism. The results of the two difFerent approaches are shown to be essentially identical for the ex- perimental device parameters. The finite temperature expressions shed light on the …

Investigation Of Solution Space Of Trees And Dags For Realization Of Combinational Logic In At 6000 Series Fpgas, Philip Ho

Dissertations and Theses

Various tree and Directed Acyclic Graph structures have been used for representation and manipulation of switching functions. Among these structures the Binary Decision Diagrams have been the most widely used in logic synthesis. A BDD is a binary tree graph that represents the recursive execution of Shannon's expansion. A FDD is a directed function graph that represents the recursive execution of Reed Muller expansion.

A family of decision diagrams for representation of Boolean function is introduced in this thesis. This family of Kronecker Functional Decision Diagrams (KFDD) includes the Binary Decision Diagrams (BDD) and Functional Decision Diagrams (FDD) as subsets. …

Local Needs Implementation For All Programs, James G. Harris, Madeleine M. Johnson, Norm Rogers, Jay Waddell

Electrical Engineering

SYNTHESIS is one of four ex1sting NSF Engineering Education Coalitions (there are apparently plans to add two others this year to bring the total number to six). SYNTHESIS consists of eight universities: Cal Poly, Cornell. Hampton, Iowa State, Southern, Stanford, Tuskgekee, and UC-Berkeley. It has been supported by NSF for over three years, being one of the first two-the other being ECSEL. The other two existing coalitions are GATEVI/AY and SUCCEED. One 9f the main goals of the 'SYNTHESIS coalition is the development of the National Engineering Education Dehvery System (NEEDS). After giving a brief overv1ew of the NEEDS, we …

National Engineering Education Delivery System (Needs), Alice M. Agogino, Sheri Sheppard, Kate Mink, James G. Harris, Lawrence Genalo, Jaya Krishnagopalan, Dave Martin, John Saylor

Electrical Engineering

The Synthesis Coalition, supported by the National Science Foundation and industrial partners, is comprised of the following eight educational institutions: California Polytechnic State University at San Luis Obispo, Comell, Hampton, Iowa State, Southern, Stanford, and Tuskegee Universities, and the University of California at Berkeley (1].

The National Engineering Education Delivery System (NEEDS) is an entirely new courseware development and distribution system which will provide Widespread, rapid, electronic access to an almost arbitrarily large number of diverse instructional modules (2-4). Curricular material in the NEEDS database are organized by a diverse range of indices. Links across disciplines are provided in the …

Vertex Ordering For A Partitioning-Based Fitting Algorithm For An Epld Device, Tongjun Gao

Dissertations and Theses

As the Application-Specific Integrated Circuit(ASIC) technology develops to the trend of high density and modulization, the ASIC device market has been dominated gradually by the more complex Erasable Programmable Logic Devices (EPLDs) and the Field Programmable Gate Array(FPGAs) instead of the ordinally Programmable Logic Devices(PLDs). Meanwhile, the design automation system for such programmable devices has also moved from schematic entry design to high level hardware description language entry design. Usually, the whole design automation process consists of three phrases, the high level hardware description language compiler, the logic synthesis stage and the layout synthesis stage. Though the layout synthesis stage …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 9, Number 9, November 1993, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Acuta Enews November 1993, Vol. 22, No. 11

ACUTA Newsletters

In This Issue

Board Report

President's message

TASA commissions

Numbering plan means net manager pains

21st Century Technology

Toll Fraud