Engineering Commons^™

Properties Of Sputtered A-Ge And A-Ge : H Thin Films, Hanjin Cho

Theses

The effect of the amorphous and glassy structure of amorphous germanium films on their electrical characteristics was investigated experimentally. The films were deposited onto silicon substrates using a modified MRC 8800 triode sputtering system. The Poole-Frenkel and Schottky mechanisms are discussed in detail and the shortcomings of the accepted picture of the former in amorphous materials are dealt with. It was concluded on the basis available evidence that the current flow in amorphous germanium favors the Poole-Frenkel mechanism at high fields.

Amorphous hydrogenated germanium films which were deposited by bias sputtering were characterized by measuring the infrared absorption. The films …

Microcomputer-Based Automated System To Monitor Flow And Respiratory Quotient, Chung C. Chien

Theses

An instrument system has been designed to monitor Respiratory Quotient experiments on rats which are living within whole-body calorimeters. By using multiplexing techniques, this system is capable of monitoring Respiratory Quotients in six calorimeters (animal chambers). It exhibits some features that make it more versatile than the previous system. One of the features of this instrument is that it uses a more accurate method of determining rapid changes in gas exchange between subject and environment. The value of this method is its ability to assess the rapid change in metabolic rate which occurs as a result of change in activity, …

A Data Compression System Using Arithmetic Code, Seokrim Choi

Theses

Generally it is difficult to compress data, from statistically unknown sources, with significant compression ratio. To achieve this, the compression scheme should have an ability to gather context information of the source, adaptively. For better compression, it is desirable to separate the context gathering scheme from coding itself. Arithmetic code is very flexible and can accept any kind of context gathering scheme which can generate probabilities. One context gathering algorithm which generates Markov type probability adaptively is studied and implemented in software using Arithmetic code. This scheme performs well and results in compression ratio better than any existing algorithms such …

Hardware Based Data Compression System Using Sliding Dictionary Algorithm, Hemant L. Nerurkar

Theses

Popular data compression schemes found in the literature are software based and present innumerable difficulties in hardware implementation. A data compression scheme, which can be directly implemented in hardware using systolic arrays, has been described. The scheme has a remarkable ability to 'adapt' itself to the changing statistics of the source file. Results generated after a comprehensive study and simulations of the algorithm have been presented. The scheme is inherently suitable for parallel processing. It can be incorporated in transmitting devices since it can be fabricated on a single VLSI chip. Comparison has been made with the LZW scheme. A …

Graphical Interpretation Of U.S. Tidal Data, Vaheh Shahbazian

Theses

Numerous Shore line operations relating to industry and conservation would benefit from convenient access to continuous tidal predictions. Easy Graphical access to continuous long term predictions of tidal heights at a location of interest will simplify operations that are sensetive to tidal predictions. A specific example, is the implementation of a protective measurements against flooding and destruction of shoreline facilities particularly at times of high tides.

This thesis consists of three things. First, rendering NOAA's data in a form accessable to a PC user. Second, it provides a Basic program for prediction of tides. Third , PC user programming Resourses …

Weighted Least Square State Estimation In Power System, Jinn-I. Wu

Theses

In this thesis two methods for power system real-time monitoring are presented, programed and tested. Method 1 is not new and method 2 is a modification of method 1. The two methods are comparable in performance and they solve the problem satisfactorily.

These methods are iterative and the problem of choosing a convergence criterion is unexplored yet. This problem has been discussed, guidelines are presented to select an optimal convergence criterion.

The concept of confidence level and techniques for error detection are investigated. programs to detect bad data and to establish a confidence level have been written and some tests …

Implementation Of Xilinx Development System And Xilinx Lca Application, Youcheng Wu

Theses

The Xilinx Application-Specific Integrated Circuit (ASIC) is a large array of programmable logic cells. Creating logic design using the Xilinx ASIC offers ease of implementation, high function density, design flexibility and lower consumption of supply power. The techniques of implementation of system and design with Xilinx CAD/CAM System include system analysis, modification, update, optimal design algorithms and real circuit emulation.

This thesis combines the setup and operation of the complete Xilinx system, and implement Xilinx LCA into 8052AH-BASIC based Single Board Computer and user's menu of real LCA chip evaluation Board. It presents our own design, construction, test and demonstration …

The Study Of The Response Of Nucleus Ambiguus Neurons To Blood Pressure Changes, Adrienne Zoe

Theses

The purpose of the project is to aid the study of the response of nucleus ambiguus neurons to changes in blood pressure. The sampling runs indicate that there is a correlation between blood pressure and neuron activity for some of the neurons monitored. Some neurons react to blood pressure increases by Increased neural firing rate while others react by decreased neural firing rate. Some neurons do not respond to blood pressure manipulation comprising the non-vagal neurons. A system was developed for the DIN PC to collect electrocardiogram, blood pressure, and neuron activity from a dog, and to perform non-real time …

Synthetic Aperture Multi-Telescope Tracker Apparatus, Richard A. Carreras, Salvatore J. Cusumano, Morton B. Jenks, Robert I. Suizu

AFIT Patents

A plurality of telescopes provide output return signals which are applied both directly and in sampled form to a photo-detector cell. The detected signals from the photo-detector will represent the constant and transient errors of the telescope system. A low pass filter insures that the tracker provides only the constant or D.C. component of the error, while a high pass filter insures that the existing measuring devices for each telescope beam provide only the transient or A.C. component of the error. The A.C. and D.C. error signals are summed together with the appropriate applied gains on each channel such that …

Influence Of Photodetachment On The Switching Characteristics Of Diffuse Discharges Containing Oxygen, G. Schaefer, G. Z. Hutcheson, K. H. Schoenbach, P. F. Williams

P. F. (Paul Frazer) Williams Publications

Externally sustained discharges can be used as opening and closing switches in pulsed power systems. Admixtures of attachers allow rapid opening when the external sustaining source is terminated; however, they will increase losses in the closing phase. Photodetachment has been proposed as an additional control mechanism to overcome these losses. This letter presents measurements on photoionization sustained discharges in argon and nitrogen containing admixtures of oxygen under the influence of laser radiation. Strong changes of the voltage-current characteristics have been observed. The influence of parameters such as percentage of O₂, laser power, laser pulse width, and circuit impedance …

Antireflection Of An Absorbing Substrate By An Absorbing Thin Film At Normal Incidence, R. M.A. Azzam, E. Bu-Habib, J. Casset, G. Chassaing, P. Gravier

Electrical Engineering Faculty Publications

An absorbing substrate of complex refractive index n₂ - jk₂ at wavelength λ can be coated by an absorbing thin film of complex refractive index n₁ - jk₁ and thickness d to achieve zero reflection at normal incidence. For given n₂,k₂ multiple solutions (n₁,k₁,d/λ) are found that correspond to infinitely many distinct antireflection layers. This is demonstrated for a Si substrate at two wavelengths (6328 and 4420 Å). The response of these absorbing antireflection layers to changes of the angle of incidence from 0 …

Fast Thermal Generation Rescheduling, F. Eugenio Villaseca, B. Fardanesh

Electrical and Computer Engineering Faculty Publications

A new dynamic programming algorithm for fast rescheduling thermal generation is presented. The savings in computational times are brought about by the introduction of two new techniques: the variable truncation dynamic programming and the limitation of the solution space to be searched. Several examples on a 20 machine system are used to illustrate the application of the algorithm and to show that optimal solutions are obtained at significantly reduced computational times.

Modeling And Simulation Studies On Nmos Vlsi, Chang-Joo Kim

Theses

This thesis has two parts. The first part deals with the theoretical analysis and experimental verification of the variation of channel resistance and threshold voltage as a function of drain and source voltages in NMOS transistor with the substrate taken as reference. And the second part deals with simulation and optimization of the NMOS sense amplifier circuits.

Firstly, the NMOS transistor with the substrate taken as reference node is analysed and a set of formulas is derived for the variation of channel resistance as a function of the terminal voltages. Experimental results (using SCL 4007AE from Signetics) show good agreement …

Performance Of Second Order Delta Modulation System, Reza Aghazadeh Alavi

Theses

The performance of an ordinary delta modulation (DM) system under three types of input signals was investigated. These signals were band limited Gaussian noise, 800 Hz sine wave, and speech signal. The affects of 2nd DM added to the ordinary DM in improving the performance of the system were researched. This is called a Second Order Delta Modulation System. The obtained data showed an increase of about 3dB in the overall Signal to Noise Ratio (SNR) of the system, in the worse case.

Input to the 2nd DM is the band limited error of the first DM. A linear phase …

The Design And Fabrication Of Dielectric Waveguides For Use With High Power Carbon Dioxide Lasers At 10.6 Microns, Jong Min Kim

Theses

The feasibility of constructing a feasible transission system to propagate 10.6 microns energy from a CO₂ laser is explored. The system is to be used in a clinical surgical setting to deliver as much as 100 watts of CW power from a surgical CO₂. laser to a surgical target.

The optimal transmission system is a slender flexible cylindrical structure, 1 mm in diameter and 1.5 m long. The structure should be sufficiently flexible to be bent into a 5 to 10 cm radius without a significant increase in the attenuation constant. For clinical applications the system must …

Digital Signal Processing Implementing The C Language With Graphics Spectrum Analysis Display, Anuraksa Mahanirananda

Theses

Digital Signal Processing discussed in this thesis is concerned with the transformation of signals or complex wave forms From time domain to frequency domain and vise-versa, implemented on microcomputer systems. The primary principles are: speed of transformation, ease of usage as an application program, capabilities of graphics displaying transformed data (such as power spectrum analysis), storing these data onto record files, and capability of using these data Files and programs with other application programs.

We begin by discussing briefly, the concepts of Fourier theory, Discrete and Fast Fourier Transform, algorithms of Fast Fourier Transform and bit-reversal. Then we implement these …

Microcomputer-Based Automated Feeding And Monitoring System For Eating Behavior Studies On Rats, Tseng-Huang Shih

Theses

An instrumentation system has been designed to monitor feeding behavioral experiments on rats. This instrumentation system is capable of performing these experiments in an automated manner without any human intervention. It is capable of monitoring these experiments concurrently in six cages. It exhibits several features that make it more versatile than previous feeding & monitoring systems. It is also capable of storing the data generated on to a floppy disk and later printing out the data for analysis.

Another feature that makes it more versatile is the flexibility of the system. Construction of a parameter file before doing the experiment …

Optically Phased Laser Transmitter, Janet S. Fender, Salvatore J. Cusumano, Robert R. Butts, Christopher R. Dehainaut

AFIT Patents

An apparatus and technique are described for phasing the outputs of a multiplier telescope array used as a laser transmitter. The technique uses samples of the transmitted beams to control optical path lengths through the separate telescopes so that the beams add coherently at the receiver. The phasing concept is applicable both to systems which provide inputs to the multiple telescopes by dividing a single laser beam and to systems in which the inputs to the telescopes and multiple, phase-locked laser beams. The approach is also compatible with single line and multi-line lasers, and it does not entail stringent alignment …

Field-Enhancement Calculations For A Field-Distortion Triggered Spark Gap, B. Pashale, G. Schaefer, K. H. Schoenbach, P. F. Williams

P. F. (Paul Frazer) Williams Publications

We present the results of numerical field calculation which supplement a recent article in which we described a new design concept for field-distortion triggered spark gaps. The calculations verify the shielding and field enhancement assumptions made in the article, and they provide insight into the interaction of the design tradeoffs associated with simultaneously maximizing the holdoff voltage and the triggering capability of the gap.

Computer-Aided Testing Of Electrical Machines: Software Development, Max Darwin Anderson, Steven A. Hauk, Robert Laramore, Hardy J. Pottinger

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Stability Of Polynomials Under Correlated Coefficient Perturbations., M. K. Saridereli, Frank J. Kern

Electrical and Computer Engineering Faculty Research & Creative Works

The robust stability of polynomials with respect to real parameter variations is investigated. The coefficients of the polynomial are assumed to be linear functions of several real parameters. An algorithm to calculate the maximum allowable variations of the parameters so the roots still remain in prescribed regions of the complex plane is presented. Examples are given to illustrate the method.

Current That Kills., Burns E. Hegler

Electrical and Computer Engineering Faculty Research & Creative Works

The authors point out the hazards associated with electricity. Several methods for preventing or coping with inadvertent shocks are described.

Computer-Aided Testing Of Electrical Machines: Software Development, Max Darwin Anderson, Steven A. Hauk, Robert Laramore, Hardy J. Pottinger

Electrical and Computer Engineering Faculty Research & Creative Works

Computer-aided test stations have been developed for research, experimentation, and testing of electric motors and generators. Data acquisition and control of the machines and drives are provided through a computer and its interfaces. Machines are connected to the computer through transducers for data acquisition, and power electronic drives for machine control. General software was written to enable the monitoring of all transducers continuously on the CRT screen while giving the user manual control of the machines and drives. Specialized software was written for automatic control of the induction, dc, and synchronous machines for specific experiments on each type of machine. …

Implementation And Performance Analysis Of Numerical Algorithms On The Mpp, Flex/32, And Cray/2, Raad A. Fatoohi

Electrical & Computer Engineering Theses & Dissertations

This dissertation presents the results of the implementation of a number of numerical algorithms on three parallel/vector computers. The object of this research is to determine how well, or poorly, a number of numerical algorithms would map onto three different architectures and to analyze the performance of these architectures using these algorithms. These algorithms are: a relaxation scheme for the solution of the Cauchy-Riemann equations, an ADI method for the solution of the diffusion equation, and a compact difference scheme for the solution of two-dimensional Navier-Stokes equations. The computers were chosen so as to encompass a variety of architectures. They …

Robust Control Of A Csi-Fed Induction Motor Drive System, Rajiva Prakash, Vittal S. Rao, Frank J. Kern

Electrical and Computer Engineering Faculty Research & Creative Works

An application of modern control theory to the control of a current-source-inverter (CSI) fed induction motor drive system is presented. A linear quadratic Gaussian (LQG) control scheme is developed in which the Kaiman filter is tuned for high robustness by a method of Doyle and Stein. The design is carried out for a sample system, and the robustness analysis and computer simulation results are included. Copyright © 1987 by The Institute of Electrical and Electronics Engineers, Inc.

Ada Tools For The Description And Simulation Of Digital Signal Processing Systems, Mark D. Happel

Retrospective Theses and Dissertations

While specialized hardware description languages allow for maximum capability and efficiency in a design automation system, the use of a general purpose language in the same role can make the system more available or more available or more practical for a larger set of users. This project demonstrates the use of ADA* for the description and simulation of small digital signal processing systems. Building on conventions and primitives proposed by Denyer and Renshaw, a simple subsystem was described in ADA and then tested with a small simulator also written in ADA.

* ADA is a trademark of the United States …

Application Of Geligam Software To The Analysis Of X-Ray Spectra, R. S. Saunders, Harold L. Pray, H. B. Eldridge

Journal of the Arkansas Academy of Science

No abstract provided.

Design Of A Meta-Assembler For Microprogramming And A Survey Of Microprogram Optimization Techniques, Rahul Saxena

Masters Theses

"The purpose of this thesis is to develop and implement a meta-assembler for microprogramming. Different methods for optimizing microprogram execution and storage are also investigated.

The meta-assembler is of an adaptive type. It allows complete flexibility in the definition of the target machine op-codes and microinstruction field formats. The assembly process consists of two main phases. In the first phase the assembler builds a description of the target machine in terms of its microinstruction field format definitions. In the second phase the source program is assembled into object microcode. The assembler is written in the language Pascal. The assembler is …

Design Of Multivariable Deadbeat Controllers Using Reduced Order Models, Joaquin Alberto Zuniga

Masters Theses

"This study is concerned with the design of minimum Frobenius norm deadbeat controllers using reduced order models. Deadbeat controllers force the non-zero initial states of a linear multivariable discrete time system to the origin of the state space in minimum time. A controller of minimum Frobenius norm achieves such response with least effort.

The deadbeat controllers are designed on the basis of eigenspectrum assignment. In general, this approach permits a freedom in the selection of the closed-loop Jordan matrix which is used in the design of parametric controllers.

In this presentation, it is demonstrated that the task of deadbeat controller …

An Assessment Of Large Scale Battery Energy Storage For Industrial Loads, Brent Edward Mckinney

Masters Theses

"Reduction of peak demand on utility systems can be beneficial to both utilities and customers. One means of achieving peak demand reduction is by the use of load-leveling batteries. This thesis describes the technical and economic factors for demand side, customer-owned battery energy storage systems. The thesis has taken into account battery costs, converter and balance of plant costs, current utility rates, and customer load profiles typical of those for which battery storage may be feasible. Battery storage system designs and costs were described and quantified by using the results of EPRI project 1275-12. Utilities in the midwest were selected …