Engineering Commons^™

Computer Solution To Inverse Problems Of Elliptic Form: V²U(X,Y) = G(A,U,X,Y), Frederick Alvin Jeter

Dissertations and Theses

One important aspect of our present age of monolithic high speed computers is the computer's capability to solve complex problems hitherto impossible to tackle due to their complexity. This paper explains how to use a. digital computer to solve a specific type of problem; specifically, to find the inverse solution of a in the elliptical equation V²U(x,y) = g(a,U,x,y), with appropriate boundary conditions. This equation is very useful in the electronics field. The knowns are the complete set of boundary values of U(x,y) and a set of observations taken on internal points of U(x,y). Given this information, plus …

Centering In Parallel Channel Systems, Allen Katz

Dissertations

Several types of signal processing systems in which the signal flows along parallel channels in a fashion similar to the auditory system have been investigated. The effect of excitation with signals containing both single and multiple spectral peaks (formants) was considered. In particular, the effect of nonlinear interaction between channels, referred to as centering, in the presence of noise was studied.

These systems were investigated for their value, both as information processing networks and as models of the auditory system.

The analysis indicates that parallel channel systems, in general, exhibit excellent performance in the presence of noise, and that a …

Sidelobe Suppression In Chirp Radar Systems, Stephen N. Honickman

Dissertations

Pulse radars extend target range detection by increasing the transmitted pulse width. On the other hand, target resolution is enhanced by reducing the system pulse width. These dichotomous requirements led to the invention of chirp radar systems which achieve greater target resolution for a given detectable range by frequency modulating the carrier frequency of the transmitted pulse. Along with the advent of chirp radars came the extremely simple and reliable technique of chirp signal generation known as "passive generation". However, one of the undesirable features of "passive generation" lies in the infinite time required for transmission of the resultant pulse, …

Measurement Of Soil Moisture By Attenuation Of A Vertically Polarized Radio Wave, Arlo D. Mickelsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this thesis is to determine feasibility and to investigate some of the problems encountered in making soil moisture measurements using radio wave propagation. The procedure consists of propagating a vertically polarized wave over the earth and measuring the field strength attenuation. A brief summary of present methods of measuring soil moisture is given.

Certain aspects of radio wave propagation theory are discussed, covering such topics as the surface wave, the space wave, the skin depth, and the effect of the dielectric constant on radio wave propagation. Based on this theory, measurement parameters such as frequency, antenna separation, …

A Statistical Theory Of Avalanche Breakdown In Silicon, Terence Vincent Sewards

Electrical and Computer Engineering ETDs

A statistical theory of avalanche breakdown in silicon is presented, based on the conventional Boltzmann transport equation. The scattering mechanisms considered are impact ionization (electron-hole pair production), phonon emission and absorption, thermal generation and recombination. The resultant critical field is found to depend on the recombination statistics, which were ignored in previous theories of avalanche breakdown. The theoretical temperature dependence is compared with the temperature dependence of the breakdown voltages of three conunercial diodes.

The Development And Use Of Scattering Parameters For Semiconductor Junction Devices, Lee Dennis Philipp

Electrical and Computer Engineering ETDs

Scattering parameters are developed for diodes and tran­sistors. The parameters are developed through a modification of the wave equation from quantum mechanics. The effects of pulsed X-ray radiation on these devices is then calculated with the use of these parameters.

Various methods of analyzing semiconductor junction de­vices are discussed. These methods include diffusion theory, invariant imbedding and quantum mechanics. The background in these areas necessary for a discussion of semiconductor models is outlined.

Models resulting from the three basic approaches are presented. These include the Ebers-Moll Model, the Charge Control Model, the Linville Model, the Gore Model, the MLB (McKelvey, …

A Study Of Early-Late Type S0-Pcm Signal Bit Synchronizers, Kuang-Cheng Hu

Masters Theses

"The steady-state phase noise performances of an absolute value type and a squaring loop type of early-late gate S0-PCM signal bit synchronizers are developed using the Fokker-Planck method. The results are compared on the basis of the performance of two configurations with equal loop bandwidth at each input signal-to-noise ratio R_s. The probabilities of bit-detection error of the two configurations are compared. These comparisons are made as a function of R_s. The absolute value type of early-late gate S0-PCM signal bit synchronizater yields better performance than that of the squaring loop type of early-late gate S0-PCM …

A Software System For Interactive Man-Machine Design And Analysis Of Electronic Circuits, Leo William Midden

Masters Theses

"The development of an interactive computer-aided circuit analysis program is presented. A graphics terminal is used as an I/O device while an SCC 650 mini-computer is used as peripheral processor. The central processor is an IBM 360/50.

Formulation, capabilities and use of the system are discussed in detail. Close attention is given to user control, making the system both useful and versatile. Both hard and soft copies of all plots and tabular data are available. Provisions are made for error corrections and changes at each step of the input. Parameter values can be altered before and after each analysis.

Additionally, …

Analysis Of Factors Affecting Station Capacitor Bank Switching Transients, M. Davarpanah

Masters Theses

"The problem presented here is a study using a computer program which predicts the transient response when energizing a station capacitor bank of a power system. The computer program gives the wave shape and magnitudes of switching surges obtained while energized capacitor banks at one location and showing the effect of switching a bank while adjacent banks are already energized. The over voltages are given in line-to-ground voltages on the line side of the capacitor banks as well as at lower voltage levels down to the customer 120 volts service voltages. The purposes are to obtain the optimum values of …

Ladder Network Transfer Function Characteristics, Thomtavanit Hatayodom

Masters Theses

"This thesis investigates the network characteristics and synthesis procedure previously developed. As a result of this investigation, location of the absolute minimum values of Navot's method is determined; a procedure is given for obtaining more desirable component values for a given ladder network without changing its transfer function; a procedure is given for obtaining the source location in a ladder network that yields the desired numerator degree of its transfer function; and a computer program for helping to obtain the above result is presented"--Abstract, page ii.

The Use Of Scattering Parameters In Amplifier Design, Yousef Neman-Ebrahim

Masters Theses

"The scattering-parameter formulation of an active two-port device is developed from the compensation theorem. The use of scattering parameters in graphical developments of forward operating power gain and tunability is considered in detail. Finally, two design examples show the application of the graphical procedures"--Abstract, page ii.

Frequency Division Using Cascaded Phase-Locked Loops, Curtis B. Abshier

Masters Theses

"In many practical communication systems it is necessary to generate phase coherent subharmonics of an input tone. A useful system for accomplishing this task is a system of phase-locked loops in cascade. It is shown that when the feed-forward function is matched, the phase error of the second loop is zero. Analytical analysis and computer simulation prove that the minimum time to achieve phase-lock is obtained when the feed-forward function is matched. Under this condition, necessary design parameters are determined with ease"--Abstract, page i.

Practical Application Of Digital Computer To Distribution Systems, Juan Vincente Saavedra

Masters Theses

"Given a three phase ac power distribution system, a digital computer program is presented which determines a complete steady state solution for a given condition. The network data is processed by the computer into an admittance matrix, and these parameters are stored in a manner that enables the computer program to operate upon them as the coefficient of a simultaneous set of nonlinear equations. This set of equations are solved by the Gauss-Seidel Iterative Process improved by a modification of the relaxation method. Practical experience with the distribution system of the Davenport, Iowa, plant of the Aluminum Company of America …

Dynamic Thermal Responses Of Fluidized Beds, James Reid Pfafflin

Electronic Theses and Dissertations

Investigations were conducted on the dynamic thermal responses of fluidized beds to changes in fluidized bed parameters. Dynamic thermal responses were characterized by the time constant in the first order exponential model of temperature response with time. Bed materials, bed particle size and reactor column size were varied over a· fairly wide range. Differences were found between the active (heating) and passive (cooling) time constants under otherwise identical conditions. It was found that time constants decay in an exponential manner with increasing superficial velocity. Models are presented for prediction of time constants, based on characteristics of the fluidized bed. Models …

A Laboratory Study Of The Transmission Of Signals Through Solid Material With Possible Application To Seismic Communication, Ronald Willis Carter

Masters Theses

"The problem of transmitting acoustic signals through solid material channels is investigated using piezoelectric transducers for generation and detection of the signals. Laboratory experiments are performed in which a solid material channel is modeled by a block of Berea sandstone. The magnitude of the frequency response for the sandstone and transducer combination is obtained over the frequency range of approximately 0 Hz to 500 kHz. Various electrical waveforms are utilized as driving sources for the transmitting transducer. It is found that the best received waveform is obtained when a gated sinewave whose frequency is approximately equal to the resonant frequency …

Perturbation And Sensitivity Analysis Of An Urban Model, Nicola Ann Nelson

Masters Theses

"This work describes a sensitivity analysis of the nine major system variables of the urban model postulated by Dr. Jay W. Forrester in his book Urban Dynamics. This model simulates the growth of a city from a nearly empty land area through a 250 year life cycle. Using small perturbations about the system trajectories, sensitivity matrices were computed at 135 years (growth period) and 240 years (equilibrium). The results show a matrix heavily weighted to give large sensitivity coefficients to the three housing variables, the PH sector being the most sensitive. Each of the housing sectors was analyzed further to …

Detection Of Delay Time And Filtering Using Sequency Domain Technique, Earl F. Richards

Doctoral Dissertations

"A procedure is presented by which it is possible to detect a known signal of unknown delay in a noisy medium contaminated by noise. From the results the characteristics of a sequency digital filter which would be required to remove the noise contamination is indicated. The Walsh functions are discussed and the sequency domain, which is analogous to the continuous frequency domain, is used in the spectral analysis of signals. The binary nature of the Walsh functions and their ease of generation makes processing of signals easier than the Fourier analysis approach. The applications of fast forward and inverse Walsh …

The Concept And Design Of A Curvilinear Character Generator For Cathode Ray Tube Display Systems, Lawrence Edward Hanebrink Jr.

Masters Theses

"The character generator is the heart of any cathode ray tube display system. The types of generators in common use are the dot matrix generator, the raster scan generator, and the linear stroke generator. Each of these generators produces symbols whose legibility is somewhat compromised. A curvilinear generator is suggested which provides improved appearance and greater legibility. A prototype unit was constructed and the results are compared with the other generators. The curvilinear generator provides the best character resolution and readability of the generator types discussed"--Abstract, page ii.

Magnetic Properties Of Ceramic Ferrites Developed For Use In Fractional Horse Power A.C. Motors, Ram Saran Bhatia

Masters Theses

"The ceramic material produced in the Ceramic Engineering Department of the University of Missouri-Rolla has been tested to determine its magnetic properties. First the B-H characteristic, Q-factor and initial permeability were measured at different frequencies and the relative-loss factor was determined from the above results. The samples prepared were in the shape of toroids of approximately 8.0 cm of mean length and were wound with standard insulated number 38 wire. The soft ferrite material was produced to determine whether or not it could be used in the design of fractional H.P. a.c. motors"--Abstract, page ii.

The Design Of A Data Set Interface, Wayne Everett Omohundro

Masters Theses

"This paper describes the data set interface which connects the SCC-650 digital computer to the IBM-360 computer by means of a data communications link over a telephone line. To provide the necessary background information, the basic concepts and techniques of digital data communications are discussed. In conjunction with these concepts, several possible system arrangements of modems, terminals, and computers are given. Also two computer-to-computer networks are discussed. The first one is the system used at the Lawrence Radiation Laboratory for the acquisition of experimental data. The second system, the one in which the interface operates, is the data communications system …

Shop Level Maintenance Of Inertial Platforms Without A Surveyed Site, Max E. Bott

Masters Theses

"The initial installation of a rotary tilt table for an aircraft inertial navigation system test facility includes accurately aligning the rotary tilt table to local level and true north coordinates. The survey techniques presently employed are an encumbrance during installation and complicate remote deployment. The objective of this thesis is to determine if an inertial platform or platforms can practically be used to replace the role of the survey techniques in the rotary tilt table alignment. The construction, capability and operation of a rotary tilt table are reviewed. The tests necessary to test and calibrate an inertial platform are outlined, …

Triangular Signal Stabilization Of Nonlinear Systems, Kamaleddin Yadavar Nikravesh

Masters Theses

"Many nonlinear systems display self-sustained oscillations which are often undesirable. The stabilizing effect of a high frequency input signal on an oscillating system with one nonlinearity is determined by the characteristics of the nonlinear element in the system, the linear portion of the system and the amplitude of the signal. This investigation has been concerned with the effect of a triangular wave stabilizing signal on these self oscillations. The equivalent gains for several common nonlinearities are derived. The pseudo describing function introduced by Oldenburger and Boyer for sinusoidal stabilization has been extended to the triangular wave case, and it is …

The Design Of A High Temperature Thermoelectric Generator Element Using Silicon Carbide, John Talmage Barrow Jr.

Masters Theses

"This report presents the design of an optimum, high temperature silicon carbide thermoelectric generator element. The analytical efforts have been divided into three basic parts, the development of the theory, the accumulation of the data, and the optimization of the design. The first step in the theory development was the derivation of accurate design equations. With this done, the design philosophy and computer program were constructed, the latter utilizing a subroutine to contain the design equations. The data was obtained from a survey of many references and, for the most part, was found to be inexact, requiring the consideration of …

Simulation Of Digital Computer Simcom, Ming-Te Hsieh

Masters Theses

"SIMCOM(SIMulated COMputer) is a hypothetical small general-purpose digital computer. It has a core memory of 4096 12-bit words and has been modeled after the Scientific Control Corporation SCC 650. The instructions of SIMCOM are completely compatible with the SCC 650, any SIMCOM program can be run on the SCC 650. The logical organization is similar but not identical to the SCC 650, the mnemonics that are used to represent all instructions are identical to those used on the SCC 650 except the Input/Output instructions. This computer can be simulated on any available commercial computer. If such a simulation is available, …

An Analysis Of Solar Noise Outbursts And Their Application To Space Communication, Marion Francis Moen

Masters Theses

"A relationship between sunspot activity, solar flare activity and noise outbursts is presented. Five different types of interference radiation in the 10MH_z to 30,000 MH_z frequency band are discussed. Data obtained by solar radio astronomy are analyzed to determine the extent of solar noise outbursts as a function of sunspot activity. An application of the burst data to future space communication is given"--Abstract, page ii.

Variable-Threshold-Mixed-Weight Threshold Element, Cheng-Chung Liu

Masters Theses

"A threshold element (TE) is a mathematical model of a class of logic gates. The desirability of a threshold element in the application of digital systems stems from its richness of logic power and its relative economy. On the other hand, the tighter tolerences required by the threshold logic element as compared to conventional logic gates have prevented them from being utilized extensively. The purpose of this thesis is to propose a versatile threshold element having high noise immunity and loose tolerance requirement. The proposed TE which has variable threshold and mixed weight capability uses current switching to enhance noise …

Screening Electrocardiograms Using Hotelling's Method Of Principle Components, Edward G. Schwartz

Electronic Theses and Dissertations

Considerable use is presently being made of computers to classify electrocardiograms (ECGs) into various heart defect categories. An example of such a program is the "Electrocardiographic Analysis Program" developed jointly by the Mayo Clinic and IBM. In one of Dr. Caceres published reports, he tells of using a computer program which involves 5,000 instructions. Dr. Caceres does not say whether this is a commercial program or one of bis own. His description does place this program in the same general category as IBM's. These programs have the common criteria of examining the ECG for the same information that a cardiologist …

A Hardware And Software Interface Between A Graphics Terminal And The Scc 650 Computer, George Irvin Rhine Jr.

Masters Theses

"This paper describes the design of a digital interface between a graphic terminal and the SCC-650 computer. The graphic terminal-computer combination can be used as a stand alone system for small applications or can be used as a satellite processor for a larger system such as the IBM System 360, The interface is designed utilizing DTL NAND type integrated circuits. Its primary functions may be divided into three main categories: (1) to give level conversion, (2) control, and (3) data manipulation. All requests for data transfers are initiated by the computer, the interface then assumes a control mode which handles …

Calculation Of Eddy Current Loss Of A Disc, Kou Quen Chang

Masters Theses

"A method is presented to calculate the eddy current losses of a uniform disc with an opening in the center and excited by a circular current loopage First, the disc is subdivided into smaller concentric rings, then the self-inductances, the mutual inductances between these smaller rings, the mutual inductances between the excitation coil and the smaller rings, and the resistance of the rings are calculated. Next, the eddy current flowing in each ring is obtained by solving a complex matrix equation of the form [X] [I] = [V] where X is the impedance matrix, I is the eddy current matrix, …

Low Frequency Lumped Element Directional Couplers, Constantine Rodolph Jenkins

Masters Theses

"Lumped element directional couplers are desirable at frequencies below the VHF range because they eliminate the large physical size necessary for the distributed element directional couplers. The purpose of this work is to describe the theory and design of such low frequency lumped element directional couplers. A model for the coupler is developed and the equations which describe it are derived. Scattering matrices for one and two section couplers are obtained. Computer solutions for three section couplers are presented. Experimental results for one, two, and three section couplers are presented and comparison with theory are made. Comparisons of theoretical and …