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Methods For Acoustic Holography And Acoustic Measurements, Wolfgang Fischer

Dissertations

In this dissertation, a novel "four-step acoustical holographic imaging system" is described and several means for its implementation are analyzed both theoretically and experimentally. This system is compared with other methods of acoustical holography, (ie. permitting to obtain a visible, 3-D image of an object insonified with supersonic waves) and some of its advantages are indicated.

The use of optical holographic techniques to convert an arbitrary acoustic image to a visible image is investigated and a new method - the "holographic sound image converter" - is introduced and analyzed. This converter consists of the "holographic interferometer" and an appropriate "coupler". …

Gallium-Arsenide-Phosphide Mis Capacitor Fabrication And Radiation-Effects Studies, Douglas H. Phillips

Electrical and Computer Engineering ETDs

GaAsP MIS capacitors were fabricated using several dielectric-growth processes, including RF sputtering, wet oxidation, and dry oxidation of GaAsP. Dry oxidation of GaAsP surfaces produced MIS devices having the best charac­teristics. Instabilities of early MIS capacitors were over­come by use of thermal cycling techniques and chromium-doped dielectrics. Deep-depletion characteristics were observed for GaAsP MIS C-V curves, even in the range of applied bias which theoretically should result in inversion of the GaAsP surface. Both low-frequency and high-frequency C-V data support the conclusion that inversion characteristics were not observed for GaAsP MIS capacitors. Calculated high-frequency surface-state density and surface-state charge values …

Low Temperature Investigations On Epitaxial Silicon Using The Micro-Hall Device, Joseph P. Baca

Electrical and Computer Engineering ETDs

This report is concerned with the feasibility of using the micro-Hall device, introduced by Colclaser and Southward, as a tool for determining important electrical characteristics of epitaxial silicon at low temperatures. The theory of carrier concentration and mobility as a function of temperature in the low temperature range is presented. A contact diffusion mask is introduced which eliminates the formation of an unwanted junction at the substrate contacts and aids in the formation of ohmic contacts. The refrigerator (cryo-tip) used to obtain low temperatures and a special designed specimen holder which connects to the cryo-tip are described.

Intense Relativistic Charged Particle Beam Transport Phenomena In Vacuum, Alan Michael Chodor

Electrical and Computer Engineering ETDs

The purpose of this report is to investigate the nature of propagation processes for intense, relativistic charged particle beams in vacuum. Three areas of the problem are studied. The first subject, envelope optics, includes a formal development of the envelope equations and consideration of this approach as a device of approximation. Secondly, assuming laminar behavior, the entire beam is modeled in a closed set of partial differential equations in configuration space. A general study of this condition emphasizes invariants of laminar flow and geometric scaling. Finally, the coupled beam-field equations are solved exactly for several special cases. The optical properties …

An Electromagnetic Boundary Value Problem In An Inhomogeneous Medium, Thomas Franklin Ezell

Electrical and Computer Engineering ETDs

This dissertation presents a general theory for the solution of electromagnetic boundary value problems for regions which are not homogeneous. The theory begins with the wave equation in Fourier frequency domain for the electric field in the interior of a closed volume; the electromagnetic property parameters, specifically conductivity and dielectric constant, are written as functions of position. The wave equation, which holds throughout the interior of the closed volume, is then converted to an integral equation by use of a Green's function for the same volume containing a homogeneous medium. Boundary conditions between homogeneous regions inside the closed volume appear …

Polarization Of Infrared Waves Due To Propagation Through The Atmosphere, J. Philip Castillo

Electrical and Computer Engineering ETDs

This study presents an investigation of the polarization of infrared waves due to propagation through the atmosphere. Cumulus cloud and Haze M particle size distributions are considered for various optical depths at wavelengths of 4.0 and 10.0µ. Results at these wavelengths are compared to results at a wavelength of 0.5µ for the same physical atmosphere. Initially the radiative transfer integral equations are derived which include the Stokes polarization vector. From these integral equations a Monte Carlo simulation technique is used to simulate photon histories through the atmosphere. The effects of multiple scattering on the polarization state of the scattered intensity …

Photo And Magnetic Gated Bi-Directional Counter, Charles Burdette Kraemer

Graduate Research Papers

The purpose of this study is to investigate digital counter circuitry, digital logic, and some special applications of digital display systems. The technical data and information ascertained from the research will be used to design and develop a four-digital counter with photo and magnetic gated inputs.

Electrical Wiring For Lower-Cost Housing, Burns E. Hegler

International Symposia on Low Cost Housing Problems

No abstract provided.

Digital Video Display System Using Cathode-Ray Tube, George M. Low, Arthur I. Zygielbaum, Warren L. Martin, Alexander Engel

School of Natural Resources: Faculty Publications

A digital video display system (DWDS) is disclosed for display of image, alphanumeric and other data on a cathode-ray tube (CRT) with sequential raster scan and two, four or eight gray shades. The DVDS includes a central processing unit for ac tivating the system, selecting the X (horizontal axis) and Z (in tensity modulation) modes, and designating the starting loca tion of two successive rasters of data from a memory accessed by a data multiplexer subsystem (DMS). At the end of each raster, the DMS interrupts the computer for a new starting lo cation of a raster of data to …

Application Of Numerical Analysis To Root Locus Design Of Feedback Control Systems, Steve William Justice

Dissertations and Theses

Many practical problems in the field of engineering become so complex that they may be effectively solved only with the aid of a computer. An effective solution depends on the use of an efficient algorithm. Plotting root locus diagrams is such a problem. This thesis presents such an algorithm.

Root locus design of feedback control systems is a very powerful tool. Stability of systems under the influence of variables can be easily determined from the root locus diagram. For even moderately complex systems of the type found in practical applications, determination of the locus is extremely difficult if accuracy is …

Gain And Dispersion Focusing In A High Gain Laser, Lee W. Casperson, Amon Yariv

Electrical and Computer Engineering Faculty Publications and Presentations

The transverse modes of a laser resonator containing a medium with a strong radial gain profile differ greatly from the modes of a similar resonator containing a low gain medium. Focusing and defocusing effects result from the gain profile and from the associated dispersion profile. The dispersion focusing causes an asymmetry in the power output as the laser is tuned across the gain line. The theory has been verified using a high gain 3.51-µ xenon laser.

Electron Cyclotron Radiation Measurements To Determine Relative Electron Temperatures In A Low-Density Magnetic-Mirror Plasma System, Andrew L. Gardner

Faculty Publications

Measurements of the electron cyclotron radiation emitted from the plasma of the Alice system were made using a synchronous detection microwave radiometer in the range of 10.2 - 11.6 GHz. Both sidebands were used to sample radiation from two nested closed shells within the plasma. For a tenuous plasma this radiation is proportional to the product of the electron density and the electron temperature. Since measurements of the plasma density were available from other detectors, relative values of the electron temperature were obtained using the measured radiation intensity.

Association Of College And University Telecommunications Administrators Presidents

ACUTA: Other Publications

ELWYN HULL

1980-1981

CONSTANCE GENTRY

1981-1982

L. STEVE HARWARD

1982-1983

MICHAEL A. TONER

1983-1984

RUTH A. MICHALECKI

1984-1985

JOHN W. SLEASMAN

1985-1986

MALCOLM READER

1978-1980

ELWYN HULL

1980-1981

CONSTANCE GENTRY

1981-1982

L. STEVE HARWARD

1982-1983

MICHAEL A. TONER

1983-1984

RUTH A. MICHALECKI

1984-1985

JOHN W. SLEASMAN

1985-1986

The Effect And Compensation Of Time-Base Perturbations In Analog Recording Systems, Clifford D. Skouby

Doctoral Dissertations

"The mean square error between recorded and reproduced signals is used as an error measure to determine the effects of time-base perturbations on an analog singal. The mean square error caused by time-base perturbations is shown to be proportional to the product of the square of the signal bandwidth and the time-base error variance for the case of low pass signal. When the signal is band pass, there is shown to be an additional error term which is proportional to the square of the signal center frequency and the time-base error variance.

Calculations are also carried out to determine the …

Data Compression Design Considerations For Airborne Test Vehicles, Kenneth Carlyle Pittman

Masters Theses

"The design goals for a data compression system are developed using previous studies as a cornerstone. Sampling theory is touched on with qualitative coverage of its effects. Consideration is given to various methods of data compression with the advantages and disadvantages of each noted. The requirement for buffering is discussed along with various methods that may be employed to achieve specific buffering goals. The impact of data reconstruction and how it may affect the choice of compression techniques is briefly covered. Selected compression algorithms and ways of increasing system effectiveness through alterations to their basic structures are described in detail. …

Sensitivity Analysis In Active Rc Bandpass Circuits, Robert Bentzinger

Masters Theses

"This thesis is concerned with the analysis and cataloguing of sensitivity functions of some selected active RC bandpass networks. The sensitivity functions of primary interest are the sensitivities of the quantities ω_o and Q with respect to changes in the element values of each circuit.

An introduction is provided to give background information on how each circuit is realized. Each circuit is then analyzed and the pertinent sensitivity functions catalogued. Some comments are made as to the approximations which are involved in several of the realizations and the validity of any sensitivity analysis made on these approximate realizations. The …

Minimum Distance Classification In Remote Sensing, A. G. Wacker, D. A. Landgrebe

LARS Technical Reports

The utilization of minimum distance classification methods in remote sensing problems, such as crop species identification, is considered. Minimum distance classifiers belong to a family of classifiers referred to as sample classifiers. In such classifiers the items that are classified are groups of measurement vectors (e.g. all measurement vectors from an agricultural field), rather than individual vectors as in more conventional vector classifiers.

Specifically in minimum distance classification a sample (i.e. group of vectors) is classified into the class whose known or estimated distribution most closely resembles the estimated distribution of the sample to be classified. The measure of resemblance …

A Method For Generating Uts Assignments With An Iterative State Transition Algorithm, Dattatraya Govind Raj-Karne

Doctoral Dissertations

"There is a lack of systematic procedures that can be used to find uni-code totally sequential (UTS) assignments from a flow table description of an asynchronous sequential circuit. Presented here is an iterative internal state assignment method. This method consists of three algorithms. The first generates a minimum variable initial assignment from a flow table description. The second tests the validity of this assignment by constructing minimum length transition paths without crossover and the third augments this assignment by adding an internal state variable in the event that all transition paths cannot be constructed without crossover. The second and the …

A Comparison Of Liapunov Functions Used To Determine Power System Stability For Multimachine Power Systems, Kiritkumar S. Shah

Masters Theses

"Four Liapunov functions used in stability studies are compared for accuracy on an eight machine power system. This comparison is made to determine which function is best in multimachine stability applications. Morgan's Estimating Technique is used to estimate when the Liapunov function would exceed its maximum value and thus to predict the critical switching time for the system"--Abstract, page ii.

A Hardware And Software Interface Between A Magnetic Tape Unit And A Nova Mini-Computer, Thomas Dean Steury

Masters Theses

"This thesis is concerned with the general operation of the Kennedy Model 1400R incremental write/continuous read magnetic tape unit and the hardware design and software implementation needed to make it compatible for use with the Data General Nova 800 mini-computer.

The hardware design was developed around a General Purpose Interface Board which provides a standard set of logic needed for interfacing any external device to the Nova. The hardware consists of decode networks, mode selection networks, and I/0 timing networks. Special circuits needed to implement the hardware design and perform voltage conversions between the tape unit and the Nova computer …

Design And Analysis Of A Phase-Locked Loop Suitable For Synchronization Of An Optical Receiver, Douglas Wayne Dreisewerd

Masters Theses

"The required synchronization of a dynamic crossed-field photomultiplier tube (DCFP) is accomplished by means of a phase-locked loop for which the salient feature is the use of the DCFP as the phase detector. This action is necessitated due to the unique sampling and phase focusing type of operation of the DCFP. The phase-locked loop is implemented by dithering the phase of the synchronizing RF drive signal, bandpass filtering the output pulses of the DCFP and using a synchronous detector at the dither frequency to determine the phase relationship between the incoming mode-locked laser pulses and the RF drive signal. The …

An Analysis Of Single Wire Earth Return (Swer) System For Rural Electrification, Balwinder Singh Samra

Masters Theses

"The primary objective of this investigation was to determine the general applicability of Single Phase Earth Return(SWER) system for rural electrification where the load density is low, for example electrification of farms and small villages in emerging nations. The limitations of SWER system of distribution are many and it is necessary to make judicious use of such transmission. In this investigation the construction costs of transmission and distribution by SWER system is compared with single phase and three phase systems for loads of 25KVA and 50KVA. Phase converters are required to operate a three phase motor on a single phase …

Decimal-Base Binary Logic (Dbbl) Adders And Registers, James Oliver Bondi

Masters Theses

"This paper discusses a new type of base n adder and storage register. This new type of logic is called "n-base binary logic", or NBBL. The NBBL system is compared and contrasted with the Post base n system (a type of n-valued logic), the binary-coded base n system, and the straight binary system. The main purpose of this paper is to show that a decimal, or base 10, system can have some important inherent advantages over a binary system, such as greater daily operational efficiency. Furthermore, it is shown that a "decimal-base binary logic" system, or DBBL system, has inherent …

Performance Comparison Of Receivers Designed To Combat Intersymbol Interference Due To Specular Multipath, George H. Smith

Masters Theses

"Bit error probabilities for biphase transmission have been computed for a known two-component multipath channel with a variety of suboptimum receivers. Performance curves are presented for each receiver, and the relative performance is summarized. Degradation due to imperfect channel knowledge is calculated, and the feasibility of countering this interference with these specially designed receivers is discussed"--Abstract, page ii.

A Study And Design Of A Cardiac Interbeat Interval Timer System, Richard William Mooney

Masters Theses

"This thesis reports the design of a system which can measure and record the cardiac interbeat times of human subjects in a continuous beat to beat manner, using the bioelectrical signal associated with the heart as an input. The design is in response to the needs of clinical researchers.

The means of obtaining the bioelectrical signal and previous designs of electrocardiographic equipment, especially electrocardiotachometers, are reviewed. A design is proposed which consists of a preamplifier to amplify the bioelectrical signal, a 60 Hz rejection filter, and a beat detector which uses a differentiation technique to obtain a reliable single output …

Computer-Aided Circuit Optimization Including The Adjoint Method Of Calculating Network Sensitivities, John Walter Olson

Masters Theses

"A complete discuss ion of the optimization of a circuit, including modeling and programming difficulties encountered, is presented. A three transistor bandpass filter is used in order to study various methods of optimization. The adjoint method of calculating the network error gradient vector is compared to the perturbation method. The adjoint method proves to have decided advantages over the other method. A generalized computer program is presented to carry out the Fletcher-Powell optimization algorithm with specialized subroutines which include a network equation solver and both methods of finding the gradient vector. The program proved very effective in realizing a desired …

A Study Of Fmfb Demodulator Operation In The Presence Of Radio Frequency Interference And Gaussian Noise, Terry D. Wormington

Masters Theses

"A digital computer model of an FMFB demodulator has been used to study the effects of radio frequency interference on the detection of a sinusoidally modulated carrier. The effectiveness of selecting the feedback factor to suppress the interference for three values of modulation index is investigated. Also, the required IF bandwidth for the minimization of the mean-square error of the loop output between a signal corrupted by interference and the same signal without interference was investigated. More work is required before the effects of Gaussian noise plus interference on loop operation can be ascertained"--Abstract, page ii.

Performance Of Self Bit Synchronizers For Binary Overlapping Signals, Chung-Tao David Wang

Doctoral Dissertations

"This research is concerned with the optimum and suboptimum ways of providing self bit synchronization for binary overlapping signals. A maximum likelihood synchronizer is derived as the optimum approach. The suboptimum ways are those employing decision-directed feedback and matched derivative filter techniques which are proposed for treating the overlapping signals. Combining the two suboptimum techniques along with the bandlimited version of the overlapping signal, a suboptimum synchronizer is derived. The performance of the above synchronizer is evaluated by Monte Carlo simulation techniques. Finally, a bit synchronizer using nonlinear filtering theory is considered. The performance of a nonlinear bit synchronizer is …

An Asynchronous Circuit Design Language System, Gregory Martin Bednar

Doctoral Dissertations

"This paper presents a system for specifying the behavior of asynchronous sequential circuits. The system consists of a special purpose Asynchronous Circuit Design Language (ACDL), a translator and a flow table generation algorithm. The language includes many special features which permit quick and precise specification of terminal behavior. It is best suited for problems originating from a word description of the circuit's operation. The translator is written with the XPL Translator Writing System and is a syntax-directed compilation method. From the translated ACDL specifications, the flow table algorithm generates a primitive flow table which is the required input for the …

Distributed-Network Realizations For The Simulation Of Partial Differential Equations, Roy Dale Hensley

Doctoral Dissertations

"A method is developed for the simulation of the partial differential equation

-u_xx + k_ou_tt + k_lu_t +k₂u = g(t)

for various boundary conditions. The boundary conditions are used to classify the problems into types and the Laplace transformed solution of the most general problem of each type is obtained.

Synthesis techniques are presented for the realization of circuits containing distributed networks that can be used to simulate the partial differential equation for given boundary conditions. Several heat flow and vibrating string examples are included to illustrate the application of the …