Digital Commons Network^™

Fast Neutron Effects On Time Delay Occuring In Gallium Arsenide Laser Diodes., James Owen Schroeder

Electrical and Computer Engineering ETDs

A study has been made on the effects of fast neutron irradiation on time delay occurring in diffused GaAs laser diodes operating at 77° K and 300° K. Measurements were performed at 300° K prior to irradiation and thence after successive exposure to neutron irradiation to a maximum of about 1.2 x 10^14 nvt (>10 KeV). At 77° K, measurements were limited to a pre-irradiation characterization and a characterization after the final irradiation. A double acceptor model is used to account for the observed changes in the delay characteristics as a result of both temperature changes and neutron irradiation. …

A New Sampling Theorem For Causal (Non-Bandlimited) Functions., Alan Baker Campbell

Electrical and Computer Engineering ETDs

It is shown in this work that whereas any causal function (i.e., any function with a definite starting point) is non-bandlimited and thus would be thought to require an infinite sample rate, there is an infinite class of causal functions (identified as "regionally bandlimited functions" (r.b.f.'s)) for which a finite sample rate is adequate.

An Experimental Study Of Ultrahigh Fluence Oxygen Ion Implantation In Silicon, Charles Burton Fite

Electrical and Computer Engineering ETDs

An investigation was made to determine the feasibility of using ultrahigh fluences of implanted oxygen ions to create a usable oxide layer on silicon for device applications. Previous studies have indicated that SiO₂ can indeed be formed in this manner, but very little work has been reported on the electrical and structural nature of the resulting oxide-silicon interface. Six implants with fluences ranging from 1.25 x 10¹⁷ to 1 x 10¹⁸ (O₂)⁺ /cm² were performed into p-type silicon wafers. The implanted material was then studied to determine how the variables of anneal time, …

Generalized Feedback Shift Register Pseudorandom Number Algorithm, Theodore Gyle Lewis, W. H. Payne

Electrical and Computer Engineering Faculty Research & Creative Works

The generalized feedback shift register pseudorandom number algorithm has several advantages over all other pseudorandom number generators. These advantages are: (1) it produces multidimensional pseudorandom numbers; (2) it has an arbitrarily long period independent of the word size of the computer on which it is implemented; (3) it is faster than other pseudorandom number generators; (4) the "same" floating-point pseudorandom number sequence is obtained on any machine, that is, the high order mantissa bits of each pseudorandom number agree on all machines— examples are given for IBM 360, Sperry-Rand-Univac 1108, Control Data 6000, and Hewlett-Packard 2100 series computers; (5) it …

Adaptive, Differential Pulse-Code Modulation For Speech Processing, Peter Cummiskey

Dissertations

The objective of the research reported here is the design of efficient speech coders that can easily be implemented in integrated circuit hardware. Companding techniques like those introduced by M. R. Winkler, J. A. Greefkes, F. DeJager, A. Tomozawa and H. Kaneko were explored along with a large body of theory concerning the application of linear prediction to speech coding.

The best features of the speech signal to be measured and coded are the overall amplitude, the resonant frequencies and dampings of the vocal cavity and the fundamental frequency of the vocal cord oscillations. Adaptive quantization was used to track …

An Intensity-Dependent Filter, James M. Thorne, Thomas R. Loree, George Mccall

Faculty Publications

It is useful in optically driven Kerr-cell shutters and other laser applications to have intense pulses with extremely low light levels between pulses. We describe here a device that accomplishes this objective external to the laser cavity.

Digital Computer Solution Of Electromagnetic Transients In Large Power Systems, Bijan Navidbakhsh

Dissertations and Theses

This thesis is an introduction to the solution of electromagnetic transients by a combination of the Bergeran method of characteristics and the application of trapezoidal rule of integration.

Three test examples solved by digital computer illustrate the step by step solution and computer programming.

To compare this method with the Laplace transformation technique, a test problem solved by both methods and also digital computer is illustrated. In conclusion, the advantages and disadvantages of both methods are compared.

The Random Sequence Closing Control System, Henri Bernard Joyaux

Dissertations and Theses

This thesis describes a digital control system used by the Network Analog Group of the Bonneville Power Administration. This system, the Random Sequence Closing Control System, provides automatic control for a special purpose analog computer used in the study of switching surge over voltages on power transmission lines. This system, which uses pseudorandom data, has made it feasible to analyze switching surge phenomena on a statistical basis.

Resonant Raman Scattering From Iodine: Spectral Changes With Excitation Frequency, P. F. Williams, D. L. Rousseau

P. F. (Paul Frazer) Williams Publications

We have recorded high-resolution resonant Raman spectra of molecular iodine which show very pronounced systematic spectral band-shape variations with incident laser frequency. This frequency dependence and the presence of the multiple overtones in resonant Raman scattering from iodine may be explained by a theory in which the scattering intensity depends on Franck-Condon overlap integrals. We have obtained semiquantitative agreement between the observed spectra and spectra calculated from this theory.

State Estimation In Discrete-Time Linear Systems With Quadratic Form Observers, James Parish Shipley Jr.

Electrical and Computer Engineering ETDs

The problem considered in this dissertation is that of estimating the state of a system with a linear plant equation but having a measurement function which is a quadratic form in the state. It is first demonstrated by constructive proof that the problem has a solution if the controls have large enough magnitude, and some requirements on the minimum size of the control are discussed.

Three algorithms for estimating the state are obtained, one using the technique of maximum likelihood, the other two utilizing a more general Bayesian approach. In addition, a first-order approximate conditional mean filter is included for …

Electrical Parameter Correlations For Radiation Hardness Assurance Of Operational Amplifiers, John L. Mullis

Electrical and Computer Engineering ETDs

In the manufacture of integrated circuits, a consider­able amount of attention is given to controlling fabrication processes. This is required if high production yield and consistent quality are to be obtained. In addition to moni­toring critical parameters which are influenced by variables in processing, the packaged circuits undergo a variety of tests to determine whether they meet the desired electrical and environmental quality specifications. The problem of quality assurance is accepted and treated as an essential part of the production cycle.

Dosimetry For High Intensity, 2 Mev Radiation., Clifford Ledth Schroeder

Electrical and Computer Engineering ETDs

The purpose of this effort is to evaluate several types of dosimeters being used with the 2-MeV flash X-ray facilities at The University of New Mexico and the Air Force Weapons Laboratory (AFWL). The types include lithium fluoride and calcium fluoride thermaluminescent dosimeters (TLD's), thin foil calorimeters, p-i-n diodes, cobalt glass chips, and #25 purple Cinemoid. The evaluation includes a comparison of dose measurements, repeatability, and useful ranges. This report describes fundamental physical mechanisms by which photons and high energy electrons interact with matter, the physical mechanisms of different dosimeters, and techniques for using the dosimeters. The calcium fluoride TLD's …

Trajectories Describing The Evolution Of Polarized Light In Homogeneous Anisotropic Media And Liquid Crystals, Rasheed M.A. Azzam, N. M. Bashara, B. E. Merrill

Electrical Engineering Faculty Publications

Trajectories are given that describe the evolution of the ellipse of polarization in the complex plane for light propagating in a homogeneous anisotropic medium and along the helical axis of a cholesteric liquid crystal. For the general homogeneous anisotropic medium that exhibits combined birefringence and dichroism the trajectory is a spiral that converges to the low-absorption eigenpolarization. For pure birefringence the trajectory becomes a complete circle that encloses one eigenpolarization, whereas for pure dichroism the trajectory becomes an arc of a circle that ends at the low-absorption eigenstate. The case of a cholesteric (or twisted nematic) liquid crystal leads to …

Cylindrical Laser Resonators, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

A general class of cylindrical laser resonators is described in which the radiation propagates partially in the radial direction. There is a strong focusing of energy at the axis of such resonators. The low-loss cavity modes are related to ordinary gaussian beam modes. Two limiting forms are the disk laser and the tube laser, and some applications are considered.

A Study Of The Measurement Of Noise Power, Larry Smith Heflin

Masters Theses

"In order to compute a power signal-to-noise ratio in the numerical simulation of a communication system, it is necessary to measure the power of the noise present. The required integration can be approximated by many numerical techniques. Five numerical integration methods are available in the user-oriented System/360 Continuous System Modeling Program. Measurements of the power of an additive Gaussian noise waveform are performed, and an analysis of the accuracy of the measurement compared to theoretical values is presented"--Abstract, page ii.

Analysis And Design For Semi-Automatic And Automatic Control Of Vehicles By Permanent Magnets, Hari K. Mehta

Masters Theses

"The analysis and design carried out in this study relates to automatic or semi-automatic lateral control of a vehicle. This is one of the three essential subsystems needed for a complete automatic control system. The other two subsystems provide longitudinal control, and intersection or lane-changing control.

The system studied employs a series of permanent magnets which have been embedded vertically in the road and spaced at an interval to be used for position reference, leading to discontinuous error signal. This system has been analyzed by classical Z-transform analysis and control models have been developed for two kinds of controls. First, …

An Accurate Digital Instrument To Measure Reactor Period, Ernest W. Scott, Paul D. Stigall

Electrical and Computer Engineering Faculty Research & Creative Works

At Facilities Having a Research-Training Reactor, such as the University of Missouri-Rolla Reactor (UMRR), One Finds It Necessary to Perform a Large Number of Rod Calibrations during the Course of the Year. in Practice Rod Worths Are Determined by Measuring the Reactor Period Created by an Incremental Withdrawal of the Rod under Calibration. Period is Then Related to Reactivity Thru the Use of a Publication Such as the AEC Publication, ID016485. This Frequent Measurement of Period Makes It Desirable to Have a Simple, Automatic and Accurate Method to Make Such Measurements. at UMRR We Have Designed, Constructed and Installed Such …

Loci Of Invariant-Azimuth And Invariant-Ellipticity Polarization States Of An Optical System, Rasheed M.A. Azzam, N. M. Bashara

Electrical Engineering Faculty Publications

The loci of polarization states for which either the ellipticity alone or the azimuth alone remains invariant upon passing through an optical system are introduced. The cartesian equations of these two loci are derived in the complex plane in which the polarization states are represented. The equations are quartic and are conveniently expressed in terms of the elements of the Jones. matrix of the optical system. As an exple the loci are determined for a system composed of a π/4 rotator followed by a quarter-wave retarder.

A Formal Description Of The Nova-800 Computer In Computer Design Language, Ronald Lee Engelbrecht

Masters Theses

"This paper presents a formal description of the operation of the NOVA 800 in Computer Design Language (CDL). For simplicity, the description does not include specific input/output devices, the multiply/divide option, or data channel operations. The description is intended to be used as a supplement in a basic course in computer organization, and an example of its use is included"--Abstract, page ii.

Analysis Of A Microcircuit, Distributed Parameter Network, Which Considers Series Inductance And Shunt Conductance, Arun Jayantilal Shah

Theses and Dissertations

In this work analysis of distributed microcircuit is carried out including effects of series inductance and shunt conductance. General solution for voltage and current are obtained in terms of arbitrary constants which are to be determined by input and output conditions. Terminal voltages and terminal currents are expressed by Indefinite Admittance Matrix and port voltage, and port currents are expressed by Indefinite Impedance Matrix. Illustrative example is solved using indefinite matrix configuration and proper boundary conditions.

Performance Degradation Due To Specular Multipath Intersymbol Interference, G. H. Smith, David R. Cunningham, Rodger E. Ziemer

Electrical and Computer Engineering Faculty Research & Creative Works

Plots of performance degradation are used to compare the effects of fading and intersymbol interference in a two-component specular multipath digital communications channel. Similar plots are then used to compare two practical receivers designed to combat the interference. Degradation plots are shown to allow easy identification of each receiver's range of usefulness, as well as identification of variance bounds demanded of channel parameter estimates which the receivers require. Copyright © 1973 by The Institute of Electrical and Electronics Engineers, Inc.

An Improved Single Flight Technique For Radar Stereo, Gordon E. Carlson

Electrical and Computer Engineering Faculty Research & Creative Works

An improved technique for obtaining stereo radar image pairs is described. The technique uses a unique combination of two different radar beam pattern characteristics. The resulting stereo radar images are illuminated from very nearly the same aircraft position which results in radar shadow and back-scatter characteristics which are very similar and in improved image registration possibilities. The reduction in illumination angle and aircraft position differences is shown to be nearly an order of magnitude or more when compared with a previously proposed single flight technique which used two vertical fan beam patterns at different azimuth angles. As a related sidelight …

On The Method Of Stationary Phase, Byungkyu Park

Electrical and Computer Engineering Faculty Research & Creative Works

The method of stationary phase (MSP), which is an asymptotic method of integration, nevertheless yields general (nonasymptotic) results when applied to certain integrals involving the spherical function. In such cases one may drop the requirement of far-field or high frequency from the results. Copyright © 1973 by The Institute of Electrical and Electronics Engineers. Inc.

Flowware -- A Flow Charting Method To Describe Digital Systems, Wayne Everett Omohundro

Doctoral Dissertations

"FLOWWARE is an interactive, graphical language to aid in the understanding and design of digital networks. The language is based upon the concept of flow charting. The user specifies the register layout of the system and the sequential operation in the form of a diagram on a graphics terminal. FLOWWARE makes full use of a local minicomputer to perform editing and drawing functions, and a remote large computer to perform translation and simulation. This division of labor allows the user to build his description off-line without having the remote computer program active"--Abstract, page ii.

Applications Of Frequency Domain Stability Criteria In The Design Of Nonlinear Feedback Systems, Allen Joseph Rushing

Doctoral Dissertations

"The Popov criterion for absolute stability of nonlinear feedback systems is applied to several example problems. Model transformations such as pole shifting and zero shifting extend the class of systems to which the criterion applies. Extensions of the criterion having simple graphical interpretations yield stronger results for systems with constant monotonic slope-bounded nonlinearities. Additional extensions lacking simple graphical interpretations in the complex plane are also demonstrated by example.

Stability throughout a region in parameter space is discussed, and the Kalman conjecture is verified for a new class of systems. The Popov criterion is also used to prove BIBO stability, process …

Considerations In The Design Of A Network Of Minicomputers, Hardy J. Pottinger

Doctoral Dissertations

"The advantages of a network consisting of a number of minicomputers coupled to a large time shared computer are described. This type of network is very useful in the areas of data acquisition, real time control of experiments, and front-end processing for computer graphics.

Problems associated with the development of a network of this type, various possible solutions, and the trade-offs involved are presented. These problems are classified into two categories: the interface between the network and the central computing facility, and the interface between the remote sites and the rest of the network.

The design constraints, rationale, and implementation …

Implementation Of Recursive Algorithms For Delay-Time Estimation Using The Fast Walsh Transform, Donald Robert Nelson

Doctoral Dissertations

"Use of the fast Walsh transform to resolve noisy signals into Walsh function series to digitally implement maximum-likelihood parameter estimators for real-time use is investigated. Realization of estimators which seek a null in the derivative of the log-likelihood function, instead of direct maximization, results in feedback algorithms which yield considerable savings in computation time and storage. Performance of these feedback delay-estimation algorithms is characterized in terms of mean-squared error (MSE) and response to a delay step by Monte Carlo simulation. The effect of changing the number of points in the transform on the MSE is also investigated. Hard limiting of …

Tilt-Table Alignment For Inertial-Platform Maintenance Without A Surveyed Site, Gordon E. Carlson, Max E. Bott

Electrical and Computer Engineering Faculty Research & Creative Works

A method for aligning the rotary tilt table for an inertial-platform maintenance facility without surveying the site is analyzed and evaluated. The method utilizes multiple measurements of the tilt-table azimuth alignment error with different inertial platforms to determine a best estimate of the alignment error. Error analysis indicates that useful facility performance can be obtained with only a small number of measurements. The tilt-table alignment accuracy can be improved as more measurements of the alignment error are made during normal facility operation. © 1973, IEEE. All rights reserved.

A Multivariable Sampled-Data Model Of An Automobile Driver, Jose A. Bermudez

Masters Theses

"In this thesis, a multivariable system model of driver performance in the basic driving tasks is presented. The driver model described acts as a serial-process, priority-accessed, time-sharing computer. This model processes the input or output task which currently possesses the highest priority. Input tasks are represented by continuous signals sampled intermittently according to priority laws. Output tasks are modeled as simple analog processes operating on the last few intermittently generated output controls. An individual priority rule is constructed for each input and output task.

The performance of the driver in the lateral control task involves a feedforward pattern which is …

Nutation Control During Precession Of A Spin-Stabilized Spacecraft, Richard James Donner

Masters Theses

"The effects of precession thrust pulses and energy dissipation upon nutation of a spin-stabilized spacecraft are studied. Methods for controlling nutation during a precession maneuver are proposed and examined. In particular, a precession modulation control law is developed which uses precession thrust pulses to control nutation. Digital simulations show that precession control with separate nutation control is the fastest precessing system; however, the precession modulation method is only fractionally slower while not requiring a separate nutation control system"--Abstract, page ii.