Electrical and Electronics Commons^™

Synthesis Of Multiarea Grid Power Systems, Bharat C. Patel

Dissertations

This dissertation presents improved development in the formation of a generalized transmission loss (B)-matrix for a multiarea grid power system. In the procedure, the individual tie powers of each area are replaced by the net interchange, sneak and circulating powers. The latter two variables are directly eliminated in the power reference frame using actual impedances, unlike current methods that require the elimination of sneak and circulating currents, the formation of complex tie current model and the complex tie power model. Consequently, manipulation of large complex current, power and impedance matrices is avoided reducing both computer time and memory requirement. Further, …

A New Mathematical Model For Nephron Macromolecular Selectivity, John Anthony Domiter

Theses

A mathematical model describing the displayed selectivity of the kidney nephron to macromolecules of varying particle size is presented. Diffusion and electrical forces are considered to be the sole mechanisms of transfer. The mass transfer principles responsible for selectivity are considered to occur within the capillary structure, and not within the membrane wall. A charge is assumed to be characteristic of the macromolecule and the membrane wall. Models describing both charged and uncharged solutes are developed.

A non-linear least squares technique, developed by Marquardt, is used to curve fit the derived functions to data relating fractional clearances of dextran and …

The Measurement Of Depolarized Radiation For Monitoring The Mass Concentration Of Particulates, Bruce E. Wilson

Theses

The depolarization of backscattered polarized incident radiation which is expressed as a depolarization ratio was investigated as a means of monitoring the mass concentration of particles in stacks from coal-fired burners. This involved the design of an instrument that would detect small levels of radiation. Two methods were investigated. The first utilized a Gallium Arsenide laser and a silicon detector diode; the second was composed of a xenon flash lamp and a photomultiplier detector tube.

The relationship between the depolarization ratio and the mass concentration of diamond particles in the 0.01 gm/m³ to 0.5 gm/m³ was determined. Diamond …

Reliability And Surface Degradation Aspects Of Synthetic Insulator Materials For Hv Application, Satyapal S. Bhatia

Dissertations

This study is a theoretical and experimental investigation on the state of the art of synthetic insulators for outdoor high voltage transmission systems.

The surface of a polymeric material is known to be degraded by, among other things, environmental stresses such as UV, air pollutants, etc. The reliability of an insulator material is governed by the surface and other characteristics that do not drift much as a function of stresses and time.

The surface characteristics of various synthetic materials, when these materials were exposed to UV radiation in the laboratory were studied. The changes in the surface properties of these …

Reliability Of Mos Devices : Threshold Voltage Instability, Sesha Rajamani Shankar

Dissertations

A very important factor in the reliability of MOS devices is the stability of the threshold voltage. This dissertation examines the effects of positive and negative gate bias stresses at elevated temperatures on the drift in the threshold voltage of MOS field effect transistors.

Over 400 p-channel enhancement mode devices were life tested under different temperature and gate bias conditions for periods of up to 15,000 hours, and the drift in their threshold voltages studied and analyzed. It was found that under both negative and positive bias-temperature tests, the threshold voltage drifted towards more negative values, though in the negative …

Acoustical Holography By Holographic Interferometry, Amin Mohamed Hanafy

Dissertations

The ability to "see" with sound has long been an intriguing concept. It is apparent that ultrasonic energy can give an image of an object not obtainable with light or even with x-rays.

In this dissertation, a novel "three-step acoustical holographic imaging system" is described and several means for its implementation are analyzed. A novel holographic acoustic image converter, which constitutes a fundamental link in the three step imaging method was also developed. The use of optical holographic techniques to convert an arbitrary acoustic image to a visible image is conducted and resulted in the introduction of the new technique …

Sparsity And Decoupling In Load Power Flow Analysis, Kenneth Nazimek

Theses

This paper presents some recent ideas on and methods created by power engineers for the solution of the Load Flow Problem. Beginning with an analysis of the solution of large systems of linear equations, techniques employing elementary matrix operations are discussed to reduce the amount of calculations necessary to achieve repeated solutions. Recent interest in taking advantage of the characteristic sparsity of the admittance matrix is also examined. The problems of operating on and computer storage of large sparse matrices are investigated. Methods to efficiently order, store and work with large sparse matrices are discussed and demonstrated. The general acceptance …

Dynamics Of The Glucose-Insulin-Glucagon System, Joseph P. Hartmann

Theses

A computer model for the Dynamics of the Glucose-Insulin-Glucagon System has been developed for a 17.5 kg canine using the Continuous Systems Modeling Program (CSMP) for the 360 Computer System. The major body components controlling the glucose dynamics (liver, pancreas, body muscle, blood flow, and body fluid compartments) have been modeled in terms of either their production, absorption, or transport of glucose, and the concentration levels of both the hormones and substrates perfusing the body component. A set of mneumonics has also been developed to label the hundreds of constant and variable terms required to describe a complex system of …

Application Of Multilevel Control Techniques To Classes Of Distributed Parameter Plants, Frederick Donald Chichester

Dissertations

This study concerns the application of a combination of multilevel hierarchical systems analysis techniques and Pontryagin's minimum principle (multilevel control) to the problem of controlling optimally two classes of dynamic distributed parameter plants representing concentrations balances in streams, rivers and estuaries. The concentrations treated in this study are those deemed the most effective indicators of water quality, dissolved oxygen (DO) and biochemical oxygen demand (BOD).

One class of plants treated in this study consists of linear continuous distributed parameter plants represented mathematically by sets of simultaneous partial differential equations. Optimal control of a plant of this class is initiated by …

The Effects Of Optical Path Perturbations During Recording On A Reconstructed Holographic Image, Stevan Israel Feldman

Dissertations

The effects of optical path perturbations occurring during recording on the reconstructed image of a hologram are investigated. It is shown that such variations of optical path are equivalent to conditions of holographic interferometry which can be classified in three categories: 1) object motion alone, 2) film motion alone, and 3) simultaneous film and object motion; all motions are defined with respect to the stationary reference source during the recording of the hologram.

The theory concerning the effects of object motion alone on the radiance distribution of a reconstructed holographic image has already been developed by previous researchers and is …

Investigation And Optimum Design Of The Generalized Second-Order Phase-Locked Loop, William Allen Novick

Dissertations

In this dissertation, a second-order phase-locked loop (PLL) in which the loop filter contains complex zeros is investigated in both its linear and nonlinear modes of operation; prior designs used a filter containing a simple zero on the negative real axis. This "generalized" second-order PLL had been heretofore essentially unexplored.

The basic characteristics of the generalized second-order PLL operating in the linear mode including the open and closed-loop responses and the corresponding root locus were generated and compared against those of the conventional second-order PLL. As in the conventional case, the generalized second-order PLL is found to be unconditionally stable. …

An Investigation Of The Optical Absorption Properties Of Silicon As Related To Its Electrical Conductivity, Onofrio Louis Russo

Dissertations

The purpose of this study is to demonstrate the feasibility of obtaining the electrical conductivity of band gap semiconductors, by considering the absorption of radiation in the visible region. The experimental evidence confirmed predictions that the conductivities of the silicon samples are related to the horizontal displacement of energy in the absorption curves. The material used in this study was p-doped silicon, although the approach should be valid in general for either elemental or compound semiconductors.

The absorption coefficient for silicon was measured in the radiation region between 2.0 and 3.0 ev. This region above the indirect band gap (= …

Optimal Control And Identification Of Stochastic Systems Using Differential Game Theory, Harry Marvin Burbank

Dissertations

This dissertation deals with linear systems subjected to stochastic disturbances. The class of stochastic processes considered is the class of second order stochastic processes characterized by having finite continuous covariance. The properties of the covariance provide means to formulate optimization problems without the difficulties present when the covariance is not finite or continuous.

The first aspect studied was several classes of optimal control problems. The effects of the stochastic processes were approximated by the effects of its first two moments. This procedure resulted in allowing optimal system controls to be found whatever the first two moments of the stochastic input …

Design Of A Yig-Tuned Oscillator, Tien Liang Jin

Theses

A technique for designing YIG (yttrium-iron garnet) tuned transistor oscillators, tunable over the range of frequencies from 500 to 950 MHZ, is presented. The approach taken differs appreciably from that used in the design of conventional LC-tuned oscillators. One major difference is that the YIG tuning mechanism is electrically controlled. The YIG tuning element is treated as a single unit and is not resolved into an equivalent LC circuit. Instead, a direct method using reflection coefficients measured at network terminals to characterize various design stages is applied. The transistor is also characterized by reflection and transmission coefficients, i.e., S-parameters. Thus …

The Theory Of Multiple Measurements Techniques In Distributed Parameter Systems, Babajimi Claudius Okunseinde

Dissertations

A comprehensive theory of multiple measurements for the optimum on-line state estimation and parameter identification in a class of noisy, dynamic distributed systems, is developed in this study. Often in practical monitoring and control problems, accurate measurements of a critical variable are not available in a desired form or at a desired sampling rate. Rather, noisy independent measurements of related forms of the variable may be available at different sampling rates. Multiple measurements theory thus involves the optimum weighting and combination of different types of available measurements. One of the contributions of this work is the development of a unique …

Synthetically-Generated Holographic Memory System Utilizing Partially Coherent Light, William A. Barrett

Dissertations

This dissertation proposes a novel form of optical ROM for the digital computer. This memory makes use of holographic techniques because of the advantages offered by holographic memories over conventional optical ones, especially with regard to dust and scratch sensitivity.

These advantages have long been recognized by workers in the field, indeed several holographic optical memories have already been proposed.

A survey of the state of the art of digital computer memories is offered in the introductory part of the thesis. Particular emphasis is placed on optical memories. A brief review of basic holographic theory is also included for reference. …

Steady State And Dynamic Performance Of Anisotropic Reluctance Motor, S. Chandrasekhara Rao

Theses

The paper deals with a special type of reluctance motor called Anisotropic rotor reluctance motor. As the name implies, advantage is taken of the internal anisotropy of the rotor magnetic structure. Axially laminated grain oriented silicon steel is used in the rotor. This unconventional configuration of assembly of rotor laminations results in a high ratio of direct axis to quadrature axis reluctance. Compared to the conventional reluctance motor, pull out torque of more than three times and a power factor as high as in an induction motor is obtained. Several motors of ratings up to 60 HP. were built and …

Dynamics Of Interconnected Systems With Pulse Frequency Modulators, Halil Ozcan Gulcur

Dissertations

The objective of this dissertation is to study the dynamics of systems consisting of interconnections of an arbitrary number of complete-reset pulse frequency modulators (CRPFM's) and linear dynamical subsystems (in general, time-varying, lumped and/or distributed). CRPFM, which represents a generalization of several types of pulse frequency modulators (PFM's), consists of two basic components; a multi-input dynamic element, called the timing-filter (TF) and a threshold device (TD). Whenever the output of the TF reaches a given threshold value the TD generates an impulse and, at the same time, resets all the states of the TF to zero. This dissertation is devoted …

Correlation Of Drain Breakdown With Excess Noise And Other Surface-Related Phenomena In Enhancement Mosfets, Jerry J. Rij

Theses

An investigation of semiconductor surface-related phenomena has been undertaken to correlate 1/F noise with drain breakdown in P-channel enhancement MOSFET's. Increases in the intensity of drain current fluctuations at 10Hz and at 1KHz, particularly at the higher frequency, was observed following accelerated life-testing for threshold voltage drift. It was also concluded that mobile ions near the oxide-semiconductor interface produce a sharp increase in fast trapping centers. It was also found that 1/F noise intensity consistently peaked at the threshold of drain breakdown and that it steadily decreased with further increases in drain current. Of all the transistors tested, those with …

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 …

Electromagnetic Wave Propagation In Nonuniform Waveguides With Perfect Conducting Walls, Irwin Share

Dissertations

The analysis of nonuniform waveguides is formulated in terms of non-orthogonal generalized coordinates by utilizing the Hertz vector potentials and the Riemann metric tensor.

When the Hertz potential is expressible as a function of the propagation coordinate times a function of the transverse coordinates, then the nonuniform waveguide may be represented by transverse equations and a set of uncoupled nonuniform transmission lines. This decomposition facilitates studying propagation along the propagation coordinate. Sufficient conditions to achieve this decomposition are investigated. It is demonstrated that these constraints may provide guidelines for selecting a useful coordinate system to describe the nonuniform waveguide. In …

An Investigation Of The Neuromuscular Command In The Control Of Respiration, Nirmal Kumar Mishra

Dissertations

The purpose of the investigation is to study the signals involved in the respiratory system and to obtain a model for the dynamics including the activity of the phrenic nerve as the input and the transpulmonary pressure, air flow and the volume as the response.

Experiments were done on anasthetized dogs under natural breathing, with steady state response to various levels of CO2 in the inspired air, and under electrophrenic stimulation. Bipolar electrodes were used at the phrenic nerve, in the cervical region, either for recording the phrenic neurogram or for supramaximal unilateral (or bilateral) stimulation using pulse frequency modulated …

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". …

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, …

Reliability Aspects Of Semiconductor Surface Protective Coatings, Robert Edward Mcmillan

Dissertations

This research was directed towards the occurrence and im-portance of surface leakage in reverse biased semiconductor diodes and the relation of this leakage to the reliability of a device under use conditions. As a result of this study, it is possible to predict one important leakage mechanism after such back-biased diode units have been subjected to long periods of temperature and humidity. This theory is consistent with tests of commercially available units, some of which have very slight surface leakage and others very large surface leakage.

Further, the usefulness of various possible passivating coatings is critically analyzed on the basis …

Oscillations In Pulse Frequency Modulated Control Systems, Warren Joseph Guy

Dissertations

This dissertation is concerned with oscillations and their stability which occur in a control system containing two nonlinearities, separated by linear elements. Specifically the nonlinearities are Integral Pulse Frequency Modulators and the linear elements are described by ordinary differential equations which are linear. The IPFM can be modelled by a quantizer with hysteresis and many other PFM laws are related to IPFM, thus the study applies to more than just IPFM alone.

Boundaries on the system parameters are identified within which free oscillation may be possible. These boundaries give sufficient conditions for stability and necessary conditions for instability. Also since …

Correlation Of 1/F Noise With Threshold Drift In Mosfet's, John Peter Rooney

Theses

A brief review of the fundamentals of MOSFET's is given. A correlation between threshold drift and surface states is made, with a following correlation between surface states and 1/f noise. It therefore follows that MOSFET's with a high 1/f noise level will drift more than those with a low level of 1/f noise. Experiments were carried out to show this effect, but no clear cut conclusions can be drawn from the experimental work.

Concepts In Lsi Servo-Control-Electronics, Alfons Alfred Tuszynski

Dissertations

This thesis deals with the engineering aspects of control electronics. It examines modern concepts of servo-control theory in the light of recent developments in the technology of monolithic circuits. Applicational considerations are slanted towards Aerospace standards of reliability and power-consumption economy.

Conclusions drawn from the discussion of fabrication constraints and performance requirements lead to a preference for digital implementations. Yield problems on one hand and aging effects on the other greatly reduce the feasibility rating of analog arrays.

Current practice in servo-control electronics revolves around purely analog implementations, sampled-data systems and Primitive on-off arrangements. The motivation behind the status quo …

The Mechanism Of Second Breakdown In Transistors, Eugene David Fabricius

Dissertations

The purpose of this dissertation is to examine the behavior of electrons and holes in a semiconductor or diode under conditions of high current density as a function of temperature, and to relate this behavior to the phenomenon of Second Breakdown. The approach used is that of magnetohydrodynamics, the electrons and holes being treated as a plasma "gas" embedded in the dielectric of the semiconductor.

This approach is unique in the following respects:

1. This is the first attempt to explain second breakdown in terms of magnetohydrodynamics.
2. This is the first time an explanation of pinching in a solid at room …