The feasibility of utilizing acoustic imaging techniques for
improving the undersea viewing capability of small submersibles is
investigated. The limiting values of major parameters in acoustic
imaging systems are established and graphs which illustrate the
parametric relationships are presented. A series of sample calculations
illustrate how the graphs can be...
The purpose of the thesis is to design, construct,
program, and test an automatic integrated circuit test
system. The class of integrated circuits tested was restricted
to digital integrated circuits. The general concept
of testing a digital integrated circuit is based on
the truth table of that circuit. A combination...
The feasibility of using the Franz-Keldysh effect in practical
light intensity controlling devices was investigated.
Reverse-biased diodes made from CdS were implemented to obtain
high electric fields necessary for the effect. The three types of
diodes studies were: MIS, metal-semiconductor barrier, and p⁺-n
heterojunction. An expression for the change in...
This thesis develops a simplified and logical simulation model
for an amplidyne excitation system for a synchronous generator with
an automatic voltage regulator.
The non-transfer function representation using field determined
parameters including variable inductance and machine saturation
was used to reduce the computing time for the stability analysis.
The simulation...
A non-volatile electrically alterable read-only memory using
an MOS field effect transistor with a threshold voltage which depended
upon the position of ionic charges for its memory was fabricated.
The conventional silicon dioxide layer was replaced by a composite
layer consisting of thermal silicon dioxide, electron beam
evaporated aluminum oxide,...
A new, computer oriented system for automatic, in situ
monitoring of water quality is proposed which makes full and effective
use of modern computer technology. The main objective of this thesis
work was the development of the concept for in situ computer controlled
experimenting as a reasonable and effective means...
The power spectral density of the acoustic signature of
Dungeness crab was calculated by the use of digital computer.
The signal produced by the Dungeness crab was an analog signal.
Therefore a conversion of the signal from analog to digital was
necessary. This was done by sampling the acoustic signature...
The purpose of this thesis is to investigate the necessity of
transposition in the construction of overhead transmission lines.
Line currents, line voltages and line losses of both the transposed
and untransposed lines were calculated and compared for two different
voltage classes. The conventional method of symmetrical components
was used...
The purpose of this study is to investigate radiation
losses in microstrip circuits. Expressions are derived to
evaluate the radiation resistances (or conductances) for
single terminated, open and short-circuited lines. The
quality factor Q of open and short-circuited stubs is
evaluated. An analytical procedure is formulated to
evaluate the radiation...
A simulation method using a hybrid computer is developed in
this dissertation to enhance the study of wind-driven ocean circulation.
The simulation is based on the mathematical model developed by
Ekman. Pure digital simulation is not economical due to excessive
computer time required for the solution of the partial differential...
Most technological problems associated with man-machine conversations
have been solved and are well documented in both the
contemporary technical and lay literature. The major remaining
technological problem is the real time conversion of a human's vocal
uterances into a "written" phoneme sequence representing the information
content of speech. The work...
It is popular belief that the volatility of the exchange rate is due
to the balance of payments, which in turn is mainly influenced by the
balance of trade. A closed-loop dynamic economic model is proposed
to describe and analyse the effect of the international trade of a
country on...
This paper investigates the benefit of various parallel processing
architectures for a Command and Control system for the Royal
Thai Air Force. Parallel processing has been shown to be useful
for air defense and air traffic control applications. Its advantages
are examined within the constraint imposed by the available
resources...
The exponentially tapered, nonuniform transmission'
line, applied as an impedance transformer, is analyzed and
modified. The analysis develops an expression for the input
reflection coefficient that has the magnitude and phase
as distinct functions. This allows ease in comparing the
approximate and exact solutions and in developing the S-parameters for...
Recent acheivements in high speed digital integrated
circuits has prompted the system designers to search for
a practical method of inter-connecting these high speed
circuits. This paper describes the implementation of the
microstrip transmission line on a high speed digital
data bus. Transmission line and characteristic impedance,
termination with single...
The dynamics of land use in the State of Oregon are simulated
on a digital computer. The introductory chapter outlines the complex
nature of the problems facing the post-industrial society and argues
that the scientific and professional estates share in the responsibility
for public policy formulation. The second chapter .presents...
This paper is concerned with the application of
hierarchial and parallel computing structures to digital
data communications processing in a multi-access telecommunications
environment. Designs are analyzed and
evaluated in terms of data collected from remote access
tele-communications traffic and in terms of the application
to several processing problems in the...
A liquid crystal thermographic technique was developed
for application to several problems in clinical
medicine and physiology. The procedure was inexpensive,
rapid, simple, versatile and acceptable to patients.
Investigators in the past have used cholesteric liquid
crystals for thermography but their use was limited to
research in the medical field...
REGTRAN (REGister TRANsfer), a hardware description
language and SYSSIM (SYStems SIMulation), a simulator for the
system described by REGTRAN were originally developed by Edward
Pett, Jr [33] at the University of Texas at Austin. These two programs
are successfully used to simulate many digital systems of
complex nature. It is...
The question of the suitability of Walsh functions or
similar bi-valued functions used as a radar electromagnetic
carrier waveform is considered. Walsh functions are
described and effective sinusoidal steady state transfer
functions are defined for transmission elements, antenna
systems, and propagation media.
The argument is made that the unit impulse...
This report is concerned with the analysis of the effect of
finite wordlength, channel capacity and source rate in digital feedback
control of linear systems. The cases considered are (1) finite
wordlength A/D conversion, no feedback delay, ideal ROM (read
only memory) controller; (2) finite A/D wordlength (source rate),
state...
The objective of this thesis is to develop criteria for a data
acquisition system for electrical machinery capable of sampling a
signal every 0.2 msec with a desired accuracy of 0.1%. The system to
be measured includes both AC and DC voltage and current signals from
several points. The main...
CP1100/GPIB Interface is an interface between the "General
Purpose Interface Bus", which is an implementation of the Universal
Bus described in IEEE Standard 488-1975, and Unibus. This interface
enables TEKTRONIX CP1100 series controllers to operate
GPIB- compatible instruments connected to the General Purpose
Interface Bus. The designer can now incorporate...
In an attempt to provide a practical means to measure the information
processing capacity of a real-time digital processing system a
theoretical framework, the Real-Time Schemata, whose basis is a
schematic description and a measure of "useful information," is presented.
The description applies to processes that would typically be
implemented...
The purpose of this thesis is to represent and calculate unsymmetrical
secondary faults on a grounded wye-to-delta transformer
bank.
This thesis is specifically concerned with the secondary connections
often encountered in industrial installations. Faults on these
systems have not been adequately investigated.
Three types of faults are considered, namely:
1....
A procedure for displaying cursory computer analyses of time
series acoustic signals is described. The graphic presentation is
optimized for visual analysis. The results displayed represent time
series signals and/or Power Spectral Density estimates.
Both hardware and software components of the procedure are
described and compared with current methods. Suggestions...
A model of a squirrel cage induction machine, d.c.-
link power supply and centrifugal pump is developed and
used in the design and evaluation of a perturbation feedback
control system for a sewage pumping station. A comparison
of the simulation model of the induction machine
and a laboratory machine to...
It has been established that bilinear models
occur frequently in nature and offer some important
advantages from the standpoint. of controllability,
optimization and modeling. The estimation of
bilinear systeim models from the Measurements
of input-output data are discussed. In the
first approach a parametric model of a discrete-time
linear system...
Bilinear systems due to their variable structure properties
offer more versatility in modelling of nonlinear processes than
linear systems.
The state estimation problem for a continuous bilinear system
with a continuous observation model is studied and the results are
extended to the case where the observations are of a discrete...
A compartmental model of the immune system is simulated.
Chapter I discusses the importance of such a
model, reviews past immune system models, and summaries
the immunological theory the model is based upon. In
Chapter II, the compartmental representation of the immune
system is developed from immunological and physiological
theory....
In this dissertation, a new computational method for equality constrained nonlinear programming is developed. Specifically, problems of minimizing a nonlinear objective function f(x) subject to constraints h(x) = 0, where f is a scalar valued, x is an n-vector and h is a m-vector with m < n is considered....
This fault detection scheme is based on sampling the instantaneous
phase voltages and checking their sum and magnitude against
a specified voltage. Faults on the system cause unbalances and
distortion of the phase voltages and currents. The currents and
voltages change in magnitude and/or phase position with respect to
the...
A new modular loop architecture for distributed computer
systems has been developed and compared with three of the most
prominent loop architectures currently being used. The competitive
loops with which the new architecture has been compared
are the Newhall loop, the Pierce loop and the DLCN loop. The four
loop...
The effect of the mutual inductances between the rotor coils of a synchronous machine on its defined reactances and predicted transients are investigated. Two linearized models of the machine are considered. One uses the Laplace-Transform approach, with minimum number of assumptions on the inter-coil couplings, in developing a model for...
Bilinear systems, encountered in many important applications of engineering, biological and socio-economic systems, represent the logical step in complexity between the linear systems which are inadequate in the modeling of various dynamic processes and the difficult realm of nonlinear systems. This dissertation studies two functional expansions in bilinear system analysis-...
Decimation and interpolation is shown to be an effective technique
for reducing the storage requirements for bandlimited time series.
Interpolation and decimation is theoretically developed using z-transform
theory and graphically interperted. A sequence of data acquired by sampling
a sonar signal is used to demonstrate the effects of decimation. Using...
With the advent of LSI, iterative forms of realization
of digital systems are becoming increasingly popular with
system designers. Many problems occurring in digital computer
design render themselves suitable for iterative
realization. These include adders, arithmetic logic units,
coding and decoding circuits and so on. Fault-free functioning
of such systems...
As a significant class of nonlinear systems, bilinear systems (BLS) are extensively developed in the past years. In addition to their advantages over linear systems which are often not adequate to represent accurately many control processes, the BLS are particularly appealing in modeling biological systems in which parametric controls are...
The purpose of this research is to develop methods to
translate a certain machine independent intermediate
language (IML) to efficient horizontal microprograms for a
class of microprogrammable machines. This IML has been
developed by Malik (12) and is compiled directly from a
high level microprogramming language used to implement a...
This thesis presents work done to verify the accuracy of a
heuristic method for computing availability percentiles for
cascaded independent systems. Previous work has provided a model
for a single line that will be used as the basis for a simulation
of cascaded and parallel systems of lines. The simulation...
A variational integral method in the Fourier transform domain is
used to calculate the characteristic normal mode parameters of a coupled
pair of nonsymmetrical microstrip transmission lines in an inhomogenous
dielectric medium under quasi-TEM conditions. These together with the
theory of such structures are used to show that ideal directional...
The purpose of this research is to design a high level language
(HLL) suitable for microprogramming. A top down design technique has
been adopted which makes the language design process simple and
accurate.
The primitive operations of a high level language for producing
emulators is shown to include special purpose...
An important step in the design of digital networks lies in the derivation of the switching formulas which describe the combinational logic networks in the system. In most large systems the number of gates and the number of connections are major factors that affect the cost of the system. An...
An advanced forward 'area tactical radar network, now under
conceptual development by the Air Force Electronic Systems Division,
can be viewed as a novel form of computer network but with
other unique problems resulting from the specialized nature of the
application. The proposed network will link together a number of...
The order of the practical system (e.g. nuclear power
plants, electrical power network and chemical plant) is
quite large. However, there are many limitations in computing
facilities for the large system. Because of these
limitations, it is often necessary to reduce the order of
the large system using an approximation....
The suitability of discrete least-squares optimal (Wiener) filters
for deconvolution of tone-burst waveforms is studied. It is shown
that: (1) such waveforms are not well suited to these filters without
preprocessing, (2) the use of exponential weighting results in a significant
improvement in filter performance and (3) that "phase-unwrapping"
in...
A simple approach to developing approximate analytical
performance models for complex systems (such as distributed
processing systems or computer networks) is presented.
The approach is applicable in cases where measurement
or simulation data describing system performance are
available but the system is too complex for exact analytical
models to be...
An application of the theory of conditionally Gaussian random
processes to filtering and stochastic control problems is presented
here. The results due to Liptser and Shiryayev are proved to hold
in the multidimensional case under somewhat relaxed conditions,
when compared to the original ones. Such a generalization is required
from...
FISHNET (Facilities Integrated in a Shared Habitat) is a communication subnet architecture utilizing a hybrid application of point-topoint and broadcast communications to achieve a high degree of network performance. This objective is achieved through utilizing a dual bus structure: a data bus and a control bus. The data bus consists...
Development of a suitable thin-film technology has stimulated research in, and production of, a.c. thin film electroluminescent (ACTFEL) devices. The aim of this thesis is to provide a better understanding of the physical processes associated with the device characteristics
of such ACTFEL devices. The unique phenomena exhibited by these devices...
The problem of synchronization arises in the interaction among
digital systems not sharing a common clock reference. The reliability of synchronizers is related to metastable operation of
bistable elements. Because of its subtle nature, the phenomenon
until recently was not widely researched. However, the literature
now contains a sound theoretical...
The electrical and optical properties of semi-insulating, epitaxial and ion-implanted GaAs and InP have been characterized and analyzed. Electron and hole traps in semi-insulating GaAs and InP, with activation energies ΔE[subscript T] ranging from 0.16 ± 0.01 to 0.98 ± 0.01 eV, have been detected and characterized by Photo-Induced Current...
The general expressions for finding the network functions, e.g.,
the immittance and the scattering parameters, of a general, uniformly
coupled n-line structure in an inhomogeneous medium are derived in
terms of the normal mode parameters of the system. These are used to
compute or to derive the explicit expressions for...
Ever-increasing size, complexity and operation costs in modern
power systems have stimulated the intensive study of an optimal
Load Shedding and Generator Rescheduling (LSGR) strategy in the
sense of a secure and economic system operation.
The conventional approach to LSGR has been based on the application of LP (Linear Programming)...
Regular structures such as PLA's are very
important to reduce VLSI design time. Interest in CAD
tools such as a practical reducing PLA generator is high.
This dissertation presents PRONTO as a practical, near-optimal
product term reduction method, whose general
heuristic approach consists of the following four steps.
First, select...
Accurate and efficient computational methods to evaluate the
quasi-TEM parameters of various planar structures such as microstrips,
coplanar lines and coplanar waveguides are developed. The characteristic
parameters of all these structures which are used extensively
in microwave integrated circuits for applications as transmission
lines and other circuit elements are computed...
The problem of optimization of stochastic dynamic systems with
random coefficients is discussed. Systems with both Wiener processes and uncertain random-process disturbances are dealt with in
this dissertation, and these include certain bilinear stochastic
systems. It is the purpose of this thesis to study the optimal control and, to some...
A new approximation technique to a certain class of nonlinear
filtering problems is considered in this dissertation. The method is
based on an approximation of nonlinear, partially-observable systems
by a stochastic control problem with fully observable state. The
filter development proceeds from the assumption that the
unobservables are conditionally Gaussian...
In microwave network analysis, proper matching of the measurement system is necessary to prevent measurement errors and provide a
proper terminating impedance for the device-under-test. To obtain
this matching, a buffer amplifier is often used in the first stage of
the network analyzer.
This study describes the design and analysis...
Local computer networks are being installed in diverse application areas. Many of the networks employ a distributed control scheme, which has advantages in performance and reliability over a centralized one. However, distribution of control increases the difficulty in locating faulty hardware elements. Consequently, advantages may not be fully realized unless...
The electrical properties of ion-implanted GaAs FET channels
are investigated by two methods. First, the channel current (I) as
a function of voltage (V) is examined at different temperatures and
using different voltage ramp rates. The standard FET I-V curve,
which can be observed on a commercial curve tracer, is...
This thesis presents a simulation technique for the
post-detection of a point-source trajectory in an
isotropic, stationary random medium. The two-dimensional
source location is estimated from spatially correlated
angle-of-arrival data which are collected simultaneously at
two sensor positions. We assume that the data are collected
at discrete, constant time intervals...
Frequency domain design of deconvolution filters is
studied using Fast Fourier Transform. Filters for both the
spike and the Gaussian reflector wavelet are obtained. True
deconvolution filters are infinitely long IIR filters,
and frequency domain analysis is an effective way of
finding its optimum finite length approximation for an
arbitary...
This paper corrects an apparent deficiency in the published
information concerning Hardware Description Languages (HDLs) by
introducing and discussing an approach for selecting an HDL for
use in a design project. Although three classes of HDLs are discussed
in this paper, High-Level Languages (HLLs), General Purpose
Simulation Languages (GPSLs) and...
Linear phase variable filters that are obtained with a frequency transformation of the form cos(ω) = P(cos(W)) were analyzed, where P is a finite degree polynomial, ω is the prototype frequency and W is the transformed filter frequency. A new transformation of third order is proposed. The new variable filter...
The scope of this project was to build a high
energy impulse generator to be used for educational
and research purposes, such as small scale modeling
of lightning and switching surges or small scale
simulation of an electromagnetic pulse (EMP).
A one-stage impulse generator was designed to
deliver a voltage...
The U.S. Air Force models many naturally occurring
phenomena. To validate such models, an automated data
collection system is used. Since validation is dependent
upon correct data, an inexpensive method to detect
erroneous data was investigated. The method uses a Wiener
filter to predict values one sample in advance. If...
A compartmental model of lymphocyte circulation
through a lymphnode is derived and simulated. The
purpose of the model is to analyze experimental data and
in turn design experimental plans from the analysis in
order to obtain sufficient data for the organ-distributed
immune response. The model will be used to predict...
Mathematical models for the doubly-fed machine are
presented. The properties of the machine with rotor excitation as supplied by a power converter with voltage
source character are reviewed. The peculiar torque-speed
characteristic of the machine in this operating mode and
its effect on the stability of the machine are presented....
A microprogramming teaching tool was designed and implemented. This tool was based on the Am 2900 bitslice microprocessor family. It provides tools for understanding software development for a simple bitslice microprocessor.
Two-way transmission of data on broadband community cable television systems is considered in this thesis. A discussion of the data transmission environment is presented which attempts to characterize the channel noise and interference which degrades data transmission performance. The analysis considers channel degradation resulting from additive gaussian noise and various...
The B lymphocyte is the immune cell responsible
for the production of antibodies. It has receptor
molecules on its surface which bind to a molecule known
as an antigen. The antigen either stimulates the cell
to produce antibodies or tolerizes it so that it is
unable to produce antibodies.
It...
In this research, a novel shunt compensation scheme
design procedure is developed for unbalanced, untransposed
n-phase transmission lines. The main function of the
scheme is to reduce the effect of the capacitive coupling
on untransposed transmission lines to levels where successful
single-pole switching is assured. The analysis procedure
is carried...
The photoresponse behavior of semi-insulating GaAs is
investigated. The photocarrier lifetime is discussed and
the influence of surface and contact recombination is
taken into account. Photocurrent-voltage characteristics
have been measured and a mechanism for the gain in terms
of space charge amplification and avalanching is suggested.
The influence of deep...
A design style is presented for a self-synchronized,
multiple input change, asynchronous state machine which
processes input changes at a speed limited only by the
required machine behavior and implementation technology.
This state machine will operate at this ultimate speed
because of a new asynchronous delay element with unequal
rising...
Control algorithms for accurate and fast moving robots require the use of the complete dynamic model of the robot. The complete dynamic model takes into account the nonlinearity and coupling terms of the whole structure. The time of computing the dynamic equations determines whether they are usable in practical applications....
The rapid development of semiconductor technology and the increasing complexity of VLSI chips have prompted both the industry and the
academic community alike to take an indepth look at the VLSI design
problem. Many design methodologies have been proposed and associated
computer-aided tools developed. This thesis is a study of...
PRONTO is a direct, one-pass heuristic method designed
to shrink the size of reducible programmable logic
arrays. Several people have contributed to the design,
and translation to a computer program, of this attempt to
produce a good solution quickly. This thesis discusses
efforts to improve PRONTO's implementation in order to...
The synchronous machine is an essential component of a power
system and determination of its parameters accurately is an
important task in securing adequate modes of operation through
certain control strategies. An estimation technique based on the
Powell algorithm was evaluated for the identification of these
parameters on the basis...
An observability problem for both deterministic and stochastic
systems is studied here.
Deterministic observability is a determination of whether every
state of the system is connected to the observation mechanism and how
it is connected, if connected. On the other hand, stochastic
observability discusses the "tightness" of the connection in...
A DC-to-DC power converter was designed on the
basis of pulse-area modulation which is applied to a
series-resonant circuit with internal frequency of 10 Khz
The series-resonant circuit was placed directly in the
energy path which provides a means for the thyristors to
be naturally commutated.
The design was tested...
Team pursuit-evasion games are studied here with one performance
index for the team as a unit in competition with one common opponent.
Particular structures of team games are discussed after a brief introduction
of the two-player differential games. The classical calculus
of variations is used to derive the feedback strategies...
An analytical expression is derived which allows the
bulk minority carrier recombination lifetime, t, and the
surface recombination velocity, S, to be extracted from a
single noncontact photoconductivity decay (PCD) measurement. This analytical expression is rather complex, but
can be reduced to a first order approximation. The first
order approximation...
The purpose of the thesis is to synthesize the major results of a continuous
research effort directed toward new applications of high speed sampling in general and Electrooptic Sampling in particular.
Equivalent time sampling of repetitive high speed signals continues to provide significant performance enhancements for present and future generations...
An important task of a Variable Speed Generation (VSG)
system is the capability to maintain and control the terminal
voltage at some desired value as determined by the
reactive power dispatch strategy.The main objective is to
design a sub-optimal fixed-parameter controller in the
sense that constraints with respect to practical...
Existing pattern recognition and classification
algorithms in computer vision require vast amounts of
computations on input data. As a result, memory access time
is a critical parameter in system performance. Tremendous
parallelism in structure and algorithm is required for the
system to operate in real-time. A preprocessing structure
for qualitative...
In order to analyze the accuracy of the navigation system LORAN-C, we have collected time - difference (TD) data from the U.S. west coast chain (9940) at a fixed receiver location (Corvallis, Oregon). The analysis of the TD data shows an unexpected high correlation between the TDs as well as...
This dissertation demonstrates the utility of the
Instruction Set Processor Specification (ISPS) in a design
environment. Although ISPS supports a wide range of
applications in the areas of architecture evaluation and
certification, design automation, software generation and
fault simulation, the .emphasis in this dissertation is
focused on using it in...