This work describes the development of an accurate, low-cost, expandable and wearable health and activity monitoring platform. Wearable monitors used to track physical activity are becoming an increasingly popular and effective way to combat our dangerously sedentary lifestyles. Unfortunately most existing wearable solutions are either costly, inaccurate or cumbersome. The...
A procedure for automating the design and layout of analog-to-digital converters (ADCs) is presented. This procedure makes use of the existing synthesis and place-and-route tools that are common in digital circuit design. A method for adding rudimentary analog cells to the standard library is described, allowing the designer to synthesize...
The aim of the research undertaken for this thesis was to develop a new high-performance amorphous oxide semiconductor (AOS) for use as a channel layer in a thin-film transistor (TFT). AOS TFTs offer higher electron mobility than the established amorphous silicon based technology. A new channel material comprised of aluminum...
New amplifier architectures are presented using non-traditional methods of biasing. Time-based dynamic biasing and signal-based dynamic biasing are discussed in the context of new architectures. This includes a new form of ring amplification with a dynamic deadzone, allowing for a structure whose coarse path does not consume static power.
Recent publications show that successive approximation register (SAR) analog to digital converters (ADC) are capable of achieving high efficiency over other ADC topologies. Furthermore, techniques have been adopted to process signals with low activity periods, such as biomedical and industrial sensors. Prior work used least- significant bit first quantization (LSBFQ)...
The primary focus of this thesis is modifying the comprehensive depletion-mode model and extending its applicability to p-channel thin-film transistor (TFT) behavior and subthreshold (subpinchoff) operation. The comprehensive depletion-mode model accurately describes depletion-mode TFT behavior and establishes a set of equations, different from those obtained from square-law theory, which can...
Indoor positioning systems can be used for many applications such as indoor navigation,emergence response, asset monitoring, and shopper assistance. Due to the weak received signal and multipath reflection, the global positioning system (GPS) generally does not work in indoor environments. There are a variety of radio frequency (RF) signals and...
Time-domain data conversion has recently drawn increased research attention for its highly digital nature in favor of process technology scaling. Also, as the time information being carried by binary voltage, time-domain operation is much less sensitive to voltage noise compared to conventional voltage domain operation. However, for analog-to-digital converter (ADC)...
The focus of this thesis is developing materials for thin-film transistors (TFTs). Cu₃SbS₄ is explored as p-channel layer. Cu₃SbS₄ TFTs show p-type, depletion-mode behavior with a small amount of gate-controlled modulation of the channel conductance. This behavior is consistent with Hall measurements indicating a mobility of 17 cm²V⁻¹s⁻¹ and hole...
In recent years, simulated laboratory experiences have become more prevalent in educational curricula. These simulations, called virtual labs, can enable learning in ways that are not limited by physical constraints. The development of virtual labs is often ad hoc, resulting in unnecessary, repetitive work. The purpose of this thesis is...
The primary objective of a grid is to maintain a balance between generation and load. If these quantities are not in balance with each other, severe damages such as voltage fluctuations, low power quality, power outages or even cascaded blackouts may occur. Hence one of the primary factors that holds...
Power generation has been an ever growing exigency since the invention of electric power. The world is gradually inching away from conventional generation toward renewable generation. Advancements in renewable energy generation have been at a steady positive pace over the past few decades with different resources developing to be feasible...
In this paper, we propose a credit-based resource allocation technique for dynamic spectrum access (DSA) systems that is robust against malicious and selfi sh behaviors and ensures good overall system fairness performance while also allowing spectrum users to achieve high amounts of service. We also propose a new objective function...
Interest in renewable energy is on the rise, in both grid-connected operations and research projects. Major types of renewable energy include: wind, solar, wave, tidal, biomass, and geothermal. The majority are variable, non-dispatchable sources, which can have a negative impact on reserve requirements. This study focused on determining the optimal...
Nowadays, needs for wideband and high accuracy analog-to-digital converter are increasing rapidly in manifold applications such as wireless communication, digital video and other consumer electronics. Besides, low power consumption is required to have longer battery life in portable systems. CMOS technology scaling and innovative modulator topology make the implementation much...
The research presented herein represents an effort to combine the ultra-smooth surface of an amorphous metal thin film (AMTF) with a solution-processed dielectric synthesized via prompt inorganic condensation (PIC). Analysis of dielectric film quality is carried out via electrical measurements of metal-insulator-metal (MIM) diodes. Anneals at 500 and 700 °C...
Gibbs sampling method is an important tool used in parameter estimation for many probabilistic models. Specifically, for many scenarios, it is difficult to generate high-dimensional data samples from its joint distribution. The Gibbs sampling provides a way to draw high-dimensional data via the conditional distributions which are typically easier to...
Scaling the supply voltage into the sub/near-threshold domain is one of the most effective methods for improving the energy efficiency of next-generation electronic microsystems. Unfortunately, the relationship between low-voltage operation and radiation-induced soft error rate is not widely known, as little research has been previously performed and reported for soft-error...
In modern digital communication systems, error correction codes (ECC) are widely used and play an important role. The main effect of ECCs is to reduce the transmission error caused by channel noise, thereby protecting data and increasing the quality of information transmission. In addition, high spectral efficiency is desired in...
The addition of thin-film alloy magnetic materials to integrated circuit processing enables a number of novel monolithic circuits. Examples include fully integrated magnetic field sensors, signal and power galvanic isolation circuits, and power supplies on chip (PwrSoC). There are several benefits to integrating these traditionally off-chip devices, including improved manufacturability,...
We consider the problem of finding unknown patterns that are recurring across multiple sets. For example, finding multiple objects that are present in multiple images or a short DNA code that is repeated across multiple DNA sequences. We first consider a simple problem of finding a single unknown pattern in...
Renewable energy, particularly wind power, has increased dramatically over the past two decades. In the Pacific Northwest, the power system has accommodated a large amount of new wind power. The variability of wind power has introduced many challenges, requiring additional reserve generation to be available to maintain system stability. The...
This dissertation addresses the problem of recognizing human activities in videos. Our focus is on activities with stochastic structure, where the activities are characterized by variable space-time arrangements of actions, and conducted by a variable number of actors. These activities occur frequently in sports and surveillance videos. They may appear...
As computation power continues to grow, the demand for data transfer bandwidth is also rising. This is reflected in the increasing data-rate of high-speed links. However, the increase in data-rate is sustainable only if the I/O energy efficiency improves as well. This dissertation explores several techniques to enable high-speed links...
The release of the IEEE802.15.6 standard has led to increased interest in low-power technologies for wireless body-area-networks (WBANs). The power dissipation, supply voltage, and die area are some of the most important criteria for successful WBAN implementations. Digital-intensive RX architectures can potentially result in sub-1V operation with significant reductions in...
Energy consumption is one of the primary bottlenecks to both large and small scale modern compute platforms. Reducing the operating voltage of digital circuits to voltages where the supply voltage is near or below the threshold of the transistors has recently gained attention as a method to reduce the energy...
Current cadmium telluride and copper indium gallium diselenide thin-film solar cells
(TFSCs) utilize thick absorbers (2 - 4 μm). For efficient carrier extraction in these TFSCs,
the absorber layer requires high carrier mobilities and a long minority carrier lifetime, which
necessitates the use of a high purity, defect-free thin film....
We studied the problem of resource allocation in large scale distributed applications such as Online Social Networks (OSN) and Cloud Computing. In such settings, resource allocation schemes need to efficient as well as adaptive to the time-varying environments. The abstract resource allocation problem concerns with how to optimally use resources...
Continues-Time (CT) Delta-Sigma (ΔΣ) Analog-to-Digital Converters (ADCs) have one important constrain, namely the excess loop delay. Most previous excess lop delay compensation methods need to know the exact value of the excess loop delay in advance. However, the value of the excess loop delay is a uniformly distribution random variable....
VCO-based ADCs have recently emerged as attractive alternative to conventional DeltaSigma (ΔΣ) modulator architectures. Few salient features of a VCObased ADC are: 1) the quantization noise is 1st order noise shaped, 2) it is an open loop architecture, and, 3) its implementation is mostly digital in nature. Hence, they are...
Sensors find a variety of applications in portable electronics, automotive and biomedical solutions. The demand for low power and high dynamic range makes the design of digital sensor readout circuits quite challenging. Traditionally, these circuits are realized using amplifiers with passive feedback or precision analog comparators which are power hungry...
The potential for electric energy generation from ocean waves is substantial and much research is being conducted on the conversion process as a renewable, grid-connected, power source. Some of the same attributes that make wave energy harvesting attractive as a grid-connected source also make it attractive as a remote, or...
IC designers are continuously facing the challenges from reduced CMOS feature sizes and supply voltages. ADCs that deliver satisfactory resolutions/speeds while utilizing the state-of-the-art technologies to save power are in high demand. The analog circuits are more and more assisted by various digital calibration techniques to get boosted performances. This...
Amorphous metal thin films (AMTFs) are of potential use for metal-insulator-metal (MIM) tunnel diode applications due to their ultra-smooth surfaces, a consequence of their amorphous microstructure. The objective of this thesis is to design a thermally-stable AMTF capable of maintaining MIM tunnel diode performance after a post-deposition anneal in excess...
Due to the wide applications of inkjet printers in industry and our daily life, characterization of liquid droplets from inkjet printers, particularly the behaviors of the impact and diffusion of the droplets on the surface of and inside porous medium is of great interest. One conventional characterization method uses high-speed...
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 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 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...
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...
Spintronics is an emerging field of research dealing with devices that can potentially exploit the additional degree of freedom provided by the electron spin along with or instead of the conventional electronic charge. One of the most promising aspects of spintronics is the potential use of magnetostatic spin waves as...
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...
In advanced integrated circuit (IC) processes, the metal fill inserted to meet foundry imposed density requirements degrades the performance of interconnects and passive components which ultimately affects the overall circuit performance. Accounting for this degradation through electromagnetic and equivalent circuit modeling is becoming a critical aspect of IC design. However,...
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...
Flexible electronics processing techniques were applied to integrate a glucose sensor with a hormone-delivery catheter in order to create a cheap and minimally invasive method for patients with type 1 diabetes to continually monitor and control their blood sugar levels. Ultimately, this work intends to move toward the development of...
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...
The broadband wireless interference in a computer platform is resulted by multiple electro-magnetic emission sources. This non-Gaussian interference is proved to be double-sided K-distributed in previous research. With the limitation of transmission power and dimension of the device, interference mitigation is an efficient way to improve received signal bit error...
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...
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...
Linear wireless sensor networks (LWSN) are special class of wireless sensor networks where sensor nodes are deployed in a straight line. Monitoring industrial pipelines, railroads, tunnels, power lines, and borders are applications of LWSNs. Wireless sensors are tiny devices with limited energy resources; therefore, efficient energy routing in LWSNs is...
Wave energy converter (WEC) devices are complicated systems containing hydrodynamic, mechanical, and electrical elements. WEC design efforts are primarily focused in the time-domain, using frequency-based energy analyses and numerical problem solving approaches that are staples in hydrodynamic design efforts to form the basic information set used in these time-domain development...
Incremental ADCs (IADCs) have many advantages for low-frequency high-accuracy data conversion—they are easy to multiplex between channels, need simpler digital decimation filter, and allow extended counting with a Nyquist-rate ADC. A single-loop incremental ADC was designed and fabricated in 90 nm for a biosensor interface circuit. It incorporates one integrator,...
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...
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,...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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....
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...
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...
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...
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...
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...
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-...
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...
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...
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...
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...
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...
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....
The Focused Ion Beam (FIB) tool is a versatile instrument for nano-machining in
circuit editing. Circuit editing is one of the most important steps in the design of an
electronic circuit on a chip. Circuit editing can be improved by imaging of silicon
plates and analyzing the resultant images. However...
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....
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...
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 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...
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...
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...
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...
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....
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...
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...
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...
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...
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...
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...
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...