In a power system, operators maintain voltage stability through adequate reactive reserves. Maintaining and accessing an efficient allocation of reactive reserves is prohibitively complex because of reactive line losses, the variety of reactive resources, and either limited or variable reactive outputs from renewable sources. By clustering the system into smaller...
The central focus of this thesis is the design, fabrication and characterization of amorphous oxide semiconductor (AOS) thin-film transistor (TFT) current mirrors. The thin-film deposition and circuit fabrication methods used to realize zinc tin oxide (ZTO) TFT
current mirrors are addressed in order to elucidate the processing challenges for this...
The primary objective of this thesis is to develop a process for fabricating integrated circuits based on thin-film transistors (TFTs) using zinc tin oxide (ZTO) as the channel layer. ZTO, in contrast to indium- or gallium-based amorphous oxide semiconductors (AOS), is perceived to be a more commercially viable AOS choice...
The number of wind turbines and wind farms in the Pacific Northwest has increased dramatically in the past six years, which represents a significant amount of electrical generation capacity connected to the public electric grid. However, the variable nature of wind sometimes introduces excessive power, or conversely shortages, in power...
Typical power outputs of commercially available diode lasers are on the
order of 5 milliwatts. This thesis discusses the growth, processing and
fabrication of high power (lOO's of milliwatts) diode lasers. Devices were
grown by Molecular Beam Epitaxy (MBE) and by Metal Organic Chemical
Vapor Deposition (MOCVD). The MOCVD diode...
To protect the environment and save human lives, the detection of various hazardous toxins of biological or chemical origin has been a major challenge to the researchers at Oregon State University. Living fish cells can indicate the presence of a wide range of toxins by reactions such as changing color...
The influence of weather on the long range radio navigation system Loran-C was investigated. The variables analyzed over a period of 255 days were: time differences (TDs), TD signal-to-noise ratios, TD standard deviations (measured at a fixed receiver location in Corvallis, Oregon), time interval numbers (TINOs) (measured at the transmitter...
The purpose of this thesis is to apply the wavelet transform WT to
multiresolution structures for analyzing the information content of images based on
multiresolution signal decomposition of the wavelet representation. The advantage
of the wavelet transform is the fact that it uses different building blocks than the
Fourier's sines...
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...
Adjustable Speed Drive (ASD) systems are widely used in industry to effectively improve process efficiency and control. Typically, an ASD system consists of a motor with its speed controlled by a power electronics converter via varying the amplitude and frequency of the input voltage. However, several abnormal insulation failures of...
A new structure for the implementation of bit/serial adaptive IIR filter is
presented. The bit level system consists of gated full adders for the arithmetic
unit and data latches for the data path. This approach allows recursive
operation of the IIR filter to be implemented without any global
interconnections, minimal...
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...
With an increasing number of wireless applications at microwave frequencies, the frequency spectrum is becoming quite crowded. Due to this congestion, the current state of technology is leading towards upper microwave and millimeter wave spectra as they also offer other distinct advantages such as larger bandwidth and smaller component footprint....
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...
Real time indoor positioning awareness systems aim to add localization capabilities to upcoming wireless technologies that are quickly becoming an important feature for indoor environment. RF-based impulse-radio ultra-wideband (IR-UWB) is a promising technology for in-door positioning systems due to obstacle penetration capabilities, immunity to multi-path and fading, and high resolution....
The Brushless Doubly Fed Machine (BDFM) is receiving attention as a candidate for use in adjustable speed drives (ASDs) and variable speed generators (VSGs). With a large percentage of a drive or generator system's cost due to power electronics content, considerable research has been conducted to find drives in which...
Over the last decade, wind penetration in the Pacific Northwest has increased rapidly. The variable nature of this massive new resource has increased stress on the hydropower resource to the point where system limits are currently being reached. In order to cultivate continued growth of the wind energy industry both...
A Mobile Ad-hoc NETwork (MANET) is collection of wireless mobile nodes without a network infrastructure or centralized administration. Although MANETs can be used in many applications, such as mobile Internet, military communication, and disaster relief networks, a number of challenges remain. These include routing, medium access control, security, scalability, energy...
Recent developments in computing technology have generated a demand for more streamlined and effective test systems. By replacing traditional in-chassis wired interconnects with a broadcast wireless system, fault detection and error susceptibility will drastically improve, input/output capabilities will expand, and routing complexity will decrease. Ultra-wideband impulse radio's (UWB-IR) characteristic multipath-immunity...