Open Access. Powered by Scholars. Published by Universities.^{®}
 Discipline
 Keyword

 Computer algorithms (5)
 Analogtodigital converters  Design and construction  Data processing (2)
 Computeraided design (2)
 Algorithms (2)
 Electric waves (2)

 Electric current converters (1)
 Bipolar transistors  Computer simulation (1)
 Digital integrated circuits  Design and construction (1)
 Laser beams  Scattering (1)
 Limnology  Washington (State)  Coldwater Lake  Computer simulation (1)
 Electric current converters  Simulation methods (1)
 Evoked potentials (Electrophysiology) (1)
 Associative storage (1)
 Cryoelectronics (1)
 Electronic circuits  Noise (1)
 Digital  Design and construction  Data processing (1)
 Chaotic behavior in systems  Mathematical models (1)
 Digital electric filters  Design and construction  Data processing (1)
 Heuristic programming (1)
 Gate array circuits (1)
 Electric filters (1)
 Computer storage devices  Mathematical models (1)
 Kalman filtering (1)
 Henry Hagg Lake (Or.) (1)
 Hydrogeology  Oregon  Multnomah County (1)
 Bipolar transistors  Noise  Measurement (1)
 Computers  Circuits (1)
 Continuoustime filters (1)
 Groundwater flow  Oregon  Multnomah County (1)
 Computer architecture  Mathematical models (1)
Articles 1  27 of 27
FullText Articles in Engineering
Modeling And Simulation Of Bipolar Transistor At Low Temperature, Swarupa Madhav Nerurkar
Modeling And Simulation Of Bipolar Transistor At Low Temperature, Swarupa Madhav Nerurkar
Dissertations and Theses
The BICMOS technology which integrates the CMOS technology with bipolar technology has drawn considerable attention as an attractive VLSI technology because of the high speed performance and low power consumption of the BICMOS. However, continued down scaling of CMOS devices has caused increased concerns with problems such as latch up, hot carriers and short channel effect. Most of the above mentioned problems can be avoided by operating the CMOS at liquidnitrogen temperature(LNT). At lowtemperatures, the CMOS exhibits lower sub threshold leakage, higher carrier mobility (which yields improved speed performance), and a steeper logarithmic currentvoltage slope. On the other hand ...
Pattern Recognition And Erp Waveform Analysis Using Wavelet Transform, Hong Qi
Pattern Recognition And Erp Waveform Analysis Using Wavelet Transform, Hong Qi
Dissertations and Theses
Wavelet transform provides an alternative to the classical ShortTime Fourier Transform (STFT). In contrast to the STFT, which uses a single analysis window, the Wavelet Transform uses shorter windows at higher frequencies and longer windows at lower frequencies. For some particular wavelet functions, the local maxima of the wavelet transform correspond to the sharp variation points of the signal. As an application, wavelet transform is introduced to the character recognition. Local maximum of wavelet transform is used as a local feature to describe character boundary. The wavelet method performs well in the presence of noise. The maximum of wavelet transform ...
Investigation Of Solution Space Of Trees And Dags For Realization Of Combinational Logic In At 6000 Series Fpgas, Philip Ho
Dissertations and Theses
Various tree and Directed Acyclic Graph structures have been used for representation and manipulation of switching functions. Among these structures the Binary Decision DiagramJilave been the most widely used in logic synthesis. A BDD is a binary tree graph that represents the recursive execution of Shannon's expansion. A FDD is a directed function graph that represents the recursive execution of Reed Muller expansion. A family of decision diagrams for representation of Boolean function is introduced in this thesis. This family of Kronecker Functional Decision Diagrams (KFDD) includes the Binary Decision Diagrams (BDD) and Functional Decision Diagrams (FDD) as subsets ...
Vertex Ordering For A PartitioningBased Fitting Algorithm For An Epld Device, Tongjun Gao
Vertex Ordering For A PartitioningBased Fitting Algorithm For An Epld Device, Tongjun Gao
Dissertations and Theses
As the ApplicationSpecific Integrated Circuit(ASIC) technology develops to the trend of high density and modulization, the ASIC device market has been dominated gradually by the more complex Erasable Programmable Logic Devices (EPLDs) and the Field Programmable Gate Array(FPGAs) instead of the ordinally Programmable Logic Devices(PLDs). Meanwhile, the design automation system for such programmable devices has also moved from schematic entry design to high level hardware description language entry design. Usually, the whole design automation process consists of three phrases, the high level hardware description language compiler, the logic synthesis stage and the layout synthesis stage. Though the ...
Simulation Of Switched Linear Networks, Dietmar Reinhard Skowronn
Simulation Of Switched Linear Networks, Dietmar Reinhard Skowronn
Dissertations and Theses
This thesis deals with the timedomain analysis of switched linear networks and investigates inherent problems which have to be considered when analyzing this class of networks. Computer simulation requires the use of numerical methods and we focus on the transmission line modelling technique (TLM) and the numerical inverse Laplace transform. A general approach based on the onegraph modified nodal description is given which allows the formulation of circuit equations of a TLMmodelled circuit by inspection. The numerical equivalence of TLM and trapezoidal rule has been found and a proof is given. A variable step size simulator has been developed based ...
A Study Of Spiking And Relaxation Oscillations In Nd:Yag Laser Using Measured Laser Parameters, Ramesh K. Shori
A Study Of Spiking And Relaxation Oscillations In Nd:Yag Laser Using Measured Laser Parameters, Ramesh K. Shori
Dissertations and Theses
It was shown analytically and experimentally that when the cavity losses are perturbed, the output intensity experiences an amplitude modulation or becomes a regular train of spikes, with the frequency depending on both the frequency of perturbation as well as pump power. Coupled nonlinear rate equations including the cavity perturbation term, are solved numerically by a RungaKutta method using experimentallymeasured parameter values for Nd: Y AG laser. A continuously pumped Nd: Y AG laser was used to verify this theory.
Modeling Of Flow And Water Quality In Henry Hagg Lake Near Forest Grove, Oregon, Michael T. Knutson
Modeling Of Flow And Water Quality In Henry Hagg Lake Near Forest Grove, Oregon, Michael T. Knutson
Dissertations and Theses
Increased population growth in Washington County, Oregon, has helped cause the water quality of the Tualatin River to decline. Henry Hagg Lake is a storage reservoir which was built to augment summer low flows in the Tualatin River. Hagg Lake also supplies the Tualatin River Basin with both irrigation and municipal water in the summer. Using the U.S. Army Corps of Engineer's model CEQUALW2 (a twodimensional hydrodynamic and water quality model) , a model of Henry Hagg Lake was created. The model was calibrated using water quality and hydraulic data for 1990 at the Hagg Lake outflow in Scoggins ...
Water Quality Modeling Of The Tualitin River, Christopher John Berger
Water Quality Modeling Of The Tualitin River, Christopher John Berger
Dissertations and Theses
Water quality problems related to excessive algal growth, high nutrient loading, and low flows have been occurring along Oregon's Tualatin River. The Tualatin River is 86 miles long and has a drainage basin of 711 square miles. The drainage basin incorporates forest, agricultural, and urban areas. Located in the Portland metropolitan area, these problems have been acerbated by the effects of urban growth. To help analyze pollution control alternatives, a river model study, funded by the Oregon Department of Environmental Quality (DEQ}, was undertaken. An instream model of hydraulics and water quality was developed. The Corps of Engineer's ...
Automatic Tuning Of Integrated Filters Using Neural Networks, Lutz Henning Lenz
Automatic Tuning Of Integrated Filters Using Neural Networks, Lutz Henning Lenz
Dissertations and Theses
Component values of integrated filters vary considerably due to· manufacturing tolerances and environmental changes. Thus it is of major importance that the components of an integrated filter be electronically tunable. The method explored in this thesis is the transconductanceCmethod. A method of realizing higherorder filters is to use a cascade structure of secondorder filters. In this context, a method of tuning secondorder filters becomes important The research objective of this thesis is to determine if the Neural Network methodology can be used to facilitate the filter tuning process for a secondorder filter (realized via the transconductanceCmethod). Since this thesis is ...
Unified Bias Analysis Of SubspaceBased Doa Estimation Algorithms, Yang Lu
Unified Bias Analysis Of SubspaceBased Doa Estimation Algorithms, Yang Lu
Dissertations and Theses
This thesis presents the unified bias analysis of subspacebased DOA estimation algorithms in terms of physical parameters such as source separation, signal coherence, number of senors and snapshots. The analysis reveals the direct relationship between the performance of the DOA algorithms and signal measurement conditions. Insights into different algorithms are provided. Based upon previous firstorder subspace perturbations, secondorder subspace perturbations are developed which provide basis for bias analysis and unification. Simulations verifying the theoretical bias analysis are presented.
Detecting Chaotic Signals With Nonlinear Models, Qin Cai
Detecting Chaotic Signals With Nonlinear Models, Qin Cai
Dissertations and Theses
In this thesis we apply chaotic dynamic data analysis to the area of discrete time signal processing. A newly developed Hidden Filter Hidden Markov Model is introduced in detection of chaotic signals. Numerical experiments have verified that this novel nonlinear model outperforms linear AR model in detecting chaotic signals buried by noise having similar power spectra. A simple Histogram Model is proposed which can also be used to do detection on the data sets with chaotic behavior. Receiver Operating Characteristics for a variety of noise levels and model classes are reported.
A New Approach To The Optimal Filtering Of Differential Phase Measurements Of Gps Signal In The Precision Survey, Shengan Wang
A New Approach To The Optimal Filtering Of Differential Phase Measurements Of Gps Signal In The Precision Survey, Shengan Wang
Dissertations and Theses
The Global Positioning System (GPS) has become popular research and application interests in surveying and many other areas. Nowadays, the accuracy of the Differential GPS can easily reach the order of a few meters. Yet, there are still many ways to exploit the GPS system signal carrier to improve the accuracy to less than meter level. In this thesis, a new approach to improve the accuracy to less than meter level is presented while the observer is in the dynamic situation. In order to reach the submeter accuracy, we measure on the carrier phase difference (The L1 carrier frequency is ...
Predicting Seepage Of Leachate From The St. Johns Landfill To Ground And Surface Water Systems, Kevin A. Schock
Predicting Seepage Of Leachate From The St. Johns Landfill To Ground And Surface Water Systems, Kevin A. Schock
Dissertations and Theses
Determination of the vertical and horizontal groundwater hydraulic gradient within a landfill is the first step in determining the potential of groundwater contamination from the landfill leachate. The length of a study and the frequency at which measurements are recorded can greatly affect the description of the local groundwater environment. A more comprehensive analysis can be preformed for longer periods of study and greater measurement frequency. The intent of this study was to install a continuous groundwater level monitoring system around the st. Johns Landfill for a minimum study length of one year. This would allow a more thorough study ...
Performance Analysis Of A Hierarchical, CacheCoherent, Shared Memory Based, MultiProcessor System, Raman Nayyar
Performance Analysis Of A Hierarchical, CacheCoherent, Shared Memory Based, MultiProcessor System, Raman Nayyar
Dissertations and Theses
We have conducted a performance analysis of a large scale multiprocessor system based on shared buses organized in a hierarchical fashion and employing an easy to implement snoopy cache protocol. · This arrangement, named TREEBUS [ 5], presents a logical extension path for multiprocessor systems based on a single shared bus whose scalability is limited by the available system bus bandwidth [26]. The multiple, independent, hierarchical buses overcome the bus bandwidth limitation and the architecture can scale to relatively large sizes. We have developed an easy to use, reasonably accurate and computationally efficient analytic model for analyzing the performance of the memory ...
Waveform Estimation With Jitter Noise By Pseudo Symmetrical Probability Density Function, WeiDa Hao
Waveform Estimation With Jitter Noise By Pseudo Symmetrical Probability Density Function, WeiDa Hao
Dissertations and Theses
A new method for solving jitter noise in estimating high frequency waveform is proposed. It reduces the bias of the estimation in those points where all the other methods fail to achieve. It provides preliminary models for estimating percentiles in Normal, Exponential probability density function. Based on the model for Normal probability density function, a model for any probability density function is derived. The resulting percentiles, in turn, are used as estimates for the amplitude of the waveform. Simulation results show us with satisfactory accuracy.
Measurement Techniques For Noise Figure And Gain Of Bipolar Transistors, Wayne Kan Jung
Measurement Techniques For Noise Figure And Gain Of Bipolar Transistors, Wayne Kan Jung
Dissertations and Theses
First, the concepts of reflection coefficients, sparameters, Smith chart, noise figure, and available power gain will be introduced. This lays out the foundation for the presentation of techniques on measuring noise figure and gain of high speed bipolar junction transistors. Noise sources in a bipolar junction transistor and an equivalent circuit including these noise sources will be presented. The process of determining the noise parameters of a transistor will also be discussed. A Pascal program and several TEKSPICE scripts are developed to calculate the stability, available power gain, and noise figure circles. Finally, these circles are plotted on a Smith ...
Designing And Simulating A Multistage Sampling Rate Conversion System Using A Set Of Pc Programs, David Joesph Hagerty
Designing And Simulating A Multistage Sampling Rate Conversion System Using A Set Of Pc Programs, David Joesph Hagerty
Dissertations and Theses
The thesis covers a series of PC programs that we have written that will enable users to easily design FIR linear phase lowpass digital filters and multistage sampling rate conversion systems. The first program is a rewrite of the McClellanParks computer program with some slight modifications. The second program uses an algorithm proposed by Rabiner that determines the length of a lowpass digital filter. Rabiner used a formula proposed by Herrmann et al. to initially estimate the filter length in his algorithm. The formula, however, assumes unity gain. We present a modification to the formula so that the gain of ...
Gravity Sedimentation: A OneDimensional Numerical Model, Joanna Robin Karl
Gravity Sedimentation: A OneDimensional Numerical Model, Joanna Robin Karl
Dissertations and Theses
A large fraction of the current cost of wastewater treatment is from the treatment and disposal of wastewater sludge. Improved design, energy efficiency, and performance of dewatering facilities could significantly decrease transport and disposal costs. Dewatering facilities are designed based on field experience, trial and error, pilot plant testing, and/or full scale testing. Design is generally timeconsuming and expensive. A fullscale test typically consists_ of sidebyside operation of 4 to 5 fullscale dewatering units for several weeks to more than 6 months. Theoretical modeling of the physics of dewatering units such as the belt filter press, based on laboratory ...
Designing And Simulating A Multistage Sampling Rate Conversion System Using A Set Of Pc Programs, David Joseph Hagerty
Designing And Simulating A Multistage Sampling Rate Conversion System Using A Set Of Pc Programs, David Joseph Hagerty
Dissertations and Theses
The thesis covers a series of PC programs that we have written that will enable users to easily design FIR linear phase lowpass digital filters and multistage sampling rate conversion systems. The first program is a rewrite of the McClellanParks computer program with some slight modifications. The second program uses an algorithm proposed by Rabiner that determines the length of a lowpass digital filter. Rabiner used a formula proposed by Herrmann et al. to initially estimate the filter length in his algorithm. The formula, however, assumes unity gain. We present a modification to the formula so that the gain of ...
QuasiStatic Deflection Compensation Control Of Flexible Manipulator, Jingbin Feng
QuasiStatic Deflection Compensation Control Of Flexible Manipulator, Jingbin Feng
Dissertations and Theses
The growing need in industrial applications of highperformance robots has led to designs of lightweight robot arms. However the lightweight robot arm introduces accuracy and vibration problems. The classical robot design and control method based on the rigid body assumption is no longer satisfactory for the lightweight manipulators. The effects of flexibility of lightweight manipulators have been an active research area in recent years. A new approach to correct the quasistatic position and orientation error of the endeffector of a manipulator with flexible links is studied in this project. In this approach, strain gages are used to monitor the elastic ...
OneDimensional Computer Modeling Of Thermal And Water Quality Characteristics Of Coldwater Lake, Wa, David Kevin Whitaker
OneDimensional Computer Modeling Of Thermal And Water Quality Characteristics Of Coldwater Lake, Wa, David Kevin Whitaker
Dissertations and Theses
Coldwater Lake is a new lake formed when a massive mudflow down the Toutle River Valley, caused by the eruption of Mount St. Helens on May 18, 1980, blocked the natural outlet of Coldwater Creek. This research utilizes physical, biological and chemical data collected at Coldwater Lake during the sun1mers of 1989 and 1990 to calibrate and verify the onedimensional computer models CETHERMRl and CEQUALRl for Coldwater Lake. CETHERMR1 was used to simulate thermal characteristics in Coldwater Lake during the summer stratification periods of 1989 and 1990. The model was calibrated to 1989 data and was verified with 1990 data ...
A Robust High Precision Algorithm For Sinewave Parameter Estimation, Kendall Ann Rydell
A Robust High Precision Algorithm For Sinewave Parameter Estimation, Kendall Ann Rydell
Dissertations and Theses
The estimation of sinewave parameters has many practical applications in test and data processing systems. Measuring the effective bits of an analogtodigital converter and linear circuit identification are some typical examples. If a sinew ave's frequency is known, there is an established linear method to estimate the other parameters. But when none of the parameters are known (which is usually the case in practical situations), the estimation problem becomes more difficult. Traditional approaches to this task applied an iterative, sinewave curvefit algorithm. Two problems with this technique are that convergence is often slow and not always guaranteed and the ...
Smart Memory: An Inexact ContentAddressable Memory, Jack Lee
Smart Memory: An Inexact ContentAddressable Memory, Jack Lee
Dissertations and Theses
The function of a ContentAddressable Memory (CAM) is to efficiently search the information stored in the memory, by using hardware rather than software with a corresponding improvement in searching speed. This hardware allows a parallel search by matching the data stored in memory to a search key rather than sequentially searching address by address as is done in a Random Access Memory. Although existing CAMs are more efficient in finding relevant information than RAM, there are additional improvements that can be made to further improve its efficiency. For example, previous CAMs use a word parallel searching scheme that can only ...
Exact Modeling Of TimeIntervalModulated Switched Networks, Weihe Niu
Exact Modeling Of TimeIntervalModulated Switched Networks, Weihe Niu
Dissertations and Theses
The frequency response analysis of switched networks plays a very important part in designing various kinds of power converter circuits. In this thesis two frequency response techniques for analyzing switching power converters are discussed. One method provides a mathematical description which treats the converter as a periodic time varying system. A linearized small signal model is subsequently derived. The major part of the thesis concentrates on this accurate exact smallsignal technique. The derivation involves state space representation and the use of the time varying transfer function. A Fourier analysis is performed to show the relationship between the frequency response of ...
Matching Points To Lines: SonarBased Localization For The Psubot, Kevin Blythe Stanton
Matching Points To Lines: SonarBased Localization For The Psubot, Kevin Blythe Stanton
Dissertations and Theses
The PSUBOT (pronounced peaesyoubought) is an autonomous wheelchair robot for persons with certain disabilities. Its use of voice recognition and autonomous navigation enable it to carry out high level commands with little or no user assistance. We first describe the goals, constraints, and capabilities of the overall system including path planning and obstacle avoidance. We then focus on localizationthe ability of the robot to locate itself in space. Odometry, a compass, and an algorithm which matches points to lines are each employed to accomplish this task. The matching algorithm (which matches "points" to "lines") is the main contribution to this ...
Minimization Of Permuted ReedMuller Trees And ReedMuller Trees For Cellular Logic Programmable Gate Arrays, Lifei Wu
Dissertations and Theses
The new family of Field Programmable Gate Arrays, CLI 6000 from Concurrent Logic Inc realizes truly Cellular Logic. It has been mainly designed for the realization of data path architectures. However, the realizable logic functions provided by its macrocells and their limited connectivity call also for new generalpurpose logic synthesis methods. The basic cell of CLi 6000 can be programmed to realize a twoinput multiplexer ( A*B + C*B ), an AND/EXOR cell ( A*B Ea C ), or the basic 2input AND, OR and EXOR gate. This suggests to using these cells for treelike expansions. These "cellular logic" devices require ...
Novel Cylindrical Illuminator Tip For Ultraviolet Light Delivery, Hanqun Shangguan
Novel Cylindrical Illuminator Tip For Ultraviolet Light Delivery, Hanqun Shangguan
Dissertations and Theses
The design, processing, and sequential testing of a novel cylindrical diffusing optical fiber tip for ultraviolet light delivery is described. This device has been shown to uniformly(+/ 15%) illuminate angioplasty balloons, 20 mm in length, that are used in an experimental photochemotherapeutic treatment of swine intimal hyperplasia. Our experiments show that uniform diffusing tips of < 400 micron diameter can be reliably constructed for this and other interstitial applications. Modeling results indicate that this design is scalable to smaller diameters. The diffusing tips are made by stripping the protective buffer and etching away the cladding over a length of 20 mm from the fiber tip and replacing it with a thin layer of optical epoxy mixed with A/203 powder. To improve the uniformity and ease of fabrication, we have evaluated a new device configuration where the tip is etched into a modified conical shape, and the distal end face is polished and then coated with an optically opaque epoxy. This is shown to uniformly scatter  70% of the light launched into the fiber without forward transmission. To our knowledge, we are the first to use this device configuration, and we have achieved a uniform cylindrical pattern of laser energy with uniformity < ± 15% of the average value. A simple computational model suitable for the interpretation of laser energy irradiance along the bare core surface of multimode optical fiber tips is proposed and experimentally verified. The model used is based on geometrical optics and Gaussian approximation. Good agreement is obtained between the calculation and experiment. We have measured the optical properties of the tips through all the sequences of the fabrication. The performances of the diffusing tips for illuminating angioplasty balloons are then evaluated by Ultraviolet Light at 365 nm. A Ti:Sapphire Ring Laser System with a doubling crystal pumped by an argon ion laser is used to generate the wavelength in this study.