Digital Commons Network^™

Determining The Number Of Clusters/Segments In Hierarchical Clustering/Segmentation Algorithms, Stan Salvador, Philip K. Chan

Electrical Engineering and Computer Science Faculty Publications

We investigate techniques to automatically determine the number of clusters to return from hierarchical clustering and segmentation algorithms. We propose an efficient algorithm, the L Method, that finds the "knee" in a '# of clusters vs. clustering evaluation metric' graph. Using the knee is well-known but is not a particularly well-understood method to determine the number of clusters. We explore the feasibility of this method, and attempt to determine in which situations it will and will not work.

A Neuromorphic Controller For A Distillation Column, Xiao-Hua Yu

Electrical Engineering

This paper investigates the design of a neural network based controller to control the concentration of the overhead and bottom product in the model of a distillation column. Satisfactory computer simulation results of this approach are obtained.

Pulse Train™, A Novel Digital Control Method, Applied To A Discontinuous Conduction Mode Flyback Converter, Mark Telefus, Anatoly Shteynberg, Mehdi Ferdowsi, Ali Emadi

Electrical and Computer Engineering Faculty Research & Creative Works

Pulse Train^TM, a new digital control technique for DC-DC converters is introduced and applied to a Flyback converter operating in discontinuous conduction mode (DCM). In contrast to the conventional analog control methods, the principal idea of this new algorithm is to use real time analysis. The proposed technique is appropriate for any converter operating in DCM. However, this work mainly focuses on Flyback converter. In this paper, the main mathematical concept of the new control algorithm is introduced and simulations as well as experimental results are presented.

New Full Wave Theory For Plane Wave Scattering By A Rough Dielectric Surface - The Fictitious Current Method, Byung-Tae Yoon

Dissertations

A new full wave method for scattering of plane waves from a rough dielectric surface is developed. This new theory begins by postulating a zero-order field solution which does not satisfy Maxwell's source-free field equations. The zero-order field, however, is made to satisfy Maxwell's source equations. This is done by introducing a fictitious volume current distribution. Since the original problem does not possess a volume current distribution, its introduction represents a measure of the error in the postulated zero-order solution. To improve this solution, the fictitious volume current distribution is cancelled by the introduction of a second fictitious current distribution, …

Time-Frequency Investigation Of Heart Rate Variability And Cardiovascular System Modeling Of Normal And Chronic Obstructive Pulmonary Disease (Copd) Subjects, Douglas Alan Newandee

Dissertations

A study has been designed to add insight to some questions that have not been fully investigated in the heart rate variability field and the cardiovascular regulation system in normal and Chronic Obstructive Pulmonary Disease (COPD) subjects. It explores the correlations between heart rate variability and cardiovascular regulation, which interact through complex multiple feedback and control loops. This work examines the coupling between heart rate (HR), respiration (RESP), and blood pressure (BP) via closed-loop system identification techniques in order to noninvasively assess the underlying physiology.

In the first part of the study, the applications of five different bilinear time-frequency representations …

Design And Evaluation Of Processes For Fuel Fabrication: Quarterly Progress Report #7, Georg F. Mauer

Fuels Campaign (TRP)

The seventh quarter of the project covered the following:

• Mr. Richard Silva continued the development of a simulation model with a Waelischmiller hot cell robot. Rich will continue to develop detailed 3-D process simulation models as his M.Sc. thesis project.

• Mr. Richard Silva presented a paper on hot cell robotics at the ANS student conference in Berkeley, CA.

• Concepts and Methods for Vision-Based Hot Cell Supervision and control, focusing on rule-based object recognition (Ph.D. Student Jae-Kyu Lee)

• Undergraduate student Jamil Renno, developed better control algorithms, and created simulations of pick and place actions for the hot …

Improving The Process Of Laser Retinal Eye Surgery Using Electro Static Micro Mirrors, Narashiman Chakravarthy

Theses

This thesis describes an improved system for laser eye surgery. The system incorporates hardware based image matching and MEMS micromirrors for feedback control of laser positioning on the eye. Many benefits are described in this thesis, such as nulling out eye movement, tracking laser firing history, enabling precise control of laser firing locations and preventing firing accidents. The aim of this work is to frame this improved laser surgery concept and prove the principle of various components of the system. A featured accomplishment is the modeling and simulation of a prototype microcontroller using VHDL that may be incorporated as part …

Spatio-Temporal Correlation Models For Indoor Mimo Channels, Kaustubha Raghukumar

Theses

Accurate modeling of the spatio-temporal cross-correlation between the subchannels of a multiple-input multiple-output (MIMO) channel is an important prerequisite of multi-element antenna system design. In this thesis, a new model for indoor MIMO channels is proposed, and a closed form expression for the spatio-temporal cross-correlation function is derived. This new analytical correlation expression includes many physical parameters of interest such as the angle-of-arrivals at the base station and the user, the associated angle spreads, and other parameters, in a compact form. Comparison of this model with narrowband indoor MIMO data collected at Brigham Young University exhibits the utility of the …

Low-Power Transceiver Design For Mobile Wireless Chemical Biological Sensors, Harshavardhan Reddy Sripuram

Theses

The design of a smart integrated chemical sensor system that will enhance sensor performance and compatibility to Ad hoc network architecture remains a challenge. This work involves the design of a Transceiver for a mobile chemical sensor. The transceiver design integrates all building blocks on-chip, including a low-noise amplifier with an input-matching network, a Voltage Controlled Oscillator with injection locking, Gilbert cell mixers, and a Class E Power amplifier making it as a single-chip transceiver. This proposed low power 2GHz transceiver has been designed in TSMC 0.35~lm CMOS process using Cadence electronic design automation tools. Post layout HSPICE simulation indicates …

High Resolution Wind Retrieval For Seawinds On Quikscat, Jeremy Blaine Luke

Theses and Dissertations

An algorithm has been developed that enables improved the resolution wind estimates from SeaWinds data. This thesis presents the development of three key portions of the high resolution wind retrieval algorithm: Compositing individual σ-0 measurements and Kp, Retrieved wind bias correction, and ambiguity selection for high resolution winds. The high resolution winds produced by this algorithm are expected to become a useful resource for scientists and engineers studying the ocean winds. The high resolution wind retrieval algorithm allows wind to be retrieved much closer to land than is available from the low resolution winds estimated from the same scatterometer by …

Polar Sea Ice Mapping For Seawinds, Hyrum Spencer Anderson

Theses and Dissertations

In recent years, the scientific community has expressed interest in the ability to observe global climate indicators such as polar sea ice. Advances in microwave remote sensing technology have allowed a large-scale and detailed study of sea ice characteristics. This thesis provides the analysis and development of sea ice mapping algorithms for the SeaWinds scatterometer. First, an in-depth analysis of the Remund Long (RL) algorithm for SeaWinds is performed. From this study, several improvements are made to the RL algorithm which enhance its performance. In addition, a new method for automated polar sea ice mapping is developed for the SeaWinds …

Corrosion Prediction Of Carbon Steel In Concentrated Lithium Bromide Solutions At High Temperature Using Bp Neural Network, Nai-Bao Huang, Cheng-Hao Liang

Journal of Electrochemistry

Neutral network model has been developed for the computation of corrosion rate of carbon steel in LiBr solutions.The results indicate that the model is capable of reproducing the effects of changes in alkalinity, temperatures, LiBr and Na₂MoO₄ concentrations on the rates of general corrsion and good agreement between calculated and experimental corrosion rate is obtained. The model can be used to satisfactorily predict the corrosion rate of carbon steel in different concentrations of LiBr solutions containing different inhibitors at different temperatures. It also provides a novel method for corrosion monitoring of metals used in LiBr absorption chiller.

A Field-Wise Retrieval Algorithm For Seawinds, Stephen L. Richards

Theses and Dissertations

In the spring of 1999 NASA will launch the scatterometer SeaWinds, beginning a 3 year mission to measure the ocean winds. SeaWinds is different from previous spaceborne scatterometers in that it employs a rotating pencil-beam antenna as opposed to fixed fan-beam antennas. The scanning beam provides greater coverage but causes the wind retrieval accuracy to vary across the swath. This thesis develops a filed-wise wind retrieval algorithm to improve the overall wind retrieval accuracy for use with SeaWinds data.

In order to test the field-wise wind retrieval algorithm, methods for simulating wind fields are developed. A realistic approach interpolates the …

Calibration Of And Attitude Error Estimation For A Spaceborne Scatterometer Using Measurements Over Land, Clarence J. Wilson Iii

Theses and Dissertations

The NASA Scatterometer (NSCAT) was launched August 20, 1996 aboard the National Space Development Agency of Japan's Advanced Earth Observing Spacecraft (ADEOS). NSCAT's primary mission was to measure radar backscatter over the world's oceans. These measurements are used to generate estimates of ocean wind speed and direction. Scatterometers must be calibrated before their measurements are scientifically useful. However, the calibration of NSCAT must be done in orbit. A new methodology for selecting land regions for use in extended target spaceborne scatterometer calibration is first developed. Next, a summary of the calibration technique used in this thesis is presented. While the …

Azimuth Modulation Of The Radar Backscatter At Near-Normal Incidence, Andrew D. Greenwood

Theses and Dissertations

Radar observations of the ocean surface are becoming increasingly important. Common applications are wind retrieval and global weather forecasting and characterization. Because of the common use of ocean radar measurements, it is important to understand the sensitivity of the backscatter to both radar parameters and surface parameters.

At near-normal incidence angles, it has been assumed that the radar backscatter exhibits little or no azimuth dependence (Colton, 1989). However, recent data taken by the BYU YSCAT radar system suggests that this is not the case. At an incidence angle of 10°, the YSCAT radar data shows from a fraction of a …

Studies To Improve Estimation Of The Electromagnetic Bias In Radar Altimetry, Justin Dewitt Smith

Theses and Dissertations

In May of 2000 Jason-1, a joint project between NASA and the French space agency CNES, will be launched. Its mission is to continue the highly successful gathering of data which TOPEX/Poseidon has collected since August of 1992. The main goal of Jason-1 is to achieve higher accuracy in measuring the mean sea level (MSL). In order to do so, the electromagnetic (EM) bias must be estimated more accurately because it is the largest contributing error. This thesis presents two different studies which add to the knowledge and improve estimation of the EM bias, and thus assists Jason-1 in achieving …

Evolutionary Algorithms For Beginners, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

This presentation offers a detailed introduction into the concepts and applications of evolutionary ideas in computing, adapted from genetics and evolution.

Implementing An Integrated Signaling And Power Distribution Control System For Remotely Located Devices, Andrew Stephen Hintz

Graduate Theses - Electrical and Computer Engineering

A system was designed and implemented that combined the distribution of high-current power with a digital control signal over a common conductor. Two different versions of this system were implemented. Initially, a design based on of commercially available parts was created and tested to prove that the concept of combining communications and power is valid. The resulting design was then miniaturized to show that the system might be combined onto a single integrated circuit. In the miniaturization process, some circuit blocks were redesigned to take advantage of the flexibility provided by ASIC designs. Both the proof of concept and the …

Real-Time Image Analysis Of Living Cellular-Biology Measurements Of Intelligent Chemistry, J.C. Solinsky, Scott E. Budge, P.D. Majors, B. Rex

Electrical and Computer Engineering Faculty Publications

This paper reports on the Pacific Northwest National Laboratory (PNNL) DOE Initiative in Image Science and Technology (ISAT) research, which is developing algorithms and software tool sets for remote sensing and biological applications. In particular, the PNNL ISAT work is applying these research results to the automated analysis of real-time cellular biology imagery to assist the biologist in determining the correct data collection region for the current state of a conglomerate of living cells in three-dimensional motion. The real-time computation of the typical 120 MB/sec multi-spectral data sets is executed in a Field Programmable Gate Array (FPGA) technology, which has …

Spatial And Temporal Considerations In Vehicle Path Tracking With An Emphasis On Spatial Robustness, Donald L. Cripps

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation researches the task and path management of an autonomous vehicle with Ackerman-type steering.

The task management problem was approached as a path training operation in which a human operator drives the desired path through an environment. A training trajectory is converted into a series of path segments that are driveable by the autonomous vehicle by first fitting a general path to the dataset. Next, transition segments are added to the general path to match the vehicle velocity and steering angle rate limit.

The path management problem has been approached by first deriving a kine- matic model of the …

Electromagnetic Modeling Of Saltwater Ingress In Mortar At Microwave Frequencies, Shanup Peer, R. Zoughi, K. E. Kurtis

Electrical and Computer Engineering Faculty Research & Creative Works

Corrosion of reinforcing steel is a major cause of damage and deterioration in reinforced concrete structures. Therefore, as the presence of a sufficient concentration of chloride ions can lead to the onset of corrosion in embedded steel, it is of utmost importance to be able to determine the free salt content and its distribution in these materials. Moreover, it is important to obtain this information nondestructively. Previous investigations have shown the capability of near-field microwave nondestructive evaluation methods, using open-ended rectangular waveguide probes, to evaluate many important properties of cement-based materials. In this Investigation, the temporal microwave reflection properties of …

Rapid Prototyping Of Digital Controls For Power Electronics, Antonello Monti, Enrico Santi, Roger A. Dougal, Marco Riva

Faculty Publications

The process for designing digital controls for power electronics is typically quite convoluted and affords many opportunities for errors to occur. We present here a new and complete, method for rapid prototyping of digital controls that allows rapid realization of new designs. The approach uses a collection of tools that include both software (the virtual test bed (VTB) and Matlab/Simulink) and hardware (dSpace DSP). An example application of the methodology completes the discussion.

Coding, Decoding, And Recovery Of Clock Synchronization In Digital Multiplexing System, Hansheng Wang, Xiaoyi Qin, Lieguang Zeng, Fuqin Xiong

Electrical and Computer Engineering Faculty Publications

High-speed broadband digital communication networks rely on digital multiplexing technology where clock synchronization, including processing, transmission, and recovery of the clock, is the critical technique. This paper interprets the process of clock synchronization in multiplexing systems as quantizing and coding the information of clock synchronization, interprets clock justification as timing sigma-delta modulation (TΔ-ΣM), and interprets the jitter of justification as quantization error. As a result, decreasing the quantization error is equivalent to decreasing the jitter of justification. Using this theory, the paper studies the existing jitter-reducing techniques in transmitters and receivers, presents some techniques that can decrease the quantization error …

Cellular Automata Realization Of Regular Logic, Andrzej Buller, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

This paper presents a cellular-automatic model of a reversible regular structure called Davio lattice. Regular circuits are investigated because of the requirement of future (nano-) technologies where long wires should be avoided. Reversibility is a valuable feature because it means much lower energy dissipation. A circuit is reversible if the number of its inputs equals the number of its outputs and there is a one-to-one mapping between spaces of input vectors and output vectors. It is believed that one day regular reversible structures will be implemented as nanoscale 3-dimensional chips. This paper introduces the notion of the Toffoli gate and …

Metrics And Models For Cost And Quality Of Component-Based Software, Sahra Sedigh, Arif Ghafoor, Raymond A. Paul

Electrical and Computer Engineering Faculty Research & Creative Works

Quality and risk concerns currently limit the application of commercial off-the-shelf (COTS) software components to non-critical applications. Software metrics can quantify factors contributing to the overall quality of a component-based system, and models for tradeoffs between cost and various aspects of quality can guide quality and risk management by identifying and eliminating sources of risk. This paper discusses metrics and models that can be used to alleviate quality concerns for COTS-based systems, enabling the use of COTS components in a broader range of applications.

Classification Of Radar Targets Using Invariant Features, Gregory J. Meyer

Theses and Dissertations

Automatic target recognition ATR using radar commonly relies on modeling a target as a collection of point scattering centers, Features extracted from these scattering centers for input to a target classifier may be constructed that are invariant to translation and rotation, i.e., they are independent of the position and aspect angle of the target in the radar scene. Here an iterative approach for building effective scattering center models is developed, and the shape space of these models is investigated. Experimental results are obtained for three-dimensional scattering centers compressed to nineteen-dimensional feature sets, each consisting of the singular values of the …

Assessing Classification Confidence Using A Weighted Exponential Based Technique With The Learn++ Incremental Learning Algorithm, Jeffrey T. Byorick

Theses and Dissertations

Pattern recognition problems span a broad range of applications, where each application has its own tolerance on classification error. The varying levels of risk associated with many pattern recognition applications indicate the need for a versatile algorithm with the ability to measure its own reliability. In this work, the supervised incremental learning algorithm Learn++ [1, 2], which exploits the synergistic power of an ensemble of classifiers, is further developed to add the capability of assessing its own confidence. Estimation of the true generalization performance of the classifier as well as the confidences on classification of individual data instances is investigated …

Wide Angle Achromatic Prism Beam Steering For Infrared Countermeasures Applications, Bradley D. Duncan, Philip J. Bos, Vassili Sergan

Electro-Optics and Photonics Faculty Publications

The design and analysis of achromatic doublet prisms for use in laser beam steering is presented. The geometric relationships describing the maximum steering angle are given, as are discussions of first- and second-order dispersion reduction. Infrared (IR) material alternatives and optimum IR material characteristics for wide-angle achromatic prism beam steering are also investigated. Sixteen materials in 120 different combinations have been examined to date. For midwave IR applications it is shown that the minimum dispersion currently achievable across the full 2 to 5 μm spectrum is 1.7816 mrad at an average maximum steering angle of 45 deg. This is accomplished …

Complex Low-Pass Filters, Peter Kiss, Vladimir I. Prodanov, Jack Glas

Electrical Engineering

Zero-if transceivers suffer from the imbalance of the I and Q paths. By using a complex low-pass filter topology instead of a conventional pair of real low-pass filters, this imperfection can be reduced. Both analytical and numerical analysis show that the proposed technique is significantly more robust to circuit imperfections than the traditional architecture.

Understanding Wavelet Analysis And Filters For Engineering Applications, Chethan Bangalore Parameswariah

Doctoral Dissertations

Wavelets are signal-processing tools that have been of interest due to their characteristics and properties. Clear understanding of wavelets and their properties are a key to successful applications. Many theoretical and application-oriented papers have been written. Yet the choice of a right wavelet for a given application is an ongoing quest that has not been satisfactorily answered. This research has successfully identified certain issues, and an effort has been made to provide an understanding of wavelets by studying the wavelet filters in terms of their pole-zero and magnitude-phase characteristics. The magnitude characteristics of these filters have flat responses in both …