Engineering Commons^™

Adaptive Notch Filter, Yuchen Huang

Dissertations and Theses

The thesis presents a new adaptive notch filter (ANF) algorithm that is more accurate and efficient and has a faster convergent rate than previous ANF algorithms. In 1985, Nehorai designed an infinite impulse response (UR) ANF algorithm that has many advantages over previous ANF algorithms. It requires a minimal number of parameters with constrained poles and zeros. It has higher stability and sharper notches than any ANF algorithm until now. Because of the special filter structure and the recursive prediction error (RPE) method, however, the algorithm is very sensitive to the initial estimate of the filter coefficient and its covariance. …

Applications Of Object Database Technology In Thermodynamics And Materials Science, R Venkatesh, David Hansen, David Maier, James T. Stanley Ii

Faculty Publications - Department of Electrical Engineering and Computer Science

Over the last few decades there has been a continual development of computer programs and databases directed at storage and manipulation of scientific data. The data these programs manipulate are typically kept in a proprietary format with little thought given to portability, upgrading or interfacing with other software. Hence, there is an inability to share data across programs of between data sources. We believe that many of the difficulties with sharing scientific data and building on previous computational efforts result from the incompatibility of programs and data in the scientific domain. We are involved in exploring an alternative data management …

Gravity And Electromagnetism In Noncommutative Geometry, Giovanni Landi, Nguyen Ai Viet, Kameshwar C. Wali

Physics - All Scholarship

We present a unified description of gravity and electromagnetism in the framework of a Z 2 non-commutative differential calculus. It can be considered as a “discrete version” of Kaluza-Klein theory, where the fifth continuous dimension is replaced by two discrete points. We derive an action which coincides with the dimensionally reduced one of the ordinary Kaluza-Klein theory.

Coping With The Risk Of Cancer In Children Living Near Power Lines, Eileen N. Abt

RISK: Health, Safety & Environment (1990-2002)

Ms. Abt briefly summarizes evidence linking power lines with a possible increase in risk of childhood cancer. She also recounts how, although many experts remain skeptical of causality, public fears, whether or not warranted, have themselves created serious problems. Finally, she proposes ways to address those problems.

Scheduling Of Unstructured Communication On The Intel Ipsc/860, Jhy-Chun Wang, Sanjay Ranka

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

In this paper we present several algorithms for decomposing all-to-many personalized communication into a set of disjoint partial permutations. These partial permutations avoid node contention as well as link contention. We discuss the theoretical complexity of these algorithms and study their effectiveness both from the view of static scheduling and from runtime scheduling. Experimental results for our algorithms are presented on the iPSC/860.

Block Qpsk Modulation Codes With Two Levels Of Error Protection, Robert H. Morelos-Zaragoza, Shu Lin

Faculty Publications

A class of block QPSK modulation codes for unequal error protection (UEP) is presented. These codes are particularly suitable either for broadcast channels or for communication systems where parts of the information messages are more important than others. An example of the latter is coded speech transmission. Not much is known on the application of block UEP codes in combined coding and modulation schemes. We exhibit a method to combine binary linear UEP (LUEP) block codes of even length, using a Gray mapping, with a QPSK signal set to construct efficient block QPSK modulation codes with nonuniform error protection capabilities …

On A Class Of Optimal Nonbinary Linear Unequal-Error-Protection Codes For Two Sets Of Messages, Robert H. Morelos-Zaragoza, Shu Lin

Faculty Publications

Several authors have addressed the problem of designing good linear unequal error protection (LUEP) codes. However, very little is known about good nonbinary LUEP codes. We present a class of optimal nonbinary LUEP codes for two different sets of messages. By combining t-error-correcting ReedSolomon (RS) codes and shortened nonbinary Hamming codes, we obtain nonbinary LUEP codes that protect one set of messages against any t or fewer symbol errors and the remaining set of messages against any single symbol error. For t ≥ 2, we show that these codes are optimal in the sense of achieving the Hamming lower bound …

Journal Of Engineering Education Round Table: Reflections On The Grinter Report, James G. Harris, Eugene M. Deloatch, William R. Grogan, Irene C. Peden, John R. Whinnery

Electrical Engineering

The Round Table is a new presentation format for the Journal of Engineering Education. The purpose of the Round Table is to present the comments of several distinguished individuals about a topic as well as their responses to the comments offered by their colleagues. For the initial Journal of Engineering Education Round Table we asked for reflections about the Grinter Report, published in September 1955.

After a brief introduction to the topic of discussion, the invited participants present their views, and, then, respond to the remarks of their colleagues. The goal is two-fold: to present a spectrum of views on …

Field Measurements Of Natural And Artificial Targets Using A Mid-Infrared Laser Reflectance Sensor, Ram M. Narayanan, Steven E. Green

Department of Electrical and Computer Engineering: Faculty Publications

tunable mid-infrared CO₂ laser reflectance sensor operating in the 9-11 pm wavelength range has been developed and field-tested at the University of Nebraska. This system is capable of gathering reflectance data at various wavelengths, incidence angles and linear polarization combinations. Preliminary measurements of various natural and artificial targets such as soil, coniferous and deciduous trees, concrete and brick building material at distances of up to 100 m demonstrate the potential of this system to characterize the mid-infrared reflectance of terrain features for remote sensing applications. Field-acquired data compare well with data on similar materials measured in the laboratory under …

Color Image Enhancement Using Both Chromatic And Luminance Components, George Eric Hague Ii

Retrospective Theses and Dissertations

A vast amount of work has been published regarding grayscale processing of digital images. Although some of this work has been adapted for color images, many of the resulting algorithms neglect the correlation that exists between the individual RGB color components. Consequently, they introduce color artifacts. Attempts have been made to decouple the RGB components through color space transformations that isolate the luminance from the chromatic information. Color image enhancement is then considered a two step process, where the luminance and the chromatic components are processed independently. However, the RGB color space only has a finite number of available colors, …

An Efficient Method For Representing And Computing Transitive Closure Over Temporal Relations, Vincent J. Kovarik

Retrospective Theses and Dissertations

The need for temporal reasoning is found throughout the engineering disciplines. James Allen introduced a representation for temporal reasoning based upon the concept of intervals. This approach provides a rich set of temporal relations for reasoning over events and changes in state. The full temporal algebra is NP-complete however. The algorithm developed by Allen executes in 0(n³) time but only ensures consistency between any three intervals.

This research presents an approach to representing interval relations as a bit-encoded form which captures the relationships between the end-points of the intervals. A bit-algebra is then defined which provides an …

Computation Of Stable Invariant Subspaces Of Hamiltonian Matrices, R. V. Patel, Z. Lin, Pradeep Misra

Electrical Engineering Faculty Publications

This paper addresses some numerical issues that arise in computing a basis for the stable invariant subspace of a Hamiltonian matrix. Such a basis is required in solving the algebraic Riccati equation using the well-known method due to Laub. Two algorithms based on certain properties of Hamiltonian matrices are proposed as viable alternatives to the conventional approach.

Neural Network Enhancement Of The Los Alamos Force Deployment Estimator, Bobby Turner, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

The Force Deployment Estimator (FDE) is a decision support system. It allocates transportation resources given inputs such as forces to be deployed and their desired arrival times. Other inputs are assumptions about conditions that affect performance: carrier start time, node capacity, sustainment shipping time, bulk sustainment per day, ammo sustainment per day, unit start time, carrier service time, carrier round trip time, and carrier reassignment time. Outputs include the mean and standard deviation of estimated unit arrival times versus goal times, and data files for post-processing. However, when a goal time is not met, the simulator gives no explanation of …

Comparison Of Self Pulsation In Multisection Lasers With Distributed Feedback And Intracavity Satuarable Absorbers, P. Phelan, D. Mcdonald, A. Egan, Joe Hegarty, R. O'Dowd, Gerald Farrell, S. Lingren

Articles

The authors report a comparison of the self-pulsing characteristics of two types of semiconductor laser. They show that the self-pulsing frequency of the DFB laser is decoupled from the resonance frequency. They discuss the various characteristics, their significance in relation to optical synchronisation, and use the results to suggest a possible explanation for the mechanism for self-pulsation in the DFB laser.

A Stochastic One-Dimensional Image Model Based On Occluding Object Images, John A. Stuller

Electrical and Computer Engineering Faculty Research & Creative Works

This Paper Provides New Insights into the Formation of One-Dimensional (Line-Scan) Image Autocorrelation Functions. We Model a Line Scan as a Composition of Individual Object-Images that Have Random Positions, Widths and Intensities and that Occlude One Another. We Derive the Autocorrelation Function of This Model as a Function of Object-Image Width and Intensity Distributions. We Show that Any Assumption Regarding the Form of the Autocorrelation Function Places a Constraint on Object-Image Width and Intensity Distributions and We Derive the Object-Image Width Distribution Associated with the Widely Used Symmetric-Exponential Autocovariance Model.

Neural Network Diagnosis Of Malignant Melanoma From Color Images, Fikret Erçal, Hsi-Chieh Lee, William V. Stoecker, Randy Hays Moss, Anurag Chawla

Computer Science Faculty Research & Creative Works

Malignant melanoma is the deadliest form of all skin cancers. Approximately 32,000 new cases of malignant melanoma were diagnosed in 1991 in the United States, with approximately 80% of patients expected to survive 5 years. Fortunately, if detected early, even malignant melanoma may be treated successfully, Thus, in recent years, there has been rising interest in the automated detection and diagnosis of skin cancer, particularly malignant melanoma. Here, the authors present a novel neural network approach for the automated separation of melanoma from 3 benign categories of tumors which exhibit melanoma-like characteristics. The approach uses discriminant features, based on tumor …

The Adaptive Control Of Smart Structures Using Neural Networks, Vittal Rao, Rajendra Damle, Chris Tebbe, Frank J. Kern

Electrical and Computer Engineering Faculty Research & Creative Works

The application of adaptive control algorithms for vibration suppression of smart structures is investigated in this paper. An accurate mathematical representation is not required in this approach. The controller adapts to the parameter variations of the structural system by updating the controller gains. When the desired performance of an unknown plant with respect to an input signal can be specified in the form of a linear or a non-linear differential equation, stable control can be achieved using model-reference adaptive control (MRAC) techniques. The conventional MRAC techniques have been successfully implemented on a smart-structure test article resulting in perfect model following. …

Voltage Collapse. An Engineering Challenge, Mariesa Crow, Bernard C. Lesieutre

Electrical and Computer Engineering Faculty Research & Creative Works

Voltage collapse is characterised by a loss of control of the voltage levels in a power system. Although all of the precise mechanisms that affect voltage collapse have not yet been identified, voltage instabilities are known to occur when the power system is operating under a stressed state. The authors discuss voltage collapse and its relationship with the point of maximum power transfer and how voltage collapse can be better predicted

The Characteristics Of Motion And Time Study In Taiwan's Electronics Industry And Their Relationship To Business Size, Betty Chang

Dissertations and Theses @ UNI

This research was conducted to investigate the characteristics of motion and time study implementation in Taiwan's electronics industry, as perceived by industrial engineers, and the relationships of these perceptions to business sizes of the firms. The questionnaires were mailed to 252 industrial engineers in the general firms group. A total of 206 (81.75%) instruments were returned. The questionnaires were then mailed to another 15 industrial engineers in the highly productive firms group. All the instruments (100%) were returned from the highly productive firm group. Telephone interviews were later conducted with six selected highly productive electronics firms to investigate their successful …

Information Processing Using Laser Speckle, Rathnakar Gopisetty

Masters Theses

"The random speckle intensity pattern, which is produced by the scattered optical field from a rough surface when illuminated, can be used as a carrier of information. A theoretical study is performed to use the speckle patterns for retrieving the information of various kinds of object motions. A mathematical model of speckle is developed and used to relate different speckle patterns at various intervals as the object is experiencing motion. Four different object motions, i.e., one dimensional perpendicular motion, axial motion, three-dimensional motion, and rotational motion of an object are analyzed. In each case an interference pattern is produced which …

Synthesis Of Numerical Integrators For The Real-Time Digital Simulation Of Continuous Systems, Michael James Panzitta

Retrospective Theses and Dissertations

Real-time digital simulation is a powerful means for engineers and scientists in government, industry, and academia to perform research and training as well as serving as a basis for many commercial applications. Due to the special constraints imposed by digitally simulating continuous systems in real time, however, many of these systems either require costly high-speed components or are unable to provide suitable performance characteristics using affordable computers.

This dissertation describes a new technique for the synthesis of numerical integrators specifically designed for the real-time digital simulation of continuous systems. This methodology is based upon the fact that the state derivatives …

Data-Feedthrough Faults In Circuits Using Unclocked Storage Elements, Waleed K. Al-Assadi, D. Lu, A. P. Jayasumana, Y. K. Malaiya, C. Q. Tong

Electrical and Computer Engineering Faculty Research & Creative Works

Some faults in storage elements (SEs) do not manifest as stuck-at-0/1 faults. These include data-feedthrough faults that cause the SE cell to exhibit combinational behaviour. The authors investigate the implications of such faults on the behaviour of circuits using unclocked SEs. It is shown that effects of data-feedthrough faults at the behavioural level are different from those due to stuck-at faults, and therefore tests generated for the latter may be inadequate

A Modular Approach To Numerical Em Modeling, Todd H. Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

Discusses the components of numerical EM modelling codes. The authors go on to discuss a modular approach to EM software development which would allow developers to focus on one component at a time. The modular approach relies on standard format input and output files for each component (or module) of the code

On Fault Modeling And Testing Of Content-Addressable Memories, Waleed K. Al-Assadi, A. P. Jayasumana, Y. K. Malaiya

Electrical and Computer Engineering Faculty Research & Creative Works

Associative or content addressable memories can be used for many computing applications. This paper discusses fault modeling for the content addressable memory (CAM) chips. Detailed examination of a single CAM cell is presented. A functional fault model for a CAM architecture executing exact match derived from the single cell model is presented. An efficient testing strategy can be derived using the proposed fault model

Microwave Diagnosis Of Rubber Compounds, Stoyan I. Ganchev, J. Bhattacharyya, Sasan Bakhtiari, Nasser N. Qaddoumi, Deborah Brandenburg, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

The results of a study investigating the dielectric properties of rubber compounds and their constituents in the frequency range of 5 to 24 GHz are presented. A completely filled short circuited waveguide technique was used to conduct these dielectric measurements. The influence of carbon black content in rubber was investigated for carefully prepared rubber samples. The results showed that for all frequencies, the dielectric constant increases as a function of increasing carbon black content. The variation of dielectric constant values decreases as frequency increases. The presence of curatives in uncured rubber samples was also detected, which indicates the sensitivity of …

Reflection High-Energy Electron-Diffraction Study Of Surface Disorder And Anomalous Expansion Of Pb(100), D. Tang, H. E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

The temperature-dependent surface structural behavior of Pb(100) is studied using reflection high-energy electron diffraction. Anomalous surface expansion for temperatures between room temperature to about 500 K is observed. A high density of surface vacancies appears at temperatures above ~ 500 K. © 1994 The American Physical Society.

Automation Of Formation Flight Control, Vincent P. Reyna

Theses and Dissertations

The research contained in this thesis explores the concepts of Automated Formation Flight Control documented in three previous AFIT theses. The generic formation analyzed consists of a Leader and Wingman, with the Wingman referencing its maneuvers off of Leader maneuvers. Specifically, planar formation flight control concerning only heading and velocity changes is considered. Next, the vertical separation constraint is relaxed to allow wing maneuvers outside of the flight plane of the lead in order to minimize the energy expended by the wing in a maneuver. Analysis of the two forms of formation flight control investigated in this thesis reveals the …

Comparison Of High-Temperature Superconductors In Multi-Chip Module Applications, D. E. Ford, S. S. Scott, S. S. Ang, W. D. Brown

Journal of the Arkansas Academy of Science

In the application of high-temperature superconductors (HTSCs) in multi-chip module (MCM) technology, it is first necessary to investigate the advantages and disadvantages of the various HTSC compounds. The standard criteria for comparing the suitability of HTSCs in electronics applications has been critical temperature (Tc )and critical current density (Jc ). It is also necessary to consider the physical properties of HTSCs in relation to the various processing techniques required in fabrication of MCMs. These techniques can be grouped into four main areas: deposition, patterning, packaging, and characterization. The four main HTSC materials, Y-Ba-Cu-O, Bi-Sr-Ca-Cu-O, Tl,Ba-Ca-Cu-O and Hg-Ba-Ca-Cu-O, will be compared …

Using The Cern Program-Library Graphics And Interactive Data Display, Morgan T. Burks, Wilson H. Howe, Christine A. Byrd, Wilfred J. Braithwaite

Journal of the Arkansas Academy of Science

Small scale Monte Carlo programming is growing rapidly due to the ease with which complex problems may be formulated by any programmer. These programmers may choose to exploit graphics and interactive displays available in the program library developed and maintained by CERN (the Center for European Nuclear Research). This paper outlines the use of graphics and interactive data display features of the CERN program library, developed for visualizing simulated data events in particle detectors. One example uses GEANT, CERN's Monte Carlo modeling program, to simulate 300 MeV/c protons incident on a silicon slab. Display packages for GEANT are available both …

Gamma Ray Emissions From Binary Pulsar Systems, Tony A. Hall, Andrew T. Sustich

Journal of the Arkansas Academy of Science

A method is developed for estimating the gamma ray flux impinging upon the earth from production in binary pulsar systems. We calculate production of the 6.13 MeV gamma ray line characteristic of 16O. These are produced by protons emitted by the pulsar interacting with 16O atoms at the surface of the companion. We examine different types of companion stars and estimate the gamma ray flux at the earth as a function of proton emission from the pulsar and distance from the earth. Prospects for detection from earth are discussed.