Electrical and Computer Engineering Commons^™

Using Matlab To Illustrate The 'Phenomenon Of Aliasing', Sol Neeman, Ph.D.

Engineering Studies Faculty Publications and Creative Works

The phenomenon of aliasing is important when sampling analog signals. In cases where the signal is bandlimited, one can avoid aliasing by ensuring that the sampling rate is higher than the Nyquist rate . But in cases where the signal is not bandlimited , aliasing is unavoidable if the signal is not filtered before it is sampled. It is then crucial to understand the phenomenon in order to estimate the distortion generated when the signal is reconstructed from its samples. Using the software package MATLAB by MathWorks, Inc ., two examples are presented. The first is a pure sinusoid which …

System Modeling And Control Of Smart Structures, Frank J. Kern, Leslie Robert Koval, K. Chandrashekhara, Vittal S. Rao

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents multidisciplinary research and curriculum efforts at the University of Missouri-Rolla in the smart structures area. The primary objective of our project is to integrate research results with curriculum development for the benefit of students in electrical, and mechanical and aerospace engineering and engineering mechanics. The approach to the accomplishment of curriculum objectives is the development of a two-course sequence in the smart structures area with an integrated laboratory. The research portion of the project addresses structural identification and robust control methods for smart structures. A brief summary of the research results and a description of curriculum development …

The Development Of A Method To Extract High Purity Oxygen From The Martian Atmosphere, Dongchuan Wu

Mechanical & Aerospace Engineering Theses & Dissertations

A glow-discharge in an ambient Mars atmosphere (total pressure of 5 torr, composed of 95% carbon dioxide) results in the dissociation of carbon dioxide molecules into carbon monoxide and oxygen. If the glow-discharge zone is maintained adjacent and close to a silver membrane, operated at temperatures above 400°C, atomic and molecular oxygen, produced by the glow-discharge, can be separated from the other species by atomic diffusion through the membrane to an ultrahigh vacuum region where the desorbed O₂ is then collected. Experiments have been conducted to study the behavior of the glow discharge in both molecular oxygen and carbon …

Acoustic Correlates Of Vowel Perception As Determined From Synthesis Experiments With Multi-Tone Stimuli, Zhongjiang Zhang

Electrical & Computer Engineering Theses & Dissertations

An essential requirement of speech signal processing is to extract information (features or parameters) from the speech signal which encode the information carried by the signal. The objective of this thesis work was to examine and evaluate two feature sets as acoustic correlates for vowel perception. They are formants and DCTCs. Formants are the frequencies of spectral peaks of the speech signal. DCTCs are the Discrete Cosine Transform Coefficients of the magnitude spectrum and are thus features which encode the global spectral shape of speech signal.

There are different opinions regarding which feature set is a more accurate representation for …

Study Of Single-Fiber Fiber Optic Lever Microphone, Trung Duc Nguyen

Electrical & Computer Engineering Theses & Dissertations

Fiber optic sensors are widely used in today's technological applications, providing many advantages that conventional sensors lack. In particular, there is a demand in hypersonic applications to develop microphones to measure acoustic pressure that performs in high temperature and noisy surroundings. This thesis analyzes fiber optic lever microphones (FOLM), since they perform at high temperatures. An FOLM system is an intensity modulated sensor, which is simple to implement and is small in size. Two models of the FOLM have been fabricated and calibrated. The first model uses a seven-element fiber array while the second uses a single-fiber to transmit and …

Variable Structure End Point Control Of A Flexible Manipulator, Shailaja Chenumalla, Sahjendra N. Singh

Electrical & Computer Engineering Faculty Research

We treat the question of control and stabilization of the elastic multibody system developed in the Phillips Laboratory, Edwards Air Force Base, California. The controlled output is judiciously chosen such that the zero dynamics are stable or almost stable. A variable structure control (VSC) law is derived for the end point trajectory control. Although, the VSC law accomplishes precise end point tracking, elastic modes are excited during the maneuver of the arm. A Linear stabilizer is designed for the final capture of the terminal state.

A Magnetic Suspension System With A Large Angular Range, Colin P. Britcher, Mehran Ghofrani

Mechanical & Aerospace Engineering Faculty Publications

In order to explore and develop technology required for the magnetic suspension of objects over large ranges of orientation, a small-scale laboratory system, the large-angle magnetic suspension test fixture (LAMSTF) has been constructed at NASA Langley Research Center. This apparatus falls into the category of large-gap, actively stabilized magnetic levitation systems. The hardware comprises five conventional electromagnets in a circular arrangement, each driven from a separate bipolar power amplifier. Electromagnet currents are commanded by a digital control system, implemented on a microcomputer, which in turn derives the position and attitude of the suspended element from an infrared optical system. The …

Measurement Of Thermal-Energy Charge-Transfer Rate Coefficient Of Mo6+ And Argon, Victor H.S. Kwong, Z. Fang, Yingtao Jiang, T. T. Gibbons, L. D. Gardner

Electrical & Computer Engineering Faculty Research

The charge-transfer rate coefficient of Mo6+ and argon has been measured at mean ion energies of 8.8 and 1.4 eV using a laser-ablation ion source and an ion trap. The rate coefficient deduced from these measurements is 1.02(0.10)×10-10 cm3 s-1 and appears to be independent of the mean ion energy at this energy range. However, the measured value is an order of magnitude smaller than the Langevin rate coefficient.

Neural Network Based Vowel Articulation Training Aid For The Deaf, Andrew E. Beck

Electrical & Computer Engineering Theses & Dissertations

Teaching the hearing-impaired to speak is both a challenging and rewarding task. Computer-based training aids are valuable teaching tools and complement the speech therapist in the speech training process. We have developed a computer based vowel articulation training aid designed to provide visual feedback for vowel production to the hearing-impaired user. This system transforms speech spectra from a multi-dimensional acoustic space to a two-dimensional phonetic space which is displayed on a computer monitor. The system signal processing includes feature extraction designed to mimic the properties of the human ear, and a transformation to a two-dimensional display space. The dimensionality transformation …

Measurement Of Thermal Noise In Condenser Microphones In A Vacuum-Isolation Vessel, Kim Chi Thi Ngo

Electrical & Computer Engineering Theses & Dissertations

The electrical noise generated by thermal agitation of the air molecules impinging upon the membrane of a condenser microphone and from its associated preamplifier has been studied analytically and experimentally over a wide bandwidth. These background noise levels constitute one of the most important specifications of a microphone for they determine the lowest sound pressure that can be detected. Therefore, a new method for measuring the thermal agitation noise within a bandwidth of 1-25600 Hz has been developed. The theoretical and experimental measurements of thermal agitation noise in a condenser microphone by enclosing the microphone in a vessel which is …

Integrated Control Of Thermally Distorted Large Space Antennas, Robert H. Tolson

Mechanical & Aerospace Engineering Theses & Dissertations

Studies on controlling the thermal distortion of large space antennae have generally investigated a single orbital position and have optimized actuator locations based on minimizing the RMS surface deviation from the original parabolic shape. One study showed the benefits of directly using far zone electric field characteristics as the performance measure; but, this approach resulted in a nonlinear programming problem. The objective of the current study is to develop an approach to designing a control system that (1) recognizes the time dependence of the distortion and (2) controls variables that are directly related to far field performance in a quadratic …

Coke Oven Emissions: A Case Study Of Technology-Based Regulation, John D. Graham, David R. Holtgrave

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

After examining and analyzing the experience with coke ovens, the authors conclude that attempts to force technology beyond its demonstrated competence can be both expensive and ineffective in controlling hazards. They also suggest implications for pending proposals to further control air pollution.

Effect Of Viscoplastic Flow Rules On The Initiation And Growth Of Shear Bands At High Strain Rates, R. C. Batra, Chang-Soo Kim

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Marchand and Duffy have reported detailed measurements of the temperature and strain as a shear band develops in a HY-100 steel. Assuming their torsional tests in thin-wall tubes can be adequately modeled by a viscoplastic block undergoing overall adiabatic simple shearing deformations, we investigate the effect of modeling the viscoplastic response of the material by a.power law, and flow rules proposed by Litonski, Bodner and Partom, and Johnson and Cook. Each of these flow rules is first calibrated by using the test data at a nominal strain-rate of 3300 s-1. Then predictions from the use of these flow rules at …

Feasibility Study Of Maine's Small Hydropower Potential, James D. Sysko

Maine Collection

Feasibility Study of Maine's Small Hydropower Potential

Prepared by James D. Sysko, Small Hydro East, for the Maine State Planning Office, Maine Office of Energy Resources, January 1989.

"This study focuses on finding potential hydropower sites of approximately 50 kw to 1000 kw in capacity."

Electric Power Transmission & Purchases : Report Of A Study By The Joint Standing Committee On Utilities, 112th Maine Legislature, Maine. Legislature. Joint Standing Committee On Utilities

Maine Collection

Electric Power Transmission & Purchases : Report Of a Study By the Joint Standing Committee on Utilities, 112th Maine Legislature

Maine Legislature. Joint Standing Committee on Utilities.

Augusta, Maine (December 2, 1986).

Contents: Introduction / Issues & Recommendations / Review of 1986 Legislation / Maine's Electric Power Picture / Technical Analysis of Transmission & Wheeling / Economic Implications of Transmission & Wheeling /. Legals Analysis of Transmission & Wheeling / Proposed Legislation / Appendices / Tables & Figures

Maine Yankee Shutdown Assessment: A Report To Governor Joseph E. Brennan, Maine State Planning Office

Maine Collection

Maine Yankee Shutdown Assessment: A Report to Governor Joseph E. Brennan

Maine State Planning Office, Maine Office of Energy Resources, Maine Public Advocate

Executive Department - May 1986

Contents: Legal Process / Decommissioning Constraints and Costs / Public and Economic Costs and Benefits / Apprendices

Design Of Multivariable Feedback Control Systems Via Spectral Assignment, Mohsen Marefat

Electrical & Computer Engineering Theses & Dissertations

During the past 15 year s significant advances have been made towards developing viable synthesis- techniques for multivariable feedback control systems. The entire aggregate of this theoretical work has been reviewed and consolidated. Diverse notations have been standardized into a single system. A two-step design philosophy for spectral assignment has been developed which first meets stability and time response requirements by assigning eigenvalues and eigenvector s and then provides for attainment of secondary objectives without significant deviation from the initial assignment. Finally, a computer-aided design package has been created to streamline the process of mathematical calculation and to allow users …

Electronic Control Of Electric Motors, Armando Castillo

Graduate Research Papers

The purpose of this study was to investigate the theoretical information on electronic control of electric motors as well as the current state-of-the-art on this topic. It was also intended to carry out some of the experimental circuits discussed, for future instructional situations.

Fundy Tidal Power Development : Preliminary Evaluation Of Its Environmental Consequences To The Resources Of The State Of Maine, Bigelow Laboratory For Ocean Sciences

Maine Collection

Fundy Tidal Power Development : Preliminary Evaluation of Its Environmental Consequences to the Resources of the State of Maine

A Report to the Maine State Planning Office by the Bigelow Laboratory for Ocean Sciences, April, 1984.

"Technical Report No. 35 - Bigelow Laboratory for Ocean Sciences, West Boothbay Harbor, Maine - A Division of Northeastern Research Foundation, Inc."

Contents: Executive Summary / Introduction / Methods / Physical and Biological Consequences / Socio-Economic Consequences / Research Needs / Bibliography / Appendix I. Written Comments on Greenberg Model

The Development Of A Microprocessor Controlled Linearly Actuated Valve Assembly, Raymond H. Wall

Mechanical & Aerospace Engineering Theses & Dissertations

The development of a proportional fluid control valve/assembly is presented. This electro-mechanical system is needed for space applications to replace the current proportional flow controllers that use bulky hydraulic or pneumatic actuation systems. The flow is controlled by a microprocessor system that monitors the control parameters of upstream pressure and requested volumetric flow rate. The microprocessor achieves the ·proper valve stem displacement by means of a digital linear actuator. A linear displacement sensor is used to measure the valve stem position. 'Ibis displacement is monitored by the microprocessor system as a feedback signal to close the control loop. With an …

Saving Energy In Rural Maine : Or Who's Doing What On The Farm, Mane Department Of Agriculture

Maine Collection

Saving Energy In Rural Maine : Or Who's Doing What on the Farm

Compiled by Bettina M. Blanchard and Edited by Bill Seekins.

Maine Department of Agriculture, Food and Rural Resources, Division of Resources Development, Augusta, Maine, 1983.

Contents: List of Photographs and Diagrams / Introduction / Projects / 1. Wind / 2. Wood Heat Applications On the Farm / 3. Solar Applications / 4. Manure Handling and Waste Utilization / 5. Energy Efficient Cooling Methods / 6. Energy Saving In Field Operations / 7. Production and Use of Alternative Fuels / 8. Multi-Project Sites / Summary and Conclusions / …

Reduction Of Capacitor Switching Transients By Controlled Closing, John Herman Brunke

Dissertations and Theses

This thesis presents the theory, analysis, testing and implementation of a scheme to reduce shunt compensation capacitor switching transients. The described method is switch the capacitors very near the instant when the bus voltage is at a power frequency zero. This was accomplished with a vacuum breaker on a 230 kV shunt capacitor bank.

Some Facts And Prospects For The Establishment Of Television Broadcasts In Mainland Tanzania, H. R. Mgombelo

Tanzania Journal of Engineering and Technology (TJET)

Abstract

The Economics Of Solar Water Heaters : A Guide For Evaluating The Cost-Effectiveness Of Active Solar Water Heating Systems In Maine, Maine Office Of Energy Resources

Maine Collection

The Economics of Solar Water Heaters : A Guide for Evaluating the Cost-Effectiveness of Active Solar Water Heating Systems in Maine

State of Maine, Executive Department, Office of Energy Resources,

Augusta, Maine (July, 1979).

Contents: Section I: Introduction / Section II: Economic Method: The Life Cycle Cost Analysis / Section III: Factors Affecting the Decision to Buy / Section IV: Explanation of the Tables / Table I - Table IIIA

Design And Operational Characteristics Of A Retrofit Solar Heating System, D. J. Wetteroff, Bassem F. Armaly

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

The construction and the operation of a retrofit solar assisted space heating system are described. Performance characteristics of each component were measured and used to estimate the contribution of solar energy to the yearly space heating energy requirements.

A Solar Energy System For Space Heating And Space Cooling, Thomas J. Mcnamara

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

To help reduce natural gas and electrical operating costs, a retrofit space heating and space cooling solar energy system is integrated into the existing conventional heating and air handling systems serving the exhibit spaces. This installation would not only provide substantial energy cost savings to the Museum, but it would also provide a means of showing and explaining the operation of an actual working solar energy system to the large number of daily visitors to the Museum. This report explains the design, operation and performance of this solar energy system.

4th Annual Umr-Dnr Conference On Energy -- Entire Proceedings, University Of Missouri--Rolla

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

No abstract provided.

Heat Recovery Devices For Building Hvac Systems, Ronald H. Howell, Harry J. Sauer Jr.

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

The opportunities and advantages of air-to-air heat recovery are described. The five basic types (rotary regenerative, coil loop run around, open run-around, heat pipe, and plate type) are described and their typical performance is presented. The potential savings in operating costs as well as initial equipment costs for common applications are presented.

An Annotated Bibliography Of Ocs Documents In Maine, Maine State Planning Office

Maine Collection

An Annotated Bibliography of OCS Documents in Maine

Outer Continental Shelf Memorandum 1

Compiled by Edward H. Shenton & Charles S. Colgan

Maine Coastal Program, Maine State Planning Office, Augusta, Maine, 1977.

Contents: 1. Introduction / 2. OCS - General / 3. OCS - Federal Regulations / 4. Economic Aspects / 5. Environmental Studies / 6. Oil Spills - Effects and Studies / 7. Onshore Effects / 8. The North Sea Experience / 9. Legal Aspects / 10. Petroleum Drilling Technology

Ua64/3 Readout, Wku Industrial Education & Technology

WKU Administration Documents

Newsletter includes articles:

• Renovation of Industrial Education Building Nearing Completion
• Tomazic, Norman. Basic Industrial Education: Futures Oriented "Sabre-toothed" Curriculum?
• Conley, Franklin. Comments re: departmental news
• New Electricity / Electronics Facilities
• WKU Student Receives KIEA Scholarship, Bonnie Thomerson
• Zax, Carol. Communication & Interaction
• Pittman, Frank. Guitars, Guitars, Guitars re: Hascal Haile
• IE&T One-Liners
• Walter Nalbach Scholarship Fund