Digital Commons Network^™

Implementation Of Dsp Applications Using The At&T Dsp32 C Compiler And Application Library, J. Tow, J. Hartung, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

The authors briefly introduce the C compiler and the application library for the DSP32 digital signal processor (DSP). Several examples are shown that illustrate the ease of writing C programs for some common filtering applications. In most cases, a small real-time penalty is incurred by using C, rather than assembly language coding. Programming in C, however, allows a dramatic improvement in programmer productivity in terms of implementing, testing, and maintaining an application

Is Central Station Photovoltaic Power Dispatchable?, Badrul H. Chowdhury, S. Rahman

Electrical and Computer Engineering Faculty Research & Creative Works

An operational tool for integrating a photovoltaic system into the utility's generation mix is introduced. The development and implementation of a new approach-a dynamic rule-based (RB) dispatch algorithm-is presented. A Box-Jenkins time-series method is used to model the subhourly solar irradiance. The model is extended to yield forecast parameters which are then used to predict the photovoltaic output expected to occur at certain lead times coinciding with the economic dispatch intervals. The RB dispatch algorithm is introduced to operate as either a substitute for or an aid to the dispatch operator. It is concluded that results depend on the time …

Still-Frame Image Transmission Using Dpcm/Interpolative Coding, Brindala Mallappa, Norman R. Cox

Electrical and Computer Engineering Faculty Research & Creative Works

Two methods of combining DPCM (differential pulse-code modulation) and interpolation are proposed for compressing still-frame teleconferencing signals. The first method uses horizontal subsampling, DPCM, and interpolation to achieve a 4:1 compression. The other method is similar but uses vertical subsampling instead. Simulation results indicate that either method can easily achieve the required 2-b/pel data rate with negligible degradation in image quality. Conventional DPCM is shown to perform slightly better in quantitative terms when fixed-wordlength coding is used. However, the two DPCM/interpolation methods offer other advantages when used with a variable-wordlength coder

Linear State Variable Dynamic Model And Estimator Design For Allison 1406 Gas Turbine Engine, Vittal S. Rao, D. Moellenhoff, J. A. Jaeger

Electrical and Computer Engineering Faculty Research & Creative Works

This paper describes a procedure for developing a State Variable Model for the Allison T406 gas turbine engine. This linear model is useful for designing controllers using modern control techniques. The engine and V-22 rotor system is modeled around an operating point by using four state variables and one input variable. For a given power setting, it is observed that two linear models are sufficient to represent the engine dynamics over the entire flight envelope. A relationship between surge margin and the state variables is also developed. It is demonstrated that these linear models are useful in designing an estimator …

Distribution Automation For The Association Of Missouri Electric Cooperatives—A Statewide Evaluation Of Load Management, Jack F. Morris, Frank J. Kern

Electrical and Computer Engineering Faculty Research & Creative Works

Presented is an in-depth technical and economic feasibility study utilizing one- and two-way management systems for statewide load control and distribution automation. Included are 1) an evaluation of the generation and transmission load patterns of the state cooperatives and the determination of the amount of controllable load for use by a load management system, 2) an in-depth economic cost-benefit study as a result of implementing a load management system on a statewide basis, 3) communication alternatives for implementing the statewide load management and distribution automation system, 4) an investigation into using an existing statewide microwave communications system for direct load …

Simulation Of Communication Systems Using Personal Computers, William H. Tranter, Carl R. Ryan

Electrical and Computer Engineering Faculty Research & Creative Works

Microcomputer simulation provides a powerful tool for computer-aided design and analysis of communication systems and requires a minimum of investment. Two different simulation examples are presented: a fixed topology simulation program for digital data links written in Pascal; and a simulation of an analog link using Fortran. These examples are followed by a consideration of the new 32-bit single-board computers and their potential impact on microcomputer simulation. © 1988 IEEE

Simulation Of Photovoltaic Power Systems And Their Performance Prediction, S. Rahman, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

A number of photovoltaic (PV) performance-analysis models are tested for their ability to estimate the AC power output and validated against historical observations from a PV test facility. A method to estimate meteorological parameters is developed for use in PV performance models for predicting future AC power output from a PV test site. Twelve such PV performance models are examined, and the PVFORM system analysis program and lifetime cost and performance models are extensively tested. These two models are tested using the typical meteorological year and the VPI model-generated estimates of long-term data. Performance prediction results are compared against actual …

A Discussion On The Diversity In The Applications Of Photovoltaic Systems, S. Rahman, Badrul H. Chowdhury, M. A. Khallat

Electrical and Computer Engineering Faculty Research & Creative Works

References on the diverse applications of photovoltaic (PV) systems around the world are classified. The classes presented are (i) stand-alone, (ii) grid-connected, (iii) PV-thermal, (iv) PV-wind, and (v) dedicated applications. 73 papers are cited and classified into these five categories including a brief summary of each paper. Out of these, 42 papers relate to grid-connected applications in many industrialized countries of the world. These papers reflect the importance given to such applications. Due to the rapidly changing nature of PV and related industries, only papers published during the last ten years are considered.

Analysis Of Interrelationships Between Photovoltaic Power And Battery Storage For Electric Utility Load Management, Badrul H. Chowdhury, S. Rahman

Electrical and Computer Engineering Faculty Research & Creative Works

The impact of photovoltaic power generation on an electric utility's load shape under supply-side peak load management conditions is explored. Results show that some utilities utilizing battery storage for peak load shaving might benefit from use of photovoltaic (PV) power, the extent of its usefulness being dependent on the specific load shapes as well as the photovoltaic array orientations. Typical utility load shapes both in the eastern (at Rayleigh, NC) and in the western (at Hesperia, CA) parts of the USA are examined for this purpose. It is concluded that while photovoltaic power generation seems to present a bigger impact …

A Rule-Based Dynamic Economic Dispatch For Power Systems, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

The author introduces a novel operation tool for economic dispatch. It deals with the development and implementation of a new approach-a dynamic rule-based dispatch algorithm that takes into account the major problems faced by the dispatch operator during a dispatch interval and channels those into a database for use by a rule-based system. The algorithm is very fast and can be used effectively in interconnected systems. It can also handle renewable technologies and is therefore considered useful for major electric power utilities contemplating adding a significant amount of these new generation sources to their existing mix

Transient Stability Simulation By Waveform Relaxation Methods, Marija D. Ilić, M. A. Pai, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a new methodology for power system dynamic response calculations is presented. The technique known as the waveform relaxation has been extensively used in transient analysis of VLSI circuits and it can take advantage of new architectures in computer systems such as parallel processors. The application in this paper is limited to swing equations of a large power system. Computational results are presented.

Power Division By Element Design In A Circularly Polarized, Series-Fed Array, James L. Drewniak, P. E. Mayes

Electrical and Computer Engineering Faculty Research & Creative Works

The feasibility of designing a wideband circular polarized (CP) array of series-fed elements using the element geometry to control the array excitation has been demonstrated. The simple array of wideband, low-profile CP elements requires no phase-shifters and only sufficient feed lines for the interconnection of the elements in a series-fed array. A complicated network is not required to obtain the excitation coefficients for a specified design. Rather, the excitation coefficients can be realized by utilizing the geometric parameters of the individual elements.

A Dual Circular Polarization Radiating-Line Antenna, James L. Drewniak, P. E. Mayes, D. Tanner, J. Woodruff

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

A New Approach To Signal Registration With The Emphasis On Variable Time Delay Estimation, Mohamad Namazi, John A. Stuller

Electrical and Computer Engineering Faculty Research & Creative Works

Signal Registration is Concerned with the Problem of Estimating a Varying Displacement between Two Random Processes. We Approach Signal Registration Here as a Recursive Demodulation Problem in Which the Recursion is between Signal Estimations and Displacement Estimation. Special Attention is Given to the Problem of Estimating a Variable Time Delay. Thus, We Present New Algorithms for Estimating D(T) from Received Processes:

r₁(t) = s(t) + n₁(t)

R₂(t) = s(t - D(t)) +n₂(t)

Where s [Formula Omitted] is Signal and n₁ (•) and n₂ (•) Are Noise. Simulation Results Are Presented …

Maximum-Likelihood Estimation Of Time-Varying Delay-Part I, John A. Stuller

Electrical and Computer Engineering Faculty Research & Creative Works

This Paper Presents, for the First Time, the Exact Theoretical Solution to the Problem of Maximum-Likelihood (ML) Estimation of Time-Varying Delay d(t) between a Random Signal s(t) Received at One Point in the Presence of Uncorrelated Noise, and the Time-Delayed, Scaled Version as(t - d(t)) of that Signal Received at Another Point in the Presence of Uncorrelated Noise. the Signal is Modeled as a Sample Function of a Nonstationary Gaussian Random Process and the Observation Interval is Arbitrary. the Analysis of This Paper Represents a Generalization of that of Knapp and Carter [1], Who Derived the ML Estimator for the …

Computer-Aided Testing Of Electrical Machines: Software Development, Max Darwin Anderson, Steven A. Hauk, Robert Laramore, Hardy J. Pottinger

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Stability Of Polynomials Under Correlated Coefficient Perturbations., M. K. Saridereli, Frank J. Kern

Electrical and Computer Engineering Faculty Research & Creative Works

The robust stability of polynomials with respect to real parameter variations is investigated. The coefficients of the polynomial are assumed to be linear functions of several real parameters. An algorithm to calculate the maximum allowable variations of the parameters so the roots still remain in prescribed regions of the complex plane is presented. Examples are given to illustrate the method.

Computer-Aided Testing Of Electrical Machines: Software Development, Max Darwin Anderson, Steven A. Hauk, Robert Laramore, Hardy J. Pottinger

Electrical and Computer Engineering Faculty Research & Creative Works

Computer-aided test stations have been developed for research, experimentation, and testing of electric motors and generators. Data acquisition and control of the machines and drives are provided through a computer and its interfaces. Machines are connected to the computer through transducers for data acquisition, and power electronic drives for machine control. General software was written to enable the monitoring of all transducers continuously on the CRT screen while giving the user manual control of the machines and drives. Specialized software was written for automatic control of the induction, dc, and synchronous machines for specific experiments on each type of machine. …

Current That Kills., Burns E. Hegler

Electrical and Computer Engineering Faculty Research & Creative Works

The authors point out the hazards associated with electricity. Several methods for preventing or coping with inadvertent shocks are described.

Robust Control Of A Csi-Fed Induction Motor Drive System, Rajiva Prakash, Vittal S. Rao, Frank J. Kern

Electrical and Computer Engineering Faculty Research & Creative Works

An application of modern control theory to the control of a current-source-inverter (CSI) fed induction motor drive system is presented. A linear quadratic Gaussian (LQG) control scheme is developed in which the Kaiman filter is tuned for high robustness by a method of Doyle and Stein. The design is carried out for a sample system, and the robustness analysis and computer simulation results are included. Copyright © 1987 by The Institute of Electrical and Electronics Engineers, Inc.

Estimation Approach To Locating Buried Geological Interfaces, A. Omar, A. Addeeb, C. Slivinsky, Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

The objective of the estimation work described in this paper is to improve algorithms for reconstructing the geometric configuration of acoustic reflecting surfaces. The conventional migration method of locating these surfaces is reviewed. A recent imaging condition which is closely related to the boundary condition at the geological interface is then described. This later procedure results in two outputs. One can be used to reconstruct the shape of the unknown acoustic reflector, while the second output estimates the acoustic wavespeed on the transmission side of the boundary. When noise is present in the reflected signal, the performance of the method …

A Log-Spiral, Radiating-Line Antenna, James L. Drewniak, P. E. Mayes, D. Tanner, R. Waller

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

An Interactive Power System Analyzer With Graphics Display For Educational Use, C. H. Lo, Max Darwin Anderson, Earl F. Richards

Electrical and Computer Engineering Faculty Research & Creative Works

The paper presents a student-oriented power-system analyzer with an interactive graphics display. Its capabilities include studies of (1) load flow, (2) load and generation, (3) voltage level control, (4) economic dispatch, and (5) contingency and planning analysis. Power network configurations of up to 30 buses can be presented clearly on one screen. The interactive nature of this program makes such studies effective and easy to use. With the support of a computer with graphics software and many graphics terminals, this program can be a useful teaching tool for power system studies. Copyright © 1986 by The Institute of Electrical and …

Alternate Presentation Of Fourier Transform Development From Fourier Series., Gordon E. Carlson

Electrical and Computer Engineering Faculty Research & Creative Works

An alternate presentation of the development of the Fourier transform from the complex exponential Fourier series is presented. It uses spectral concepts to aid the mathematical development and a redefined spectral form for the spectral information obtained with the Fourier series. It has been used a number of times in the classroom and has been found to aid the students' understanding of the Fourier transform and the spectra of an aperiodic signal.

An Interactive Power System Analyzer With Graphics For Educational Use, Chin Hwanglo, Max Darwin Anderson, Earl F. Richards

Electrical and Computer Engineering Faculty Research & Creative Works

The paper presents a student-oriented power system analyzer with an interactive graphics display. Its capabilities include studies of (1) load flow, (2) load and generation, (3) voltage level control, (4) economic dispatch, and (5) contingency and planning analysis. Power network configurations of up to 30 buses can be presented clearly on one screen. The interactive nature of this program makes such studies effective and easy to use. With the support of a computer with graphics software and many graphics terminals, this program can be a useful teaching tool for power system studies. Copyright © 1986 by The Institute of Electrical …

Electrodeposition And Analysis Of Tin Selenide Films, R. D. Engelken, Jack L. Boone, A. Shahnazary

Electrical and Computer Engineering Faculty Research & Creative Works

Sn1±xSe films have been electrodeposited from aqueous solutions containing SnCl2 and ionically dissolved SeO2 or H2SeO3 and DMF solutions containing SnCl2 and molecularly dissolved selenium powder. The as-deposited films ranged from amorphous to polycrystalline and exhibited indirect or nondirect bandgaps from 0.85 to 0.95 eV. There was little difference between the appearance or material data of the films grown by the two techniques. Direct reaction between Sn++ and H2SeO3 or HSeO3_ in the aqueous solutions yielded a Se/SnxSe suspension/precipitate. Although this does not seem to have any serious effect on the deposition process, it does produce a decrease in the …

Growth Of Ultrafine Particles By Brownian Coagulation, S. H. Suck Salk, R. E. Thurman, Chang-Soo Kim

Electrical and Computer Engineering Faculty Research & Creative Works

Current atmospheric observations tend to support the view that continental tropospheric aerosols (particularly urban aerosols) show multimodal mass distributions in the size range of 0.01-100 μm. The origin of these aerosols is both natural and anthropogenic. Recently, trimodal sub-μm size distributions from combustion measurements at 0.008, 0.035 and 0.15 μm were also observed. Our interest in the present study is the secondary process of growth of sub-μm size aerosols by the coagulation process alone. Using the 'J-space' (integer-space) distribution method of Salk (Suck) and Brock (1979, J. Aerosol Sci. 10, 58-590), we report an accurate numerical simulation study of the …

Free Electron Density Measurements By Ir Absorption In Cds, Jack L. Boone, Gene Cantwell, Michael D. Shaw

Electrical and Computer Engineering Faculty Research & Creative Works

A contactless method for determining the spatial variation of the free carrier density in CdS is presented. The method involves the correlation of IR transmission with the free carrier density via the IR absorption coefficient. Preliminary measurements indicate a free electron density sensitivity of less than 5x1014 cm-3 and a spatial resolution which is limited only by the spot size of a CO2 (λ=10.6 μm) laser; this should be of the order of 100 μm. Experimental results indicate that the predominate scattering is due to impurity interaction at room temperature; this is indicative of the high degree of compensation in …

Minimum Probability Of Electron-Hole Pair Generation By Blackbody Radiation, Cheng-Hsiao Wu

Electrical and Computer Engineering Faculty Research & Creative Works

Using the small-perturbation assumption that all the useful work is in the form of electron-hole pairs when photons from a blackbody radiation source are incident on a quantum device, we derive the minimum probability of generation of one or more pairs of electron holes. Using the Planck radiation formula for the solar spectrum at 6000 K and for the quantum device at 300 K, this minimum probability is about 0.8 at low photon frequency and approaches the limiting value of 0.95 at high frequency. Its relation to maximum efficiency of a quantum device is discussed.

Fourier Transforms Over Warped Domains., Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

The Author Shows that There May Be an Advantage to Computing Fourier Transforms Over Warped Domains. an Example of Such an Improvement is Provided. It is Also Shown How the Fourier Transform May Be Evaluated from Data Observed over a Warped Domain.