Engineering Commons^™

Moment Method Solution Of The Time-Dependent Transport Equation To Describe The Scattering Of Gaussian Plane Wave Pulses By A Forest, Nack Yang Cho

Theses

The time dependent transport equation is used to study the transmission of periodic pulses through a forest. The forest is assumed to occupy a half-space region, to be statistically homogeneous and to scatter energy isotropically A periodic sequence of Gaussian plane wave pulses is assumed to enter the forest normally from free space. The transport equation is solved by the moment method using triangular expansion functions. Numerical results indicate the dependence of the incoherent intensity on penetration depth, observation angle, albedo and pulse repetition rate.

Computer Aided Analysis Of Electroencephalographic Waveforms, Edward Tadeusz Polkowski

Theses

An approach to analysis of EEG waveforms is described. The procedure utilizes a PDP -11 computer to perform a Fast Fourier Transform on four channels of data simultaneously. The transforms are done in real time and. the results are plotted in a manner which allows the operator to easily determine the major background activity and to check for left-right symmetries in brain waves. Patient data is used to verify the computer output against actual clinical diagnoses.

Complex Reflection Coefficients For The Parallel And Perpendicular Polarizations Of A Film-Substrate System, R. M.A. Azzam, M. Emdadur Rahman Khan

Electrical Engineering Faculty Publications

The complex reflection coefficients R_v(ø,ζ) of a film-substrate system for the parallel (v = p) and perpendicular (v = s) polarizations are examined in detail as functions of the angle of incidence ø(0 ≤ ø ≤ 90°) and the reduced normalized film thickness ζ(0 ≤ ζ < 1). For definiteness, the reflection of light of wavelength λ = 0.6328 µm by the air–SiO₂–Si system is assumed. Families of circles that represent the constant-angle-of-incidence contours, their envelopes, and the associated constant-thickness contours ofR_p and R_s are all presented in the complex plane. Furthermore, the amplitude-reflectance and phase-shift functions, |R_v|(ø,ζ) and argR_v(ø,ζ) …

Improved Wavenumber Resolution For Small Arrays, Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

The Objective of the Method Described is to Compute the Fourier Transform of a Function of Space and Time with a Significant Improvement in the Resolution of Spatial Frequencies, particularly in the Case of Small Arrays for Which the Size of the Array is on the Order of One Wavelength (Or less). This Improvement is Initially Developed by Considering the Conversion of Spatial Frequency into Temporal Frequency through the Oscillatory Motion of a Single Receiver. a More Practical Scheme is Next Presented in Which the Oscillatory Motion is Created Synthetically by the Appropriate Sequential Sampling of Individual Elements in a …

Bibliography Of Power Systems Operator Training Resources Ieee Committee Report Prepared By The Pes Working Group On Operator Training (Wg78-4), Max Darwin Anderson

Electrical and Computer Engineering Faculty Research & Creative Works

This paper provides a current listing of training courses, programs, and resource materials for Power System Operator/ Dispatcher training. The training resources are subdivided into five (5) categories: I. Dispatcher training courses and facilities developed by the Suppliers/Manufacturers II. University Short Courses III. Conference Publications IV. Reference Books V. Correspondence Courses A brief description of the offerings of each of the Suppliers/ Manufacturers is included. Copyright © 1983 by The Institute of Electrical and Electronics Engineers, Inc.

Bibliography Of Power Systems Operator Training Resources, Max Darwin Anderson

Electrical and Computer Engineering Faculty Research & Creative Works

This paper attempts to provide a current listing of training courses, programs, and resource materials for Power System Operator/Dispatcher training. The training resources are subdivided into five (5) categories: I. Dispatcher training courses and facilities developed by the Suppliers/Manufacturers II. University Short Courses III. Conference Publications IV. Reference Books V. Correspondence Courses A brief description of the offerings of each of Suppliers/Manufacturers is included. Copyright © 1982 by The Institute of Electrical and Electronics Engineers, Inc.

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 / …

Line-Adaptive Hybrid Coding Of Images, Tai On Tam, John A. Stuller

Electrical and Computer Engineering Faculty Research & Creative Works

This Paper Describes Novel Adaptation Strategy for Hybrid Transform/DPCM Image Coders. This Strategy Has Yielded a 2–8 DB Increase in Signal-To-Noise Ratio in the Transmission of a Head and Shoulders Image at Bit Rates of 1–4 Bits Per Pel and One-Dimensional Transform Block Sizes of 2–16. © 1983 IEEE

The Application Of Bond Graphs To Electrical Machinery And Power Engineering, K. Sirivadhna, Earl F. Richards, Max Darwin Anderson

Electrical and Computer Engineering Faculty Research & Creative Works

The bond graph technique, which has been related almost entirely to the field of mechanics, is a modeling procedure where emphasis is placed on the flow of power and energy in a system. Through specific digital simulation programs such as ENPORT IV and V and THTSIM the state space representation, associated output equations and system dynamic response are directly obtainable from the bond graphs. This approach has a great advantage where a complex system is composed of electrical, mechanical, thermal, hydraulic or pneumatic subsystems, such as would exist, for example; in a boiler, turbine, generator exciter system together with its …

Considerations In Developing And Utilizing Operator Training Simulators, T. E. Dyliacco, M. K. Enns, J. D. Schoeffler, J. J. Quada, D. L. Rosa, C. W. Jurkoshek, Max Darwin Anderson

Electrical and Computer Engineering Faculty Research & Creative Works

Effective electric system operation depends on strengthening the relationship between the system operator and the electrical system with its associated control system. This relationship can be developed through a training medium which increases the operator's knowledge of the behavior of the power system under various operating conditions and contingencies, and its response to control actions. An Operator Training Simulator (OTS), which simulates the static and dynamic responses of the operator's power system and his control system, can accomplish these training objectives. The concepts developed in this paper are based on the work of the project team through funding by the …

The Application Of Bond Graphs To Electrical Machinery And Power Engineering, K. Sirivadhna, Earl F. Richards, Max Darwin Anderson

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Analysis Of The Isolated Induction Generator, L. Ouazenne, George Mcpherson

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Estimation Of Ocean Wave Wavenumber And Propagation Direction From Limited Synthetic Aperture Radar Data., Gordon E. Carlson

Electrical and Computer Engineering Faculty Research & Creative Works

A method for estimating wavenumber and propagation direction for the dominant wave component in an ocean wave field from a few scans of synthetic aperture radar data is described and analyzed. The use of just a few radar scans rather than a complete image reduces data storage requirements significantly. The analysis shown uses actual synthetic aperture radar data and provides parameter tradeoffs and statistical performance results. While reasonable estimates of wavenumber and propagation direction are achieved in some cases, the estimates are not sufficiently consistent to be satisfactory over a wide range of cases. The primary problem is one of …

Real Time Interactive Graphics Systems Identification, Youcef Hammada

Masters Theses

“This thesis describes the implementation of an identification procedure as a package of graphic programs. This package of graphic programs will allow the user to perform a least squares parameter estimation, a recursive least squares parameter estimation, and a maximum likelihood parameter estimation of a linear second-order transfer function model. This model describes in a linear form the dynamic response of an automobile in a field operating environment.

The model is to reasonably reproduce the physical behavior of an automobile through two of its dynamic variables. These are the yaw rate as output and wheel angle as input. The model …

Electrical Engineering, C. J. Thomforde

UND Departmental Histories

This departmental history was written on the occasion of the UND Centennial in 1983.

Microcomputer Control Of A Model Robot System Using Programmable Pulse Width Modulation, Richard Eugene Wainwright

Masters Theses

"The hardware design of a model robot system for experimentation in microcomputer control is presented. A special interface board is designed to allow an Apple II Plus microcomputer to control a model robot system which consists of a three-jointed robot with an electromagnet end effector and a conveyor belt, with an optional vision system. A programmable pulse-width modulator is designed to drive the DC motors which operate the robot and conveyor belt. Improvements and additional uses for the model system are discussed"--Abstract, page ii.

Error Detection For Data Communication Systems, John Biancamano

Theses

A description of the problems encountered in the data communications field and the various solutions can be found in a number of diverse, and often theoretical sources. My intention in writing this thesis is to bring together, in a practical and understandable manner, the theory and the application of a method of error detection used extensively in data communication systems known as the Cyclic Redundancy Check (CRC).

To provide some background on the subject, a description of a data communication system is presented, and the possible sources of error are explored in some detail. Data transmission formats are described, and …

The Performance Of Full Response Multi-H Modems In Practical Environments, Mark Alan Wickert

Doctoral Dissertations

The power and bandwidth efficiency of multi-h continuous- phase modulation (CPM) schemes in practical environments are considered. Specific impairments considered are transmitter filtering, amplitude limiting, and receiver symbol timing, phase error, and decision depth sensitivities. A coherent receiver model is employed which uses the Viterbi algorithm (VA) to perform maximum likelihood sequence estimation. For (2/4,3/4), ll (3/8,4/8) and (4/8,5/8) linear phase codes, a signal-to noise ratio (SNR) power gain of 1.85 dB, 1.9 dB, and 2.4 dB at a bit error rate (BER) of 10^-5 over differentially coded minimum-shift keyed (MSK) modulation are obtained, respectively. With transmitter filtering the …

Model Studies Of Oxygen-Intercalated Graphite, Aldona M. Butkus, Cary Y. Yang, Y. W. Tsang, C. Y. Fong

Electrical and Computer Engineering

The possibility of intercalating oxygen to reduce the conductivity of graphite has been investigated by modified intermediate neglect of differential overlap 3 and tight-binding methods. The cluster calculations suggest that the most stable position for the oxygen atom is 1.25 A above a carbon-carbon bond. The tight-binding band calculation predicts the stage-I intercalated graphite to be a zero-indirect-gap semiconductor. Higher-stage intercalated graphite is expected to have a finite insulating gap whose value is governed by the carbon-oxygen interaction.

Subharmonic Generation By Resonant Three‐Wave Interaction Of Deep‐Water Capillary Waves, Partha P. Banerjee, Adrianus Korpel

Electrical and Computer Engineering Faculty Publications

Subharmonic generation has been observed during the propagation of deep‐water capillary waves. The observations are shown to be in agreement with the theory of degenerate resonant noncollinear three‐wave interaction in a nonlinear, dispersive medium.

Effects On Electrolytic Cells Of Magnetic Fields Applied To Single Electrodes, Craig Allen Cousins

Dissertations and Theses

The primary goal of this research was to investigate the effects associated with the application of magnetic fields to single electrodes.

Coherence Effects In Synchronously Pumped Mode‐Locked Dye Lasers, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

A formalism is developed for describing the evolution of picosecond mode‐locked pulses in synchronously pumped dye lasers. The finite phase memory of the molecular wave functions is included, and it is found that the resultant coherence effects can be dominant for operation close to exact synchrony. Considerations of the isotropic molecular orientational distribution and the finite vibrational relaxation times are also essential in obtaining quantitative agreement with experimental results.

Explicit Determination Of The Complex Refractive Index Of An Absorbing Medium From Reflectance Measurements At And Near Normal Incidence, R. M.A. Azzam

Electrical Engineering Faculty Publications

Measurement of reflectance at normal incidence R and its fractional change ΔR/R caused by a change of the angle of incidence from 0 to a small angle ϕ (ϕ≲ 20°) permits explicit determination of both the refractive index n and extinction coefficient k of an isotropic absorbing medium. The medium of incidence (ambient) is assumed to have a known refractive index (e.g., =1 for vacuum or air), and the incident light is either p or s linearly polarized.

Adaptive Delta Modulation, Aliuddin Ahmad

Theses

The objective of this thesis is the study of the performance of instantaneously companded adaptive delta modulation (ADM) systems in comparison with linear delta modulation (LDM) in terms of signal to quantization noise ratio (SNR). Various schemes for ADM are discussed and their advantages and disadvantages are indicated. SNRs are calculated by simulation, with IBM's continuous system modeling programming (CSMP) language being used as a tool for simulation. LDM, first and second order constant factor delta modulation (CFDM), has been simulated and responses for different types of input signals are presented.

Polarization-Preserving Single-Layer-Coated Beam Displacers And Axicons, R. M.A. Azzam, M. Emdadur Rahman Khan

Electrical Engineering Faculty Publications

A design procedure is described to determine the thicknesses of single-layer coatings of a given dielectric on a given metallic substrate so that any input polarization of light is preserved after two reflections at the same angle of incidence from a parallel-mirror beam displacer or an axicon. This is achieved by equalizing the net complex p and s reflection coefficients (also called the radial and azimuthal eigenvalues of an axicon) after two reflections. The net polarization-independent reflectance (insertion loss) of the device is computed and found to exceed the net minimum parallel reflectance of the uncoated device for incidence above …

Scheme To Polarization-Correct A Waxicon, R. M.A. Azzam

Electrical Engineering Faculty Publications

No abstract provided.

Stationary Property Of Normal-Incidence Reflection From Isotropic Surfaces, R. M.A. Azzam

Electrical Engineering Faculty Publications

The complex reflection coefficients for the parallel (p) and perpendicular (s) polarizations of light that are normally incident upon an isotropic surface are proved to be stationary with respect to small changes of the angle of incidence in the neighborhood of zero. This is true not only for a single interface between isotropic media but also for any one-dimensionally inhomogeneous or multilayer reflecting structure that is stratified in the direction of the surface normal. For incident light of certain intensity, phase, and polarization, the intensity, phase, and polarization of the reflected light all remain stationary with …

An Investigation To Model Radar Backscatter From Ridged First Year Sea Ice, Betty Lou W. Jackson

Electrical & Computer Engineering Theses & Dissertations

This thesis investigates the response of a radar type sensor, the microwave scatterometer, to meter scale roughness of first-year sea ice. The scatterometer measures the absolute backscattered power from a target, and use of the radar equation permits calculation of the surface reflectivity expressed as the radar scattering coefficient, σ⁰ also called the normalized radar cross section. This thesis develops an empirical, one dimensional model to predict the backscattered power from ridged first-year sea ice of known surface topography, by interpreting the surface as a series of angular facets and summing the proportional power from each facet. The model …

Thermal Hysteresis In Acoustic Resonators, Lee W. Casperson, Lloyd M. Davis, John D. Harvey

Electrical and Computer Engineering Faculty Publications and Presentations

In some applications of piezoelectrically driven acoustic resonators, the power dissipated in the resonating material may be sufficient to significantly change the temperature and hence the resonance frequency. A straightforward analysis shows that this effect can lead to severe hysteresis and thermal bistability. This model is in agreement with experiments that have been performed using a fused silica acousto‐optic modulator.

Remote Attitude Measurement Techniques, Frank John Elmer

Dissertations

A method has been developed for solving practical problems which can be expressed in terms of physical geometry. These problems often involve combining directional information observed by remotely located sensors reported in their own respective local coordinate systems. To transform this information into a common coordinate system, the attitude of the sensors must be measured with respect to this common coordinate system.

Physical geometry is a generalization of mathematical -geometry where objects define the endpoints of figures composed of ensembles of lines. A probabilistic approach has been taken which is based on the fundamental assumption that the objects can be …