Digital Commons Network^™

Precise Frequency Control Of The Voltage Controlled Oscillator Using Finite Digital Word Lengths, Timothy Peter Hulick

Electrical & Computer Engineering Theses & Dissertations

For an oscillator that is periodically swept in frequency between some upper and lower bound, the output amplitude may easily be made constant and therefore known with a high degree of certainty. The instantaneous frequency exists only at a point in time and therefore possesses a zero probability of existing at any point. This thesis deals with the development of a method for interchanging the probability density functions of amplitude and frequency so that the latter becomes known with certainty while the former is known only to the extent that it is within a certain range.

The method developed makes …

Single Particle Scattering With Focused Laser Beams, Lee W. Casperson, Cavour W. Yeh

Electrical and Computer Engineering Faculty Publications and Presentations

A scattering technique is described in which the incident laser beam is tightly focused to isolate the effects of a single particle. In this way the individual particles may be studied in their natural environment, and experiments with latex spheres are in agreement with the theory.

Probability Of Anomaly Expressions For Random Waveform Registration, George L. Bair, Gordon E. Carlson

Electrical and Computer Engineering Faculty Research & Creative Works

Registration by integral-square error correlation of one-dimensional Discrete Time waveforms which are treated as random processes with specified autocorrelation functions is considered. An important design parameter for this class of problems is the probability of anomaly (a false dip in the correlation function) because it gives an indication of system immunity to gross registration errors. Explicit expressions for this parameter are not possible, so bounds and approximations must be derived. Two upper bounds and an approximation for the probability of anomaly are derived here. The use of these expressions is illustrated by an example. The relative utility of these performance …

Signal Processing For The Multistate Myoelectric Channel, Philip A. Parker, John A. Stuller, R. N. Scott

Electrical and Computer Engineering Faculty Research & Creative Works

In the Multistate Myoelectric Channel, a Single Myoelectric Signal Source is Used to Control a Multifunction Powered Prosthesis. the Selection of a Prosthesis Auction Requires a Receiver to Process the Myoelectric Signal, Contaminated with Noise, and to Decide on the Basis of the Received Signal Which Function is Desired. Thus, the Channel Dearly Presents a Problem of Choice of Receiver and of Decision Strategy. Previous Solutions to This Problem Have Been Basically Empirical. in This Paper We Seek the Optimum Receiver Where Optimum is in the Minimum Probability of Error Sense. First a Model is Developed for the Bipolar Myoelectric …

The Attenuation Of Acoustic-Gravity Waves In A Slightly Dissipative Atmosphere, R. (Richard) E. Dubroff, K. C. Yeh, C. H. Liu

Electrical and Computer Engineering Faculty Research & Creative Works

This Paper is Concerned with Computation of the Attenuation Coefficient of Internal Acoustic-Gravity Waves in a Slightly Dissipative Horizontally Stratified Atmosphere. Two Models Are Generally Used in Deriving This Attenuation Coefficient. in One Model, the Nonlinear Hydrodynamic Equations Are Analyzed by using a Stokes Expansion and the WKB Solutions to the Linearized Perturbations Are Sought by using the Coupled Mode Formulation. in the Second Model, the Attenuation is Viewed as the Dissipation of Pseudo energy. We Show in This Paper that in a Slightly Dissipative Atmosphere, These Two Models Give Identical Results as Far as Computation of the Attenuation Coefficient …

Threshold Characteristics Of Mirrorless Lasers, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Detailed analytical expressions are developed for the output power and spectral characteristics of high‐gain mirrorless laser amplifiers. With regard to intensity variations and spectral narrowing, such lasers are similar in behavior to conventional laser oscillators. A threshold transition region is apparent as saturation sets in, and spectral rebroadening occurs in inhomogeneously broadened laser systems. These solutions take full account of saturation by both the right and left propagating radiation, and the results agree with experiments that have been reported.

Control Of Population Densities Surrounding Nuclear Power Plants, A. V. Nero, C. H. Schroeder, W. W.S. Yen

Faculty Scholarship

In view of the requirement that the California Energy Resources Conservation and Development Commission must specify land-use/population density control measures to be used in the vicinity of nuclear power plants being granted land use, the possible forms of such measures are examined. Since these measures must maintain population densities below Nuclear Regulatory Commission criteria, if appropriate, NRC criteria for land use and population densities are given particular attention. In addition, a preliminary comparison of the cost of possible control measures with the reduced potential for damage to the public health and safety is made, yielding the result that control measures …

Beam Modes In Complex Lenslike Media And Resonators, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

General sets of higher-order beam modes are derived for light propagation in media having spatial variations of the gain or loss. The resulting expressions are also valid for propagation through conventional optical elements and graded transmission filters. The four basic mode sets obtained include off-axis Hermite-Gaussian and Laguerre-Gaussian modes of both real and complex argument. A procedure is developed for finding the resonant modes of laser oscillators containing arbitrary complex lens elements, and the mode stability properties of lasers can be interpreted physically by means of these formulas.

Reply To “Comment On 'Resonance Raman Scattering And Collision-Induced Redistribution Scattering In I2’ ”, D. L. Rousseau, G. D. Patterson, P. F. Williams

P. F. (Paul Frazer) Williams Publications

We demonstrate that neither laser broadening nor inelastic collisional broadening plays a dominant role in the data of our recent experiments as has been suggested, and again we conclude that our results can only be explained by redistribution emission resulting from phase-changing processes.

Pulse Evolution In Co₂ Lasers, Lee W. Casperson, M. J. Herbst, John J. Turechek

Electrical and Computer Engineering Faculty Publications and Presentations

Explicit formulas are examined for the development of optical pulses in gain‐switched or Q‐switched laser oscillators and for the distortion of such pulses in succeeding stages of laser amplification. The results are compared to data obtained with a TEA CO₂ oscillator‐amplifier system.

Optimal Fuel Supply Control For Electrical Energy Systems -- A Real Time Computer Technique, J. Derald Morgan, Richard Thomas Smith

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

The techniques of linear-integer programming are applied to the problem of supplying coal to power plants. A heuristic technique for optimizing the supply of coal to power companies is created. The optimization minimizes the purchase, transportation, and demurrage costs of coal subject to power system operations, power plant demands, coal purchase supply, power plant coal handling operations, and transport options. A procedure for calculation and analysis of cost sensitivity of optimal solutions to input data perturbations is presented which utilizes the optimizing technique.

The nature of the constraint set developed allows for the inclusion of loading and unloading operations in …

Analytic Modeling Of Gain‐Switched Lasers. I. Laser Oscillators, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Detailed mathematical models are derived for the evolution of light pulses in gain‐switched laser oscillators. Unlike previous instantaneous‐switching models, arbitrary pump and spontaneous relaxation rates are considered. Explicit expressions are obtained for the gain and pulse characteristics in several practical situations, and both homogeneous and inhomogeneous limits are considered. By proper adjustment of the laser pump any output‐pulse shape can be obtained. The results are especially relevant for recent short‐pulse ultraviolet lasers and also for more conventional devices such as TEA CO₂ lasers.

Analytic Modeling Of Gain‐Switched Lasers. Ii. Laser Amplifiers, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

The pulse transfer characteristics of gain‐switched laser amplifiers are investigated analytically. New closed‐form solutions have been obtained including arbitrary space‐ and time‐dependent pump distributions. The general results are specialzied to the important cases of uniform and traveling‐wave excitation. Input‐pulse shapes considered include step functions, practial oscillator output pulses, and also the inherent spontaneous‐emission noise. The results lead to improved models for pulse amplifiers and mirrorless traveling‐wave lasers. By proper choice of pump characteristics arbitrary output‐pulse waveforms can be synthesized.

Application Of Multilevel Control Techniques To Classes Of Distributed Parameter Plants, Frederick Donald Chichester

Dissertations

This study concerns the application of a combination of multilevel hierarchical systems analysis techniques and Pontryagin's minimum principle (multilevel control) to the problem of controlling optimally two classes of dynamic distributed parameter plants representing concentrations balances in streams, rivers and estuaries. The concentrations treated in this study are those deemed the most effective indicators of water quality, dissolved oxygen (DO) and biochemical oxygen demand (BOD).

One class of plants treated in this study consists of linear continuous distributed parameter plants represented mathematically by sets of simultaneous partial differential equations. Optimal control of a plant of this class is initiated by …

The Topolotron: A High Beta Device With Topological Stability, Keith H. Brown, H. R. P. Ferguson, J. H. Gardner, Larry V. Knight, H. Mark Nelson

Faculty Publications

The concept of topological or structural stability is introduced and its importance in the magnetic confinement of plasmas is discussed. Topological stability requires the presence of a pair of limit cycles in the magnetic field configuration. This paper deals with the design of an experimental device possessing limit cycles. The design includes a high beta (b=1), high density (10^16), hot (100 eV) hydrogen plasma which is to be compressed by a factor of about 5 in a torodial device of 25 cm average major radius with a capacitor bank rise time of less than 2 µsec. Two shaped toroidal coils …

Ohmic Magnetoresistance In Nonparabolic Semiconductors: Application To N-Insb, Mahmoud Jaafarian

Masters Theses

No abstract provided.

Frequency-Mixing Detection (Fmd) Of Polarization-Modulated Light, R. M.A. Azzam

Electrical Engineering Faculty Publications

When a light beam whose polarization and intensity are weakly modulated at a frequency ω_m passes through a periodic analyzer of frequency ω_a(<ω_m) and the transmitted flux is linearly detected, the resulting total signal S_t consists of two components: (i) a periodic baseband signal S_bb with harmonics of frequencies nω_a (n = 0,1,2,…) and (ii) an amplitude-modulated-carrier signal δS_mc with center (carrier) frequency ω_m and sideband frequencies at ω_m ± nω_a(n = 1,2,…). In this paper we show that the average polarization of the beam is determined …

The Effects Of Optical Path Perturbations During Recording On A Reconstructed Holographic Image, Stevan Israel Feldman

Dissertations

The effects of optical path perturbations occurring during recording on the reconstructed image of a hologram are investigated. It is shown that such variations of optical path are equivalent to conditions of holographic interferometry which can be classified in three categories: 1) object motion alone, 2) film motion alone, and 3) simultaneous film and object motion; all motions are defined with respect to the stationary reference source during the recording of the hologram.

The theory concerning the effects of object motion alone on the radiance distribution of a reconstructed holographic image has already been developed by previous researchers and is …

Modulated Generalized Ellipsometry, R. M.A. Azzam

Electrical Engineering Faculty Publications

We extend ellipsometry to the direct measurement of small perturbations of the Jones matrix of any linear nondepolarizing optical sample (system) subjected to a modulating stimulus such as temperature, stress, or electric or magnetic field. The methodology of this technique, to be called Modulated Generalized Ellipsometry (MGE), is presented. First an ellipsometer with arbitrary polarizing and analyzing optics is assumed, and subsequently the discussion is specialized to a conventional ellipsometer having either the polarizer-sample-analyzer (PSA) or the polarizer-compensator-sample-analyzer (PCSA) arrangement. MGE provides the tool for the systematic study of thermo-optical, piezo-optical, electro-optical, magneto-optical, and other allied effects for both isotropic …

Comment On “Two-Magnon Resonant Raman Scattering In Mnf2”, D. L. Rousseau, R. E. Dietz, P. F. Williams, H. J. Guggenheim

P. F. (Paul Frazer) Williams Publications

We have not been able lo reproduce the recently reported resonance enhancement of Raman scattering from magnons in MnF₂ by Amer, Chiang, and Shen. Fifteen crystals ranging from extremely pure samples to ones with high concentrations of impurities, in addition to one supplied by Amer, Chiang, and Shen, were investigated. By observing the off-resonance scattering, we conclude that if an enhancement of greater than a factor of 2 were present, it would have been seen in our resonance spectra.

Resonance Raman Scattering Of Light From A Diatomic Molecule, D. L. Rousseau, P. F. Williams

P. F. (Paul Frazer) Williams Publications

No abstract provided.

Wind-Powered Hydrogen Electric Systems For Farm And Rural Use, Final Report, United States Department Of Energy

Agriculture

The objective of this study has been to determine the current technology of a wind-energy conversion system (WECS) of minimal cost for rural applications. Specifically, IGT has evaluated available methods for converting shaft horse-power from a wind turbine to electricity and hydrogen. A workable mix of these two energy forms with storage that can support the energy needs of selected farming operations and the rural home was sought.

Energy load patterns of several farming operations were examined for interfacing with the energy storage and delivery systems that are supplied by wind turbines dependent on the prevalent winds. Several preliminary designs …

An Efficient Dft Algorithm Using The Walsh Transform, Albert P. Gerheim

Electrical & Computer Engineering Theses & Dissertations

The matrix transformation relating the sequency and frequency domains is derived. It is shown that these­ frequency-to-frequency conversion can be performed via a computationally efficient sparse matrix algorithm. The sequency-to-frequency algorithm can be used with a fast Hadamard transform to implement a discrete Fourier trans­ form. The efficiencies of this combined algorithm and a radix-two fast Fourier transform are compared.

The algorithm is applied to the sequency domain de­ sign of a Wiener digital filter. Improved computational efficiencies are achieved relative to the procedure de­veloped by Kahveci and Hall (9).

Some Comments On The Plasmon Spectrum Of Tetrathiafulvalene Tetracyano-P-Quinodimethane (Ttf- Tcnq), P. F. Williams, A. N. Bloch

P. F. (Paul Frazer) Williams Publications

Our random-phase-approximation model calculation of the high-frequency dielectric response of a quasi-one-dimensional metal is generalized to the case of n conducting strands per unit cell. For a model of the two-band system tetrathiafulvalene tetracyano-p-quinodimethane we obtain good agreement with recent experiments, and also predict an acoustic-plasmon branch, Some implications for the physics of the material are discussed.

Computer Analysis Of 3-Phase Induction Motor Operation On Rural Open-Delta Distribution Systems, Stephen C. Seematter, Earl F. Richards

Electrical and Computer Engineering Faculty Research & Creative Works

Open-delta/open-delta and open-wye/open-delta transformer banks are often used as an economic means of supplying simultaneous single-phase and 3-phase loads in rural areas. If the 3-phase load is an induction motor, the inherent voltage unbalance causes increased losses and uneven heating that may lead to motor failure. Often these motors are submersible or deep well pump motors located in remote unattended areas or air conditioning motors which may not have sufficient over-design to handle the voltage unbalance. The theory analyzing the open-delta distribution system has existed for many years, however, because of the tedious and almost infinite differences in distribution topology, …

A Suboptimal Control Law To Improve The Transient Stability Of Power Systems, Aditya Kumar, Earl F. Richards

Materials Science and Engineering Faculty Research & Creative Works

The application of optimal control theory to damp the electromechanical oscillations associated with the transient conditions in power systems has been given little attention. A suboptimal control law which minimizes the sum of the performance indices of the two linear systems given by a piecewise linear model of a power system improves the transient stability better than the usual "optimal" control law obtained from a linearized model. Further, the suboptimal control law presented in this paper assures stability of the system for all disturbances resulting in rotor oscillations of magnitudes less than a preselected limit. Copyright © 1976 by The …

3rd Annual Umr-Mec Conference On Energy -- Entire Proceedings, University Of Missouri--Rolla

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

No abstract provided.

Design Of Film-Substrate Single-Reflection Linear Partial Polarizers, R. M.A. Azzam, A.-R. M. Zaghloul, N. M. Bashara

Electrical Engineering Faculty Publications

The results of a preceding paper [J. Opt. Soc. Am. 65, 1464,(1975)] are viewed from a different angleas providing the basis for the design of film-substrate single-reflection linear partial polarizers (LPP),which also operate as reflection optical rotators. The important characteristics of a comprehensive set of discrete designs of SiO₂-Si LPP’s at λ = 6328 Å are shown graphically.

Polarizer-Surface-Analyzer Null Ellipsometry For Film-Substrate Systems, R. M.A. Azzam, A.-R. M. Zaghloul, N. M. Bashara

Electrical Engineering Faculty Publications

Single-pass polarizer-surface-analyzer null ellipsometry (PSA-NE) can be used to characterize film-substrate systems, provided that the film thickness lies within one of a set of permissible-thickness bands (PTB). For a transparent film on a transparent or absorbing substrate, the PTB structure consists of a small number of finite-bandwidth bands followed by a continuum band that extends from a film thickness of about half the wavelength of light to infinity. We show that this band structure is a direct consequence of the periodicity of the ellipsometric function ρ (the ratio R_p/R_s, of the complex amplitude-reflection coefficients for …

Threshold Characteristics Of Multimode Laser Oscillators, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

The oscillation characteristics of a multimode laser are considered in detail, and for the first time saturation by all of the cavity modes is included. Analytical expressions are obtained for the mode amplitudes, linewidths, and over‐all spectral characteristics of lasers operating above and below threshold. It is found that with increasing excitation the spontaneous emission spectrum is gradually resolved into a set of narrow discrete modes. Slightly above threshold the number of modes reduces in a homogeneoulsy broadened laser until only a single mode is oscillating strongly. The theoretical results are in agreement with experimental data that have been reported …