This thesis describes the design of a device for generating a reproduceable noise signals. The noise signal is generated by adding three periodic waveforms having non-multiple periods. Pulse techniques are used in the generation of the member functions so that the output may be reproduced exactly. Theoretical and experimental determinations of the amplitude probability distribution and of the autocorrelation function of the signal were made. On the basis of tests and observations made, it is concluded that the signal generated may be considered a noise signal having a near-Gaussian amplitude probability distribution, very little correlation for time-shifts greater than 30 seconds, and a bandwidth of about 60 cps. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

Thesis PlanB (M.S.)--University of Wisconsin--Stout, 2009. / Includes bibliographical references.

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The transient response of one-dimensional nonuniform dispersive media is studied through the use of numerical techniques for the inversion of the Laplace transforms of the transient signals. The media considered are those in which the permittivity varies in one spatial dimension only and for which an analytical or numerical solution of the wave equation can be obtained. Two numerical techniques for the inversion of Laplace transforms are used, one in which the inverse transform is obtained in terms of a series of generalized Laguerre polynomials and the other in which the inverse is obtained by direct numerical integration of the complex inversion integral. Responses are calculated for the following cases; (a) a uniform isotropic plasma, (b) dielectric media with a piecewise linear variation in permittivity and (c) isotropic cold plasmas with a piecewise linear variation in electron density, for step-modulated and rectangular-pulse-modulated carrier input signals. It is shown that the results for case (a) compare favorably with the known exact solution, for a unit-step-modulated carrier input signal. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

D.Ing. (Electrical And Electronic Engineering) / Please refer to full text to view abstract

In recent years the United States Navy has concentrated most of its Anti-Submarine Warfare (ASW) research and development efforts toward passive sonar. Its ability to locate enemy targets without being detected gives the passive sonar system a supreme strategic advantage over its active counterpart. One aspect of passive sonar signal processing is the time delay estimation of an underwater acoustic wavefront. From this estimation the location and velocity of the radiating source (target) can then be determined. This report compares two popular methods of estimating time delay utilizing computer simulations of each: the cross correlator and the beamformer.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Current rates of technological advancement continue to translate into changes on our battlefields. Aerial robots capable of gathering reconnaissance along with unmanned underwater vehicles capable of defusing enemy minefields provide evidence that machines are playing key roles once played by humans within our military. This thesis explores one of the major problems facing both commercial and military UUVs to date. Successfully navigating in unfamiliar environments and maneuvering autonomously to avoid obstacles is a problem that has yet to be fully solved. Using a simulated 2-D ocean environment, the work of this thesis provides results of numerous REMUS simulations that model the vehicle's flight path over selected sea bottoms. Relying on a combination of sliding mode control and feedforward preview control, REMUS is able to locate obstacles such as seawalls using processed forward look sonar images. Once recognized, REMUS maneuvers to avoid the obstacle according to a Gaussian potential function. In summary, the integration of feedforward preview control and sliding mode control results in an obstacle avoidance controller that is not only robust, but also autonomous.

Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr. Jim P. Zheng, Florida State University, College of Engineering, Dept. of Electrical and Computer Engineering. Title and description from dissertation home page (viewed June 18, 2004). Includes bibliographical references.

Thesis (M.S. in Modeling, Virtual Environments and Simulation (MOVES))--Naval Postgraduate School, March 2004. / Thesis advisor(s): Christian Darken, Curtis Blais. Includes bibliographical references (p. 103-104). Also available online.