Thesis (Ph.D.)--University of Delaware, 2007. / Principal faculty advisor: Charles G. Boncelet, Dept. of Computer & Information Sciences. Includes bibliographical references.

This thesis is concerned with the adaptive adjustment of digital data receivers employed m synchronous serial data transmission systems that use quadrature amplitude modulation The receiver employs a pre-detection filter that forms the first part of a decision feedback equalizer or else is used ahead of a near maximum-likelihood detector. The filter is ideally adjusted such that the sampled impulse response of the channel and filter is minimum phase.

A monochromatic image can be represented by a real function f(x,y,t) of two spatial variables and time. Picture transmission research is directed at finding methods of transmitting a facsimile of f(x,y,t) at minimum cost which still satisfies some quality criteria. The ensemble of source, functions, and the measures of cost and quality are defined by the application. For many applications, the subjective quality is an important measure of performance. Generally, it is difficult if not impossible to find a tractable analytic relationship between the source and system parameters, and the subjective quality. Thus,for picture processing research, equipment must be available for simulating proposed systems so that pictures can be produced and estimates made of the subjective quality. This thesis will describe a system which was devised for studying low resolution picture transmission systems. The system employs an image dissector to input picture data to a PDP-9 computer. The data can be stored on magnetic tape, processed and then displayed on a picture output device which employs a Tektronix 561 Oscilloscope. A set of general purpose programs was developed for manipulating picture data using this hardware configuration. Three test pictures were read in and particular programs were written to calculate some picture statistics. The statistics include signal histograms, auto-covariance functions and, some run length statistics for the two level material. These statistics were then used as design information for some simulation programs. A program was written to simulate Pulse Code Modulation (PCM) and Differential Pulse Code Modulation (DPCM) systems in order to evaluate the subjective effect of channel errors on pictures transmitted by PCM and DPCM. An attempt was also made to develop a simple two-dimensional filter program to reduce the effect of channel noise. Since the channel noise in the PCM and DPCM systems produced two-dimensional noises which were very different in appearance, two filtering routines were necessary. Subjective rating tests were conducted to evaluate the filtered and unfiltered PCM and DPCM pictures. For the unfiltered systems, these tests indicate that for good channels, the DPCM system is better than the PCM system while for very bad channels, the pictures produced by the PCM system are subjectively better than those of a DPCM system using the same number of bits. It was found also that the PCM filter proposed, improved the noisy pictures while the proposed DPCM filter produced no improvement and even lowers the quality of some of the pictures. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

We present a design for a remote database access facility, which uses a message system as its communication medium. Adopting a message-based design offers a number of advantages over more conventional connection-oriented architectures for those remote database applications where the interaction between user and DBMS involves a single query followed by a single result. By complying with the CCITT X.400 Recommendations on Message Handling Systems, the design allows for networkwide access to remote DBMSs that is independent of the nature of DBMSs being accessed, the systems on which they reside and the network over which they are accessed. An initial implementation using the EAN distributed message system, developed at the University of British Columbia, is described as a means of demonstrating the design's feasibility. / Science, Faculty of / Computer Science, Department of / Graduate

No description available.

M.Ing. (Electrical and Electronic Engineering Science) / This study presents a simple methodology developed to set up and establish a simplex communication system over a power line using load signatures. Traditional concepts such as normalization and matched filtering form the core of these algorithms. The analysis also relies extensively on the voltage and current measurements made over a fixed period of time on a single phase. Furthermore, analyses on the capacity of this kind of system are also presented, taking into consideration various disturbances.

Thesis (M.S.)--University of Delaware, 2006. / Principal faculty advisor: Javier Garcia-Frias, Dept. of Electrical and Computer Engineering. Includes bibliographical references.

Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, March 2004. / Thesis advisor(s): John C. McEachen. Includes bibliographical references (p. 67-68). Also available online.

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 94-102). Available also in a digital version from Dissertation Abstracts.

This thesis describes computer simulations of a new wavefront sensing technique for Adaptive Optics based on local wavefront curvature measurements, along with edge slope measurements. The output signal from the curvature measurements, along with edge slope measurements. The output signal from the curvature sensor can be directly applied to the electrodes of a bimorph or membrane mirror. The mirror is used as an analog device to solve the Poisson Equation, providing a fast real time compensation for atmospheric disturbances. The open loop characteristics of the system are presented. The ideal response is analyzed, and side effects such as non-linearity, photon and diffraction noises are discussed. Closed loop simulations are presented thereafter. A seven actuator system showed a few unstable modes. A 13 actuator system with proper filtering corrects the atmospheric perturbations. To simulate atmospheric distorted wavefronts, an algorithm based on spectral decomposition of the Zernike covariance matrix was derived. This sensor can also be used to test large telescope mirrors using a modified program that solves the Poisson Equation with Neumann boundary conditions.