Engineering Commons^™

Design And Applications Of Volume Holographic Optical Elements, Steven C. Dunn

Retrospective Theses and Dissertations

Volume gratings were studied both theoretically and experimentally in order to design and analyze practical volume holographic optical elements. The diffraction of finite (Gaussian) beams by transmission gratings is investigated. A closed form solution for the off-Bragg profiles is obtained, and the distortion in the resulting profiles is analyzed. Criteria for when the finiteness of the beam has a minimal effect on the angular selectivity response are given. A model is developed to investigate the cross talk in multiplexed gratings Experimental verification in LiNb0₃ and PTR glass is demonstrated. The diffraction efficiency and output profiles of finite beams diffracted …

Low Voltage Regulator Modules And Single Stage Front-End Converters, Wei Gu

Retrospective Theses and Dissertations

Evolution in microprocessor technology poses new challenges for supplying power to these devices. To meet demands for faster and more efficient data processing, modem microprocessors are being designed with lower voltage implementations. More devices will be packed on a single processor chip and the processors will operate at higher frequencies, exceeding 1GHz. New high-performance microprocessors may require from 40 to 80 watts of power for the CPU alone. Load current must be supplied with up to 30A/µs slew rate while keeping the output voltage within tight regulation and response time tolerances. Therefore, special power supplies and Voltage Regulator Modules (VRMs) …

Use Of Incremental Adaptation And Habituation Regimens For Mitigating Optokinetic Side-Effects, David A. Graeber

Retrospective Theses and Dissertations

The use of incremental and repeated exposures regimens have been put forth as effective means to mitigate visually induced motion sickness based on the Dual Process Theory (DPT) (Groves & Thompson, 1970) of neural plasticity. In essence, DPT suggests that by incrementing stimulus intensity the depression opponent process should be allowed to exert greater control over the net outcome than the sensitization opponent process, thereby minimizing side-effects. This conceptual model was tested by empirically validating the effectiveness of adaptation, incremental adaptation, habituation, and incremental habituation regimens to mitigate side-effects arising from exposure to an optokinetic drum. Forty college students from …

A Framework For The Implementation Of An Iso 9000 Based Certification Program For Printed Circuit Board Manufacturers, Adam Y. Maamoun

Retrospective Theses and Dissertations

ISO 9000:2000 is the newest version of the ISO 9000 family of standards. Unlike the 1994 version, it does not distinguish between servicing, testing and designing standards. It emphasizes quality improvement rather than quality control and briefly explains how to implement the Plan-Do-Check- Act (PDCA) cycle for improvement and the use of statistical techniques to improve the quality of process and product instead of controlling the quality of the output. The thesis explains why companies need to be certified and how to implement quality improvement programs.

The objective of this thesis is to provide generic certification guidelines for printed circuit …

Computing A Diameter-Constrained Minimum Spanning Tree, Ayman Mahmoud Abdalla

Retrospective Theses and Dissertations

In numerous practical applications, it is necessary to find the smallest possible tree with a bounded diameter. A diameter-constrained minimum spanning tree (DCMST) of a given undirected, edge-weighted graph, G, is the smallest-weight spanning tree of all spanning trees of G which contain no path with more than k edges, where k is a given positive integer. The problem of finding a DCMST is NP-complete for all values of k; 4 ≤ k ≤ (n - 2), except when all edge-weights are identical.

A DCMST is essential for the efficiency of various distributed mutual exclusion algorithms, where …