Digital Commons Network^™

Is There A Difference In Learning Styles Of Honors Versus Non-Honors Students As Assessed By The Geft?, Debra Lee Hollister

Retrospective Theses and Dissertations

No abstract provided.

Gate And Throughput Optimizations For Null Convention Self-Timed Digital Circuits, Scott Christopher Smith

Retrospective Theses and Dissertations

NULL Convention Logic (NCL) provides an asynchronous design methodology employing dual-rail signals, quad-rail signals, or other Mutually Exclusive Assertion Groups (MEAGs) to incorporate data and control information into one mixed path. In NCL, the control is inherently present with each datum, so there is no need for worse-case delay analysis and control path delay matching. This dissertation focuses on optimization methods for NCL circuits, specifically addressing three related architectural areas of NCL design.

First, a design method for optimizing NCL circuits is developed. The method utilizes conventional Boolean minimization followed by table-driven gate substitutions. It is applied to design time …

Scintillation Behind The Collecting Lens Of A Receiver, Clarissa A. Fleming Russell

Retrospective Theses and Dissertations

One of the negative effects that a laser beam experiences as it propagates through the atmosphere is intensity fluctuations or scintillation. Because scintillation-- as it pertains to laser radar and laser satellite communication systems-- is the main subject of this research, the assumption of an optical element ( such as a Gaussian lens) along the propagation path in front of the detector is valid. The mathematical addition of optical elements to the propagation path is treated using the ABCD ray matrix method. The expression for scintillation is derived, analyzed, and numerically calculated for positions to the left and right of …

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 …

A Comparative Study Of The Feeding Ecology Of Chelonia Mydas (Green Turtle) And The Incidental Ingestion Of Prorocentrum Spp, Karen Gayle Holloway Adkins

Retrospective Theses and Dissertations

The diets of green turtles from five dissimilar aggregations of juvenile C. mydas on the East Coast of Florida were analyzed. C. mydas were captured by tangle net from four of the study sites and a dietary sample was collected by an esophageal flushing technique. The gut content of stranded individuals was collected for the fifth site. The vegetation in these study areas differs in varying degrees of abundance and diversity. Analysis of the samples revealed the alga types preferred by green turtles from each population and provided the basis for examination of similarities and differences in their diets.

Large …

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 …

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) …

Ultrafast Nonlinear Spectrometer For Material Characterization, Raluca A. Negres

Retrospective Theses and Dissertations

This work describes the use of a broadband spectral source for nonlinear spectroscopy to characterize various materials with potential applications in confocal microscopy, biological sample markers, optical limiting devices and optical switches. The goal is to study the spectrum of nonlinear absorption and the dispersion of nonlinear refraction as well as the dynamics of the nonlinearities by means of femtosecond excite-­probe experiments.

The principle is quite simple: if a sample is under the influence of a strong fs excitation pulse and a pro be pulse beam is incident at the same time, or shortly after (within the decay time of …

An Adaptive Integration Architecture For Software Reuse, Denver Robert Edward Williams

Retrospective Theses and Dissertations

The problem of building large, reliable software systems in a controlled, cost-effective way, the so-called software crisis problem, is one of computer science's great challenges. From the very outset of computing as science, software reuse has been touted as a means to overcome the software crisis issue. Over three decades later, the software community is still grappling with the problem of building large reliable software systems in a controlled, cost effective way; the software crisis problem is alive and well. Today, many computer scientists still regard software reuse as a very powerful vehicle to improve the practice of software engineering. …

A Unified Approach To Dynamic Modeling Of High Switching Frequency Pwm Converters, Christopher J. Iannello

Retrospective Theses and Dissertations

This dissertation will present the development of a unified approach for dynamic modeling of the PWM and soft-switching power converters. Dynamic modeling of non-linear power converters is very important for the design and stability of their closed loop control. While the use of equivalent circuits is often preferred due to simulation efficiency issues, no unified and widely applicable method for the formulation of these equivalents exists.

A review of conventional modeling technique via the method of state-space averaging will be carried out. Complete development of the averaged, equivalent circuit models for the nonlinear power switch/diode combination in modem power converters …

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 …

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 …