Digital Commons Network^™

Bandwidth, Edgesum And Profile Of Graphs, Yung-Ling Lai

Dissertations

No abstract provided.

The Design And Fabrication Of A Thermal Microprobe Integrated On An Atomic Force Microscope Probe Tip, Yongxia Zhang

Dissertations

A thermal microprobe has been designed and built for high resolution temperature sensing. The thermal microprobe consists of a very-thin-film thermocouple junction confined to the very end of a low mass Atomic Force Microscope (AFM) probe tip. Essential to high resolution temperature sensing is the confinement of the thermocouple junction to a short distance at the AFM tip. This confinement is achieved by controlled photoresist coating.

Experimental prototypes have been made with the junction confined to within 0.3 µm of the tip. The couple is made of Au/Pd, and the two metals are electrically separated elsewhere by a thin insulating …

Efficient Parallel Processing With Optical Interconnections, Lili Hai

Dissertations

With the advances in VLSI technology, it is now possible to build chips which can each contain thousands of processors. The efficiency of such chips in executing parallel algorithms heavily depends on the interconnection topology of the processors. It is not possible to build a fully interconnected network of processors with constant fan-in/fan-out using electrical interconnections. Free space optics is a remedy to this limitation. Qualities exclusive to the optical medium are its ability to be directed for propagation in free space and the property that optical channels can cross in space without any interference. In this thesis, we present …

Adaptive Space-Time Processing For Digital Mobile Radio Communication Systems, Amit Shah

Dissertations

The performance of digital mobile radio communication systems is primarily limited by cochannel interference and multipath fading. Antenna arrays, with optimum combining (OC), have been shown to combat multipath fading of the desired signal and are capable of reducing the power of interfering signals at the receiver through spatial filtering. With OC, the signals received by several antenna elements are weighted and combined to maximize the output signal-to-interference-plus-noise ratio (SLNR). We derive new closed-form expressions for (1) the probability density function (PDF) of the SINR at the output of the optimum combiner, (2) the average probability of bit error rate …

An Investigation Of The Oxygraphic Response Of Stressed Bovine Blood, Cristin Mckenna

Dissertations

Oxygraphic profiles of stressed bovine blood in a temperature controlled 2 ml reactor vessel provide the basis for an investigation of blood's response to various conditions. This response is broken down into an initial response (within 3 seconds), the response over 1 hour and the response over 24 hours. Fast-assay runs which investigate the initial response display a dose-response relationship when chemically stressed by phenol. Phenol concentrations in the 1,000 ppm range indicate a decrease in dissolved oxygen (DO) and higher phenol concentrations of over 20,000 an increase in DO. In addition to phenol concentration, other factors investigated with respect …

Development Of A Mathematical Model Of Gait Dynamics, Tae Ho Choi

Dissertations

There exists hypothesis that gait selection is strongly correlated with mechanical energy efficiency in normal subjects. The hypothesis is experimentally proven, and intuitively taken for granted. However, it is not mathematically proven that the minimum energy consumption hypothesis is the underlying principle for the normal human gait. To prove the hypothesis we have developed a mathematical model of human walking, in which it is possible to predict an optimal gait at any given speed of walking based on the principle of minimum mechanical energy consumption.

This improved model, which includes the double-support phase of walking as well as the swing …

Particle Deposition From Turbulent Flow In A Divergent Channel, Wai-Ting Huang

Dissertations

This dissertation presents a numerical analysis of particle deposition from a dilute gas-solid two-phase suspension in a divergent channel. The Lagrangian governing equations for particle motion include inertia force, viscous force, gravity force and image force from electrostatic charge on the particle. The incompressible two-dimensional turbulent flow field in a divergent channel is solved by employing a Κ-ε modeling technique with FIDAP finite element CFD software. A computational procedure is developed to incorporate the flow field into numerical simulation of particle trajectories from which the fraction of deposition is determined. Several divergent channels (half divergent angles of 0°, 7.5°, 10° …

Scheduling In Assembly Type Job-Shops, Nutthapol Asadathorn

Dissertations

Assembly type job-shop scheduling is a generalization of the job-shop scheduling problem to include assembly operations. In the assembly type job-shops scheduling problem, there are n jobs which are to be processed on in workstations and each job has a due date. Each job visits one or more workstations in a predetermined route. The primary difference between this new problem and the classical job-shop problem is that two or more jobs can merge to foul' a new job at a specified workstation, that is job convergence is permitted. This feature cannot be modeled by existing job-shop techniques. In this dissertation, …

Multi-Wavelength Infrared Imaging Computer Systems And Applications, Jun Li

Dissertations

This dissertation presents the development of three computer systems for multi-wavelength thermal imaging.

Two computer systems were developed for the multi-wavelength imaging pyrometers (M-WIPs) that yield non-contact temperature measurements by remotely sensing the surface of objects with unknown wavelength-dependent emissivity. These M-WIP computer systems represent the state-of-art development in remote temperature measurement system based on the multi-wavelength approach. The dissertation research includes M-WIP computer system integration, software development, performance evaluation, and also applications in monitoring and control of temperature distribution of silicon wafers in a rapid thermal process system.

The two M-WIPs are capable of data acquisition, signal processing, system …

Modeling Of 3d Swept Volumes Using Sde/Sede Methods And Its Application To Five-Axis Nc Machining, Liping Wang

Dissertations

This research falls in two important areas in solid modeling and manufacturing automation: (1) swept-volume modeling; (2) computer-based NC (Numerically controled) machining simulation and verification. The swept volume is defined as the volume swept by an object undergoing an arbitrary motion. Modeling of 3D swept volumes includes the boundary computation and representation of a swept volume generated by a general object undergoing general motion in three dimensional space. The Sweep Differential Equation (SDE) and Sweep Envelope Differential Equation (SEDE) methods are two of the important swept volume modeling methods employed in this dissertation. They exploit differential equations to obtain the …

High Speed Protocols For Dual Bus And Dual Ring Network Architectures, Yaling Zhou

Dissertations

In this dissertation, two channel access mechanisms providing fair and bandwidth efficient transmission on dual bus and dual ring networks with high bandwidth-latency product are proposed. In addition, two effective priority mechanisms are introduced to meet the throughput and delay requirements of the diverse arrays of applications that future high speed networks must support.

For dual bus architectures, the Buffer Insertion Bandwidth Balancing (BI_BWB) mechanism and the Preemptive priority Bandwidth Balancing (P_BI_BWB) mechanism are proposed. BI_BWB can significantly improve the delay performance of remote stations. It achieves that by providing each station with a shift register into which the station …

Sampling And Analysis Of Trace Level Volatile Organic Compounds From Air Via Membrane Permeation, Naihong Zhu

Dissertations

The objective of this study is to develop air sampling techniques using membrane permeation. Two novel techniques for sampling and analysis of trace level VOCs from air via membrane permeation are presented:

1. selective concentration of VOCs into a canister using a membrane permeator;
2. on-line membrane extraction for direct introduction of VOCs from air emissions into a gas chromatograph.

In the membrane permeator-canister sampling system (MPCS), the air sample containing trace level VOCs as well as some interferences such as moisture are passed through the membrane module. Polydimethyl siloxane membrane used in this research is highly permeable to organic compounds, but …

On Document Filing Based Upon Predicates, Zhijian Zhu

Dissertations

This dissertation presents a formal approach to modeling documents in a personal office environment, proposes a heterogeneous algebraic query language to manipulating objects (folders) in the document model, and investigates a predicate-driven document filing system for automatically filing documents.

The document model was initially proposed in [38] which adopts a very natural view for describing the office documents using the relational and object-oriented paradigms. The model employs a dual approach to classifying and categorizing office documents by defining both a document type hierarchy and a folder organization. This dissertation extends and specifies formally the document model. Documents are partitioned into …

Membrane-Based Reactors For Ozonolysis Of Organic Pollutants In Aqueous And Gaseous Streams, Purushottam V. Shanbhag

Dissertations

Many gaseous and aqueous waste streams contain multiple organic pollutants at low concentration levels. It is not economical to recover and reuse these compounds; it would be advantageous to destroy them efficiently within the waste stream. This work employed ozone, a powerful oxidizing agent, in concert with a compact membrane-based phase-contacting device. Three types of membrane devices were studied: two of them (the single-phase membrane ozonator and the two-phase membrane ozonator) treated organic pollutants in wastewater, while the third (the integrated absorption-oxidation membrane ozonator) removed volatile organic compounds (VOCs) from a gaseous waste stream.

In the single-phase membrane ozonator, the …

The Fatigue Problems Of Cracks Subjected To Obliquely Incident Stress Waves, I-Chung Weng

Dissertations

Catastrophic failure of aircraft and other structures are often caused by undetected cracks. Fracture mechanics has been developed to augment traditional static and fatigue design. In the static theory of fracture mechanics, extensive treatment has been given to the stress distribution around sharp cracks and notches under various loading conditions. Previous works on the problems of dynamic loadings are not accurate in dealing with singularities at high frequencies. The numerical solutions become unrealistic at high frequencies in many practical applications.

To address the need to obtain the stress intensity factor in high frequency dynamic loading situations, we studied the use …

Role Expectation Of Chief Nurse Executive Officers In Integrated Healthcare Systems Located In Highly Managed Care Markets, Daniel L. Gross Dnsc

Dissertations

The healthcare industry is undergoing radical transformation. Healthcare's transformation is characterized by new patterns of organization, alliance, management, administration, and governance. Traditional fee-for-service reimbursement strategies are rapidly dissolving and managed health care is proliferating. Managed care and managed competition are forcing hospitals and healthcare providers to reduce expenses and identify improved methods for healthcare delivery. Integrated healthcare delivery systems (IDSs) and networks are at the center of healthcare reform. Chief Nurse Executive Officers (CNEOs) are increasingly finding themselves in roles within complex IDSs located within highly managed care markets (HMCMs). This new work environment is altering old and mandating new …

Study Of Impurity Modes In Photonic Crystals And Study Of Power Gaas Mesfets, Michael G. Khazhinsky

Dissertations

The dissertation consists of two projects. In the first project, impurity modes in Photonic Crystals are studied in one- and two-dimensional Photonic Crystals. Onedimensional systems are formed from an infinite layered array of dielectric slabs and are studied for linearly polarized electromagnetic waves propagating perpendicular to the plane of slabs. Two-dimensional systems consist either of parallel cylindrical dielectric rods in vacuum or cylindrical holes containing vacuum in dielectric medium. These rods/holes are arranged in a square lattice array. The electromagnetic waves in these system propagate perpendicular to the axes of the rods and are of E or H polarization. Green’s …

Reconstruction Of Wetland Hydrology Dynamics Using Tree Rings, Allan P. Hascall Iii

Dissertations

Increment core samples were collected and examined to test the hypothesis that the history of punctuated or intermediate-term changes in wetland soil-moisture conditions can be reconstructed from the annual growth-ring record of trees. The hypothesis is based on plant physiological principles that indicate a relationship between water surplus stress and impaired physiological activity that could lead to reduced growth.

Sampling sites were selected for their ostensible historic hydrologic variability and the availability of documentation of hydrologic disturbances. A conceptual model was developed by which trees were sampled along a hydrotopographic gradient for comparison of radial stem growth in uplands versus …

Analytical Solutions Of Openings Formed By Intersection Of A Cylindrical Shell And An Oblique Nozzle Under Internal Pressure, Hengming Cai

Dissertations

Since several decades ago, many authors have published their research results about local stress distributions of shells and shell-nozzles both analytically and numerically. However, there has not been a published paper, which deals with analytical solutions of cylindrical shell and oblique nozzle, even though in the case of openings formed by intersection of a cylindrical shell and an oblique nozzle.

A comprehensive analytical study of local stress factors at the area of openings formed by intersection of a cylindrical shell and an oblique nozzle under internal pressure is presented in this dissertation.

By means of traditional approach in theory of …

Adaptive Distributed Detection With Applications To Cellular Cdma, Jian-Guo Chen

Dissertations

Chair and Varshney have derived an optimal rule for fusing decisions based on the Bayesian criterion. To implement the rule, probabilities of detection P_D and false alarm P_F for each detector must be known, which is not readily available in practice. This dissertation presents an adaptive fusion model which estimates the P_D and P_F adaptively by a simple counting process. Since reference signals are not given, the decision of a local detector is arbitrated by the fused decision of all the other local detectors. Adaptive algorithms for both equal probable and unequal probable sources, for independent …

Least Space-Time First Scheduling Algorithm : Scheduling Complex Tasks With Hard Deadline On Parallel Machines, Bo-Chao Cheng

Dissertations

Both time constraints and logical correctness are essential to real-time systems and failure to specify and observe a time constraint may result in disaster. Two orthogonal issues arise in the design and analysis of real-time systems: one is the specification of the system, and the semantic model describing the properties of real-time programs; the other is the scheduling and allocation of resources that may be shared by real-time program modules.

The problem of scheduling tasks with precedence and timing constraints onto a set of processors in a way that minimizes maximum tardiness is here considered. A new scheduling heuristic, Least …

Bilinear Time-Frequency Representations Of Heart Rate Variability And Respiration During Stress, Rindala Saliba

Dissertations

Recently, joint time-frequency signal representation has received considerable attention as a powerful tool for analyzing a variety of signals and systems. In particular, if the frequency content is time varying as in signals of biological origin which often do not comply with the stationarity assumptions, then this approach is quite attractive. In this dissertation, we explore the possibility of better representation of two particular biological signals, namely heart rate variability (HRV) and respiration. We propose the use of time-frequency analysis as a new and innovative approach to examine the physical and mental exertion attributed to exercise. Two studies are used …

Two Dimensional Agonistic Control, Daqing Yang

Dissertations

The conventional method of precise multiple-axis motion control entails use of a multiple axis positioning system with each axis carrying not only the workpiece but also the positioning system of the remaining axes. The resultant structure is heavy, sluggish, and expensive. An alternative positioning technique is being investigated in which the motion of the workpiece is controlled by pulling it with tendons, each of which has its own actuator. Since the actuators can be mounted on the base of the structure instead of being carried by motion system of the other axes, they can be relatively large and powerful without …

Evaluation Of Environmental Characteristics Of Wtp Residuals For Disposal In Monofills, Ping Tian

Dissertations

Disposal of water treatment plant (WTP) have raised great concerns due to the stringent water quality standards and environmental regulations, and limited availability of land for ultimate disposal. The ultimate disposal of water treatment plant residuals by using monofill may be one of the most economical, and feasible options. Design and operation of such a monofill will be simple because of the uniformity of the characteristics of WTP residuals.

The objectives of this project were to determine the environmental characteristics of WTP residuals and to apply these characteristics for the design of monofills and development of the metal leaching model …

Safe Code Transfromations For Speculative Execution In Real-Time Systems, Mohamed Mohamed Younis

Dissertations

Although compiler optimization techniques are standard and successful in non-real-time systems, if naively applied, they can destroy safety guarantees and deadlines in hard real-time systems. For this reason, real-time systems developers have tended to avoid automatic compiler optimization of their code. However, real-time applications in several areas have been growing substantially in size and complexity in recent years. This size and complexity makes it impossible for real-time programmers to write optimal code, and consequently indicates a need for compiler optimization. Recently researchers have developed or modified analyses and transformations to improve performance without degrading worst-case execution times. Moreover, these optimization …

Counterpulsation Cardiac Assist Device Controller Defection Filter Simulation And Canine Experiments, Carl Edward Werner

Dissertations

Electronic control systems for counterpulsation Cardiac Assist Devices (CADs) are an essential part of cardiac assistance. Synchronization of the counterpulsation CAD controller with the cardiac cycle is critical to the efficacy of the CAD. The robustness of counterpulsation CAD controllers varies with the ability of the CAD controller to properly trigger on aortic pressure (Pa) and electrocardiogram (ECG) signals for sinusoid rhythms, non-sinusoid rhythms and non-ideal signals resulting from surgical intervention. An analog-to-digital converter and digital-to-analog converter based CAD controller development platform was devised on a 33Mhz PC-AT.

Counterpulsation Pa systolic rise and dicrotic notch detectors were demonstrated with a …

Massively Parallel Reasoning In Transitive Relationship Hierarchies, Yugyung Lee

Dissertations

This research focuses on building a parallel knowledge representation and reasoning system for the purpose of making progress in realizing human-like intelligence. To achieve human-like intelligence, it is necessary to model human reasoning processes by programs. Knowledge in the real world is huge in size, complex in structure, and is also constantly changing even in limited domains. Unfortunately, reasoning algorithms are very often intractable, which means that they are too slow for any practical applications. One technique to deal with this problem is to design special-purpose reasoners. Many past Al systems have worked rather nicely for limited problem sizes, but …

Shaped Charges Having A Porous Tungsten Liner-An Experimental And Theoretical Study Of Metal Compression, Jet Formation And Penetration Mechanics, Brian Edward Fuchs

Dissertations

The use of porous tungsten as a liner for shaped charges to improve their penetration was proposed by Ki-Hwan Oh in his invention disclosure "Shock Extrusion of Ingots from Powders or Solids", at the New Mexico Institute of Mining and Technology, Socorro NM on June 7, 1988. The intention was to increase the ductility of the normally brittle metal by heating the liner to a high temperature by shock compaction during its acceleration just before jet formation.

The feasibility of increasing the ductility of tungsten in this way is the subject of the present study. The theory and prior experimental …

Romanticizing Leadership: A Historical And Cultural Critique, Elisa Maureen Sandra Carlson Edd

Dissertations

Romanticism, a cultural and intellectual ideology of the late 18th and early 19th century, left a historical legacy of ecstasy and disaster upon subsequent generations. Manifestations of neo-romanticism are evident in many areas of contemporary culture. These modern manifestations, which include an infusion of the spiritual into everyday life, pantheistic adoration of nature, glorification of the self, fascination with the irrational, focus on the power of the imagination, subjugation of the individual to the common good, and apocalyptic hope for a new world, are influencing, theories and practices of leadership. This research set out to find out whether leadership studies …

An Investigation Of The Utility Of Using Local Curriculum-Based Measurement Norms Versus Group Standardized Norms To Predict Students At Riskfor Academic Failure In Reading And Mathematics, Lara E. Druckman

Dissertations

No abstract provided.