Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

PDF

Theses/Dissertations

2003

Discipline
Institution
Keyword
Publication

Articles 1 - 30 of 5889

Full-Text Articles in Entire DC Network

Multi-Spectral Light Interaction Modeling And Imaging Of Skin Lesions, Sachin Vidyanand Patwardhan Dec 2003

Multi-Spectral Light Interaction Modeling And Imaging Of Skin Lesions, Sachin Vidyanand Patwardhan

Dissertations

Nevoscope as a diagnostic tool for melanoma was evaluated using a white light source with promising results. Information about the lesion depth and its structure will further improve the sensitivity and specificity of melanoma diagnosis. Wavelength-dependent variable penetration power of monochromatic light in the trans-illumination imaging using the Nevoscope can be used to obtain this information. Optimal selection of wavelengths for multi-spectral imaging requires light-tissue interaction modeling. For this, three-dimensional wavelength dependent voxel-based models of skin lesions with different depths are proposed. A Monte Carlo simulation algorithm (MCSVL) is developed in MATLAB and the tissue models are simulated using the ...


Dielectrophoretic Manipulation Of Biological And Non-Biological Analytes In A Microfluidic Channel, Dawn J. Bennett Dec 2003

Dielectrophoretic Manipulation Of Biological And Non-Biological Analytes In A Microfluidic Channel, Dawn J. Bennett

Dissertations

Micro-total-analytical systems (μTASs) for analyzing chemical/biological substances are now used across a wide variety of applications ranging from biological warfare agent detection to the healthcare industry. The first step in the operation of a μTAS consists of concentrating and separating the analytes of interest from the background matrix and positioning them into selected locations for subsequent analysis. The use of ac electric fields was demonstrated to have promising potential for a μTAS because the application of an ac field suppresses undesirable electrolytic effects in the liquid. The main purpose of this work is to study micro-scale phenomena in a ...


Adaptive Learning For Event Modeling And Pattern Classification, Shuangshuang Dai Dec 2003

Adaptive Learning For Event Modeling And Pattern Classification, Shuangshuang Dai

Dissertations

It is crucial to detect, characterize and model events of interest in a new propulsion system. As technology advances, the amount of data being generated increases significantly with respect to time. This increase substantially strains our ability to interpret the data at an equivalent rate. It demands efficient methodologies and algorithms in the development of automated event modeling and pattern recognition to detect and characterize events of interest and correlate them to the system performance. The fact that the information required to properly evaluate system performance and health is seldom known in advance further exacerbates this issue.

Event modeling and ...


A Micromachined Thermo-Optical Light Modulator Based On Semiconductor-To-Metal Phase Transition, Lijun Jiang Dec 2003

A Micromachined Thermo-Optical Light Modulator Based On Semiconductor-To-Metal Phase Transition, Lijun Jiang

Dissertations

In this research, a micromachined thermo-optical light modulator was realized based on the semiconductor-to-metal phase transition of vanadium dioxide (VO2) thin film. VO2 undergoes a reversible phase transition at approximately 68 0C, which is accompanied with drastic changes in its electrical and optical properties. The sharp electrical resistivity change can be as great as five orders. Optically, VO2 film will switch from a transparent semiconductor phase to a reflective metal phase upon the phase transition. The light modulator in this research exploits this phase transition related optical switching by using surface micromachined low-thermal-mass pixels to achieve good ...


The Use Of A Water Quality Model To Evaluate The Impacts Of Combined Sewer Overflows On The Lower Hudson River, Wen-Pin Shu Dec 2003

The Use Of A Water Quality Model To Evaluate The Impacts Of Combined Sewer Overflows On The Lower Hudson River, Wen-Pin Shu

Dissertations

CSO discharges have long been recognized as a significant source of water pollution. While many sources of water pollution have been controlled over the past 20 years, CSOs continue to be a main environmental concern in several areas, especially in old cities. In the past, most CSO research focused on the CSO control processes, including floatables and suspended solids removal. Few studies have been conducted in the area of the impacts of CSO discharge on the receiving water quality. To achieve this purpose, a powerful water-modeling tool, WASP 6.1, is utilized in this study. The Lower Hudson River is ...


An Analysis Of The Periodicity Of The Cell Cycle And Apoptotic Regulatory Proteins In Prostate Xenografts Using Anova And Cosinor Methods, Aleen Hosdaghian Dec 2003

An Analysis Of The Periodicity Of The Cell Cycle And Apoptotic Regulatory Proteins In Prostate Xenografts Using Anova And Cosinor Methods, Aleen Hosdaghian

Theses

Circadian rhythms have been found in both plants and animals, in normal tissues as well as in most tumors and human cancers. By following these rhythms in healthy and cancerous tissue, it has been possible to find optimal times to deliver a dose of drug, such that efficacy is maximized and toxicity to normal tissues is minimized. In this study, the periodicity of several cell cycle and apoptotic regulatory proteins were studied in two prostate cancer models against a dietary therapeutic agent, Selenium. The ALVA-3 1 (androgen-independent) and PC-3 (androgen-independent) prostate cancer cell lines were grown in vivo, as a ...


Patient Handling Ergonomics, Paul Reichert Dec 2003

Patient Handling Ergonomics, Paul Reichert

Theses

The incidence of musculoskeletal injuries among healthcare workers has been well documented in the medical and ergonomic literature. The epidemiological evidence demonstrates high injury rate among nurses, nurse's aides, therapists and other medical workers who frequently handle patients. The biomechanical research has shown large compressive forces developed in the lumbar spine performing various patient handling transfers that exceed the National Institute of Occupational Safety and Health's recommended guideline. One of the most strenuous patient handling tasks is transferring the patient from bed to the chair and vice versa.

One of the objectives of this thesis is to design ...


A Conceptual Framework For Using Feedback Control Within Adaptive Traffic Control Systems, Renu Chhonkar Dec 2003

A Conceptual Framework For Using Feedback Control Within Adaptive Traffic Control Systems, Renu Chhonkar

Dissertations

Existing adaptive traffic control strategies lack an effective evaluation procedure to check the performance of the control plan after implementation. In the absence of an effective evaluation procedure, errors introduced in the system such as inaccurate estimates of arrival flows, are carried forward in time and reduce the efficiency of the traffic flow algorithms as they assess prevalent traffic conditions. It is evident that the feed-forward nature of these systems cannot accurately update the estimated quantities, especially during oversaturated conditions.

This research is an attempt to develop a conceptual framework for the application of feedback control within the basic operation ...


The Impacts Of Delphi Communication Structure On Small And Medium Sized Asynchronous Virtual Teams, Hee-Kyung Cho Dec 2003

The Impacts Of Delphi Communication Structure On Small And Medium Sized Asynchronous Virtual Teams, Hee-Kyung Cho

Dissertations

The improvement of Internet technology has motivated distributed work groups to collaborate without meeting face to face. Although asynchronous meetings through Web-based group communications systems enable groups dispersed temporarily and geographically to collaborate more flexibly, parallel and non-linear communication among dispersed members also challenge effective and efficient group coordination. Moreover, the Web-based asynchronous meeting is distinguished not only from the face-to-face meeting but also from the synchronous computer-supported meeting in terms of coordination process. However, previous asynchronous group communications or virtual team research focused more on the comparison of this new type of meeting with the face-to-face meeting. Not many ...


Virtual Teams Combining Mobile Devices With Web-Based Communication On Group Decision Making, Hyo-Joo Han Dec 2003

Virtual Teams Combining Mobile Devices With Web-Based Communication On Group Decision Making, Hyo-Joo Han

Dissertations

Organizations have moved from a face-to-face team environment to a virtual team environment using communication technology during the last decade. More and more workers use asynchronous tools (including email, discussion groups, information sharing tools, and group calendaring systems), and synchronous tools, such as instant messaging and web-based chatting features, to coordinate and share information with people within and outside of organizations. This empirical study on how virtual teams work, integrating mobile devices with web-based group communication for decision-making tasks, examines which technologies and communication modes are the best for distributed group teamwork, and, mainly, what are the predictive characteristics making ...


Intercity Travel Demand : A Utility-Consistent Simultaneous Trip Generation And Mode Choice Model, Guilin Li Dec 2003

Intercity Travel Demand : A Utility-Consistent Simultaneous Trip Generation And Mode Choice Model, Guilin Li

Dissertations

An intercity travel decision includes a complex set of subdecisions, such as when to travel, where to travel, which mode to choose, and others. The main focus of this dissertation is to examine trip frequency and mode choice of intercity non-business travel.

The objective of this study is to understand intercity travel behavior using disaggregate models. The proposed conceptual framework for intercity travel behavior leads to a nested logit/continuous choice model that is rigorously linked to the utility maximization theory. Compared to a traditional intercity travel demand model, the proposed model is utility consistent in that trip generation and ...


Fabrication And Characterization Of Microcrystalline Silicon Solar Cells, Liwei Li Dec 2003

Fabrication And Characterization Of Microcrystalline Silicon Solar Cells, Liwei Li

Dissertations

In this study, single junction p-i-n μc-Si:H solar cells were prepared using plasma of silane diluted by hydrogen in a low-cost, single chamber, non-load-locked RF-PECVD system. Direct structural characterization of μc-Si:H solar cells, rather than stand-alone films, was conducted using Raman Spectroscopy, XRD, and AFM. Strong correlations among device deposition, i-layer structural properties, and device performance have been established. With such correlations, critical issues in fabricating low-cost, large-scale, high performance μc-Si:H solar cells were identified.

The critical importance of seeding processes in determining the microstructure of μc-Si:H i-layers and performance of μc-Si:H solar ...


Migration Of An Intruder Particle In A Boundary Driven Shear Flow, Jian Liu Dec 2003

Migration Of An Intruder Particle In A Boundary Driven Shear Flow, Jian Liu

Dissertations

This study reports on three-dimensional, discrete element simulations of a single large spherical intruder in a Couette shear flow composed of uniform sized particles. The simulation results are useful in providing a numerical reproduction of the experiments for size segregation and mixing. This in turn has a major importance in many industries which are concerned with handling of particles and powders, such as pharmaceutical manufacturing, agriculture, chemical and mineral processing.

Discrete element simulations are carried out using the "soft sphere" model of Walton, et. al., which provides a method for obtaining the information at a macroscopic level from multi-body collisions ...


Statistical Study Of Solar Radio Bursts, Gelu-Marius Nita Dec 2003

Statistical Study Of Solar Radio Bursts, Gelu-Marius Nita

Dissertations

The peak flux distribution of 40 years of solar radio burst data recorded by NOAA, as a function of frequency and time over a wide range of frequencies, was investigated to quantify the potential impact of radio bursts on wireless systems. Tables of fit parameters, which can be used to find burst occurrence rates in a number of frequency ranges, are presented. The typical power-law index of number density distribution, -1.8, is similar to that found in many hard X-ray studies. Significant changes were found in power-law index with frequency. The results may be useful for designers of current ...


Oblivious Data Hiding : A Practical Approach, Husrev T. Sencar Dec 2003

Oblivious Data Hiding : A Practical Approach, Husrev T. Sencar

Dissertations

This dissertation presents an in-depth study of oblivious data hiding with the emphasis on quantization based schemes. Three main issues are specifically addressed:

1. Theoretical and practical aspects of embedder-detector design.

2. Performance evaluation, and analysis of performance vs. complexity tradeoffs.

3. Some application specific implementations.

A communications framework based on channel adaptive encoding and channel independent decoding is proposed and interpreted in terms of oblivious data hiding problem. The duality between the suggested encoding-decoding scheme and practical embedding-detection schemes are examined. With this perspective, a formal treatment of the "processing" employed in quantization based hiding methods is presented. In ...


Effect Of Fullerene Containing Lubricants On Wear Resistance Of Machine Components In Boundary Lubrication, Andriy Titov Dec 2003

Effect Of Fullerene Containing Lubricants On Wear Resistance Of Machine Components In Boundary Lubrication, Andriy Titov

Dissertations

Fullerenes, a new form of carbon nanomaterials, possess unique physical and mechanical properties that make their use as additives to liquid lubricants potentially beneficial. The goal of this study was to investigate the effect of fullerene containing lubricants on wear resistance of steel-bronze couples operating under boundary lubrication conditions. A mathematical model of deformed asperity contact was built to calculate real contact area and real contact pressure. Computer controlled wear friction testing methodology and equipment were designed, developed and implemented for obtaining reliable and objective experimental data. In addition, optical and scanning electron microscopy and standard surface texture analysis were ...


Reactive Modification Of Polyesters And Their Blends, Chen Wan Dec 2003

Reactive Modification Of Polyesters And Their Blends, Chen Wan

Dissertations

As part of a broader research effort to investigate the chemical modification of polyesters by reactive processing a low molecular weight (MW) unsaturated polyester (UP) and a higher MW saturated polyester, polyethylene terephthalate (PET), alone or blended with polypropylene (PP) were melt processed in a batch mixer and continuous twin screw extruders. Modification was monitored by on-line rheology and the products were characterized primarily by off-line rheology, morphology and thermal analysis. Efforts were made to establish processing/property relationships and provide an insight of the accompanying structural changes. The overall response of the reactively modified systems was found to be ...


Studies On Improved Integrated Membrane-Based Chromatographic Process For Bioseparation, Yanke Xu Dec 2003

Studies On Improved Integrated Membrane-Based Chromatographic Process For Bioseparation, Yanke Xu

Dissertations

To improve protein separation and purification directly from a fermentation broth, a novel membrane filtration-cum-chromatography device configuration having a relatively impermeable coated zone near the hollow fiber module outlet has been developed. The integrated membrane filtration-cum-chromatography unit packed with chromatographic beads on the shell side of the hollow fiber unit enjoys the advantages of both membrane filtration and chromatography; it allows one to load the chromatographic media directly from the fermentation broth or lysate and separate the adsorbed proteins through the subsequent elution step in a cyclic process.

Interfacial polymerization was carried out to coat the bottom section of the ...


Development Of Supercritical Processes For Particle Coating / Encapsulation With Polymers, Yulu Wang Dec 2003

Development Of Supercritical Processes For Particle Coating / Encapsulation With Polymers, Yulu Wang

Dissertations

This work presents the investigation of particle coating using supercritical fluid processes as novel coating approaches to coat particles from 20 nanometers to 500 microns with different polymers. Particle coating using different supercritical technologies of a modified rapid expansion of a supercritical solution (RESS) for particle coating and a supereritical antisolvent (SAS) process was described.

In the modified RESS process for particle coating, experiments were performed using a pilot-scale supercritical apparatus, glass beads as host particles and two different polymers as coating materials. By adjusting temperature and pressure, the polymer nucleated and precipitated onto the surface of the host particles ...


High Resolution Solar Observations In The Context Of Space Weather Prediction, Guo Yang Dec 2003

High Resolution Solar Observations In The Context Of Space Weather Prediction, Guo Yang

Dissertations

Space weather has a great impact on the Earth and human life. It is important to study and monitor active regions on the solar surface and ultimately to predict space weather based on the Sun's activity. In this study, a system that uses the full power of speckle masking imaging by parallel processing to obtain high-spatial resolution images of the solar surface in near real-time has been developed and built. The application of this system greatly improves the ability to monitor the evolution of solar active regions and to predict the adverse effects of space weather. The data obtained ...


Ip-Based Virtual Private Networks And Proportional Quality Of Service Differentiation, Jingdi Zeng Dec 2003

Ip-Based Virtual Private Networks And Proportional Quality Of Service Differentiation, Jingdi Zeng

Dissertations

IP-based virtual private networks (VPNs) have the potential of delivering cost-effective, secure, and private network-like services. Having surveyed current enabling techniques, an overall picture of IP VPN implementations is presented.

In order to provision the equivalent quality of service (QoS) of legacy connection-oriented layer 2 VPNs (e.g., Frame Relay and ATM), IP VPNs have to overcome the intrinsically best effort characteristics of the Internet. Subsequently, a hierarchical QoS guarantee framework for IP VPNs is proposed, stitching together development progresses from recent research and engineering work.

To differentiate IP VPN QoS, the proportional QoS differentiation model, whose QoS specification granularity ...


Vibration-Induced Densification Of Granule Materials, Ninghua Zhang Dec 2003

Vibration-Induced Densification Of Granule Materials, Ninghua Zhang

Dissertations

Physical experiments as well as discrete element simulations of vibration are carried out. The use of different amplitudes and frequencies are applied in the experiments to facilitate the observation of densification trends with mono-disperse acrylic spheres and multi-disperse polyethylene pellets. For mono-disperse acrylic spheres, four densification trends are found at different vibration conditions, and attaining the "maximum density" is closely related to the combination of vibration frequency and amplitude, in agreement with experiments in the literature. For multi-disperse polyethylene pellets, there is a substantial increase in solids fraction due to the effects of particle shape and surface friction. Computer simulations ...


Simulation And Mathematical Notation Of Alarms Unit For Computer Assisted Resuscitation Algorithm, Swaroop Malangi Dec 2003

Simulation And Mathematical Notation Of Alarms Unit For Computer Assisted Resuscitation Algorithm, Swaroop Malangi

Theses

The Computer Assisted Resuscitation Algorithm [CARA] is a system that is used to drive a high output infusion pump used for infusing saline into patients suffering from conditions that lead to hypotension. The infusion pump infuses saline at a particular rate into the patient depending on the blood pressure of the patient.

The alarms unit of CARA was simulated for the infusion pump in which the occurrence of alarms depends on the various criteria the infusion pump encounters when saline is being infused into patients. Various criteria may vary from an air bubble in the line to varying high and ...


Characterization Of Aluminum Powder Ignition, Salil Mohan Dec 2003

Characterization Of Aluminum Powder Ignition, Salil Mohan

Theses

Heating rate effect and particle size effect on ignition temperature of Al powder were studied to collect data for development of a possible Al powder ignition model. Aluminum ignition is associated with a highly accelerated burn rate and high combustion enthalpy. A new ignition model, which can adequately interpret these conditions, is needed to develop better propulsion fuels, explosives and incendiaries that use Al as an additive. This experimental program was focused on preparing framework for characterization of ignition kinetics of Al powder by determining the ignition temperature for different, systematically varied, heating rates and particle size. The experimental setup ...


Modeling And Analysis Of Hospital Facility Layout Problem, Amol Shrikrishna Padgaonkar Dec 2003

Modeling And Analysis Of Hospital Facility Layout Problem, Amol Shrikrishna Padgaonkar

Theses

The optimal solution to any facility layout problem is an important aspect and a major concem as it involves significant material handling and transportation cost. The objective is to arrange the departments within the predefined facility boundaries in the way that the interaction between the functions is efficient and the overall movement cost is minimized. While facility layout problems have traditionally focused on manufacturing facilities, there has been little work on analyzing layouts for hospitals. The thesis focuses on hospital facility layout problems (HLP) to (i) minimize the movements of patients and (ii) minimize the movements of accompanying resources such ...


Kinetics Of Ho2 Abstraction Of H Atoms From Hydrocarbons And Thermochemical Properties Of Urethane Monomers And Radicals, Rajul Shah Dec 2003

Kinetics Of Ho2 Abstraction Of H Atoms From Hydrocarbons And Thermochemical Properties Of Urethane Monomers And Radicals, Rajul Shah

Theses

SECTION I: Kinetics of HO2 Abstraction of H Atoms From Hydrocarbons

Structures, internal rotational barriers and ideal gas thermochemical properties, ΔH°f98 for representative series of transition states for abstraction of H atoms from primary, secondary and tertiary hydrocarbons by the HO2 radical, TC-HOOH (1), TCC-HOOH (2), TC2C-HOOH (3), TC3C-HOOH (4), TC2CC-HOOH (5), TC2CC-HOOHC (6) and TC3CCC-HOOH (7) are analyzed in this study. Molecular structures and vibrational frequencies are determined at the B3LYP/6-3111G(d,p) density functional level. The S°298 and Cp(T) values (300 ...


Adaptive Turn-Prohibition Routing Algorithm For The Networks Of Workstations, Amey Bhaskar Shevtekar Dec 2003

Adaptive Turn-Prohibition Routing Algorithm For The Networks Of Workstations, Amey Bhaskar Shevtekar

Theses

Deadlock occurrence is a critical problem for any computer network. Various solutions have been proposed over last two decades to solve problem of deadlocks in networks using different routing schemes, like up/down routing algorithm used in Myrinet switches. However, most of existing approaches for deadlock-free routing either try to eliminate any possibility of deadlock occurrence, which can result in putting extra restrictions on the routing in the networks or put no restrictions on routing, which leads to other approach namely deadlock recovery. In this thesis emphasis is on developing hybrid approach for routing in wormhole networks, wherein some prohibition ...


Evaluation Of Postural Stability Using Sensory Organization Test, Tiffany Sims Dec 2003

Evaluation Of Postural Stability Using Sensory Organization Test, Tiffany Sims

Theses

Poor postural stability of the elderly and other patients has been a major concern.The cost of treating injuries due to poor stability is expected to rise to $32.4 Billion by 2020. Many interventions have been proposed and used to improve stability. In order to determine the efficacy of these interventions, an objective evaluation of postural stability before and after intervention is important.

The aim of this thesis was to scientifically analyze the ambiguities in the equilibrium score (ES) given by the Neurocom Smart Equitest (NSE) machine, and compare it to a new measure of stability that has been ...


Wavelet Transform Methods For Identifying Onset Of Semg Activity, Janina Wilen Dec 2003

Wavelet Transform Methods For Identifying Onset Of Semg Activity, Janina Wilen

Theses

Quantifying improvements in motor control is predicated on the accurate identification of the onset of surface electromyograpic (sEMG) activity. Applying methods from wavelet theory developed in the past decade to digitized signals, a robust algorithm has been designed for use with sEMG collected during reaching tasks executed with the less-affected arm of stroke patients. The method applied both Discretized Continuous Wavelet Transforms (CWT) and Discrete Wavelet Transforms (DWT) for event detection and no-lag filtering, respectively. Input parameters were extracted from the assessed signals.

The onset times found in the sEMG signals using the wavelet method were compared with physiological instants ...


Magneto-Rheological Fluid Orthosis For Suppressing Tremor, Hyoung-Joo Yeo Dec 2003

Magneto-Rheological Fluid Orthosis For Suppressing Tremor, Hyoung-Joo Yeo

Theses

Tremor is a common movement disorder that occurs with specific neurological conditions. This condition may seriously impact daily living activities. The aim of the present study is to evaluate the possibility of the development of a wearable technology that is capable of exerting torques at a user's joints for suppressing tremor.

This thesis is based on the concept of "smart structures" which are made of Magneto-Rheological (MR) fluid that can dynamically alter its viscosity under magnetic field. The wearable tremor suppressing orthosis needs several conditions. It should be safe, light weight, simple and small in structure, and easily attachable ...