Digital Commons Network^™

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 mode …

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 …

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 …

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 …

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 selected …

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 …

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 …

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 compromises …

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 by …

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 …

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 …

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 …

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 and …

The Creation And Development Of An Afrocentric Christian College: Imani Kuumba College And Graduate School, Juanita M. Browne Edd

Dissertations

The study examines Imani Kuumba College, (IKC), an Afrocentric Christian College. Since previous research does not examine any higher institution that provides a type of learning that focuses totally on the study of the Afrocentric world, this historical case study describes a unique educational institution that proposes to teach from a focus designed to raise self-esteem for African-Americans and racial understanding for other groups by studying the African-American experience, historically, spiritually and culturally. The study begins with an introduction that outlines the environmental and societal issues that motivated the creation of this innovative institution and its unique program. After discussion …

A Dictionary Of Middle Egyptian For Students Of Biblical Archaeology And Old Testament Studies, Robert D. Bates

Dissertations

Problem. Middle Egyptian has played an increasingly important role in Biblical Archaeology and Old Testament studies. Much of biblical chronology is closely connected to Egyptian chronology; many biblical events record Egyptian involvement, and some of these are included on Egyptian monuments. A knowledge of Middle Egyptian has been crucial in understanding the historical background and cultural context of the biblical world because this phase of the Egyptian language influenced the widest range of Egyptian writing, particularly as it pertains to Old Testament history. Unfortunately, students do not have all the necessary tools for searching for unfamiliar words in Middle Egyptian. …

Perceptions Of Board Effectiveness In Selected Institutions Of Higher Education In Zimbabwe, Bonginkosi Zvandasara

Dissertations

Problem

The purpose of this study was to identify the level of board effectiveness in selected private and public universities in Zimbabwe as perceived by board members. Also, the study sought to determine the influence of such demographic variables as age, education level, and years of service on the seven factors of university functioning: institutional mission, institutional planning, physical plant, financial management, board membership, board organization and performance, and board/vice chancellor relations.

Method

The survey method was used to collect data. Respondents were asked to complete a 47-item questionnaire and indicate their level of agreement on each of the questions …

Attitudes Of Junior High Teachers Towards Teaching Students With Learning Disabilities In Inclusive Classes In Public Schools In New Providence, Bahamas, Virginia Alicia Romer

Dissertations

Problem. The implementation of inclusive programs has met disapproval and concerns from many general educators regarding the presence of students with learning disabilities in their classes. The purpose therefore of this study was to survey junior high teachers in New Providence, Bahamas, to determine their attitudes toward teaching students with learning disabilities in general education classes; to investigate the type of instructional methodology used in general classes and to determine if instructional delivery is modified to assist students with learning disabilities; examine whether general educators collaborate with special educators when planning their instruction; and to identify if there are differences …

How Instructional Leadership Is Addressed In Educational Administration/Leadership Programs, Lolethia Jones Kibble

Dissertations

Problem

Instructional leadership is a major factor in school effectiveness and student achievement, yet it is not widely practiced by school principals. One of the contributing factors, identified in the literature, is a lack of skills and knowledge. Although there is a great deal of information about principal preparation programs, there is very little information on the preparation of school leaders in the practice of instructional leadership behaviors. The purpose of this study was to examine how instructional leadership is addressed in both traditional and restructured educational administration/leadership programs and to what extent this is related to institutional and demographic …

A Robust Two-Sample Procedure To Estimate A Shift Parameter, Feridun Tasdan

Dissertations

This study estimates the location shift parameter in the two-sample problem. The classical method, Least Square(LS), obtains the shift parameter estimate under the normality assumption. A departure from normality assumption makes the estimate inefficient and unreliable. One alternative to the least square estimate is Hodges-Lehmann (HL) estimate which uses Wilcoxon ranks to estimate the shift parameter. This estimate is robust against contaminations and large outliers. The proposed method in this study combines two samples and uses convolution technique to find a density function for the combined sample. This new density function is later used in the construction of the log …

Determination Of Spatial Strata For Environmental Regulatory Purposes, John Edward Daniels

Dissertations

This dissertation introduces spatial strata modelling, a methodology that combines spatial statistics, cluster analysis, and geographic information system theories to analyze the background level of naturally occurring contaminants of concern (COCs). The objective of spatial strata modelling is to divide a geographic area of interest into mutually exclusive geographic zones (spatial strata): with each stratum representing a different level of COC concentration. An estimate of each stratum's COC concentration level, representing an upper regulatory limit, will also be provided. Data provided by the Michigan Department of Environmental Quality describing the spatial location and arsenic concentrations of 211 Michigan sites (arsenic …

Geochemical And Isotopic Characterization Of Shallow Basinal Brines From The Makgadikgadi Pans Complex, Northeastern Botswana: Determination Of The Sources Of Salinity, Loago N. Molwalefhe

Dissertations

Isotopes and chemical tracers have been used to constrain the sources and causes of salinity in shallow groundwater brine from the Makgadikgadi Basin, northeastern Botswana. The brine is massively rich in chloride and sodium, and moderately rich in carbonates, sulphate and potassium, and is distinctively poor in divalent cationic species. Various models that have been advanced to explain the origin of the brines include evaporative enrichment at the surface and density-induced infiltration, dissolution of evaporites, and trapped connate water.

This study presents the compositional variability and behaviors of ·the stable isotopes of carbon (S¹³C) and oxygen (S^{18 …}

How Secondary School Mathematics Teachers Construct An Understanding Of "Appropriate Use" Of Graphing Calculators In The Context Of Collegial Inquiry, Marcia L. Weller Weinhold

Dissertations

No abstract provided.

Irradiation Induced Order-Dis Order Transformations In Ni-Mo Alloys, Ovidiu F. Toader

Dissertations

No abstract provided.

An Investigation On The Impact Of The Structure Of Summative Student Evaluation On Self-Regulated Learning, John Charles Ritzler

Dissertations

Many hypotheses have been offered regarding the impact on learning caused by the most traditional practice of summative student evaluation, namely that of assigning marks to students. Sufficient evidence exists to suggest this practice often has detrimental effects. This study was designed to investigate the following three questions: (1) How does the method of summative student evaluation impact self-regulated learning in low-achieving high school mathematics students? (2) How does the cognitive level of the task mediate the relationship between method of summative student evaluation and self-regulated learning? (3) How does the length of time students are exposed to a method …

Programming Language Trends : An Empirical Study, Yaofei Chen

Dissertations

Predicting the evolution of software engineering technology trends is a dubious proposition. The recent evolution of software technology is a prime example; it is fast paced and affected by many factors, which are themselves driven by a wide range of sources. This dissertation is part of a long term project intended to analyze software engineering technology trends and how they evolve. Basically, the following questions will be answered: How to watch, predict, adapt to, and affect software engineering trends?

In this dissertation, one field of software engineering, programming languages, will be discussed. After reviewing the history of a group of …

Capacity, Coding And Interference Cancellation In Multiuser Multicarrier Wireless Communications Systems, Christian Ibars Casas

Dissertations

Multicarrier modulation and multiuser systems have generated a great deal of research during the last decade. Orthogonal Frequency Division Multiplexing (OFDM) is a multicarrier modulation generated with the inverse Discrete Fourier Transform, which has been adopted for standards in wireless and wire-line communications. Multiuser wireless systems using multicarrier modulation suffer from the effects of dispersive fading channels, which create multi-access, inter-symbol, and inter-carrier interference (MAI, ISI, ICI). Nevertheless, channel dispersion also provides diversity, which can be exploited and has the potential to increase robustness against fading. Multiuser multi-carrier systems can be implemented using Orthogonal Frequency Division Multiple Access (OFDMA), a …

Optimal And Intelligent Decision Making In Sustainable Development Of Electronic Products, Meimei Gao

Dissertations

Increasing global population and consumption are causing declining natural and social systems. Multi-lifecycle engineering and sustainable development address these issues by integrating strategies for economic successes, environmental quality, and social equity. Based on multi-lifecycle engineering and sustainable development concepts, this doctoral dissertation aims to provide decision making approaches to growing a strong industrial economy while maintaining a clean, healthy environment. The research develops a methodology to complete both the disassembly leveling and bin assignment decisions in demanufacturing through balancing the disassembly efforts, value returns, and environmental impacts. The proposed method is successfully implemented into a demanufacturing module of a Multi-LifeCycle …

Thermochemistry And Kinetic Analysis On Radicals Of Acetaldehyde + O2, Allyl Radical + O2 And Diethyl And Chlorodiethyl Sulfides, Jongwoo Lee

Dissertations

Thermochemical properties for reactants, intermediates, products and transition states important in the radicals of acetaldehyde + O₂ and allyl radical + O₂ reaction systems are analyzed with density functional and ab initic calculations, to evaluate the reaction paths and kinetics in oxidation and pyrolysis. Ketene is one important product resulting from acetaldehyde oxidation; thus thermochemistry plus isomerization and conversion reactions of ketene are also analyzed. Enthalpies of formation are determined using isodesmic reaction analysis at the CBSQ composite and density functional levels. Entropies and heat capacities are determined using geometric parameters and vibration frequencies obtained at the HF/6-31G(d') …

Selective Removal Of Nox From Catalytic Cracking Regenerator Effluent Using Wet Scrubbing With Aqueous Sodium Chlorite Solutions, Pin Gu

Dissertations

In most refineries, the flue gas from the regenerator in the fluid catalytic cracking (FCC) unit represents a key source of NOx, SOx, particulate, and CO emissions. Wet scrubbing systems have been used with great success to control particulate and SOx emissions from typical FCC regenerator flue gas. Development of relatively inexpensive and safe additives that can be used in existing scrubbing systems to oxidize and absorb NOx is important in order to increase the industrial options to meet the provisions of the Clean Air Act and recently proposed EPA rules. This paper explores the feasibility of removing NOx from …

Measurement Of The Nonlinear Refractive Index (N2) And Stimulated Raman Scattering In Optical Fibers As A Function Of Germania Content, Using The Photorefractive Beam Coupling Technique, Ferdinand Anayo Oguama

Dissertations

One of the greatest challenges in optical communication is the understanding and control of optical fiber nonlinearities. While these nonlinearites limit the power handling capacity of optical fibers and can cause noise, signal distortion and cross talk in optically amplified transmission systems, they have been equally harnessed for the development of new generations of optical amplifiers and tunable laser sources. The two prominent parameters that characterize the nonlinear properties of an optical fiber are the nonlinear refractive index n₂ and the Raman gain coefficient g_R. These parameters are related to the third order nonlinear susceptibility [x^{(3) …}