Digital Commons Network^™

Modules From Tilted To Cluster-Tilted Algebras, Stephen M. Zito

Doctoral Dissertations

'Archival abstract submitted'

Surface Chemistry With Machine Learning And Quantum Mechanics, Venkatesh Botu

Doctoral Dissertations

Surface chemistry is a phenomenon manifesting itself in several key areas; catalysis, materials fabrication, and emissions mitigation, to name a few. At the present time, atomistic computational driven efforts to study such processes are dominated by models based on quantum mechanics. Their flexibility in studying diverse chemistries, along with the ability to predict accurate thermodynamic and kinetic insights of surface processes, makes them increasingly popular. From ultra-low temperature and pressure to normal operating conditions these methods are now commonly utilized. Nevertheless, the computational burden inherent in the method renders it insufficient to keep up with the current need for quick …

Online Updating Methods For Big Data Streams, Chun Wang

Doctoral Dissertations

Big data are data on a massive scale in terms of volume, intensity, and complexity that exceed the capacity of standard analytic tools. They present opportunities as well as challenges to statisticians. This dissertation summarizes recent methodological and software developments in statistics that address the big data challenges at first and then presents statistical methods for big data arising from online analytical processing, where large amounts of data arrive in streams and require fast analysis without storage/access to the historical data, which is called online updating methods. In particular, iterative estimating algorithms and statistical inferences are developed for linear models …

Generalized P-Adic Gauss Sums, Sandi Xhumari

Doctoral Dissertations

In 2005 Blache studied certain generalized Gauss sums and established an analogue for them of Stickelberger's congruence for classical Gauss sums over finite fields. We improve on Blache's work in two ways: (i) simplify Blache's proof and give a second proof that works for a larger family of generalized Gauss sums, and (ii) give a p-adic lifting of Stickelberger's congruence for the larger family of generalized Gauss sums that is partial progress towards a version of the Gross-Koblitz formula for these sums. In addition, we study this larger family of generalized Gauss sums, prove a formula for them which simplifies …

Imprecisely Supervised Learning, Xin Wang

Doctoral Dissertations

Modern technologies have enabled us to collect large quantities of data. The proliferation of such data has facilitated knowledge discovery using machine learning techniques. However, it has also imposed great challenges for human annotators to label the massive data, which then offers proper supervision to learning algorithms. How we can improve learning accuracy with limited or imprecise supervision has recently become a much focused research subject. In this dissertation, we design effective algorithms based on modern machine learning theories to address the following two problems of: (1) learning from inconsistent labels collected from multiple annotators with varying expertise; and (2) …

Experimental Studies On Flow Field And Flame Stabilization Of A Premixed Reacting Jet In Vitiated Crossflow, Jason A. Wagner

Doctoral Dissertations

Archival abstract submitted

Evaluation Of Soft Material Microstructure Through High-Frequency Ultrasound, Jeremy D. Stromer

Doctoral Dissertations

Ultrasonic measurement allows for nondestructive testing and inspection of the internal structure of tissues and materials. Ultrasound has a number of advantages over other commonly used nondestructive methods. It is safe, relatively inexpensive, and is the most commonly used health diagnostic imaging method. Nevertheless, traditional ultrasound does have disadvantages. Standard methods detect the presence of flaws and inclusions from amplitude and time-of-flight information. However, these techniques provide little insight into the actual material characteristics of the sample. Available techniques use a limited, low range of frequencies. The measurements also need to be interpreted by trained technicians and can vary among …

Bernstein-Sato Polynomials For Quivers, Andras Cristian Lorincz

Doctoral Dissertations

In this thesis we investigate an important singularity invariant, Bernstein-Sato polynomials, also called b-functions. Together with the classical notion of the b-function (of one variable) of a single polynomial, we also consider more general ones, such as the b-function of several variables (of several polynomials) and Bernstein-Sato polynomials (of one variable) of arbitrary varieties. We propose several techniques for their computation in various equivariant settings. The main applications will belong to the quiver setting, namely (semi-)invariant polynomials (resp. nullcones, orbit closures) of quivers.

We give a formula relating b-functions of semi-invariants corresponding to each other under castling transforms (or reflection …

Hypoelliptic Heat Kernel On Nilpotent Lie Groups, Malva Asaad

Doctoral Dissertations

The starting point of our analysis is an old idea of writing an eigenfunction expansion for a heat kernel considered in the case of a hypoelliptic heat kernel on a nilpotent Lie group. One of the ingredients we have is the generalized Fourier transform. The formula one gets using this approach is explicit as long as we can find all unitary irreducible representations of the group. In this thesis we consider a nilpotent Lie group of step n as an illustration of this technique. First we apply Kirillov’s orbit method to describe all unitary irreducible representations for the group. This …

Real-Time Hybrid Substructuring For System Level Vibration Testing Of Mechanical Equipment, Joseph A. Franco Iii

Doctoral Dissertations

Vibration of mechanical equipment in structures can result in fatigue, detection, and/or environmental concerns. Numerical simulation of these mechanical/structural systems to verify the system meets these performance requirements can be difficult and can require full system testing. During the design phase of a system, however, the mechanical portion of the system may be pre-existing and can be physically tested while the support structure is still existent as a computer aided design concept which can be numerically simulated. The challenge in verifying the full system meets performance requirements is to accurately combine the physical and numerical substructures. One forma of substructuring, …

Measuring Segregation Patterns And Change: A Co-Location Quotient Approach, Natalia Vorotyntseva

Doctoral Dissertations

There are many segregation measures introduced and utilized in geographic research up to this date. Because residential segregation can be defined in more than one way the measure’s formulation is dependent on the particular definition the researcher is trying to reflect. Another distinctive feature of the quantitative exploration of segregation is the role of geographic scale. In contrast, global indices focus on overall level of spatial separation of population in the urban area while local indices assume that the index magnitude varies from place to place across the city. The main purpose of this study is to introduce a new …

Physical Interaction-Process Driven Investigation Of Quantum Mechanics, Michael Ambroselli

Doctoral Dissertations

Quantum Mechanics (QM) represents the currently best mathematical theory and computational tool available to quantitatively model the outcomes of measurements in the microscopic world. However, the various interpretations of the theory, including the currently dominant Copenhagen Interpretation, remain actively debated and contested in mainstream scientific journals. This puts us in the curious position of having a theory which evidently maps a significant portion of physical reality, but we still do not fully understand the relationship between its mathematical constituents and physical reality. This thesis develops a more intuitive understanding of QM based on the physical interaction processes occurring within our …

Modules Over Rank 2 Klr Algebras, Jonathan Brian Judge

Doctoral Dissertations

The module categories of Khovanov-Lauda-Rouquier algebras categorify the integral form of the negative half of the quantum group U_q(g) coming from any symmetrizable Kac-Moody algebra g. We construct a family of simple modules over KLR algebras and show how they can be used to obtain the building blocks of existing classifications of simple finite-dimensional modules in finite types. The construction extends to infinite types, where we obtain simple modules whose structures are easy to describe. We give many explicit examples of this construction in rank 2 cases.

Identification And Quantification Of Heterogeneity In Freezing And Primary Drying Steps Of Lyophilization, Pooja Sane

Doctoral Dissertations

The ultimate goal of the freeze-drying process is to deliver a consistently stable, efficacious, easily reconstitutable, and non-immunogenic final product to the patient at an affordable cost. However, heterogeneity in the heat transfer to vials across the batch and in mass transfer resistance to sublimation were found to lead to variation in the factors affecting product quality both intra- and inter-batch. The overall objective of this research was to identify and quantify the sources of variation in the freeze-drying process, which alter the thermal history of the product and investigate their effects on the product quality attributes.

Effects of processing …

Two Essays On The Effect Of Alphanumeric Brand Names On Consumers’ Brand Related Decisions, Selcan Kara

Doctoral Dissertations

Because consumers tend to rely on simplifying heuristics to reduce processing and judgmental operations (Bettman, Johnson, and Payne 2008; Tversky and Kahneman 1974), they use brand names as a judgmental heuristic, a phenomenon commonly referred to as the brand name heuristic (Maheswaran, Mackie and Chaiken 1992). From this perspective, in recent years, the use of alphanumeric brand names has emerged as an interesting test case for the role of cognition in consumers’ brand evaluations in the Marketing field. Alphanumeric brand names consist of combinations of letters and numbers either in digit or word form (Pavia and Costa 1993), such as …

The Impact Of Social Class In The Hiring Process, Nicole Cj Young

Doctoral Dissertations

Social class describes individuals’ possession of economic, social, and cultural capital, and their subjective social rankings relative to others (Bourdieu, 1984). As social class can be easily detected, it is quite likely that it plays a significant role in many workplace processes, such as selection. By considering the context of the hiring process, my dissertation explores the impact of social class from the perspective of hiring managers. First, I conducted a construct clarity study to clarify the multidimensional nature of the construct of social class. Second, using the factors found from my construct clarity study, I developed applicant stimulus materials …

Health Care Experiences Of The Uninsured At The Dawn Of The 21st Century, Sylvia Jalil-Gutierrez, Sylvia Jalil-Gutierrez

Doctoral Dissertations

Using the framework of critical medical anthropology “Health Care Experiences of the Uninsured at the Dawn of the 21st Century” investigates how those lacking health insurance in a U.S. mid-sized northeastern city strive to meet their health care needs. Fieldwork was based on in-depth semi-structured interviews, participant observation, and demographic data of patients who sought care at a non-government, non-profit primary care mobile health clinic, between November 2012 and July 2013. In addition to exploration of health care seeking strategies, I investigated how migration issues played an important role in the health and health care experiences of participants since 80% …

Detecting And Screening Of The Prostate Cancer By Using An Optical Nanoporous Thin-Film Sensor, Salah Eldeen Mofleh Alzghoul

Doctoral Dissertations

Prostate cancer (PC) affects elderly men more than young men. The currently used cancer biomarker, prostate-specific antigen (PSA), highly overestimates PC population. Men with high PSA levels often have to go through unnecessary, but physically painful, and expensive prosesses, such as prostate biopsies. Finding a prostate cancer marker that is produced selectively by cancer, but not by normal prostate cells will increase the reliability of PC test. In 2006, our collaborator (Dr. Girish Shah) discovered a novel protein, referred as neuroendocrine marker (NEM), secreted only by malignant prostate cells and released in blood circulation.

To examine whether the combined NEM-PSA …

Implementing The Unified English Braille Code: Perspectives Of Teachers Of Students With Visual Impairments, Laura Leigh Bostick

Doctoral Dissertations

With change process theory as a framework, the researcher used the diagnostic tools of the Concerns-Based Adoption Model to investigate both the concerns and behaviors of teachers of students with visual impairments (TVIs) during the transition to Unified English Braille (UEB). Quantitative data from the Stages of Concern Questionnaire and qualitative data from Open-Ended Concerns Statements and Levels of Use interview transcripts were consolidated to address the research questions: (1) What are TVIs' attitudes and beliefs toward the transition to UEB? and (2) To what extent are TVIs currently using UEB?

Participants were limited to TVIs in one southern state. …

Electromagnetic Properties Of Metal-Dielectric Media And Their Applications, Shravan Rakesh Animilli

Doctoral Dissertations

The main objective of this dissertation is to investigate nano-structured random composite materials, which exhibit anomalous phenomena, such as the extraordinary enhancements of linear and non-linear optical processes due to excitation of collective electronic states, surface plasmons (SP). The main goal is to develop a time and memory efficient novel numerical method to study the properties of these random media in three dimensions (3D) by utilization of multi core processing and packages such as MPI for parallel execution. The developed numerical studies are then utilized to provide a comprehensive characterization and optimization of a surface plasmon enhanced solar cell (SPESC) …

Energy Harvesting Using Photovoltaic And Betavoltaic Devices, Ashish Sharma

Doctoral Dissertations

There is an important need for improvement in both cost and efficiency of photovoltaic cells. For improved efficiency, a better understanding of solar cell performance is required. An analytical model of thin-film silicon solar cell, which can provide an intuitive understanding of the effect of illumination on its charge carriers and electric current, is proposed. The separate cases of homogeneous and inhomogeneous charge carrier generation rates across the device are investigated. This model also provides for the study of the charge carrier transport within the quasi-neutral and depletion regions of the device, which is of an importance for thin-film solar …

Tunable Controlled Release Of Molecular Species From Halloysite Nanotubes, Divya Narayan Elumalai

Doctoral Dissertations

Encouraged by potential applications in rust coatings, self-healing composites, selective delivery of drugs, and catalysis, the transport of molecular species through Halloysite nanotubes (HNTs), specifically the storage and controlled release of these molecules, has attracted strong interest in recent years. HNTs are a naturally occurring biocompatible nanomaterial that are abundantly and readily available. They are alumosilicate based tubular clay nanotubes with an inner lumen of 15 nm and a length of 600-900 nm. The size of the inner lumen of HNTs may be adjusted by etching. The lumen can be loaded with functional agents like antioxidants, anticorrosion agents, flame-retardant agents, …

Mutlifunctional Platforms For Gene And Drug Delivery For Cancer Therapy, Jeffery J. Ambrose Jr.

Doctoral Dissertations

The National Cancer Institute and the American Cancer Society estimate that 1.6 million new cancer incidences and over half a million cancer related deaths occur annually [1][2]. Cancer the second most common cause of death in the United States [1], [2]. Although the causes of cancer can vary depending on cell type, all or almost all instances of cancer arise from a mutation or from an abnormal activation of the cellular genes that control cell growth and mitosis [3].

Treatment of a given cancer type depends on the subtype, stage and progression of the cancer. Varieties of cancer therapy include …

Cooperative Effects In The Optical Response Of Dense Atomic Gases, Yi Li

Doctoral Dissertations

At high density, dipole-dipole interactions between the atoms may have a major impact on light propagation in a dense gas. We have developed a classical-electrodynamics simulation to study the cooperative response of a near-resonant gas to light. We take into account the motion of the radiators using classical trajectories, including collisions with the walls of the container and atom-atom collisions, and describe the transition from homogeneously broadened to inhomogeneously broadened phenomenology.

Development Of Plga Microsphere/Pva Hydrogel Composite Coatings For Long-Term Biosensor Functioning, Bing Gu

Doctoral Dissertations

This work focuses on the development of poly (lactic-co-glycolic acid) (PLGA) microsphere/polyvinyl alcohol (PVA) hydrogel composite coatings to permit long-term glucose sensor functionality. Two aspects were addressed: 1) prevention of the foreign body reaction (FBR) for 6 months; and 2) investigation of the long-term effects of such coatings on glucose transport.

PLGA microspheres were prepared via blending low (RG503H, 25 kDa) and high (DLG7E, 113 kDa) molecular weight (MW) polymers. “Real-time” in vitro studies demonstrated that the dexamethasone release profiles were dependent on the polymer ratios. The duration of drug release lasted for approximately 2-6 months with varied burst release …

Dynamic Simulation, Optimization, And Control Of Flexible Chemical-Looping Combustion Processes, Lu Han

Doctoral Dissertations

Combustion of hydrocarbon fuels using the concept of chemical-looping combustion (CLC) is a novel approach projected to have higher energy efficiency than conventional CO₂ capture technologies. For CLC technologies to become commercially relevant, it is important to optimize the design of CLC reactor systems for high efficiencies for CO₂capture and power generation. From an engineering point of view, CLC is a complex system with a large number of candidate materials and reactor configurations that need to be considered for process improvement. In this work, a model-based methodology was proposed as a formal framework to guide in developing …

Using Digital Stories And Ipads To Promote Writing Skills, Writing Self-Efficacy, And Motivation To Write Among 9th Grade Students, Anthony J. Girasoli

Doctoral Dissertations

This study explores the use of digital storytelling as a prewriting activity to help 9^th grade students plan narrative essays in English writing lessons. Students (N = 62) in three course sections taught by the same teacher completed a 10-week intervention. Each section was assigned to one of three groups according to their learning environment: a normal educational practice (NEP) group, a bulletin board system (BBS) group, and an asynchronous audio/video (AAV) group. The BBS and AAV groups created digital stories to plan their narratives while the NEP group developed written outlines.

Students’ writing self-efficacy, writing motivation, writing performance, …

Continuous Processing Of Liposomes To Control And Predict Physical Properties, Antonio P. Costa

Doctoral Dissertations

Archival abstract submitted

Information Fusion For Pattern Classification In Complex Interconnected Systems, Nayeff Najjar

Doctoral Dissertations

Typical complex interconnected systems consist of several interconnected components with several heterogeneous sensors. Classification problems (e.g., fault diagnosis) in these systems are challenging because sensor data might be of high dimension and/or convey misleading or incomplete information. So, this thesis performs optimal sensor selection and fusion to lower computational complexity and improve classification accuracy. First, the thesis presents the novel Unsupervised Embedded algorithm for optimal sensor selection. The algorithm uses the minimum Redundancy Maximum Relevance (mRMR) criterion to select the candidate list of sensors, then uses K-means clustering algorithm and entropy criterion to select the optimal sensors. The Unsupervised Embedded …

Optimizations For Energy-Aware, High-Performance And Reliable Distributed Storage Systems, Cengiz Karakoyunlu

Doctoral Dissertations

With the decreasing cost and wide-spread use of commodity hard drives, it has become possible to create very large-scale storage systems with less expense. However, as we approach exabyte-scale storage systems, maintaining important features such as energy-efficiency, performance, reliability and usability became increasingly difficult. Despite the decreasing cost of storage systems, the energy consumption of these systems still needs to be addressed in order to retain cost-effectiveness. Any improvements in a storage system can be outweighed by high energy costs. On the other hand, large-scale storage systems can benefit more from the object storage features for improved performance and usability. …