Digital Commons Network^™

Embedding Oriented Graphs In Books, Stacey R. Mcadams

Doctoral Dissertations

A book consists of a line L in [special characters omitted]3, called the spine, and a collection of half planes, called pages, whose common boundary is L. A k-book is book with k pages. A k-page book embedding is a continuous one-to-one mapping of a graph G into a book such that the vertices are mapped into L and the edges are each mapped to either the spine or a particular page, such that no two edges cross in any page. Each page contains a planar subgraph of G. The book thickness, denoted bt( …

Automated, Efficient, And Practical Extreme Value Analysis With Environmental Applications, Brian Bader

Doctoral Dissertations

Although the fundamental probabilistic theory of extremes has been well developed, there are many practical considerations that must be addressed in application. The contribution of this thesis is four-fold. The first concerns the choice of r in the r largest order statistics modeling of extremes. Practical concern lies in choosing the value of r; a larger value necessarily reduces variance of the estimates, however there is a trade-off in that it may also introduce bias. Current model diagnostics are somewhat restrictive, either involving prior knowledge about the domain of the distribution or using visual tools. We propose a pair …

Simulation And Analysis Of Gradient Frequency Neural Networks, Amirali Farokhniaee

Doctoral Dissertations

The methodologies introduced and applied in this work have fundamental roles in connecting the component level descriptions of brain dynamics (single neurons) to population level (neural networks). The synchronization regions of a single neuron with respect to a periodic external stimulus either deterministic or noisy is evaluated. Many neurons in the auditory system of the brain must encode periodic signals. These neurons under periodic stimulation display rich dynamical states including mode-locking and chaotic responses. Periodic stimuli such as sinusoidal waves and amplitude modulated (AM) sounds can lead to various forms of n:m mode-locked states, in which a neuron fires n …

Seeking The Constituent Signal: Exit Poll Measures Of Public Opinion And Dynamic Congressional Responsiveness, Clifford D. Vickrey

Doctoral Dissertations

Do American political institutions comport with accepted norms of democratic representation? The three arguably most important American political scientists of the 20^th century—Harold Lasswell, V.O. Key, and Robert Dahl—each held that if policymaking does not generally respond to the policy attitudes of constituents, then democracy in America is a fiction. The institutional design of the House of Representatives, which emphasizes frequent elections and small constituencies, makes it a likely locus of responsiveness in our political system. However, the vast literature investigating House responsiveness has failed to provide unambiguous answers about the phenomenon’s nature and extent. One reason for this …

Bayesian Analysis Of Item Response Theory And Its Applications To Longitudinal Education Data, Abhisek Saha

Doctoral Dissertations

Inferences on ability in item response theory (IRT) have been mainly based on item responses while response time is often ignored. This is a loss of information especially with the advent of computerized tests. Most of the IRT models may not apply to these modern computerized tests as they still suffer from at least one of the three problems, local independence, randomized item and individually varying test dates, due to the flexibility and complex designs of computerized (adaptive) tests. In Chapter 2, we propose a new class of state space models, namely dynamic item responses and response times models (DIR-RT …

An Efficient Leakage Free Countermeasure Of Aes Against Side Channel Attacks, Abdulaziz M. Miyajan

Doctoral Dissertations

Archival abstract submitted

Individual Differences In Evaluating The Credibility Of Online Information In Science: Contributions Of Prior Knowledge, Gender, Socioeconomic Status, And Offline Reading Ability, Elena Forzani

Doctoral Dissertations

This study investigated how seventh grade students performed on a measure of online critical evaluation in science (the ORCA). The analysis included evaluating the extent to which critical evaluation also appeared to be an aspect of other elements of online research and comprehension, including reading to locate information, reading to synthesize information, and reading and writing to communicate information. Additionally, this study examined the extent to which several important individual difference variables affected students’ ability to critically evaluate information during online reading in science. The individual difference variables evaluated in this study included prior knowledge, gender, socioeconomic status, and offline …

Finite Element Methods Of Dirichlet Boundary Optimal Control Problems With Weakly Imposed Boundary Conditions, Cagnur Corekli

Doctoral Dissertations

In the present work, we consider Symmetric Interior Penalty Galerkin (SIPG) method to approximate the solution to Dirichlet optimal control problem governed by a linear advection-diffusion-reaction equation on a convex polygonal domain.

The main feature of the method is that Dirichlet boundary conditions enter naturally into bilinear form and the finite element analysis can be performed in the standard setting. Another advantage of the method is that the method is stable and can be of arbitrary high degree. We show existence and uniqueness of the analytical and discrete solutions of the problem and derive optimal error estimates for the control …

Liouville-Type Theorems For Higher Order Elliptic Systems, Frank Arthur

Doctoral Dissertations

ABSTRACT

We study positive solutions of the following higher order elliptic system

(-∆)^m u =|x|^a v^p and

(-∆)^m v =|x|^b u^q in R^N.

Here p ≥ 1, q ≥ 1, (p, q) ≠ (1, 1). Henon-Lane-Emden conjecture says (1.0.1) admits no positive solutions if (1+a/N)/(p+1) + (1+b/N)/(q+1) >1-2m/N.

When a = b = 0, we solve the conjecture under the additional assumption

max ((2m(p+1)+a+bp)/(pq-1) , (2m(q+1)+aq+b)/(pq-1)) > N − 2m − 1.

In particular, when N = 2m + 1 or N = 2m + 2, the conjecture hold true.

When a > 0, b …

Evaluation Of The Effect Of Vitamin D Pharmacokinetics On Bone Health Using A Multi-Scale Systems Pharmacology Model (Mspm), Alanna S. Ocampo-Pelland

Doctoral Dissertations

Objectives: Relationships between Vitamin D dose, 25OHD, and indicators of bone health (serum calcitriol, parathyroid hormone (PTH), and bone mineral density at the lumbar spine (BMDLS)) were explored by considering the combined effects of Vitamin D3 and calcium administration (D3CA) on bone-health endpoints.

Methods: Population PK models were developed to predict D and 25OHD, and the final model was integrated with a previously published MSPM, describing calcium, PTH, and bone-remodeling. Public-source D and 25OHD PK data in healthy or osteoporotic populations, including 74 studies, representing 5684 individuals, were selected using PUBMED. Nonlinear-mixed-effects models were developed simultaneously for D and 25OHD …

An Examination Of Administrators’ Framing Of The Basic Skills Test Requirement, Ann Traynor

Doctoral Dissertations

This collective case study examines how teacher preparation program administrators framed the basic skills test requirement (BSR) in the context of its impact on the diversification of teacher education programs. The BSR is an entry gate requirement for admission to teacher education programs. Basic skills and subject area teacher licensure tests present a disproportionate entry barrier to teaching for students of color. Research questions were designed to elicit administrators’ policies, practices and supports for students of color to meet the BSR. Methods included interviews with eight administrators at three institutions, document analysis, and the use of framing theory as an …

Generalized Linear Model Approach To Adjusting Expected Assumptions Of Long-Term Care Incidence Rates, Rozita Ramli

Doctoral Dissertations

Generalized Linear Model Approach to Adjusting Expected Assumptions of Long-Term Care Incidence Rates

Rozita Ramli, PhD

University of Connecticut, 2016

Actuarial assumptions are needed in most of actuarial works, for example pricing and reserving and setting capital standards. In long-term care (LTC) insurance, three main actuarial assumptions are incidence, termination and utilization rates. These assumptions can be seen as factors affecting the financial progress in LTC insurance business. Insurance companies must make sure the assumptions they use adequately reflect actual experience to avoid adverse financial consequences. Hence, a regular systematic methodology to monitor expected assumptions is essential. This work proposes …

Stabilization By Noise Of Systems Of Complex-Valued Odes, Fan Ny Shum

Doctoral Dissertations

D. Herzog and J. Mattingly have shown that a complex-valued polynomial ODE with finite-time blow-up solutions may be stabilized by the addition of complex-valued Brownian noise. In this paper, we extend their results to two-dimensional complex-valued systems of coupled ODEs with finite-time blow-up solutions. We show analytically and numerically that stabilization can be achieved in our setting by adding a suitable Brownian noise, and that the resulting systems of SDEs are ergodic. For one of the systems, the proof uses the Girsanov theorem to induce a time change from that two-dimensional complex system to a quasi-one-dimensional complex system similar to …

Topics In Establishing Environmental Markets: Performance Of A Multi-Units Public Good Auction And Credit Stacking Policy, Pengfei Liu

Doctoral Dissertations

The purpose of my study is to better understand the current obstacles in establishing a functional environmental market. In the dissertation, I study this problem from both supply and demand sides; that is, I consider the available actions from the environmental credit suppliers, such as landowners or farmers, under different market institutions, and I also study the buyers’ behaviors for a potential environmental market for a public good, such as private individuals who hold positive values toward various types of ecosystem services.

I mainly address two questions. The first question is how to raise revenue from private individuals to support …

Implementation Planning As A Proactive Approach To Treatment Integrity Maintenance Of An Academic Intervention, Justin Byron

Doctoral Dissertations

Reform in educational policy and federal legislation has placed an emphasis on data collection pertaining to student outcomes in the academic setting. In response, school systems have shifted to multi-tiered frameworks that utilize varying levels of support through the implementation of evidence-based interventions. Data-based decision making determined by student success within these interventions is, at best, inconclusive without the collection of treatment integrity data. However, present evidence-based methods of improving treatment integrity are reactive and also require time and staffing demands that may not be feasible in the school setting. The present research aimed to investigate Computer-Guided Implementation Planning as …

Categories Of Conceptions Of Proofs By Students Of Computer Science, Thérèse Smith

Doctoral Dissertations

Guided by constructivism, which posits that students assimilate new knowledge into what has made sense to them previously, we researched student conceptualizations of proof. We used the qualitative research methods of thematic analysis and phenomenography to learn and categorize student conceptualizations of proof, and of mathematization more generally. Our published work exhibited an explanatory connection between publications of others in the mathematics education community and the computer science education community. The connection we found is lack of understanding of proof by mathematic induction as an argument, as occurs among students of mathematics and of computer science, explains lack of understanding …

High Performance Embedded Systems, Ahmed Abdullah Alsheikhy

Doctoral Dissertations

Embedded systems exist almost everywhere since 95% of the current market chips contains embedded devices; they can be seen as the brain of such systems. They control everything in their platforms such as access, store and processing of data. They are typically dedicated to perform specific tasks. They range from portable devices such as smart phones and MP3 players to a very complex one such as systems controlling air planes or automotive. Their complexity varies from a single system, which includes a single processing unit, to very complicated one with multiple units. They are designed to be used in many …

Essays On Religion, Conflict, And Economic Development, Sadullah Yildirim

Doctoral Dissertations

This dissertation will examine, theoretically and empirically, the relationship between religion and state and how the historical evolution of this relationship has affected current economic outcomes. Developing an argument centered on legitimizing relationship between political rulers and religion, and using a new dataset that has information on the religious and political histories of today's nations since the year 1000, it first demonstrates how state religion has evolved over time and across space since the year 1000, then analyzes how historical religious differences between rulers and segments of populations affect current civil conflict, and finally extend the analysis to the historical …

Magnetic Materials For Biomedical Applications, Michael E. Zilm

Doctoral Dissertations

Magnetic materials are of interest for biomedical applications for the ability to remotely control magnetic particles through the use of non-invasive magnetic fields. Specific applications of magnetic materials in biomedical fields include magnetic resonance imaging, drug delivery, and hyperthermia-based cancer treatments. The most commonly used material for these applications are iron oxides, which suffer from acute toxicity and unknown fate in vivo and thereby limit their applications.

An alternative approach is to substitute magnetic ions into a biocompatible and biodegradable material to impart magnetic properties. Hydroxyapatite (HA), the main inorganic component of natural bone, is widely studied as a biomaterial …

Thermal Analysis In A Triple-Layered Skin Structure With Embedded Vasculature, Tumor, And Gold Nanoshells, Casey O. Orndorff

Doctoral Dissertations

In hyperthermia skin cancer treatment, the objective is to control laser heating of the tumor (target temperatures of 42-46 °C) so that the temperatures of the normal tissue surrounding the tumor remains low enough not to damage the normal tissue. However, obtaining accurate temperature distributions in living tissue related to hyperthermia skin cancer treatment without using an intruding sensor is a challenge. The objective of this dissertation research is to develop a mathematical model that can accurately predict the temperature distribution in the tumor region and surrounding normal tissue induced by laser irradiation. The model is based on a modified …

Direct And Inverse Scattering Problems For Domains With Multiple Corners, Jiang Yihong

Doctoral Dissertations

Direct and inverse scattering problems have wide applications in geographical exploration, radar, sonar, medical imaging and non-destructive testing. In many applications, the obstacles are not smooth. Corner singularity challenges the design of a forward solver. Also, the nonlinearity and ill-posedness of the inverse problem challenge the design of an efficient, robust and accurate imaging method.

This dissertation presents numerical methods for solving the direct and inverse scattering problems for domains with multiple corners. The acoustic wave is sent from the transducers, scattered by obstacles and received by the transducers. This forms the response matrix data. The goal for the direct …

Computational Micro-Flow With Spectral Element Method And High Reynolds Number Flow With Discontinuous Galerkin Finite Element Method, Haibo Zhang

Doctoral Dissertations

In this dissertation, two numerical methods with high order accuracy, Spectral Element Method (SEM) and Discontinuous Galerkin Finite Element Method (DG-FEM), are chosen to solve problems in Computational Fluid Dynamics (CFD). The merits of these two methods will be discussed and utilized in different kinds of CFD problems. The simulations of the micro-flow systems with complex geometries and physical applications will be presented by SEM. Moreover, the numerical solutions for the Hyperbolic Flow will be obtained by DG-FEM. By solving problems with these two methods, the differences between them will be discussed as well.

Compressible Navier-Stokes equations with Electro-osmosis body …

Personal Factors, Domain Specificity, And Risky Decision-Making, Rose Niles

Doctoral Dissertations

Adults make many risky decisions daily, such as choosing to drive over the speed limit or going outside without previously applying sunscreen. How and why adults make such decisions remains relatively unknown and has gained much research attention. Traditional models of decision-making, such as Expected Utility Theory (Bernoulli, 1954) and Prospect Theory (Kahneman & Tversky, 1972) have proven too simplistic, as they do not account for the regular deviations from expected decision-making processes. Likewise, models that attempt to categorize individuals as risk seeking and risk-averse do not hold up well when decisional-domain is examined (Blais & Weber, 2006). Contemporary research …

Studies On The Electrical Transport Properties Of Carbon Nanotube Composites, Taylor Warren Tarlton

Doctoral Dissertations

This work presents a probabilistic approach to model the electrical transport properties of carbon nanotube composite materials. A pseudo-random generation method is presented with the ability to generate 3-D samples with a variety of different configurations. Periodic boundary conditions are employed in the directions perpendicular to transport to minimize edge effects. Simulations produce values for drift velocity, carrier mobility, and conductivity in samples that account for geometrical features resembling those found in the lab. All results show an excellent agreement to the well-known power law characteristic of percolation processes, which is used to compare across simulations. The effect of sample …

Experimental Investigation And Numerical Simulation Of A Copper Micro-Channel Heat Exchanger With Hfe-7200 Working Fluid, Eric Borquist

Doctoral Dissertations

Ever increasing cost and consumption of global energy resources has inspired the development of energy harvesting techniques which increase system efficiency, sustainability, and environmental impact by using waste energy otherwise lost to the surroundings. As part of a larger effort to produce a multi-energy source prototype, this study focused on the fabrication and testing of a waste heat recovery micro-channel heat exchanger. Reducing cost and facility requirements were a priority for potential industry and commercial adoption of such energy harvesting devices. During development of the micro-channel heat exchanger, a new fabrication process using mature technologies was created that reduced cost, …

Experimental And Numerical Evaluation Of A New Composite Pressure Pipe For A Trenchless Rehabilitation Technology, Xuanchen Yen

Doctoral Dissertations

The information presented in this dissertation is based on research work conducted at Trenchless Technology Center (TTC) at Louisiana Tech University. This work was performed through a contract with China University of Geoscience (CUG) for a gas company. China's gas pipelines need replacement or rehabilitation after 15 to 30 years of service. China's gas industry is looking for suitable techniques to transfer into their market.

When compared to conventional excavation pipeline renewal or replacement methods, there are obvious advantages of TRT for gas pipelines that can impact the triple bottom-line of economic, social and environmental benefits. An introduction of TRT …

Production Efficiency And Productivity Change In Chinese Agriculture: A Case Study Of Agricultural Production In Shanxi Province, Wenqiang Bao

Doctoral Dissertations

This dissertation studies the production efficiency and productivity of agriculture in Shanxi province after Chinese economic reforms. The main question about the economic aspects of agriculture we want to address is the performance of Chinese agriculture since 1980. We use a newly constructed county-level input and output quantity data set to obtain technical efficiency and measure the Malmquist productivity index and its components.

We first use the nonparametric method of Data Envelopment Analysis (DEA) to obtain Pareto-Koopmans measures of technical efficiency of individual counties in Shanxi province during year 1981-2010 in a multi-output, multi-input production framework. We disaggregate overall efficiency …

Fast Algorithms For Structured Matrices And Laurent Polynomials, David Miller

Doctoral Dissertations

The Vandermonde matrix and Cauchy matrix are classical and are encountered in polynomial and rational interpolation computation respectively. The structure of these matrices lead to fast inversion algorithms and system solvers. We look to extend these properties to other structured matrices, including Cauchy-Vandermonde matrices and systems involving Laurent polynomials.

Design Of Hardware-Efficient Signal Reconstruction For Embedded Computing, Guoxian Huang

Doctoral Dissertations

Conventional sensing techniques often acquire the signals entirely using a lot of resources and then just toss away a large portion of the obtained data during compression. This motivates an emerging research area called as Compressive Sensing (CS) that allows efficient signal acquisition under the sub-Nyquist rate while still able to promise reliable data recovery. Despite the benefits of compressive sensing, one critical issue in the practical applications of compressive sensing is how to reliably recover the original signals from only a few measurements in an efficient way. The Orthogonal Matching Pursuit (OMP) algorithm has shown a good capability for …

Analysis And Control Of Thermoacoustic Instability: A Time Delay Systems Approach, Umut Zalluhoglu

Doctoral Dissertations

Thermoacoustic instability arises from the interaction between unsteady heat release and pressure perturbations in an acoustic enclosure. The pressure oscillations grow and lead to excessive stress reversals in the structure, raising fatigue concerns and mechanical failures. This common phenomenon in the realistic combustors and rocket engines has been broadly studied over a simplistic laboratory abstraction called the Rijke tube. This simple set-up offers a convenient platform to elucidate the fundamental physics of thermoacoustic instabilities. As evident from the most recent literature, there are numerous aspects of this phenomenon even in the Rijke tube setting that are not fully understood and …