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A Multiscale Systems Model For Advancement Of A New Line Of Therapy For Osteoporosis, Rena J. Eudy

Doctoral Dissertations

The osteocyte is a load-sensing bone cell, which plays a pivotal role in the bone modeling process. This process is highly regulated by feedback control and poorly described by isolated in vivo or in vitro experiments. In silico systems models present a way by which experimental and clinical data can be integrated in a mathematical framework so that physiology, pharmacology and disease progression as it relates to bone health, at the level of cell signaling networks up to the tissue level, can can be better understood. The Multiscale Systems Pharmacology Model presented here began as an endeavor to link biological …

Experimental & Computational Approaches Towards Improving Mesoscale Understanding Of Particle Interactions In Pharmaceutical Systems, Saurabh Sarkar

Doctoral Dissertations

Despite solid oral and inhaled dosage forms making a significant proportion of marketed pharmaceutical products, a better understanding of particulate processes will enable more science-based product optimization and scale up. A combination of experimental and computational approaches can be used to improve our current understanding of particulate processes. The current dissertation aims at improving understanding of particulate systems by investigating applications in several multiphase multicomponent flow regimes, each capturing a fundamental force, by systematic experiments and computational modeling.

Computational Fluid Dynamics (CFD) modeling of aerosol flow through pressurized metered dose inhaler (pMDI) – spacer systems and correlation of fluid flow …

Substantive Theories Of Epistemic Justification: An Exploration Of Formal Coherence Requirements, Michael Hughes

Doctoral Dissertations

Abstract. Are there formal coherence constraints governing categorical belief? If so, what are they? Those who answer the first question affirmatively typically hold that categorical belief is governed by logical consistency and closure principles. However, such principles are difficult to maintain in the face of the epistemic inconsistency paradoxes.The debate on this issue usually revolves around the question of whether deductive logic can be afforded a significant enough role in guiding rational inquiry. We shall take up these questions from a different angle. Various substantive theories of justified belief have been thought to carry commitments to logical consistency and closure …

Multiple Periodic Solutions Of A Nonlinear Suspension Bridge System Of Partial Differential Equations, Ryan H. Pellico

Doctoral Dissertations

A nonlinear system of partial differential equations is presented to model the vertical motions of the roadbed and main cable of suspension bridge. The model is subjected to periodic forcing and numerical methods are presented for the computation of the periodic responses in the system.

Newton's method, continuation algorithms and Floquet theory are used to produce bifurcation diagrams which capture the multiplicity and stability of the periodic solutions. Separable solutions are investigated using methods for ordinary differential equations while general solutions are investigated using a finite difference scheme and an implicit-explicit initial value solver.

The method of steepest descent is …

Modeling And Experimental Studies Of Miniature Lithium Air Batteries And Alkaline Direct Ethanol Fuel Cells, Jing Huang

Doctoral Dissertations

Batteries and fuel cells directly convert chemical energy to electricity through controlled electrochemical reactions. Batteries also serve as energy storage devices, while fuel cells rely on a continuous supply of fuel to maintain power output. In this dissertation, modeling and experimental studies on lithium air batteries and alkaline direct ethanol fuel cells are presented. Both technologies can be designed as small-scale electrochemical devices that are suitable for miniature electronics and energy systems. Innovative concepts are presented regarding miniaturization of both technologies, including detailed physical simulation. The lithium air (Li-air) battery is considered a promising candidate for next generation secondary battery …

Dynamic Modeling Of Multivariate Counts - Fitting, Diagnostics, And Applications, Volodymyr Serhiyenko

Doctoral Dissertations

An adequate statistical methodology is required for modeling multivariate time series of counts. The proper specification of the underlying distribution in such modeling could be very challenging, as it should account for the possibility of overdispersion, an excessive number of zero values, positive and negative association between counts, etc.

This dissertation is focused on modeling multivariate time series of counts as a function of location-specific and time-dependent covariates. The Bayesian framework for estimation and prediction is discussed. We focus on Markov chain Monte Carlo (MCMC) methods for fully Bayesian inference and the Integrated Nested Laplace Approximation (INLA) for fast implementation …

Unitary K-Hessenberg Matrices, Michael Mackenzie

Doctoral Dissertations

In 1971, Householder and Fox [26] introduced a method for computing an orthonormal basis for the range of a projection. Using a Cholesky decompo- sition on a symmetric idempotent matrix A produced A = LL T , where the columns of the lower triangular matrix L form said basis. Moler and Stewart [32] performed an error analysis on the Householder-Fox algorithm in 1978. It was shown that in most cases reasonable results can be expected, however a recent paper by Parlett and Barszcz [36] included a numerical experiment by Kahan in which the Householder-Fox method performed poorly. Parlett proposed an …

Interplay Of Cofilin And Capping Proteins In Branched Actin Networks And Integration Of Linear And Branched Nucleation In Actin Comets, Sofya Borinskaya

Doctoral Dissertations

Rearrangements of the actin cytoskeleton underlie many physiological processes. I investigated actin dynamics in broad thin protrusions (lamellipodia) at the front of migrating cells, and in locally induced dynamic actin structures (comet tails).

Cofilin is an actin regulatory protein that induces either polymerization or depolymerization in live cells. Through biochemical modeling in Virtual Cell software I examined the function of cofilin in a dynamic branched network at the tip of a lamellipodium. Cofilin and capping protein play synergistic roles in regulating branched actin polymerization. The model predicts that cofilin promotes actin disassembly when capping concentration is low and promotes actin …

Social Network Community Detection, Guang Ouyang

Doctoral Dissertations

This dissertation has its main focus on the development of social network community detection algorithms. Real world social networks are usually found to divide naturally into small communities. In the big data age, effective and scalable algorithms detecting network community structures are in demand in a wide range of business applications, such as marketing segmentation, friend recommendation in online social networks, and product recommendation for online retailers such as Amazon. We aim to leverage the power of statistical inference over uncertainty to scalable community detection algorithms. We developed three novel community detection algorithms: the first is a statistical model-based clustering …

Estimating Equations For Spatial Extremes With Applications To Detection And Attribution Analysis Of Changes In Climate Extremes, Zhuo Wang

Doctoral Dissertations

In inference for max-stable processes in regional frequency analysis, it is found that, when the dependence model is misspecified, the pairwise likelihood method leads to biased estimator. Motivated by the fact that the primary interest in many studies is the inference about marginal generalized extreme value (GEV) parameters and that the spatial dependence is a nuisance, we propose a combined score equations (CSE) approach that does not need dependence assumptions beyond the univariate GEV distribution. The CSE method combines the score equations of GEV model at each site with an approximate correlation function of the scores to improve the estimation …

Induced And Coinduced Modules Over Cluster-Tilted Algebras, Khrystyna Serhiyenko

Doctoral Dissertations

We propose a new approach to study the relation between the module categories of a tilted algebra C and the corresponding cluster-tilted algebra B. This new approach consists of using the induction functor as well as the coinduction functor. We give an explicit construction of injective resolutions of projective B-modules, and as a consequence, we obtain a new proof of the 1-Gorenstein property for cluster-tilted algebras. We show that the relation extension bimodule is a partial tilting and a tau-rigid C-module and that the corresponding induced module is a partial tilting and a tau-rigid B-module. Furthermore, …

Color Tuning Neutrality And Gel Polymer Electrolyte Materials For Optoelectronic Application, Yumin Zhu

Doctoral Dissertations

Conjugated polymers (CPs), also known as conducting polymers are polymers consisting of alternating single/double bonds along the polymer backbone. They are known to be conductive upon doping. One important property of CPs is their ability to undergo reversible redox switch from a neutral (insulting) state to an oxidized (conducting) state upon potential application. Induced by electrical stimuli, accompanied with the change in electronic state of the material is usually a distinguishable change in the materials absorption characteristics within the visible region (400–800 nm) or near IR region, resulting in the material’s color change, known as “electrochromism”.

In order to …

Dissecting And Modeling A Transcriptional Dynamics During Stochastic Phase Of Somatic Reprogramming, Kyung Min Chung

Doctoral Dissertations

Forced ectopic expression of the transcription factors OCT4, SOX2, KLF4, and c-MYC (OSKM) can directly reprogram various somatic cells into induced pluripotent stem cells (iPSCs). These reprogrammed cells offer great potential as a source for patient-matched regenerative therapies thanks to their striking molecular and phenotypic similarity to embryonic stem cells. However, despite years of research, this process remains highly inefficient and produces considerable cellular heterogeneity. Moreover, long latency has stalled the effort to understand the mechanisms and molecular changes underlying the reprogramming process. To improve and facilitate the development of efficient and rapid reprogramming strategies, a clear understanding of fundamental …

Computation Of Intrinsic Breakdown Based On Computational Quantum Mechanics, Ying Sun

Doctoral Dissertations

A first principles quantum mechanical method for estimating intrinsic breakdown field of insulating materials has been implemented based on an average electron model which assumes that breakdown occurs when the average electron energy gain from the electric field exceeds the average energy loss to phonons. The approach is based on density functional perturbation theory and on the direct integration of electronic scattering probabilities over all possible final states, with no adjustable parameters. The computed intrinsic breakdown field for many prototypical materials over a range of elemental compositions and crystal structures compares favorably with experimental data. This model also provides physical …

Passive Sensor Bias Estimation Using Targets Of Opportunity, Djedjiga Belfadel

Doctoral Dissertations

Most of the literature pertaining to target tracking assumes that the sensor data are corrupted by measurement noises that are zero mean (i.e., unbiased) and with known variances (accuracies). However in real tracking systems, measurements from sensors exhibit, typically, biases. This thesis aims to solve several key problems in passive sensors residual bias estimation, when only targets of opportunity are available. For angle-only sensors, imperfect registration leads to systematic Line of Sight (LOS) angle measurement errors in azimuth and elevation. If uncorrected, registration errors can lead to large tracking errors and potentially to the formation of multiple tracks (ghosts) on …

An Evaluation Of The Alignment Method For Detecting Measurement Non-Invariance In Noncognitive Scales, Jessica K. Flake

Doctoral Dissertations

In recent years a new methodology, the alignment method (Asparouhov & Muthén, 2014), has surfaced for estimating measurement models and detecting measurement noninvariance (i.e., DIF) across many groups. The purpose of the current study was to investigate the alignment method for use with non-cognitive scales across groups of students from different educational contexts (e.g., schools or programs). Asparouhov and Muthén (2014) have investigated the method with continuous and binary item scales, thus I extended previous research by using simulation techniques to evaluate the method with polytomous items, which are often used to measure noncognitive constructs. I also evaluated the new …

Model-Based Clustering Of Incomplete Data, Chantal Larose

Doctoral Dissertations

Several important questions have yet to be answered concerning clustering incomplete data. For example, how can disparate solutions from multiply imputed cluster results be resolved? Additionally, can a model-selection criterion be developed which can detect the correct number of LCA classes after multiple imputation has been performed? Finally, as cluster analysis depends on measures of uncertainty, what is the eect of missing values on such measures? This thesis presents new theorems, methodologies, and applications which demonstrate solutions to these pressing questions.

Stability Analysis And Novel Control Concepts For Multiple Time-Delay Systems, Qingbin Gao

Doctoral Dissertations

Systems with delays exist universally in engineering, such as manufacturing process, networked control systems, tele-operation of robots, multi-robot systems, internal combustion engines, and traffic dynamics. Delays are ubiquitously observed in these systems due to the unavoidable time, which is required to gather information needed for decision-making, to generate control decisions, and to execute these decisions. These delays are crucial factors that may deteriorate or even destabilize the performance of the controlled systems. A critical question is: How to design controllers so that these time-delayed control systems can tolerate larger delays? To answer this, we first explore the interplay between the …

Individual Adaptability As A Predictor Of Job Performance, Stephanie L. Murphy

Doctoral Dissertations

In the new global economy, organizations frequently have to adjust to meet challenging demands of customers, competitors, or regulatory agencies. These adjustments at the organizational level often cascade down to employees, and they may face changes in their job responsibilities and how work is performed. I-ADAPT theory suggests that individual adaptability (IA) is an individual difference variable that includes both personality and cognitive aspects and has both trait- and state-like properties. As a result, IA may be an acceptable alternative for traditional, stable selection tests for operating within unstable environments. The present paper examined the relationship of individual adaptability, cognitive …

Crystallized Intelligence And Openness To Experience: Drawing On Intellectual-Investment Theories To Predict Job Performance Longitudinally, Christopher B. Patton

Doctoral Dissertations

Various approaches to conceptualizing and measuring intelligence have been utilized throughout history. Despite the plethora of intelligence theories, the field of industrial and organizational (I-O) psychology has been largely dominated by the psychometric tradition of intelligence and Spearman's general factor theory of intelligence (g). Moreover, other approaches to intelligence (e.g., the developmental perspective) have generally been ignored by I-O psychology. This is puzzling given the widespread acceptance among I-O psychologists of intelligence's substantial and increasing importance in the modern workplace.

Supported by a vast amount of research, g has often been recognized as the single best predictor of …

Administrators' Perceptions Of Stem Education And Their Influence On Classroom Practices In Louisiana Schools, Misty Davis

Doctoral Dissertations

The purpose of this study was to examine administrators' understandings and perceptions of STEM education and their influence on classroom practices. Due to the well-documented need throughout decades of literature for quality STEM programming in the nation's schools, the knowledge gained in this study was valuable because of the potential impact administrators' perceptions and understandings can have on program implementation. This study focused on the implementation of Project Lead the Way (PLTW) STEM programs.

In this mixed-methods investigation, quantitative and qualitative data were gathered through the use of surveys and interviews. The study participants were administrators of schools utilizing at …

Nanoformulation For Anticancer Drug Delivery: Enhanced Pharmacokinetics And Circulation, Gaurav Parekh

Doctoral Dissertations

In this study, we have explored the application of the Layer-by-Layer (LbL) assembly technique for improving injectable drug delivery systems of low soluble anticancer drugs (e.g. Camptothecin (CPT), Paclitaxel (PTX) or Doxorubicin (DOX)). For this study, a polyelectrolyte shell encapsulates different types of drug nanocores (e.g. soft core, nanomicelle or solid lipid nanocores).The low soluble drugs tend to crystallize and precipitate in an aqueous medium. This is the reason they cannot be injected and may have low concentrations and low circulation time in the blood. Even though these drugs when present in the cancer microenvironment have high anti-tumor inhibition, the …

Intrusion Detection System Of Industrial Control Networks Using Network Telemetry, Stanislav Ponomarev

Doctoral Dissertations

Industrial Control Systems (ICSs) are designed, implemented, and deployed in most major spheres of production, business, and entertainment. ICSs are commonly split into two subsystems - Programmable Logic Controllers (PLCs) and Supervisory Control And Data Acquisition (SCADA) systems - to achieve high safety, allow engineers to observe states of an ICS, and perform various configuration updates. Before wide adoption of the Internet, ICSs used "air-gap" security measures, where the ICS network was isolated from other networks, including the Internet, by a physical disconnect [1]. This level of security allowed ICS protocol designers to concentrate on the availability and safety of …

Scan Statistics For Detecting A Local Change In Variance For Normal Data, Bo Zhao

Doctoral Dissertations

In this dissertation scan statistics for detecting a local change in variance are proposed for both one and two dimensional normal observations. When the size of the window where a local change has occurred is known, fixed window scan statistics are proposed. Approximations for the distributions of fixed window scan statistics are investigated. When the correct window size is unknown, variable window scan statistics based on generalized likelihood ratio tests and multiple window minimum P-value scan statistics are developed. When population variance, where the null hypotheses of no change in variance, is also unknown, a conditional approach is employed, for …

Design And Synthesis Of Electrochromic And Highly Conductive Polymers For Flexible And Stretchable Electronics, Michael Thomas Otley

Doctoral Dissertations

Archival Abstract submitted

Portfolio Choice With Life Annuities Under Probability Distortion, Wenyuan Zheng

Doctoral Dissertations

Retirement planning has attracted considerable attentions from retirees, finance industry and the government. Its significance lies in the protection against individual longevity risk. As a result, optimal portfolio selection problem in a market with annuities has been extensively studied. Yarri (1965) first suggested that individuals with no bequest motive should annuitize all her savings. However, the volume of the voluntary annuity purchases is much lower than predicted by such model, which is the so-called “annuity puzzle”. In this dissertation, I aim to explore the annuity puzzle from the behavioral economics point of view. Particularly, one major finding from the behavioral …

Risk Assessment And Pricing For Group Health Claims, Shujuan Huang

Doctoral Dissertations

Risk assessment is essential for insurance pricing and risk management. This study develops several predictive models with data from a major national health insurer. Specifically, four models (lognormal, gamma, log-skew-t, and Lomax) for Episode Treatment Groups based costs are compared using four different metrics (AIC and BIC weights, random forest feature classification, and Bayesian model averaging). Several case studies are provided for illustration. Experimental results show that random forest feature classification is preferred for large data set for its computational efficiency and sufficient accuracy. For small data sets, Bayesian model averaging is recommended for its better accuracy.

Given the target …

Computability Theory And Ordered Groups, Caleb J. Martin

Doctoral Dissertations

Ordered abelian groups are studied from the viewpoint of computability theory. In particular, we examine the possible complexity of orders on a computable abelian group. The space of orders on such a group may be represented in a natural way as the set of infinite paths through a computable tree, but not all such sets can occur in this way. We describe the connection between the complexity of a basis for a group and an order for the group, and completely characterize the degree spectra of the set of bases for a group. We describe some restrictions on the possible …

Scalable Optimization Algorithms For High-Throughput Genomic Data, James Lindsay

Doctoral Dissertations

The problem of interpreting biological data is often cast into a mathematical optimization framework where a large body of existing computational theory and practical techniques can be leveraged. While this strategy has been particularly successful in the bioinformatics domain, the massive datasets generated by high-throughput genomic technologies are challenging the scalability of even the most advanced mathematical optimization algorithms. Indeed, as the cost per base of of DNA sequencing has dropped precipitously, even outpacing Moore's law, the size of many bioinformatics problems has grown beyond the limit of existing methods, necessitating new algorithms. This effect is felt even more acutely …

Gifted Secondary School Students: The Perceived Relationship Between Enrichment And Achievement Orientation, Carla B. Brigandi

Doctoral Dissertations

Gifted and talented students have special needs that require interventions, such as academic acceleration and academic enrichment. Additionally, without appropriate modifications gifted and talented students are at risk of underachievement. Grounded in the Schoolwide Enrichment Model and the Achievement Orientation Model, the purpose of this qualitative case study was to build understanding of the relationship between participation in academic enrichment, achievement attitudes, and the resultant behavior (self-regulation) of gifted secondary school students. Achievement attitudes include self-efficacy, goal valuation, and environmental perceptions. Participants included 10 students enrolled in one distinctive enrichment program, their parents, and their classroom teacher. The enrichment program …