Digital Commons Network^™

Statistical Methods For Analyzing Bivariate Mixed Outcomes, Ved Deshpande

Doctoral Dissertations

Multivariate outcomes are ubiquitous. Joint analysis of multivariate outcomes provides several benfits over separate analysis of each outcome. However, joint analysis of multivariate outcomes that are mixed, i.e., not on the same scale of measurement, can be challenging. This dissertation provides novel methods to analyze bivariate mixed outcomes, where we have exactly one continuous outcome and one binary outcome. A penalized generalized estimating equations framework to perform simultaneous estimation and variable selection for bivaraite mixed outcomes in the presence of a large number of covariates is provided. Next, fully Bayesian and empirical Bayes approaches to estimating the association between the …

Protein-Based Autofluorescent Hydrogel And Nano/Micro-Particles For Bio-Imaging Applications, Xiaoyu Ma

Doctoral Dissertations

Fluorescent polymeric materials such as hydrogels and polymeric particles have been attracting attention in many biomedical applications including bio-imaging, optical sensing, tissue engineering and therapy, due to their good biocompatibility, biodegradability, and advanced optical property. This PhD project aims at developing novel autofluorescent protein materials in different configurations with good biocompatibility and biodegradability for bio-imaging applications.

Early research focused on the development of autofluorescent protein hydrogels for in vivo bio-imaging application. Glutaraldehyde cross-linked Bovine Serum Albumin (BSA) hydrogel were facilely prepared. Various advanced techniques were employed to characterize the as-prepared material. SEM study clearly revealed its 3-dimentional pore structure, while …

Multi-Level Dynamical Parameter Estimation: Hypothesis Testing With Dynamical Systems, Henry S. Harrison

Doctoral Dissertations

The practice of dynamical modeling of perception-action behavior has lagged behind the proliferation of the dynamical perspective. Two methodological roadblocks to dynamical modeling are discussed. First, parameter selection is difficult with current tools. Second, it is unclear what role models have in the larger scientific project beyond their use as descriptions or proofs of concept. In this dissertation, a new parameter selection method is developed to address these issues, Multi-Level Dynamical Parameter Estimation (MLDPE). Like its precursor DPE, MLDPE uses an extended Luenberger observer to stabilize the synchronization manifold in combined model-data space. MLDPE also embeds a regression model into …

Statistical Models For Single Molecule Localization Microscopy, Ahmed Elmokadem

Doctoral Dissertations

Single-molecule localization microscopy (SMLM) has revolutionized the field of cell biology. It allowed scientists to break the Abbe diffraction limit for fluorescence microscopy and got it closer to the electron microscopy resolution but still it faced some serious challenges. Two of the most important of these are the sample drift and the measurement noise problems that result in lower resolution images. Both of these problems are generally unavoidable where the sample drift is a natural mechanical phenomenon that occurs during the long time of image acquisition required for SMLM (Geisler et al. 2012) while the measurement noise, which arises from …

Computational Design Of Multifunctional Nanodielectrics, John Mangeri

Doctoral Dissertations

In this dissertation, a mesoscale modeling approach is developed aimed at simulating the properties of dielectric nano/microstructures with coupled polar, elastic, and thermal degrees of freedom, as well as the dependence of these properties on the structure size, shape, morphology and applied conditions. The versatility of this computational method to predict functional behavior is exemplified in the following systems: (i) Semiconducting core-shell nanoparticles and the influence of their size, anisotropy, microstructure and applied pressure on their optical properties; (ii) Ferroelectric nanoparticles embedded in a dielectric medium, and the dependence on their polarization-field topology and transitions on particle shape and size, …

Ecophysiology And Taxonomy Of Saccharina Latissima Forma Angustissima (Laminariales, Phaeophyceae) From The Gulf Of Maine, Usa, Simona Augyte

Doctoral Dissertations

The overarching theme of this doctoral dissertation was to resolve the taxonomic status of an endemic narrow-bladed kelp, Saccharina latissima forma angustissima (Laminariales, Phaeophyceae), which has a very restricted distribution of 8 nautical miles in the Gulf of Maine, USA. Since the kelp only grows on ledges and islands exposed to high ocean swells, it was unknown if phenotypic plasticity alone was driving its morphology or if the kelp was a distinct genotype (a population with heritable traits). I incorporated lab and fieldwork to discriminate genetic divergence of this kelp, investigated temperature and light requirements of the gametophytic and juvenile …

Advancing Our Understanding Of Performance During Sleep Deprivation, Jeffrey Blake Bolkhovsky

Doctoral Dissertations

Sleep deprivation is a concern in professional, military, and personal settings and can potentially lead to critical, life threatening errors. Predicting a person’s behavior under the effects of sleep deprivation allows for the mitigation of risk due to reduced performance. The objectives of this dissertation are 1) to examine the role of sleep deprivation on cognitive and motor performance with the goal of contributing to a predictive model of complex real-world tasks, and 2) to explore non-invasive and non-disruptive physiological correlates of sleep deprivation through eye-tracking. Currently lacking in literature, and consequently from predictive models, are the generalized effects that …

Teachers' Navigation Of Mathematical Representations In Argumentation, Steven Lemay

Doctoral Dissertations

Mathematical argumentation has recently received more prominent attention in K-12 classrooms which has immediate consequences in the undergraduate mathematics classroom, including the critical intersection with representing mathematical concepts. Educators' perceptions of this intersection is important to understand as they have a significant impact on the skills undergraduates bring to their mathematics classrooms. This qualitative study investigated (1) how K-5 elementary educators conceptualized argumentation, (2) the role(s) and purpose(s) they attribute to representations within argumentation, and (3) the criteria for representations they use/offer when arguing claims of generality. Eight elementary educators participated in this study. Each completed two interviews and a …

An Accuracy Study Of Rtk Gnss Positioning Applied To Comparing Maps For Bentgrass Habitat Modeling, Jinwon Chung

Doctoral Dissertations

Theory and previous research suggest that sky obstructions and humidity can degrade global navigation satellite system (GNSS) positioning accuracy for static observation sessions. It is reasonable to suppose that these effects might be even worse for real-time kinematic (RTK) positioning, because the observer will likely collect fewer observations for RTK positioning than for a static occupation, so the statistics used to estimate the positions have fewer data to work with. These effects have not been thoroughly studied, which provided the motivation to conduct several experiments to quantity the effects. Temperature and humidity are variables of interest, so the first experiment …

A Materials Genome Approach To The Design, Synthesis, And Testing Of High Energy Density Dielectric Materials For Capacitor Applications, Gregory Treich

Doctoral Dissertations

The rapid implementation and improvement of renewable energy technologies require advanced dielectric materials to enable capacitive energy storage under high fields. Since capacitors are among the most pervasive electronic device in many of these systems, my search for improved dielectrics focused on the application of film capacitors. To overcome these current problems, new polymers need to be developed that can serve as the dielectric material in electronic devices. Such a comprehensive search requires careful prior planning to ensure that effort is not needlessly wasted and thus a rational co-design approach was developed. Through this approach, high-throughput computational predictions are used …

Point Cloud Model Shape Analysis, Reed Williams

Doctoral Dissertations

Shape analysis of point cloud surface models produces quality results and avoids the pitfalls of working with mesh models.

Shape analysis is concerned with understanding the shape of models geometrically, topologically, and relationally. Traditionally, shape analysis methods have operated on solid and surface models of objects, especially surface mesh models.

Recent advances in 3D camera technology has driven demand for automatic shape analysis tools.

Devices like the Microsoft Kinect are democratizing 3D sensing and such expansion of what was once an academic and industrial space is making it clear that there is a need for generally-applicable techniques which don't require …

Riparian Impacts To Stream Water Quality Across Spatial Scales, David J. Rosa

Doctoral Dissertations

This research contributes new knowledge to two major challenges: 1) up-scaling water quality results from riparian treatment plots to larger watersheds and 2) determining if a short-rotation woody crop (SRWC) can be an effective riparian buffer for treating agricultural nonpoint source pollution. An exhaustive literature review was conducted to provide detailed insight into the methods of scaling, the associated mathematical equations, and their application to the problem of predicting water quality. Dimensional analysis was identified as an underutilized but promising technique for water quality scaling. Dimensional analysis was used to predict total phosphorus (TP) concentrations across heterogenous watersheds ranging from …

The Margination And Transport Of Particles In Blood Flow, Erik James Carboni

Doctoral Dissertations

Archival abstract submitted.

Computer Aided Design Solutions For Testability And Security, Qihang Shi

Doctoral Dissertations

As technology down scaling continues, new technical challenges emerge for the Integrated Circuits (IC) industry. One direct impact of down-scaling in feature sizes leads to elevated process variations, which has been complicating timing closure and requiring classification of fabricated ICs according to their maximum performance. To address this challenge, speed-binning based on on-chip delay sensor measurements has been proposed as alternative to current speed-binning methods. This practice requires advanced data analysis techniques for the binning result to be accurate. Down-scaling has also increased transistor count, which puts an increased burden on IC testing. In particular, increase in area and capacity …

Statistical Methods For Information Assessment And Data Compatibility With Applications, Daoyuan Shi

Doctoral Dissertations

Various modifications have been suggested in the past to extend the Shannon entropy to continuous random variables. We propose a new entropy called the fractional size adjusted entropy and later extend it to the generalized fractional size adjusted entropy. These two proposed entropies always exist and maintain non-negative values. The generalized fractional size adjusted entropy also includes many well-known entropies as its special cases, such as the Shannon entropy and the Renyi entropy. We apply our proposed entropies on various distributions and a phylogenetic example to demonstrate their good performances.

In addition, we propose a partition based measure to quantify …

Ultra-Low Chloride Content Water Production For Corrosion Control, Lewis Crone

Doctoral Dissertations

A process was developed to produce ultra-low chloride content on the industry standard strongly basic, gel -type anion resin employed in an equivalent mixture with companion cation resin in the deep bed condensate polishers at Dominion’s Millstone Power Station. The low chloride anion facilitated on-line conversion of the polisher resins to the amine chemical form, enabling an increase in secondary cycle amine concentration and pH for the purpose of minimizing general and erosion corrosion. This dissertation describes the research, testing, and full scale implementation of this unique application of ion exchange resins that led to an eighty percent reduction in …

Novel Methods To Address Measurement Error Issues In Gifted Identification, Huihui Yu

Doctoral Dissertations

This study applied statistical simulation techniques to posit a practical situation of gifted identification based on students’ performance on the intelligence test and academic achievement tests of math and reading. Three tests were generated based on the one-parameter item response theory model. The marginal reliabilities were .95, .90, and .80 for observed intelligence and observed abilities in math and reading, respectively. Totally, 1,000,000 pairs of true and observed abilities in each of the three domain areas were generated. Results suggest that using different combination rules is conceptually aimed to identify different gifted populations. Using the conjunctive rule to combine a …

Design And Architecture Of Hardware-Based Random Function Security Primitives, Fatemeh Tehranipoor

Doctoral Dissertations

In recent years, security has grown into a critical issue in modern information systems. Electronic hardware security, in particular, has emerged as one of the most serious challenges due to electronic devices penetrating every aspect of our society. Furthermore, due to the trend in globalization, system integrators have had to deal with integrated circuit (IC)/intellectual property (IP) counterfeiting more than ever. These counterfeit hardware issues counterfeit hardware that have driven the need for more secure chip authentication, since traditional ID or key storage have been demonstrated to be vulnerable to various kinds of attacks. In addition, due to the need …

Neural Coding And Models For Natural Sounds Recognition: Effects Of Temporal And Spectral Features, Seyedeh Fatemeh Khatami Firoozabadi

Doctoral Dissertations

The mammalian brain is able to recognize natural sounds in the presence of acoustic uncertainties such as background noise. A prevailing theory of neural coding suggest that neural systems are optimized for natural environment signals and sensory inputs that are biologically relevant. The optimal coding hypothesis thus suggests that neural populations should encode sensory information so as to maximize efficient utilization of environmental inputs. In the first part of my thesis, I will explore the origins of scale invariance phenomena which has been previously described for natural sounds and has been observed in a variety of natural sensory signals including …

Piezoelectric Structures With Circuitry Integration For Wave Guiding And Energy Manipulation, Jiawen Xu

Doctoral Dissertations

The objective of this dissertation research is on the designing and optimization of promising wave guiding and energy manipulation approach. Specifically address above-mentioned issues of modeling and application of piezoelectric metamaterials and energy harvesting. The first research task is to develop fundamental modeling and understanding of piezoelectric metamaterial integrated with LC shunts to create local resonances. We establish the lumped-parameter model. Taking advantage of the model, we identify the influence of a key parameter to the behavior of the metamaterial. The second research task is to explore the application of the piezoelectric metamaterials in acoustic wave guiding. This work is …

Optimization And Bayesian Inference In Model-Based Decision Making, Ali Abdollahi

Doctoral Dissertations

The focus of this dissertation is on using optimization and Bayesian inference in model-based decision making. We discuss two problems: (a) optimal battery charging and battery life management; (b) fault diagnosis using probabilistic graphical models. In the first part of this thesis, we address the optimal charging problem using a two-time-scale algorithm which performs fast-charging at the lower-level (fast time-scale), while managing the battery life at the higher-level (low time-scale). At the lower-level, we derive optimal charging algorithms for Li-ion batteries using equivalent electrical circuit models and quadratic optimization approaches. The objective function is considered as a linear combination of …

Pequot Cultural Entanglement In 17th-Century Connecticut, William A. Farley

Doctoral Dissertations

The primary goal of this dissertation is to explore the nature of cultural change and continuity during the earliest years of colonial interaction in southern New England. It will focus primarily on the Pequot, a Native American polity who in the early 17^th-century controlled territories in present-day Connecticut and Rhode Island. The dissertation utilizes a combination of artifactual, ecofactual, spatial, and historical data to elucidate the ways that the Pequot mitigated the harsh realities of early colonial life including during times of war. This dissertation adds substantively to the scholarship of indigenous architecture, household archaeology, cultural entanglement, and …

Analysis Of Syntactic Complexity And Its Relationship To Writing Quality In Argumentative Essays, Thilagha Jagaiah

Doctoral Dissertations

Syntactic complexity has been recognized as an important construct in writing by numerous previous studies. However, there was no consensus on the precise and salient syntactic complexity measures (SCMs) to examine syntactic complexity. This is because most previous studies examined SCMs manually using a small sample size with few SCMs. In the current study, the author seeks to address these gaps using Confirmatory Factor Analysis (CFA) to test a hypothesized model of 28 SCMs and four latent variables (Sentence Pattern, Sentence Length, Sentence Connector, Sentence Sophistication). The data was analyzed using 1,029 eighth-grade, argumentative essays that were scored using an …

Polymer Nanocomposites And Biomaterials: From Chemical Cross-Linking To 3d Printing, Huseini Patanwala

Doctoral Dissertations

Part 1:

Aerogel is an open-celled, microporous, solid foam composed of a network of interconnected structures formed by replacing the solvent in wet gel with air. Integrating the intrinsic mechanical and electrical properties of carbon nanotubes (CNTs) with those of an aerogel provides a new class of material with unique multifunctional properties which may find applications not limited to fuel cells, super capacitors and batteries. I attempt at improving the mechanical integrity by first functionalizing the CNTs with carboxylic (-COOH) groups and subsequently cross-linking the CNTs using diisocyanate to form polyurea-CNT (PUA-CNT) composite aerogels. Mechanical properties of the final PUA-CNT …

Stagewise Estimating Equations, Greg Vaughan

Doctoral Dissertations

Stagewise estimation is a slow-brewing approach for model building that has recently experienced a revival due to its computational efficiency, its flexibility in handling complex data structures, and its intrinsic connections with penalized estimation. Synthesizing generalized estimating equations to handle correlated non-Gaussian data with stagewise techniques, this thesis proposes general stagewise estimation approaches that perform model selection in the presence of complex covariate structures.

First, the setting where there is a prior covariate grouping structure or hierarchy is considered. As the grouping structure in practice is often not ideal as even important groups may contain unimportant variables, the key is …

Semantics, Meaning, Truth And Content: Disentangling Linguistic And Philosophical Approaches To The Study Of Meaning, Toby Napoletano

Doctoral Dissertations

The purpose of this dissertation is to clarify the relationship between two research programs engaged in the investigation of linguistic meaning: the philosophy of language, broadly conceived, and semantics as it is pursued within generative linguistics.

It is often assumed that philosophers of language and semanticists in linguistics are working broadly within the same research program, addressing the same questions about language, its meaning, and its use. At least, it is assumed that the two research programs are continuous with one another, so that each places important constraints on the other. Philosophical theories of meaning, the thought goes, must square …

Electrochemical Behavior Of Dense Electrodes For Impedancemetric Nox Sensors, Nabamita Pal

Doctoral Dissertations

NOx (NO and NO2) exhaust gas sensors for diesel powered vehicles have traditionally consisted of porous platinum (Pt) electrodes along with a dense ZrO2 based electrolyte. Advancement in diesel engine technology results in lower NOx emissions. Although Pt is chemically and mechanically tolerant to the extreme exhaust gas environment, it is also a strong catalyst for oxygen reduction, which can interfere with the detection of NOx at concentrations below 100 ppm. Countering this behavior can add to the complexity and cost of the conventional NO x sensor design. Recent studies have shown that dense electrodes are less prone to heterogeneous …

Full Simulation For The Qweak Experiment At 1.16 And 0.877 Gev And Their Impact On Extracting The Pv Asymmetry In The N→Δ A Transition, Hend Abdullah Nuhait

Doctoral Dissertations

The Qweak project is seeking to find new physics beyond the Standard Model. It is aimed to measure the weak charge of the proton, which has never been measured, at 4% precision at low momentum transfer. The experiment is performed by scattering electrons from protons and exploiting parity violation in the weak interaction at low four-momentum transfer.

In this experiment, two measurements were considered: which are elastic and inelastic. The elastic is to measure the proton's weak charge. In addition, the inelastic asymmetry measurement, which will extract the low energy constant dΔ. That measurement works in the neutral current …

Motion-Capture-Based Hand Gesture Recognition For Computing And Control, Andrew Gardner

Doctoral Dissertations

This dissertation focuses on the study and development of algorithms that enable the analysis and recognition of hand gestures in a motion capture environment. Central to this work is the study of unlabeled point sets in a more abstract sense. Evaluations of proposed methods focus on examining their generalization to users not encountered during system training.

In an initial exploratory study, we compare various classification algorithms based upon multiple interpretations and feature transformations of point sets, including those based upon aggregate features (e.g. mean) and a pseudo-rasterization of the capture space. We find aggregate feature classifiers to be balanced across …

Understanding The Surface Fouling Mechanism Of Ultrananocrystalline Diamond Microelectrodes Using Microfluidics For Neurochemical Detection, An-Yi Chang

Doctoral Dissertations

Electrochemical methods are widely used for chronic neurochemical sensing, but thus far, the organic solution redox reactions fouled the electrodes' surface. It caused the reduction of sensitivity and the electrodes' lifetime.

Here, we present the boron-doped nanocrystalline diamond microelectrodes (BDUNCD) as the next generation electrode material for neurochemical sensor development. To aid in long-term chronic monitoring of neurochemicals, they have a wide window of electrochemical potential, extremely low background current, and excellent chemical inertness. The main research goal is to reduce the rate of electrode fouling due to the reaction by-products, and significantly extend their useful lifetime.

We systematically characterize …