Digital Commons Network^™

The Relationship Between School Mobility And Gifted Identification In Connecticut Public Schools, Christina M. Amspaugh

Doctoral Dissertations

Educators and policy makers are interested in understanding the impact of school mobility, which is often associated with negative outcomes including declines in academic achievement and increases in behavioral and discipline problems. Changing schools also puts students at risk of not having their academic needs recognized and met. For high ability, academically gifted students, this means that moves involving school changes may be associated with barriers that limit access to gifted identification. Lack of identification for students with gifted education needs limits the ability to advocate for or gain access to gifted education services within or beyond the school, ultimately …

Plasmonic Effect On Exciton And Multiexciton Dynamics Of Quantum Dots Near Metal Nanostructures, Swayandipta Dey

Doctoral Dissertations

Recent scientific progress has resulted in the development of sophisticated hybrid nanostructures composed of semiconductor nanocrystals (quantum dots, QDs) and metal nanoparticles (MNPs). These hybrid structures open up new possibilities for developing next generation nanoscale optoelectronic devices that combine the best attributes of each component material.The optical response of MNPs is dominated by surface plasmon resonances which create large local electromagnetic field enhancements. When coupled to surrounding semiconductor components, the enhanced local electric field results in strong absorption/emission, alteration in emission decay rates, enhancement in exciton emission and other interesting non-linear effects (multiphoton generation). Although hybrid nanostructures are poised to …

Jointly Learning Features And Temporal Contingency For Prediction In Large Scale Datasets, Tingyang Xu

Doctoral Dissertations

Temporal data such as time series data and longitudinal data are pervasive across almost all human endeavors, including medicine, finance, climate, and genetics. As such, it is hardly surprising that temporal data mining has attracted significant attention and research effort. Only very recently, feature selection has drawn adequate attention in the context of longitudinal modeling. Standard statistical techniques, such as generalized estimating equations (GEE), have been modified to identify important features by imposing sparsity-inducing regularizers. However, they do not explicitly model how a dependent variable relies on features measured at proximal time points. Recent machine learning models can select features …

Uas Collision Warning And Passive Sensor Fusion Algorithms For Multiple Acoustic Transient Emitter Localization, Wenbo Dou

Doctoral Dissertations

This dissertation considers two important topics in the area of estimation, target tracking and sensor fusion. The first topic is closest point of approach (CPA) prediction for unmanned aircraft systems (UAS) collision warning and the second topic is passive sensor fusion for multiple acoustic transient emitter localization.

To operate within a controlled airspace, UAS must have the capability to sense and avoid collisions with non-cooperative aircraft. This dissertation presents an inexpensive system design and develops an algorithm for estimating the CPA between the ownship and the intruder and a collision warning scheme using only bistatic range and range rate measurements …

Adiabatic Expansion In Quantum Field Theory And Quantum Non-Equilibrium Dynamics, Robert Dabrowski

Doctoral Dissertations

In this dissertation we study semi-classical effects in Quantum Field Theory (QFT) and made use of the universal behavior of the asymptotic expansions to study of quantum non-equilibrium dynamics. We consider the evolution of quantum field theoretical systems subject to a time-dependent perturbation and demonstrate a universal form to the adiabatic particle number, corresponding to optimal truncation of the (divergent and asymptotic) adiabatic expansion. In this optimal basis, the particle number number evolves smoothly in time according to the universal smoothing of adiabatic evolution in the Stokes Phenomenon, thus providing a well-defined notion for evolution through a non-equilibrium process. The …

Equilibrium And Kinetically-Limited Lattice Relaxation Of Multilayered And Compositionally-Graded Semiconductor Metamorphic Heterostructures, Tedi Kujofsa

Doctoral Dissertations

Metamorphic buffer layers (MBLs) allow tremendous flexibility in designing novel semiconductor heterostructures for application in various microelectronic and optical devices. However, device fabrication, reliability and performance are limited by lattice relaxation mechanisms and dislocation defects that are associated with the growth of mismatched material systems. Therefore, understanding the extent of strain relaxation and dislocation dynamics in semiconducting heterostructures has important implications in the design of devices which exhibit desired strain and dislocation characteristics. In this dissertation, we present equilibrium and plastic flow models which are applicable to multilayered and compositionally-graded semiconductor heterostructures and have studied both the thermal equilibrium and …

Torsion Of Rational Elliptic Curves Over Abelian Extensions Of Q, Michael Y. Chou

Doctoral Dissertations

Let $E$ be an elliptic curve defined over $\mathbb{Q}$. We investigate $E(K)_{\text{tors}}$ for various abelian extensions $K$ of $\mathbb{Q}$. For number fields, a theorem of Merel implies a uniform bound on the size of the torsion subgroup based on the degree of the number field. We discuss a number of results that classify torsion subgroups of elliptic curves over number fields of a fixed degree. We prove a classification of torsion subgroups for elliptic curves $E/\mathbb{Q}$ base extended to quartic Galois number fields. For infinite extensions of $\mathbb{Q}$, the Mordell-Weil theorem no longer applies, and so the torsion subgroup of …

Investigating The Role Of Surface Hydrophobicity In Protein Aggregation, Elizabeth Zecca

Doctoral Dissertations

Hydrophobic interactions between protein molecules are considered to be a significant contributor to attractive protein-protein interactions (PPIs) in solution. Attractive PPIs play critical roles in self-association and aggregation, thus affecting the overall protein stability. Surface hydrophobicity of three model proteins was characterized by hydrophobic interaction chromatography and fluorescence spectroscopy. To compensate for known limitations of these two widely used methods, a novel approach, based upon Nuclear Magnetic Resonance Spectroscopy (NMR), was investigated as a potential alternative. The degree of decrease in the transverse relaxation time (T2) of small molecule probe, such as phenol, due to its interaction with the protein …

Existence Of Diffusions On 4n Carpets, Ulysses A. Andrews Iv

Doctoral Dissertations

Following the methods used by Barlow and Bass to prove the existence of a diffusion on the Sierpinski Carpet, we establish the existence of a diffusion for a class of planar fractals which are not post critically finite. We conjecture that specific resistance estimates hold on our class of fractals. We further conjecture that these resistance estimates imply the existence of the spectral dimension for our class of fractals. Under these assumptions we use the methods of Barlow and Bass to establish heat kernel asymptotics. From there, we can use the techniques of Barlow, Bass, Kumagai, and Teplyaev to show …

Toggling Involutions And Homomesies For Maps On Finite Sets, Noncrossing Partitions, And Independent Sets Of Path Graphs, Michael J. Joseph

Doctoral Dissertations

This paper explores the orbit structure and homomesy properties of various actions on finite sets. The homomesy phenomenon, meaning constant averages over orbits, was proposed by Propp and Roby in 2011. For many of the known instances of homomesy, Reiner, Stanton, and White's cyclic sieving phenomenon (CSP) is also present. However, we prove homomesy for several maps whose order is large relative to the size of the set, implying that a natural CSP is unlikely. Sometimes we can prove facts about the orbit sizes either as a corollary to the homomesy or by the technique used to prove homomesy.

Many …

Learning To Self-Regulate: Crafting Co-Regulation Experiences In An Online Learning Environment, Rasis A. Alanazi

Doctoral Dissertations

This mixed methods study aims to describe and explain the effects of co-regulation on students’ self-regulation, which is hypothesized to lead to better learning. Students (N = 42) in six online undergraduate and graduate courses worked in dyads for six weeks on shared activities. Variables of interest included students’ self-regulated learning, co-regulated learning, and students’ perceptions of the online course delivery based on a Community of Inquiry framework. Six students were also interviewed about their experiences in the dyads. A mediation analysis was conducted to detect if co-regulation mediated the relationship between students’ self-regulation before and after working in dyads. …

Hume's "Of Scepticism With Regard To Reason", Benjamin M. Nelson

Doctoral Dissertations

The arguments in “Of scepticism with regard to reason” get their start from Hume’s claim that, thanks to our “fallible and uncertain faculties,” we must “check” any present judgment from reason in a step of corrective reasoning (T 1.4.1.1; SBN 180). A corrective step is meant to “correct and regulate” present judgments from reason through reflection on past judgments from reason (T 1.4.1.5; SBN 181-82). Hume argues that this ushers in the extinction of knowledge and belief because reflection on past judgments will inevitably diminish our assurance for any present judgment. Why Hume thinks diminishment is inevitable has remained elusive. …

Simulations With Radiative3d: A Software Tool For Radiative Transport In 3-D Earth Models, Christopher J. Sanborn

Doctoral Dissertations

This dissertation presents Radiative3D, a computer code for radiative transport simulations of seismic events, including earthquakes and explosions, in 3-D Earth models, and allowing output of seismogram envelopes from virtual seismometers or information representing bulk energy transport through the model. Radiative transport is an efficient algorithm for Monte-Carlo simulation of high-frequency elastic wavefield energy transport through models featuring both large-scale (larger than wavelength) structure, simulated by deterministic ray tracing, and small-scale structure (wavelength scale and smaller), simulated by a stochastic scattering process. The 3-D models are composed of a collection of adjoining model cells inside of which material properties have …

Computability Theoretic Results For The Game Of Cops And Robbers On Infinite Graphs, Rachel D. Stahl

Doctoral Dissertations

Several results about the game of cops and robbers on infinite graphs are analyzed from the perspective of computability theory and reverse mathematics. Computable robber-win graphs are constructed with the property that no computable robber strategy is a winning strategy, and such that for an arbitrary computable ordinal n, any winning strategy has complexity at least 0⁽ⁿ⁾. Symmetrically, computable cop-win graphs are constructed with the property that no computable cop strategy is a winning strategy. However the coding methods used in the robber-win case fail here. Locally finite infinite trees and graphs are explored using tools of …

Application Of Uv Light Scattering To Detect Reversible Self-Association And Aggregation Of Proteins In Solution, Japneet Kaur

Doctoral Dissertations

Monoclonal antibodies and their derivatives have emerged as one of the most successful class of biologics in the past few decades. Antibodies are often formulated at high concentrations in order to achieve the desired therapeutic levels on subcutaneous administration. Reversible self-association and aggregation are two of the major challenges associated with formulating high concentration antibodies. The use of static light scattering as a tool for characterizing self-association and aggregation in protein solutions is reviewed. A detailed understanding of the effect of absorption on Rayleigh light scattering intensity and turbidity was developed for wavelengths where both scattering and absorption occur simultaneously. …

Modeling Of Structural, Elastic, And Polar Properties Of Organic And Inorganic Ferroelectrics, Fu-Chang Sun

Doctoral Dissertations

Computational materials science has become an important branch of research with the advent of high performance computers and efficient algorithms. The viability of solving fundamental theories allows not only to understand experimental results, but predict properties of exotic materials or materials at extreme conditions. There exists fundamental theories that has been applied in different domains of length and time scales, where certain approximations are employed which enable improved performance with minimum compromise of accuracy.

In this Thesis, various computational approaches at different length scales are considered to investigate different classes of organic and inorganic ferroelectric materials to describe structural-property relations. …

Phase Change Devices For Nonvolatile Logic, Nadim H. Kanan

Doctoral Dissertations

Memory access latencies are some of the major limitations on data intensive computation performance nowadays. The possibly achievable CPU clock frequencies must be limited to the maximum access speed of the off-chip memory which constrains the overall system speed, regardless of the power consumption constraints. This computational bottleneck is commonly referred to as the Von-Neumann bottleneck. Memory access latencies can be drastically decreased by integrating the main memory onto the CPU. Phase change memory (PCM) provides the possibility of integration of high-density high-speed non-volatile memory banks on top of the CMOS layer. This computer-on-chip concept has the potential to achieve …

Cardiac Effects Of Purinergic P2x Channel Activation, Ronghua Yang

Doctoral Dissertations

Purinergic receptors respond to extracellular nucleotides and their metabolites. They act as important signaling transduction molecules in a variety of biological processes and are important in a number of pathophysiologic conditions that impact human health. A subset of these receptors acts as non-selective cation channels, designated as P2X receptors, which can induce electrical activities in the cellular membrane and thus impact cellular function. A number of longitudinal studies following surgically or genetically induced heart failure animals have demonstrated potential improvement of cardiac function with P2X4 receptor overexpression. We explore here how P2X signaling affects cardiomyocyte excitability and leads to changes …

Akap7Γ Regulation Of Pka Substrate Phosphorylation, Marc J. Rigatti

Doctoral Dissertations

In the cell, cAMP-protein kinase A (PKA) signaling is compartmentalized. Two different receptor types, both utilizing cAMP and PKA as second messenger and signal effector, are able to convey separate signals that result in phosphorylation of distinct substrates. Signal compartmentation is possible primarily because of A Kinase Anchoring Proteins (AKAPs) that bind both PKA and a target substrate, effectively co-localizing them. AKAPs are also capable of binding to other necessary signaling components like adenylate cyclase and phosphodiesterase, thus enabling AKAPs to coordinate a signaling microdomain containing many of necessary components. In this thesis I present multiple lines of evidence demonstrating …

Reliability-Based Design Optimization With Mixture Of Random And Interval Uncertainties, David Yoo

Doctoral Dissertations

This study presents novel reliability-based design optimization (RBDO) methods with mixture of random and interval uncertainties. While conventional second-order reliability method (SORM) contains three types of errors, novel SORM proposed in this study avoids the other two types of error by describing the quadratic failure surface with the linear combination of noncentral chi-square variables and using the linear combination of probability of failure estimation. Sensitivity analysis on the developed SORM is then performed for more accurate RBDO. As an alternative to analytic RBDO, sampling-based RBDO is used in case when gradients of performance functions are not available. In this study, …

Spectral Properties Of The Hata Tree, Antoni Brzoska

Doctoral Dissertations

The Hata tree is the unique self-similar set in the complex plane determined by the contractions φ₀(z) = cz and φ₁(z) = (1-|c|²)z+|c|², where c is a complex number such that |c| and |1-c| are in (0,1). There are four main results in the paper. First, by applying linear algebra and spectral theory it is possible to construct a dynamical system that can compute the eigenvalues of the probabilistic Laplacian on graph approximations to the Hata tree. Conclusions are made about the spectrum …

Lithography, Spectroscopy, And Super Resolution Terahertz Imaging For Quality Assurance And Authentication, Kiarash Ahi

Doctoral Dissertations

The supply chain today spreads all around the globe. For assembling a system, several components, each of which may be produced in a different country and by a different manufacturer, need to travel the globe to get to the assembly sites. In such a global supply chain, tracing the components could be a great challenge and counterfeiters can find open doors to infiltrate the markets. Several billions of dollars of counterfeit integrated circuits (IC)s are sold each year. Low-quality authentic ICs might also pass the quality control sections and enter the supply chain occasionally. The endurance and reliability of the …

Heart And Soul: A Phenomenology Of Dementia Spouse Caregivers’ Relationship Closeness, Elena Schjavland

Doctoral Dissertations

All persons with dementia exhibit combinations of cognitive impairment (memory loss and aphasia), functional losses (changes in activities of daily living), and neuropsychiatric disease manifestations (fluctuating moods, behaviors and psychoses). The spouse caregiver role and life are affected by these symptoms which can cause intimacy, reciprocity, and communication issues, and frequently result in the caregiver’s feelings of inadequacy, hopelessness, and embarrassment. Yet caregivers somehow manage to reconstruct and maintain a closeness as a couple.

Relationship closeness (RC) found in all marriages is simply depicted as the quality of the communal and emotional bond between husband and wife. Limited research demonstrates …

Transient Performance Evaluation, Bottleneck Analysis And Control Of Production Systems, Zhiyang Jia

Doctoral Dissertations

The focus of production system is to analyze, improve, and control the flow of products in the manufacturing process. In the field of study, the major difficulties are unreliable machines and finite buffers capacities, which lead to nonlinear and stochastic mathematical models. Extensive results on production systems have been derived for steady state operations, while their transient performance and properties are also of practical importance but paid with significantly less attention.

In this dissertation, we study the problems of transient performance evaluation, bottleneck analysis, and production control of serial lines, closed lines and assembly systems. Specifically, in the framework of …

Anticipating The Effects Of Economic Displacement In Marine Space With Agent Based Models, Kevin P. Nebiolo

Doctoral Dissertations

As marine space is managed into appropriate resource use areas, it is inevitable that some is allocated towards a mutually exclusive spatial activity. This exclusion results in displacement that has real economic consequences. When a wind energy area is placed in coastal waters, navigable space is reduced and vessels are displaced from their former routes. The USCG is concerned that re-routing will result in vessels navigating within closer proximity than they would otherwise in an open ocean scenario, and fear that this will increase the risk of vessel collision (USCG 2016). They recommend research into tools that are capable of …

The Statistical Dynamics Of Nonequilibrium Control, Grant Murray Rotskoff '09

Doctoral Dissertations

Living systems, even at the scale of single molecules, are constantly adapting to changing environmental conditions. The physical response of a nanoscale system to external gradients or changing thermodynamic conditions can be chaotic, nonlinear, and hence difficult to control or predict. Nevertheless, biology has evolved systems that reliably carry out the cell’s vital functions efficiently enough to ensure survival. Moreover, the development of new experimental techniques to monitor and manipulate single biological molecules has provided a natural testbed for theoretical investigations of nonequilibrium dynamics. This work focuses on developing paradigms for both understanding the principles of nonequilibrium dynamics and also …

Improvement Of Fluorescence-Based Microfluidic Dna Analyzers, Collin Tranter

Doctoral Dissertations

A tremendous effort continues in the development of micro-total-analysis-systems; in support of this, many chemical passivation methods have been developed to enhance the biocompatibility of such microfluidic systems. However, the suitability of these passivation techniques to many fluorescence-based assays still remains inconsistent. This part of this work is focused on the performance of a third generation intercalating DNA dye when used within microfluidic devices treated with a select variety of passivating coatings. The results of these tests indicate that passivation coatings which are intended to shed DNA based on electrostatic repulsion will in fact imbibe the fluorescent DNA intercalating dye …

The Effect Of Gamification On Audiology Awareness Among Young Adults, Shenque Lester

Doctoral Dissertations

The profession of audiology is projecting a critical shortage of practicing professionals in the near future. Although there are many potential factors that are contributing to this problem, it is generally agreed that audiology as a profession is not readily identified as a career choice by undergraduate students, nor a recognizable healthcare field/service among the general public. Due to the increased instances of hearing loss in the general population as well as the aging of the population and need for audiological services, it is imperative to find an efficient means to improve the awareness of audiology as a potential career …

The Development And Validation Of An Automatic-Item Generation Measure Of Cognitive Ability, Scott Hines

Doctoral Dissertations

Cognitive ability is perhaps the most studied individual difference available to researchers, being measured quickly and effectively while demonstrating a predictable influence on many life outcomes. Historically, the evolution of the psychometric study of cognitive abilities has pivoted on the development of new and better methodologies allowing for a more complete and efficient capture of intellect. For instance, recent advances in computer and Internet technology have largely replaced traditional pencil-and-paper methods, allowing for innovative item development and presentation. However, concerns regarding the potential adverse impact and test security of online measures of cognitive ability, particularly in unproctored situations, are well …

Second-Order Modal Logic, Andrew Parisi

Doctoral Dissertations

This dissertation develops an inferentialist theory of meaning. It takes as a starting point that the sense of a sentence is determined by the rules governing its use. In particular, there are two features of the use of a sentence that jointly determine its sense, the conditions under which it is coherent to assert that sentence and the conditions under which it is coherent to deny that sentence. From this starting point the dissertation develops a theory of quantification as marking coherent ways a language can be expanded and modality as the means by which we can reflect on the …