Digital Commons Network^™

Neural Correlates Of Post-Traumatic Brain Injury (Tbi) Attention Deficits In Children, Meng Cao

Dissertations

Traumatic brain injury (TBI) in children is a major public health concern worldwide. Attention deficits are among the most common neurocognitive and behavioral consequences in children post-TBI which have significant negative impacts on their educational and social outcomes and compromise the quality of their lives. However, there is a paucity of evidence to guide the optimal treatment strategies of attention deficit related symptoms in children post-TBI due to the lack of understanding regarding its neurobiological substrate. Thus, it is critical to understand the neural mechanisms associated with TBI-induced attention deficits in children so that more refined and tailored strategies can …

Trustworthy Machine Learning Through The Lens Of Privacy And Security, Thi Kim Phung Lai

Dissertations

Nowadays, machine learning (ML) becomes ubiquitous and it is transforming society. However, there are still many incidents caused by ML-based systems when ML is deployed in real-world scenarios. Therefore, to allow wide adoption of ML in the real world, especially in critical applications such as healthcare, finance, etc., it is crucial to develop ML models that are not only accurate but also trustworthy (e.g., explainable, privacy-preserving, secure, and robust). Achieving trustworthy ML with different machine learning paradigms (e.g., deep learning, centralized learning, federated learning, etc.), and application domains (e.g., computer vision, natural language, human study, malware systems, etc.) is challenging, …

Ai Approaches To Understand Human Deceptions, Perceptions, And Perspectives In Social Media, Chih-Yuan Li

Dissertations

Social media platforms have created virtual space for sharing user generated information, connecting, and interacting among users. However, there are research and societal challenges: 1) The users are generating and sharing the disinformation 2) It is difficult to understand citizens' perceptions or opinions expressed on wide variety of topics; and 3) There are overloaded information and echo chamber problems without overall understanding of the different perspectives taken by different people or groups.

This dissertation addresses these three research challenges with advanced AI and Machine Learning approaches. To address the fake news, as deceptions on the facts, this dissertation presents Machine …

Mapping Programs To Equations, Hessamaldin Mohammadi

Dissertations

Extracting the function of a program from a static analysis of its source code is a valuable capability in software engineering; at a time when there is increasing talk of using AI (Artificial Intelligence) to generate software from natural language specifications, it becomes increasingly important to determine the exact function of software as written, to figure out what AI has understood the natural language specification to mean. For all its criticality, the ability to derive the domain-to-range function of a program has proved to be an elusive goal, due primarily to the difficulty of deriving the function of iterative statements. …

Importance Of Vegetation In Tsunami Mitigation: Evidence From Large Eddy Simulations With Fluid-Structure Interactions, Abhishek Mukherjee

Dissertations

Communities worldwide are increasingly interested in nature-based solutions like coastal forests for the mitigation of coastal risks. Still, it remains unclear how much protective benefit vegetation provides, particularly in the limit of highly energetic flows after tsunami impact. The present thesis, using a three-dimensional incompressible computational fluid dynamics model with a fluid-structure interaction approach, aims to quantify how energy reflection and dissipation vary with different degrees of rigidity and vegetation density of a coastal forest.

In this study, tree trunks are represented as cylinders, and the elastic modulus of hardwood trees such as pine or oak is used to characterize …

Pbm And Dem Simulations Of Large-Scale Closed-Circuit Continuous Ball Mill Of Cement Clinker, Nontawat Muanpaopong

Dissertations

Cement milling is known to be inefficient and energy-intensive. Thus, even small improvements in cement milling's performance could significantly reduce operation costs. This dissertation aims to develop a simulation tool for dry milling and generate a fundamental process understanding, which enables process optimization. To this end, a true unsteady-state simulator (TUSSIM) for continuous dry milling is developed and applied to model various processes: (a) open circuit continuous mills, (b) closed-circuit continuous mills, and (c) vertical roller mills. TUSSIM is based on the solution of the cell-based population balance model (PBM) for continuous milling, which consists of a set of differential …

Continuum Modeling Of Active Nematics Via Data-Driven Equation Discovery, Connor Robertson

Dissertations

Data-driven modeling seeks to extract a parsimonious model for a physical system directly from measurement data. One of the most interpretable of these methods is Sparse Identification of Nonlinear Dynamics (SINDy), which selects a relatively sparse linear combination of model terms from a large set of (possibly nonlinear) candidates via optimization. This technique has shown promise for synthetic data generated by numerical simulations but the application of the techniques to real data is less developed. This dissertation applies SINDy to video data from a bio-inspired system of mictrotubule-motor protein assemblies, an example of nonequilibrium dynamics that has posed a significant …

Coronal Magnetometry And Energy Release In Solar Flares, Yuqian Wei

Dissertations

As the most energetic explosive events in the solar system and a major driver for space weather, solar flares need to be thoroughly understood. However, where and how the free magnetic energy stored in the corona is released to power the solar flares remains not well understood. This lack of understanding is, in part, due to the paucity of coronal magnetic field measurements and the lack of comprehensive understanding of nonthermal particles produced by solar flares. This dissertation focuses on studies that utilize microwave imaging spectroscopy observations made by the Expanded Owens Valley Solar Array (EOVSA) to diagnose the nonthermal …

Deep Hybrid Modeling Of Neuronal Dynamics Using Generative Adversarial Networks, Soheil Saghafi

Dissertations

Mechanistic modeling and machine learning methods are powerful techniques for approximating biological systems and making accurate predictions from data. However, when used in isolation these approaches suffer from distinct shortcomings: model and parameter uncertainty limit mechanistic modeling, whereas machine learning methods disregard the underlying biophysical mechanisms. This dissertation constructs Deep Hybrid Models that address these shortcomings by combining deep learning with mechanistic modeling. In particular, this dissertation uses Generative Adversarial Networks (GANs) to provide an inverse mapping of data to mechanistic models and identifies the distributions of mechanistic model parameters coherent to the data.

Chapter 1 provides background information on …

V-Shaped Temperature Dependences And Pressure Dependence Of Elementary Reactions Of Hydroxyl Radicals With Several Organophosphorus Compounds, Xiaokai Zhang

Dissertations

Organophosphorus compounds have brought increasing attention since they are widely used as flame-retardants, which can take effect in combustion via reactions with reactive radicals. These reactions are influenced by variables such as temperature and pressure, resulting in a temperature and pressure dependent rate constant. Studying this reaction kinetics has great importance in both combustion reaction and atmospheric environment.

This study is focused on kinetics of several elementary reactions of combustion importance. The kinetics of hydroxyl radicals were studied using pulsed laser photolysis coupled to transient UV-vis absorption spectroscopy over the 295 - 837 K temperature range and the 1 - …

Large-Scale And Meso-Scale Ion Dynamics Of The Near-Earth Space Environment, Matthew Cooper

Dissertations

The mechanisms whereby low energy (order of lOs to 100s of eV) solar wind and ionosphere sourced particles are accelerated to high energy (order of 10s to 100s keV) in the Earth's magnetosphere are a trending research topic due to impacts on radiation belt populations, coupling to the high-latitude ionosphere, and energy budgets for collision-less plasma in dipole fields. Ultra-low frequency (ULF, order of 1-100 mHz) Alfven waves observed in the nightside inner magnetosphere during geomagnetic activity are one such acceleration mechanism. Several source processes for these waves, including the micro-scale drift-mirror mode, have been previously suggested but observational evidence …

Design, Synthesis, Biological And Computational Studies Of Flavonoid Acetamide Derivatives, Daniel Kasungi Isika

Dissertations

Flavonoid compounds (FC) have extensive biological applications through potent antimicrobial, anti-inflammatory, anticancer, antidiabetic, and antioxidant properties. These applications are nevertheless limited by low bioavailability, poor aqueous solubility, enzymatic degradation, rapid metabolism, and fast body clearance. FC show unique structure-activity relationships (SARs) essential in assessing and mitigating the prevalent challenges impeding their applications. These challenges can be addressed by structural modification of the FC through functionalization of the phenolic rings, modification of the ketone group, and modification of the phenolic hydroxyl groups with bioisosteres.

The objectives of this work are to (i) design and synthesize novel flavonoid acetamide derivatives (FADs) and …

Topics On Asymmetric Classification, Subhrasish Chakraborty

Dissertations

Asymmetric classification refers to a situation where the cost of misclassifying one class is significantly higher than the cost of misclassifying the other class. This problem is common in many real-world scenarios, such as medical diagnosis or fraud detection. In this dissertation two of the common types of asymmetric classification problems have been dealt with — imbalanced classification and ordinal classification. An example of imbalanced classification is to detect fraudulent credit card transactions where the distribution of the normal and fraud transactions are extremely skewed. On the other hand, ordinal classification, also known as ordinal regression, is widely used in …

Domain Decomposition Methods For Linear And Non-Linear Elliptic Problems, Tadanaga Takahashi

Dissertations

The primary purpose of this dissertation is to expand upon the circle of domain decomposition methods (DDM) which are algorithms that reformulate a boundary value problem in terms of multiple localized problems on subdomains. The first project involves expanding upon DDMs in a relatively mature field: the Helmholtz equation for wave scattering applications. The proposed method is an adaptation of a continuous cross-point Finite Element Non-overlapping DDM algorithm. The usual unbounded computational domain is truncated and then the near-field wave pattern is solved with a parallelized finite element method. Several improvements over the standard transmission operator are discussed in this …

Molecular Simulations Of Mechanical Effects Of Adsorption In Gas And Liquid Phases, Alina Emelianova

Dissertations

Fluids adsorbing in nanoporous solids cause high pressures that affect the solids and the properties of the fluids themselves. This work explores the mechanical response of solids to the adsorption of gas and liquid. Chapter 1 outlines the current achievements in investigating the mechanical response of adsorbents to the adsorption process, specifically, the computational approaches to predict adsorption-induced deformation. Chapter 2 introduces the theoretical and computational methods employed in this work. Chapters 3-7 address the design and application of the computational techniques for such prediction in different systems: mesoporous silica, microporous zeolites, and metal-organic frameworks, and Chapter 8 focuses on …

Diabetes-Related Distress Experienced By Saudi Adults With Type Two Diabetes Mellitus, Ibtesam Alqahtani

Dissertations

Living with a chronic condition such as diabetes mellitus (DM) and adhering to its complex treatment regimen strongly affect patients' psychological well-being as well as their physical health. Diabetes-related distress (DRD) is a common issue, affecting 40% of DM cases, but it often goes unnoticed and untreated. Despite the high prevalence of DM in the Saudi population, DRD has received little research attention.

This study explored the lived experience of DRD among Saudi adults with type 2 diabetes mellitus (T2DM) in the Kingdom of Saudi Arabia.

Special Education: Inclusion And Exclusion In The K-12 U.S. Educational System, Erik Brault

Dissertations

The U.S. Department of Education defines students with disabilities as those having a physical or mental impairment that substantially limits one or more life activities. Previous research has found that students with disabilities placed in inclusive environments perform better academically and socially compared to students with disabilities who are placed in segregated environments. Yet, we know that inclusion in K-12 general education classrooms across the country is not consistently implemented.

The purpose of this study was to better understand the effects, if any, of general education high school teachers’ personal and professional experiences and knowledge on their attitudes toward educating …

Utilizing New Technologies To Measure Therapy Effectiveness For Mental And Physical Health, Jonathan Ossie

Dissertations

Mental health is quickly becoming a major policy concern, with recent data reporting increasing and disproportionately worse mental health outcomes, including anxiety, depression, increased substance abuse, and elevated suicidal ideation. One specific population that is especially high risk for these issues is the military community because military conflict, deployment stressors, and combat exposure contribute to the risk of mental health problems.

Although several pharmacological approaches have been employed to combat this epidemic, their efficacy is mixed at best, which has led to novel nonpharmacological approaches. One such approach is Operation Surf, a nonprofit that provides nature-based programs advocating the restorative …

Growth Mindset: Exploration Of Career Development, Employee Engagement, And Disparity Among Working Professionals, Dillon Harper

Dissertations

A large body of literature has explored the beneficial impact of adopting a growth mindset and its relationship with academic performance. While the literature has provided many valuable findings as it pertains to academic settings, there is a gap in understanding growth mindset’s influence in the workplace as well as understanding if growth mindset’s effect is different for individuals who come from marginalized communities. This study aimed to close the gap by investigating if growth mindset is a predictor of higher work engagement in working professionals. Findings indicated that growth mindset is not a predictor of work engagement among working …

Effects Of Membrane Components On The Oligomerization Of Amyloid-Β (Aβ) In Alzheimer Disease, Jhinuk Saha

Dissertations

Deposition of extracellular proteinaceous plaques of amyloid-β (Aβ) is one of the major hallmarks of Alzheimer disease (AD). Although, insoluble high molecular fibrils of Aβ are the main constituents of the senile plaques in AD, low molecular weight soluble Aβ oligomers have emerged as the key toxic species involved in memory impairment and neuronal cell death in AD. The process for generation of oligomers can be highly diverse and can involve homotypic interactions of Aβ as well as heterotypic interaction of Aβ with other macromolecules. Previously, the generation of Aβ oligomers with distinct biochemical and biophysical characteristics catalyzed non-esterified fatty …

Organizational Citizenship Behaviors, Self Efficacy, Job Satisfaction, And Organizational Commitment Of Science And Math Teachers In Alabama, Andrew N. Wood

Dissertations

This study investigated the correlations between occupational citizenship behaviors, self-efficacy, job satisfaction, and organizational commitment of math and science teachers. The purpose was to discern how these variables interacted to determine how best to support these teachers so they may be more likely to stay teaching in their organizations until retirement. The researcher surveyed math and science teachers within the State of Alabama. There were 314 math and science teachers who completed the survey instrument. Six hypotheses were evaluated to determine if all the variables had positive relationships with each other. From the correlation analysis, used for hypothesis testing, total …

Connecting Social And Ecological Systems In Small-Scale Fisheries In The Philippines, Sara Eisler Marriott

Dissertations

Nearly 50% of all marine fish capture in the Philippines is from artisanal fisheries, most of which is un- or under-reported. As in many emerging nations around the world, the Philippines cannot fully address overfishing by managing only half of the catch that comes from commercial fisheries. Marine reserves are a popular governance strategy for conservation and of growing interest for fisheries management. Many marine reserves in the Philippines, however, are not considered effective. In 2014, Rare, an international NGO, implemented a community-based management program to increase the effectiveness of the marine reserves, and while it found biomass increased, there …

Origin And Structure Of The First Sharp Diffraction Peak Of Amorphous Solids, Devilal Dahal

Dissertations

Several explanations have been reported in the literature about the origin of extended-range oscillations (EROs) in the atomic pair-correlation function of amorphous materials. Although the radial ordering beyond the short-range order of about 5 Å has been extensively studied in amorphous materials, the exact nature of the radial ordering beyond a nanometer is still not resolved. This dissertation address this problem and explains the nature of the EROs by using high-quality models of amorphous silicon (a-Si) obtained from Monte Carlo and Molecular Dynamics simulations. The extended-range ordering in a-Si is examined through radial oscillations on the length …

"If These Walls Could Speak": Judson College And The Formation Of The New Baptist Woman, 1838-1930, E.Gabrielle Walker

Dissertations

Southern Baptist women’s collegiate education and experiences led to their questioning traditional Baptist gender roles and interpreting religion to fit a modern, progressive worldview. Judson College established in 1838 in Marion, Alabama, created a space for its Baptist students to consider socially appropriate ways, outside of doctrinal boundaries, to serve God, themselves, their families, and humanity. Judson remained theologically and culturally conservative, perpetuating inherited religious and social notions of female subordination to men, while increasingly offering students more progressive curricula to meet changing economic and cultural realities. In compliance with white Southern and Baptist conservative values, Judson’s students generally accepted …

Note-Taking In College Mathematics: An Examination Of The Effectiveness Of Guided Notes And Interactive Notebooks On Student Achievement In College Algebra, Verlonda Neal

Dissertations

The purpose of this study was to investigate how the use of interactive guided notes influences the mathematical performance of college algebra students when solving univariate linear equations. The research involved 68 students enrolled in College Algebra at a community college. The participants were divided into two groups: those who took notes using an interactive guided notes method and those who did not use the interactive guided notes note-taking method to cite instructional information. The participants were administered a test on solving univariate linear equations before and after receiving instruction to answer the research questions posed by the study. An …

An Examination Of Teachers’, Instructional Support Staff, And Administrators’ Attitudes And Beliefs Concerning Data, Data-Driven Decision-Making And Its Relationship To Student Achievement., Lashandra Antionette Hodge-Mcclure

Dissertations

The Every Student Succeeds Act has an accountability model that holds the educational system in the United States accountable. It was decided that students throughout the United States should be held to the same standards, independent of where they lived. Furthermore, the Every Student Succeeds Act seeks to provide considerable opportunity for all students to obtain a fair, equitable, and high-quality education and reduce academic performance disparities. The study aims to identify the role teachers, instructional support staff, and administrators’ attitudes and beliefs regarding data-driven decision-making plays in student achievement.

Data-driven decision-making is the systematic process of gathering, evaluating, and …

Spectral Multistep Methods For The Scalable Simulation Of Time-Dependent Phenomena, Bailey Rester

Dissertations

Krylov subspace spectral (KSS) methods are high-order accurate, one-step explicit time-stepping methods for partial differential equations (PDEs) that also possess stability characteristic of implicit methods. Unlike other time-stepping approaches, KSS methods compute each Fourier coefficient of the solution from an individualized approximation of the solution operator of the PDE, using techniques developed by Golub and Meurant for approximating bilinear forms involving matrix functions. As a result, KSS methods scale effectively to higher spatial resolution.

This dissertation will present spectral multistep methods, explicit and implicit, designed through the combination of KSS methods and Adams methods. This combination allows spectral multistep methods …

The Effect Of Sulfonamides Structural And Reactive Properties Examined Through Difunctionalization Of Alkenes, Gavin Rustin

Dissertations

Alkenes as masked functional groups have been a hallmark of organic chemistry and have been utilized to diversify natural products and medicinal targets. Disubstitutions have been a challenge for researchers as the reactions that are implemented most are not selective for the face that they attack. Investigations into electrophilic cyclization looked to overcome this phenomenon by introducing a known chiral center α to an amine where a protecting group, sulfonamide, is added to increase the torsional and allylic strain in the molecules. X-ray crystal structures and NMR techniques prove that the strain does affect the diastereoselectivity of the reaction through …

The Impact Of A Culturally Responsive Approach In Science Education On Kindergarten Students, Monique Hite-Patterson

Dissertations

Classrooms today are more ethnically and linguistically diverse. Unfortunately, students of color demonstrate a history of marginalized educational inequities (Williamson et al., 2007). These marginalized educational inequities impact academic achievement across all content areas especially literacy, math, and science. To improve the academic performance of students who are culturally, racially, ethnically, and linguistically diverse, methods of instruction and pedagogy that better facilitate learning among diverse student populations must be instituted (Ladson-Billings, 2005). A mixed methods study was conducted in response to the need to examine the impact of using culturally responsive strategies on kindergarten student’s attitudes towards science and their …

The Effects Of Lecture Capture Design On Student Performance In An Online, Asynchronous Nonmajors Biology Course, Melissa Ann Gutierrez

Dissertations

Lecture capture technology, the ability to provide multimedia recordings of instructional content, has become an essential technology for online learning. One of the ways online courses have tried to appeal to the digital lifestyle of today’s students is providing different lecture capture styles, such as audio (podcasts), video, or interactive videos, due to the popularity of mobile media players providing anytime and anywhere learning. Although lecture capture technology provides educators with a diverse set of tools on how content is delivered, studies have shown mixed results on the impact of lecture capture styles on learning.

For this study, the main …