Digital Commons Network^™

Design And Experimental Observation Of Topological States In Photonic Metasurfaces, Anton Vakulenko

Dissertations and Theses

Topological phases in photonics attract a lot of attention due to their unique properties which allow controlling optical coupling and electromagnetic field distributions in nanostructures. Diverse phenomena supported by photonic topological structures include robust scatter-free waveguiding, an extreme confinement of light, lasing and strong coupling with novel low- dimensional materials. A very convenient integration with on-chip optical devices and also with quantum dots or monolayers of van der Waals materials promise even brighter future for photonic topological insulators as a useful platform for innovative photonic and compact quantum devices.

In the course of my dissertation work, I investigated topological structures …

Scalable Quantum Compilation Approaches For Reliable Quantum Computing, Vedika Saravanan

Dissertations and Theses

Quantum computing has the potential to revolutionize various industries, from pharmaceuticals to finance and transportation. Unlike classical computers, quantum computers are based on the principles of quantum mechanics and can perform specific calculations exponentially faster than classical computers. However, quantum computing is still in its early stages of development. It faces several challenges, including the high rate of errors and the limited number of qubits in quantum hardware. Therefore, more efficient and scalable methods are needed to translate quantum algorithms into executable forms on a quantum computer. To overcome these challenges, several research efforts are underway to develop scalable noise-aware …

Urban Freight Transportation: The Interaction Of Home Deliveries In Cities, Carla A. Tejada

Dissertations and Theses

The movement of freight in urban areas is a key factor in the sustainable development of cities. If managed correctly, it can potentiate economic growth and support urban lifestyles. Nevertheless, the movement of goods in cities is usually in conflict with other urban flows and is generally perceived as having more negative externalities, above all for environmental and social sustainability. While the first focuses on measuring the impact on the environment, the latter focuses on measuring the impacts of business decisions on people. The main goal of this dissertation is to study the relationship that urban goods movements, mainly residential …

Classifying Sidewalk Materials Using Multi-Modal Data, Jiawei Liu

Dissertations and Theses

Navigating safely and independently presents considerable challenges for people who are blind or have low vision (BLV), as it requires a comprehensive understanding of their neighborhood environment. Our user study reveals that materials and objects on sidewalks play a crucial role in navigation tasks. Unfortunately, current methods for assessing sidewalk materials are suboptimal, often relying on labor-intensive and expensive manual assessments that fail to capture the full range of sidewalk features critical to individuals with BLV.

In response to this problem, this master’s thesis investigates deep learning approaches specifically designed for the classification of multi-modal sidewalk materials. The proposed framework …

Tdcs Effects On Synaptic Plasticity And Motor Skill Learning, Forouzan Vasheghani Farahani

Dissertations and Theses

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that involves the application of low-intensity constant current to the brain through electrodes placed on the scalp. Its potential to enhance brain function and treat brain-related disorders has led to its increasing popularity due to its safety, simplicity, and affordability. However, its effectiveness remains a topic of debate.

Machine Learning Approach To Predict Tdcs-Induced Electric Current In The Human Brain, Chikako Olsen

Dissertations and Theses

Background: Transcranial direct current stimulation (tDCS) is a promising non-invasive method for treating neurological and psychiatric disorders and enhancing cognitive function. However, the underlying mechanisms of tDCS are not fully understood, and there is no ground truth for determining, non-invasively, where in the brain tDCS electrical currents flow. At the same time, effective neuronal engagement from tDCS requires accurate localization of the induced currents to specific brain target regions. Machine Learning (ML) has the potential to significantly improve the accuracy and precision of tDCS current prediction. This study aims to develop a novel approach using ML to predict the location …

Analysis Of Chemical Elements In Basalts Using Mislabeled Data, A Machine Learning Approach, Jenifer Vivar

Dissertations and Theses

Scientists use basalt chemistry to discriminate among different tectonic settings. There are well-known chemical elements used to classify tectonic settings. An exploration of new features is done using Logistic Regression and Random Forest to discover any new elements of interest. The models were used with other tools, such as recursive feature elimination and permutations, to increase reliability. Among the scarcely explored chemical elements are Terbium (Tb), Holmium (Ho), Samarium (Sm), and Erbium (Er). The data used for the exploration contained many outliers. Therefore, an ensemble model was created to explore the location and composition of such outliers. The ensemble was …

Exploring Information Leakage In Historical Stock Market Data, Edison Hua

Dissertations and Theses

Information leakage is a major concern for traders who want to execute large orders without affecting the market price. In this paper, we explore the sources and effects of information leakage in historical stock market data using various methods and metrics. We first define information leakage as a pattern caused by a trader that would otherwise not occur without the trader’s activity. Using historical data, the direct impact of a potential large trade cannot be measured, but we consider a minimal impact large trade to be one that minimizes changes to the established trading data. We then analyze how information …

Lidar Remote Sensing Of Aerosol And Ozone Profiles And Application To Air Quality Studies In New York City Area, Dingdong Li

Dissertations and Theses

Ozone (O₃) and PM2.5 (Particulate Matter with a diameter less than 2.5 μm) are the main pollutants in New York City (NYC) due to high levels of anthropogenic emissions, complex urban meteorology, and regional transport. However, vertical distribution observations are still lacking. This thesis utilizes lidar remote sensing techniques to retrieve the vertical distribution of O₃ and aerosols and study air pollution episodes in the NYC metropolitan area.

The thesis includes three parts. The first part analyzes continuous ceilometer observations of aerosols and atmospheric mixed-layer height (ML). We investigate the vertical, diurnal, and seasonal characteristics of the …

Anomaly Based Intrusion Detection System Through Remote Virtual Machine Introspection, Huseyn Huseynov

Dissertations and Theses

Research on identifying malicious applications is an important direction in information security, especially when it comes to detection of evasive malware such as keyloggers, trojans, rootkits and their derivatives. Inspired by a biological immune system and based on negative selection algorithm approach to detect various types of malwares is proposed in this paper.

By deeply studying Linux kernel, understanding links behind different internal system processes, examining, and experimenting with hundreds of various keyloggers we propose a single Artificial Intelligence based solution as a comprehensive protection against wide range of malwares. Developed Intrusion Detection System (IDS) can be deployed in the …

Mechanically Driven In Vivo Osteocyte Ca2+ Signaling: Aging And Pharmacologic Effects, James Padgett

Dissertations and Theses

Bone’s ability to respond and adapt to mechanical loading declines significantly with age which is a major contributor to bone fragility. It is widely accepted that osteocytes are the key cells responsible for orchestrating the development of the “ideal” skeleton. This ability is attributed to osteocyte’s role as the primary mechanosensing cell that is responsible for maintaining the skeleton’s integrity throughout life. Recent work from our laboratory has shed light into how osteocytes respond to mechanical loading in vivo. The breakthrough approaches that enabled these discoveries were development of: (1) the first ever reporter mouse model with a genetically encoded …

Microfluidic Dual-Gel Cell Culture Model For Studying Cell Migration Under Controlled Interstitial Flow, Alimohamamd Anbari

Dissertations and Theses

Abstract

Interstitial flow, the slow flux of fluid occurring in the interstitial space of the extracellular matrix (ECM), affects the migration of many cell types through individual and synergistic contributions of several biophysical and biochemical phenomena. Notably, interstitial flow is linked to ECM permeability and provides direct mechanical cues via shear and normal stress. Additionally, the flow also couples with biomolecular diffusion to provide chemotactic signals to the cells. Recent in vitro studies have indicated that tumor cell migration is affected by interstitial fluid velocity and ECM permeability through the mechanisms of (1) autologous chemotaxis and (2) integrin-mediated focal adhesion …

Optimization Of Optical Nanosensor Response For The Detection Of Anthracyclines Using A Binary Machine Learning Classifier, Myesha Thahsin

Dissertations and Theses

Pharmacokinetic variables such as interindividual variation in metabolizing and eliminating drugs makes dose selection of chemotherapeutic anthracyclines difficult. One potential solution to determining dosing levels of an anthracycline is the development of non-invasive sensors to monitor their pharmacology in vivo. Single-walled carbon nanotubes (SWCNT) have substantial potential for in vivo sensor development, as they exhibit near-infrared fluorescence in the tissue-transparent window and a robust response to their local environment. An emerging method for evaluating and optimizing SWCNT sensor response is through machine learning. In this study, anthracyclines Daunorubicin, Doxorubicin, Epirubicin, Mitoxantrone and Idarubicin, were used to interrogate 12 SWCNT preparations …

Understanding The Kinetics And Mechanisms Of The Desired And Undesired Reactions During Electrochemical Hydrogenation And Hydrogenolysis Of Furfural On Copper In Acidic Media, Andrew S. May

Dissertations and Theses

The decarbonization of the chemical industry would have an immense impact on lowering greenhouse gas emissions and assisting in mitigating global warming. To achieve this there is a growing interest in implementing renewable feedstocks like biomass and coupling of chemical processes with renewable energy. Furfural is a biomass derived species that has been identified as a platform molecule. Electrochemical processes are more easily coupled with renewable electricity and can be used to valorize biomass derived species such as furfural. The installation of electrochemical processes is hindered by a smaller knowledge base compared to thermochemical processes. This dissertation investigates the electrochemical …

Shallow Water Coral Distribution And Its Response To Climate Change, Amaury De Jesus

Dissertations and Theses

Shallow water corals are one of the main reef-building organisms that secrete carbonates as their skeletons, and therefore, are one of the major sinks of CO2 in the ocean. These reef builders are also very crucial to marine environments and human society. As the global energy demand continues rising, fossil fuel burning increases at a faster pace despite the increase in energy supply using clean and renewable energy. The increase of CO2 in the atmosphere has been shown to exacerbate global warming and may cause ocean acidification, threatening the habitat of shallow-water corals. Many recent observations show alarming signs of …

Interventions That Move: Characterizing The Language Of Therapist Responses To High Patient Arousal, Karen Tocatly

Dissertations and Theses

The Referential Process (RP) is defined as a set of functions (Arousal, Symbolizing, and Reflecting/Reorganizing) that describe the rendering of subsymbolic experience into verbal, symbolized form (Bucci, 2021). Movement through the RP — beginning with the subsymbolically-dominated Arousal function — has been tied to multiple theoretical and clinical understandings of therapeutic progress and personality change (Bucci, 2013; Mariani et al., 2013). The present exploratory study seeks to identify whether certain therapist language features are linked to the facilitation of patients’ movement from Arousal to Symbolizing. Using treatment transcripts from the RP Group Data Base, cases of high patient Arousal were …

Nonlinear And Time-Modulated Metamaterials: Applications At Microwave Frequencies, Hady Mohammed Saied Sayed Moussa

Dissertations and Theses

Metamaterials (the Greek prefix meta, means beyond) are artificially structured materials that interact with the incoming waves in extraordinary ways, beyond the properties of natural materials, yielding unusual and exotic electromagnetics phenomena. By careful engineering of the material properties, invoking nonlinear elements and/or time-modulating some of the material parameters, linearity and/or time-invariance can be broken in metamaterials, enabling extraordinary wave phenomena that open opportunities for the microwave engineering community, including the creation of nonreciprocal devices, frequency conversion, and more. In this dissertation, we explore, investigate, design, and fabricate metamaterials that open new applications for nonlinearity-based and time-varying devices, particularly in …

Ultra-High Field Mri Methods For Precise Anatomical And Spectroscopic Measurements In The Brain And Application To Neurological And Neuropsychiatric Diseases, Judy Alper

Dissertations and Theses

Neurological and neuropsychiatric diseases and disorders are a major burden on society, impairing the health and functioning of millions of people every year. There is a need to define the biological bases of these diseases and identify potential biomarkers to improve diagnosis, monitoring, and treatment efficacy across multiple diseases.

Magnetic resonance imaging (MRI) is a noninvasive imaging technique which facilitates detection of brain lesions and visualization of the brain overall. However, limitations in contrast and resolution at clinical field strengths may hinder investigation of the underlying biological mechanisms of these diseases. Ultra-high field MRI scanners, such as those at 7-Tesla, …

Factors Influencing Hard Running Distances In Ncaa Division I Female Soccer Players, Isaac A. Sam

Dissertations and Theses

As the total distances covered in soccer games have remained relatively constant, the hard running distances covered by players have shown varying changes due to the higher physical demands and dynamics of team running performances. Although factors affecting the total distances covered in a match are multifactorial, no study has specifically examined match performance indicators (MPI) that impact hard running distances (HRD). Consequently, the purpose of this study was to better understand how MPI (hard running efforts, turnovers, minutes played, duels won, duels lost, and pass completions) are associated with HRDs and to investigate how each variable contributes to HRDs …

A Study Of Verbal Rumination, Relationships, Stress And Identity On Health Communication In Collegiate Athletics, Landon Mary Ellen Kemp

Dissertations and Theses

College athletes are a unique group of individuals as they face many positive and negative challenges when competing in a collegiate sport. Verbal rumination is repetitive talk about a particular issue, accompanied by adverse effects for an individual. Verbal rumination is a common strategy athletes use to cope with difficulties along with managing challenging situations in their athletic program. To explore factors that might inspire or impede verbal rumination in collegiate athletics, the present study examines the quality of coach and teammate relationships, perceived stress and athlete identity. Results revealed the impact of relationships between coaches and athletes in respect …

In Whitman's Wake, Kacie Megan Fodness

Dissertations and Theses

In Whitman’s Wake argues that nineteenth-century American writing includes a living invitation for its future readers. The kind of invitational writing prioritized in this work has not yet been fully accounted for in literary criticism. What’s more, even when we as readers have experienced such an invitation (one we feel is for us) we have not followed the feeling far enough. As a result, scholarship has largely neglected, and perhaps has consciously rejected, the intentional action of a writer that creates an encounter with their future reader. My project contributes to the ongoing critical conversation around the relationship of readers …

Teacher Retention: Retaining Teachers In High-Needs, Urban Secondary Schools In A Midwest State Post-Pandemic, Christopher Kenneth Schmit

Dissertations and Theses

Teacher retention has been a challenge for most schools for several years. High-needs schools have been known to have twice the trouble with teacher retention as schools not considered high-needs. The purpose of this study was to identify effective practices school principals can implement to retain teachers at high-needs, urban secondary schools. This quantitative study called on teachers from high-needs schools in Iowa to complete a survey identifying principal qualities related to retention, perceived reasons for teacher attrition, and reasons they continue to teach at their current school. Three hundred eighty-five teachers from five different Iowa school districts participated in …

Closing The Digital Divide: Understanding Organizational Approaches To Digital Accessibility In Higher Education, Angela Kae Jackson

Dissertations and Theses

Digital accessibility practices are becoming standardized in higher education as institutions seek to meet compliance with federal and state equal access laws. Students with disabilities have equal rights to access university programs and services in digital format. The widespread use of assistive technology, artificial intelligence, and content available in digital format brings forth ethical and legal concerns about equal access for individuals with disabilities. While broad approaches to digital accessibility in higher education are in the literature, there is a growing need for more studies to examine comprehensive approaches to digital accessibility across multiple units, disciplines, and the organization's hierarchy. …

Highly Power Dense Dc To Three-Phase Ac Modular Converters With Tiny Module Capacitors, Wiwin Hartini Lew

Dissertations and Theses

A Modular Multilevel Converter (MMC) is an attractive candidate in high power conversion due to its modularity and scalability. The energy storage element, namely the module capacitance in the MMC submodule circuit, is typically large and when scaled to convert high power, requires very bulky module capacitors. In addition to deteriorating the power density, the design necessitates the use of electrolytic capacitors, which further affects the overall converter efficiency and reliability. This research presents an MMC submodule topology and the accompanying modulation approach that reduces the submodule capacitance requirements significantly compared to conventional MMC topology (few micro-farads versus several milli-farads). …

Increasing Collaboration To Improve Student Outcomes: Improvement Science, Cassandra Diane Thonstad

Dissertations and Theses

The aspiration of achieving equitable outcomes for all students is a focus of schools, districts, and communities but has largely remained unattainable with the top-down implementation of change ideas and directives that come and go as quickly as they are implemented. Too often the direct users, students and classroom staff, are left out of the conversations around what works best to improve student success, contributing to the achievement gaps experienced by our students of color, students receiving special education or English language services, or in the case of a hook discipline, young men. By utilizing Improvement Science through collaboration across …

Scientology's Faq: Sciencing, Tech-Romancing, Simulacra, & Simulation An Estranged Content Analysis, David Scott Morrill

Dissertations and Theses

This thesis examines how the practice of sciencing, tech-romancing, simulacra, and simulation manifests in both the text and symbols used on audiences of the Church of Scientology’s outreach materials. It specifically examines its official FAQ page. Self-framing was observed that satisfied the definition of sciencing and tech-romancing. Under an Estranged approach, Morrill examined selections of the Church’s FAQ pages, coding for instances of sciencing, tech-romancing, simulacra, and simulation. The data indicate that the Church frequently adopts simulacra and engages in simulation. The Church was seen frequently adopting technological and scientific symbols and jargon. The degree of sciencing, tech-romancing, simulacra, and …

Confederate Statues In University Opinion Newspaper Articles: An Analysis Of Themes And Attachment, Jamie Nicole Knopf

Dissertations and Theses

Many have asked for Confederate monuments' removal while others argue that they should remain or be recontextualized. Knopf analyzed themes found in Southern university student newspapers on the monument issue and how the statues related to community attachment. Using thematic analysis, Knopf identified six themes across the articles, and found that both removal and recontextualization arguments refer to the ideology behind the statues and the impacts this can have on students. Instances of attachment were used in both removal and recontextualization articles.

Possibilities For Inertial Electrostatic Confinement Fusion, Jeffrey Edward Black

Dissertations and Theses

While most of the fusion energy research is focused on magnetic confinement, there have been several alternative confinement methods aimed at the development of smaller and less expensive reactors. A number of these devices utilize a spherically convergent beam of recirculating ions, a technique known as inertial electrostatic confinement (IEC). This study looks at several aspects of IEC devices, including measurements of the fusion rate of an IEC device with a wire mesh electrode cathode, and a solid titanium cathode. In addition, several computational studies were performed to explore the possibilities for IEC fusion. These include development of a 1D-1P …

Agenda Setting And Europe's Common Immigration Policy, Jamie P. Surface

Dissertations and Theses

For over a decade the European Union has been immersed in an immigration crisis. As the desired destination for millions of people fleeing unrest in the Middle East and war in Ukraine, the EU has developed its own social, political, and humanitarian crisis. Lacking policy commonality across its member states on how to accept and manage the mass waves of migrants, the EU continues to struggle with implementing a common immigration policy. This research examines EU immigration issues, policies, and the failures of successful collaboration stymying the implementation of a standard immigration policy. Using the agenda setting model of John …

Scaling Epa-Rimm With Multicore System Management Interrupt Handlers, Alexander K. Freed

Dissertations and Theses

Continuous runtime integrity measurement mechanisms (RIMMs) can be used for timely detection of kernel and hypervisor rootkits. Researchers have proposed running RIMMs in privileged execution environments, such as the x86 architecture’s System Management Mode (SMM), to detect interference from rootkits that have gained control of the host operating system. However, the extended amount of time in SMM required to perform inspections can cause severe disruption to the host. A previously proposed RIMM design called EPA-RIMM addresses this by decomposing long inspections across multiple System Management Interrupts (SMI), the interrupt used to invoke SMM.

EPA-RIMM is intended for deployment on server-class …