Digital Commons Network^™

Spectral Properties And The Behavior Of The Current-Current Correlation Measure For The Luttinger-Sy Model, Jonathan Benoit

Theses and Dissertations--Mathematics

The Luttinger-Sy Model, sometimes referred to as the Pieces Model, is a Random Schrodinger Operator on L²(R) which is characterized in part by "pieces" whose endpoints are chosen by a Poisson Point Process. The Hamiltonian in this setting is then given as a direct sum of Laplacians with Dirchlet boundary conditions on each piece. In this work, we show several spectral properties of the Luttinger-Sy Model, including proving the deterministic spectrum is [0,infinity) and that a Wegner-type and Minami-type estimate both hold. Additionally, we show that the finite-volume Current-Current Correlation Measure is singular continuous with respect …

A Major Update And Improved Validation Functionality In The Mwtab Python Library And The Metabolomics Workbench File Status Website, P. Travis Thompson, Hunter N. B. Moseley

Markey Cancer Center Faculty Publications

Background: The Metabolomics Workbench (MW) is a public scientific data repository consisting of experimental data and metadata from metabolomics studies collected with mass spectroscopy (MS) and nuclear magnetic resonance (NMR) analyses. Although not as rapidly as in the past, MW has steadily evolved, updating its mwTab and JSON deposition text file formats and its web-based infrastructure. However, the growth of MW has been exponential since its inception in 2013 and continues to be exponential, with the number of datasets hosted on the repository increasing by 50% since April 2024. As part of regular maintenance to keep up with changes to …

Challenges And Applications Of Fine-Grained Temporal Action Understanding: Modeling Temporal Granularity And Data Efficiency, Halil I. Helvaci

Theses and Dissertations--Electrical and Computer Engineering

Fine-grained Temporal Action Segmentation (TAS) has become a cornerstone of video understanding, offering dense frame-level predictions essential for clinical assessment, surgical skill evaluation, and human-computer interaction. While TAS methods have delivered strong results on coarse-grained benchmarks, two fundamental challenges persist: (1) global attention mechanisms dilute boundary information critical for subsecond precision, a phenomenon we term the temporal granularity bottleneck, and (2) dense frame-level annotation remains prohibitively expensive, with most datasets requiring exhaustive labeling of lengthy untrimmed videos. These challenges are particularly pronounced in medical domains, where sub-second primitives define clinical outcomes while expert annotation remains scarce. In this dissertation, we …

Advancing Edge Intelligence: Strategies For Improving Machine Learning On Embedded Devices, Prakash Dhungana

Theses and Dissertations--Electrical and Computer Engineering

Artificial intelligence (AI) has demonstrated tremendous success in handling complex tasks across multiple domains, a leap largely attributed to complex deep neural network (DNN) architectures. However, the increasing demand for real-time processing, low latency, limited connectivity, and enhanced privacy necessitates edge intelligence, where computation is performed directly on resource-constrained embedded devices rather than relying on cloud infrastructures. While optimized TinyML techniques such as pruning, quantization, and neural architecture search (NAS) have made edge deployment feasible by significantly reducing computation and memory demands, achievable performance remains severely limited by hardware constraints. Furthermore, models deployed in highly dynamic real-world environments suffer from …

Impact Of Land Use On Soil Properties, Clay Mineralogy, And Behavior Of Ammonium Across A Precipitation Gradient, Isabel Delamater

Theses and Dissertations--Plant and Soil Sciences

Like soil texture, clay mineralogy is considered a permanent or inherent characteristic of soils reflecting the influence of soil forming factors over long periods of time. Despite the importance of clay mineralogy in providing ecosystem services, much remains unknown about whether land use (native grassland sod versus no-tillage) can modify clay mineralogy under short periods of time. Furthermore, in no-tillage agroecosystems, lower crop yields are often ascribed to immobilization of added N fertilizer where inorganic nitrogen (such as ammonium) is converted to organic nitrogen. The possible role of clay mineralogy in retaining added ammonium has been overlooked in no-tillage systems. …

Effects Of Student And School Technology Adoption On Student Reading Achievement In The United States: The Case Of Pisa 2018, Mikah J. Hughes

Theses and Dissertations--Educational, School, and Counseling Psychology

This study examined the relationship between student and school-level information and communication technology (ICT) factors and reading achievement using data from the Programme for International Student Assessment (PISA) 2018 in the United States. In an increasingly digital world, reading and information literacy are essential skills, yet significant gaps in digital competencies persist. This study investigated how ICT access, use, and perceptions relate to reading achievement in the context of student and school background factors.

A two-level hierarchical linear modeling (HLM) framework was employed to account for the nested structure of students within schools. The sample included approximately 4,000 students across …

Supramolecular Self-Assemblies Of Ru( Ii ) Phototherapeutics: Biological Activity Of Micro- And Nano-Particles Acting As Reservoirs, Jérôme Laisney, Sarah M. Kriger, Dmytro Havrylyuk, Jason M. Unrine, David K. Heidary, Edith C. Glazer

Chemistry Faculty Publications

Ruthenium( II) coordination complexes have many appealing properties as prodrugs, but can suffer from poor aqueous solubility and short circulation times, drastically decreasing efficiency in vivo. Nanoformulations using a variety of carriers, such as inclusion in polymers/lipids or adsorption on inorganic nanoparticles have been applied to overcome this limitation, but unfortunately, these approaches raise additional concerns regarding the fate of the carriers, with potential long-term toxicity and accumulation in vital organs. Here, we present an alternative delivery strategy with formation of pure and polymer-supported supramolecular self-assemblies of Ru(II) complexes acting as ‘‘reservoirs’’. A facile preparation of size-controlled particles was achieved …

Characterization And Antimicrobial Activity Of Lignin-Derived Compounds In Ground Hurd Tissue Of Cannabis Sativa L. (Hemp) Cultivars, Jourdan E. Lakes, Anjam Sadik, Robert C. Pearce, Barbara L. Knutson, Stephen E. Rankin, Bert C. Lynn, Michael D. Flythe

Chemistry Faculty Publications

Objectives: Characterize lignin-derived compounds from the hurd of 10 fiber/grain Cannabis sativa L. cultivars and investigate the antimicrobial activity of select compounds on the wasteful ruminant bacterium, Acetoanaerobium sticklandii SR.   Methods: Hurd was processed using an aqueous ethanol solvent system and analyzed via GC-MS to identify and characterize lignin derivatives. Antimicrobial activity of the hurd and three monomers was assessed using solid (hurd) and liquid medium (monomers) bioassays against SR.   Results: 27 compounds were identified, most as monomers but a few were dimers, ethylated derivatives, and organic acids. There were approximately equal G- and S-units with substantially fewer H-units. Several …

Enhanced Photostability Through Rapid Exciton Decay In Desymmetrized Cyclopentannulated Acenes With Strong Face-To-Face Pi Stacking, Chad D. Cruz, Karl J. Thorley, Zachary J. Knepp, Jared Wahlstrand, Gil M. Repa, John C. Stephenson, Sean Parkin, Lisa A. Fredin, John E. Anthony, Emily G. Bittle

Chemistry Faculty Publications

The photophysics of organic semiconductors impacts their efficiency in optoelectronic devices where exciton transitions, including singlet fission, intersystem crossing and the formation of charge transfer states influence the ability to convert between bright and dark states and to dissociate into free charges. Unfortunately, photodegradation and spurious signals often confound the results of optical studies, especially of important triplet states. Here four asymmetric cyclopentannulated acenes are synthesized and studied. This system represents an extreme in photophysics achieved via molecular design to fully quench the photoluminescence and bypass triplet formation allowing for comparative studies with other highly absorbing acenes. Rapid molecular exciton …

Aqueous Synthesis Of Luminescent Semiconductors For Opto-Electronic Applications, Saurabh Singh

Theses and Dissertations--Chemical and Materials Engineering

The advancement of opto-electronic and scintillation technologies relies heavily on developing low-temperature, eco-friendly, and scalable synthesis routes for high performance luminescent halide-based semiconductor materials. However, traditional synthesis methods for halide-based semiconductors, including hot-injection, solvothermal, solid-state reactions, Ligand-Assisted Reprecipitation (LARP), microwave-assisted synthesis, and thin film deposition techniques (spin coating, physical vapor deposition (PVD), chemical vapor deposition (CVD), etc.), often demand toxic organic/inorganic solvents, elevated processing temperatures, and high vacuum/inert environments. Such constraints limit their scalability, raise environmental concerns, and impede their commercial-level device integration. This research overcomes these long-standing challenges by employing water as a powerful crystallization-directing, and environmentally benign medium …

Utilizing Coal For Mesophase Pitch-Based Carbon Fiber Production: Precursors, Processes, And Progress, Christina M. Thompson

Theses and Dissertations--Chemistry

Graphitic materials possess unique properties due to the unique combination of layered crystalline structure and carbon’s low atomic weight. High performance carbon fiber is one such example, displaying exceptional strength-to-weight ratios, stiffness, and thermal and chemical resistance. These properties render high performance carbon fiber a critical structural reinforcement material in the manufacture of composites across various industries, such as for automotive and aerospace applications. However, balancing fiber performance with precursor and processing costs remains a challenge. As alternative carbonaceous feedstocks are explored, coal has gained interest for utilization in graphitic products as a relatively abundant and low-cost source of aromatic …

Elucidating The Impacts Of Non-Covalent Interactions In Organic Materials Through A Multiscale Computational Approach, Sashen A. Ruhunage

Theses and Dissertations--Chemistry

Noncovalent interactions (NCIs) in π-conjugated organic materials serve as tunable levers that influence molecular structure and intermolecular interactions in the condensed phase and, in turn, impact the electronic, optical, and mechanical properties of these materials. NCIs include attractive dispersion, electrostatic, and induction interactions, as well as repulsive exchange interactions. However, how to design materials with NCI considerations remains an open question across many fields. Here, we seek to provide an electronic and atomistic perspective on these interactions through multiscale simulations to aid materials design, processing, and performance optimization. In this study, we investigate NCIs and their effects across various systems …

Student Familiarity With The Periodic Table Of The Elements: Results From Cued-Recall And Eye-Tracking Assessments On Memory, Victor A. Okuo

Theses and Dissertations--Chemistry

Learning element symbol–name associations and the spatial organization of elements on the periodic table is a foundational step in learning chemistry, supporting later understanding of chemical formulas, equations, bonding, and stoichiometry. Although students often rely on memorization strategies to learn periodic table content, this task is challenging due to the large number of elements and the apparent ambiguity in matching some element symbols to their names.

This study explores students’ recall of element names when given element symbols as cues and their knowledge of element locations on the periodic table when given element names as cues. The study also examines …

Relative Utility Governs Working Memory For Drug-Associated Stimuli In A Novel Translational Paradigm, Maxwell E. Boileau

Theses and Dissertations--Psychology

Substance use disorder (SUD) remains a prevalent health concern, partially characterized by continued drug use despite aversive consequences. Contrary to accounts emphasizing cognitive deficits, drug versus non-drug choice data reflect sensitivity to reinforcement dimensions, with preference shifting systematically as a function of magnitude and probability. The present study tested whether another cognitive system, working memory, is similarly affected by relative utility. Preclinical studies have demonstrated sensitivity of working memory to reinforcement dimensions, but these are often attributed to the differential outcomes effect. Generalized matching models were fit to allomorphic choice data, allowing estimation of exchange rate parameters. A concurrent solid- …

Numerical Modeling Of Multi-Scale Jet Feedback In Seyfert Galaxies, Julianne Goddard

Theses and Dissertations--Physics and Astronomy

We present a suite of high-resolution cosmological zoom-in simulations investigating the impact of mechanical and thermal feedback from low-luminosity jets launched from supermassive black holes (SMBHs) on Seyfert galaxy evolution from early cosmic times to the present (z ≤ 10). Our models follow the formation of central galaxies within identical dark matter halos of logMhalo/M⊙ ∼ 11.8 at z = 0, seeded with ∼ 10^6M⊙ SMBHs at z ∼ 9.1 and z ∼ 3.7. Feedback from active galactic nuclei (AGN) is implemented in the form of bipolar jets launched along the SMBH spin axis, with jet powers spanning Ljet ∼ …

Regulating Galaxy Growth: Ionized Gas Conditions, Star Formation Histories, And Environmental Effects, Shweta Jain

University of Kentucky Doctoral Dissertations

Understanding galaxy formation and evolution requires tracing how baryons cycle between stars, gas, and the interstellar medium (ISM) across cosmic time. The efficiency of star formation, the buildup of metals, and the regulation of gas inflows and outflows are governed by evolving physical conditions within galaxies and their environments. My thesis investigates how the ionized ISM, star formation histories, and environmental processes have shaped galaxy evolution over the past ∼ 12 Gyr. The primary focus of this work is the evolution of the physical conditions of ionized gas in galaxies, including gas-phase metallicity and ionization state. Using new and archival …

Multiscale Modeling Of The Thermomechanical Behavior Of Polymeric And Molecular Organic Semiconductors, Kehinde H. Fagbohungbe

University of Kentucky Doctoral Dissertations

Organic semiconductors, derived from π-conjugated polymers and molecules, enable the development of deformable, stretchable and flexible electronics due to their tunable redox, optical, electronic and mechanical properties. However, an informed understanding of how multi-scale morphological characteristics of the polymeric and molecular semiconductors influence bulk properties that contribute to electronic and optical performance, especially under operational thermal and mechanical stresses, remains incomplete. This lack of understanding poses a challenge to scalability and commercialization of organic electronics. This dissertation develops and deploys computational modeling approaches, particularly atomistic molecular dynamics (MD) simulations, to investigate the multiscale morphological behavior of these synthetic semiconducting materials …

Promptable Segmentation For Adaptive And Data-Efficient Medical Image Analysis, Tyler Ward

University of Kentucky Doctoral Dissertations

Image segmentation is a fundamental task in computer vision. While segmentation models have traditionally been trained in a fully-supervised manner, recent approaches have leveraged large-scale pre-training and prompting mechanisms to great effect. However, the performance of such approaches often degrades when applied to domain-specific tasks like medical image analysis. A major reason for this lies is that these models are trained on large, labeled datasets of natural images, which have drastically different characteristics compared to medical images, limiting the generalizability of the methods when applied to medical data. This dissertation presents several data-efficient, adaptive, and promptable medical image segmentation models. …

Personality Exceptions: Enhancing Character In Narrative Planners With Internal Memory, Elinor Rubin-Mcgregor

University of Kentucky Doctoral Dissertations

Stories and narratives are powerful tools for forging connections between people, as they induce emotions shared through their audience and help build empathy and understanding through sharing unique perspectives. Interactive stories can do all this and more, as they can be used to better educate and engage their audience. But in such stories, the characters must have consistent personality and human-like emotions in order for the audience to relate to them. Current implementations of personality in interactive narratives either portrays characters with static personality that feel less realistic, or else require a great deal of additional work from the author …

Coexistence Between Ci And Feminization Inducing Symbionts: A Theoretical Perspective, Dylan Thorp

University of Kentucky Master's Theses

Endosymbiotic bacteria that manipulate the reproduction of their host are abundant in arthropods. Theoretical efforts to model these bacteria have seldom included symbionts that feminize their hosts, and those that do have assumed an environmental sex determination system. Here, I expand upon other theoretical works to model the dynamics of a host population with an XX/X0 sex determination system that contains separate CI and feminization inducing symbionts. I found that coexistence cannot occur without double infection, consistent with previous models. However, I also found that without double infection, the presence of the feminizing symbiont can facilitate the spread of the …

Development Of An Atmospheric Particle Imaging System (Apis), James W. Hebert

University of Kentucky Master's Theses

The study of atmospheric particulates plays a crucial role in both climate change studies and the improvement of hypersonic travel. The current issue at hand is a lack of knowledge of stratospheric particulate content and the high cost that is associated with conducting research at these altitudes. This project focuses on the development of an Atmospheric Particle Imaging System (APIS) to be a low-weight, low-cost optical payload. The goal is to make a device that can be mounted onto an uncrewed aerial system that has the capability of imaging particulates moving at steady flow velocities, and thereby characterize the individual …

H2 Matrix Compression For Fast Magnetic Field Post-Processing, Calvin M. Demps

University of Kentucky Master's Theses

Large-scale computational electromagnetic simulations frequently require the assembly of dense system matrices, whose computation time and memory cost grow rapidly with problem size and can render high-resolution simulations impractical. This thesis presents a benchmark of the H² hierarchical matrix method applied to the construction of a coupling matrix that maps magnetization current in a structure to the magnetic field at observation points external to the structure. The underlying field interaction is derived from Maxwell's equations and discretized using a Nyström approach, producing a dense matrix.

The method is benchmarked across various geometries of increasing complexity and for increasing mesh …

Enhancing International School Implementation Capacity: Supporting Contextualized Learning At An International Baccalaureate School In China, Christopher J. Hayden Iv

Theses and Dissertations--Educational Leadership Studies

International schools allocate substantial resources to implement progressive curricular innovations; however, the advantages offered by these developments are contingent on their effective execution within classroom settings. This mixed methods action research (MMAR) study examined the implementation of the International Baccalaureate (IB) Global Context (GC) Strategy in the Middle Years Programme (MYP) at an international school in China and asked how the school might strengthen its capacity to enact this and similar innovations. Following a sequential MMAR design, a reconnaissance phase combined a whole-staff survey (n=87) with qualitative interviews to diagnose the individual, organizational, and contextual factors shaping implementation. Analyses identified …

Test-Retest Reliability And Validity Of The Gas Exchange Threshold, Erik Ryan Snell Mr.

Theses and Dissertations--Kinesiology and Health Promotion

Theoretically, the gas exchange threshold (GET) demarcates the moderate and heavy intensity domains, whereby exercise performed at and below the GET results in a change in oxygen consumption ([ΔVO₂] ≤ 200 mL), and exercise above the GET results in a slow component (ΔVO₂ > 200 mL). This study examined the reliability and validity of the GET. 14 subjects performed two maximal graded exercise tests (GXTs) to determine the GET and its reliability. The minimal difference (MD = 21W) was applied to determine the GET above (GET_+MD) and below (GET_-MD) power outputs for 30 min …

Are Multiple-Choice And Open-Ended Assessments Consistent In Predicting Science Achievement? Multivariate Multilevel Evidence From Chinese Students And Schools, Quan Wu

Theses and Dissertations--Education Sciences

A multivariate multilevel model was developed and applied to secondary data from a large-scale science assessment of Grade 8 students in China to examine the consistency between multiple-choice and open-ended formats of assessment in predicting science achievement at the student and school levels. The sample included 44,534 students from 159 schools across two regions. Multivariate multilevel results indicated a moderately positive consistency between the two formats at the student level and a strongly positive consistency at the school level; these consistencies were stable across regions and did not depend on student and school characteristics. The findings have important practical implications …

Effects Of Yoga And Mindfulness On Emotional Regulation, Behavior, And Teacher Burnout, Sara E. Smith

Theses and Dissertations--Education Sciences

This dissertation comprises three studies that examine the effects of physical activity, yoga, and mindfulness interventions on students' emotional regulation, behavior, and academic outcomes in rural Kentucky schools. These studies as a whole contribute to understanding how movement-based and mindfulness practices can enhance social-emotional and academic well-being in schools.

The first study describes the effects of classroom-based physical activity on student achievement and social-emotional well-being. Forty-five elementary students participated in a 6-week intervention with two 7-minute movement breaks per day. Results indicated statistically significant improvements in Reading (t(44) = 2.55, p < .001, d = .38), Math (t(44) = 4.63, p < .001, d = .69), and social-emotional competence (t(44) = 3.67, p < .001, d = .55). These findings demonstrate that brief, structured physical activity can meaningfully enhance academic and emotional outcomes when implemented by classroom teachers.

The second study shows the effects of a five-week …

Exploring High School Students’ Learning Interests And Information Sources On Viruses And Covid-19, Sahar Alameh, James W. Keck, Elizabeth Loh, Lin Xiang, Scott M. Berry, Anna G. Hoover, Abigail Knapp, Savannah Tucker

Science, Technology, Engineering, and Mathematics (STEM) Education Faculty Publications

This study investigates high school students’ health-information seeking behaviors related to COVID-19 and viruses in a rural area of the south-central United States, and how these behaviors relate to students’ knowledge, perceptions, and learning interests. Survey data were collected from 83 students in Spring 2023, during the post-pandemic period, as part of a STEM and public health unit. Drawing on frameworks from Health Information-Seeking Behavior and student interest, the study examines students’ COVID-19 information sources, how these sources relate to their knowledge about viruses and their perceptions of COVID-19, and the specific topics about which they were most interested in …

A Historical Case Study Of The Effects Of The Coordinate Interagency Partnership Regulating International Students (Cipris) System And The Student Exchange Visitor Information System (Sevis) On Foreign Students Coming To The United States For Higher Education From 1990 To 2008, M. Ann Livingstone

Theses and Dissertations--Educational Policy Studies and Evaluation

The United States has welcomed foreign scholars and students since 1774, but their numbers increased dramatically after World War I, and again after World War II, as America became a world power leader and interest in the United States and its educational system and technological developments grew internationally. The Immigration and Naturalization Service (INS) was set up to oversee immigrants, visitors, and nonimmigrants who included students and diplomatic staff and families. This study deals with the changing laws and responsibilities of the INS during the period 1990 to 2008 to track foreign students in higher education, specifically with the introduction …

Bringing Pandemic Science To The Classroom: Building Public Health Capacity At A Rural Kentucky High School, Sahar Alameh, Anna G. Hoover, James W. Keck, Scott M. Berry, Sagan Goodpaster, Savannah Tucker, Ashley Goodin

Science, Technology, Engineering, and Mathematics (STEM) Education Faculty Publications

In response to the COVID-19 pandemic, a multidisciplinary team at the University of Kentucky developed an interdisciplinary science, technology, engineering, and mathematics and environmental health unit—the Wastewater Assessment for Coronavirus in Kentucky: Implementing Enhanced Surveillance Technology (WACKIEST) Unit—for high school students in summer 2022. This case study outlines the WACKIEST Unit, which focused on wastewater surveillance and COVID-19, the obstacles faced during development and recruitment, and implementation of the WACKIEST Unit in conjunction with a rural wastewater surveillance initiative. The unit was implemented in spring 2023 at a rural high school in Kentucky, spanning 12 days and engaging 190 students. …

Quantifying Nuanced Differences In Hand Dexterity Between The Dominant And Nondominant Hands Of Healthy, Right-Handed, Young Adults, Brian J. Conway, Léon Taquet, Timothy F. Boerger, Kaitlin Goetschel, Kate B. Krucoff, Sergey Tarima, Brian D. Schmit, Max O. Krucoff

Biostatistics Faculty Publications

When individuals present with hand injuries, clinicians often use the contralateral hand as an internal control. However, subtle differences in baseline dexterous abilities between the dominant and nondominant hands are poorly understood. To address this gap, here we quantified such differences, measured as independence (individuation) and smoothness of finger movements. A cohort of 47 right-hand-dominant healthy adults (22 males and 25 females) moved each finger independently 10 times, while joint angle data were tracked with a dataglove (CyberGlove III, CyberGlove Systems, San Jose, CA). Each finger’s performance was compared with its counterpart on the opposite hand using Wilcoxon-signed rank tests. …