Physical Sciences and Mathematics Commons^™

Characteristics Based Factor Models - Comparison Of Estimation Procedures, Henri Ohl

McKelvey School of Engineering Theses & Dissertations

Understanding cross-sectional and time series variation of asset returns is fundamental in finance, particularly in asset pricing. This thesis explores the integration of factor theory with machine learning to deepen our comprehension of these dynamics. Characteristics based factor models offer a systematic framework for quantifying an asset's underlying risk-return structure, leveraging time-varying conditional information on model parameters carried by firm-specific characteristics. These models serve as valuable tools for discerning the driving components of an asset's expected excess return. Recent research established a novel methodology for consistent parameter estimation within this framework, only requiring a large cross-section but not a long …

Assessing Reproducibility Of Brain-Behavior Associations Using Bootstrap Aggregation Methods, Zhetao Chen

Arts & Sciences Electronic Theses and Dissertations

在本论文中，随着越来越多地利用静息态功能连接 MRI (rs-fcMRI) 将神经活动与病理状况联系起来，我们面临着对此类数据可靠性的普遍担忧。我们的探索集中于提高人类连接组计划（HCP）数据集框架内大脑行为关联的可重复性。我们采用两种不同的引导聚合方法来研究功能连接可靠性的增强：使用循环块引导（CBB）的单独时间序列装袋和使用线性支持向量回归（LSVR）模型的主题级装袋。我们对 CBB 个体时间序列 bagging 的调查表明，这种方法并不能显着增强大脑行为关联的可重复性。这一发现指出了实现可靠的功能连接措施的复杂性以及某些聚合方法在克服这一挑战方面的局限性。相比之下，我们的学科水平考试 通过 LSVR 模型装袋呈现出更有希望的结果。这种方法显着增强了分析之间模型权重的可靠性，证明了其在提高数据稳健性和可重复性方面的功效。两种方法的这种不同影响强调了适当的分析策略在提高神经影像数据可靠性方面的关键作用。通过描述这两种方法的结果，本论文有助于对神经影像领域的数据可靠性进行更广泛的讨论。它强调了在不同数据集上持续进行方法创新和验证的必要性，以提高 rs-fcMRI 研究的可靠性和可解释性。

Mending Trust In Ai: Trust Repair Policy Interventions For Large Language Models In Visual Data Journalism, Hangxiao Zhu

McKelvey School of Engineering Theses & Dissertations

Trust in Large Language Models (LLMs) emerged as a pivotal concern. This is because, despite the transformative potential of LLMs in enhancing the interpretability and interactivity of complex datasets, the opacity of these models and instances of inaccuracies or biases have led to a significant trust deficit among end-users. Moreover, there is a tendency for people to personify AI tools that utilize these LLMs, attributing abilities and sensibilities that they do not truly possess. This thesis exploits this personification and proposes a comprehensive framework of trust repair policies tailored to address the challenges inherent in LLM annotations within data journalism …

The Soundscape Of The Grove: The Acoustic Environment Of A Visual Landmark, Bryce Barrett

Honors Theses

The objective of this project was to evaluate the soundscape throughout the Grove and the Circle (two popular outdoor spaces on the University of Mississippi campus) by determining the sound levels and people’s perceptions of sounds. The term soundscape is defined by a person’s perception of an acoustic environment in context. The human perceptions of sounds were gathered during soundwalks, which are walking tours of a given environment where participants provide opinions on their acoustic surroundings. Five soundwalk sessions were conducted with a total of 10 participants with varying environmental conditions. Statistically significant variations in perceptions and sound levels …

Development And Application Of Photoresponsive Small Molecule Probes To Modulate And Characterize Neuroreceptors, Spencer Kim

Dissertations - ALL

The field of neuroscience is rapidly evolving and so the development of novel tools that support innovative research is urgently needed. Two tools that have proven to be particularly impactful to the field of neuroscience are activity-based protein profiling (ABPP) and optogenetics, both of which have seen widespread application but with relatively limited advancement of the underlying technology. Limitations of ABPP and optogenetics have become increasingly apparent and research output is stalling due to lack of technological advancement. For example, few systems exist for targeting low-abundance and unstable proteins via ABPP and application of ABPP and optogenetic systems thus far …

On The Limitations And Restrictions Of The Hardy-Littlewood Circle Method, Daniel W. Havens

Mathematics & Statistics ETDs

We discuss herein the history, layout, and philosophy of the Hardy-Littlewood Circle method, as well as the more modern renditions thereof. The limitations and scope of each method presented is discussed in detail, providing examples of cases where the failure of the circle method is of relevance. We include a summary of famous problems which have been resolved using each methodology, as well as what limitations each methodology showcases.

Agroecology And Soil Stewardship: Values And Techniques Of Smallholder Farmers In Bernalillo County, Stephanie Olivas

Geography ETDs

Agrarian movements around the world use agroecology to build sovereignty and steward dynamic ecosystems. Research has shown that agroecological farmers steward more resilient crops, more resilient soil biomes, and greater biodiversity than conventional agriculture. GIS and remote sensing offer many tools to detect the impacts of these farmers on the environment, but it is less clear how such technologies fit into agroecological goals. This study asks: what values, experiences and knowledge do smallholder producers in Bernalillo County embody in their soil stewardship practices? Also, what experience or knowledge do smallholder producers in Bernalillo County have about remote sensing, and would …

Molecular Dynamics Insights Into The Structural Behavior And Interactions Of Complex Biological Systems, Shenghan Song

Chemistry and Chemical Biology ETDs

All-atom molecular dynamics (MD) simulations are essential for examining the structural and dynamic aspects of proteins at high resolution, complementing experiments limited by resolution, size, and complexity. Advancements in algorithms and hardware have enhanced the role of computational tools in scientific research, allowing for more accurate simulations of proteins with standard residues. However, simulating real biological systems, which include non-standard residues such as lipid membranes, remains challenging despite the assistance of tools like CHARMM-GUI. My research initially focused on simulating the PICK1 BAR dimer using steered MD simulations to investigate its structure and dynamics. Simulation works expanded to include systems …

Burning Calories, Burning Ocean: Metabolic Rate In Bivalves As A Predictor Of Extinction Selectivity Through Time And During Rapid Global Warming, Siddharth Gavirneni

Theses - ALL

Organismal metabolic rate is linked to environmental temperature and oxygen consumption, and as such, may be a useful predictor of extinction risk during major climate- driven crises. However, metabolic attributes can be quantified in many ways, highlighting differing aspects of organisms’ ecology. Here, we estimate resting whole-body and mass-specific metabolic rates in post-Carboniferous bivalve taxa using body size and seawater paleotemperature to assess how metabolic rate determines survival both during and outside of intervals of rapid climate warming, or ‘hyperthermals’. Accounting for the effects of geographic range size, we find a pattern of preferential extinction of bivalves with lower total …

Investigating The Formation Of The Zirconium-Rich Lithologies Of The Grenville Province Using Zircon Thermometry Of Granitoids From The Adirondack Mountains, John St. Denny

Theses - ALL

The Grenville Province (1200-980 Ma) is known to consist of many rocks which are abundant in zircon. This is seen by the large size of Grenville-age zircons and their abundance in the detrital record. A possible explanation for this is the temperature at which these rocks formed. This hypothesis states that the melts which formed the zircon-rich Grenville lithologies were exceptionally high temperature, enabling them to incorporate a significant amount of zirconium. As it is believed that most zirconium in a melt is incorporated into zircon, a high concentration of zirconium in a magma would crystallize an abundance of zircon. …

Fire Reconstructions In The Far North: Late Holocene Ecological Responses To Fire In Northern Alaska, Lee Frank-Depue

Theses - ALL

Palaeoecological reconstruction can characterize regional fire-regimes and reveal how drivers such as anthropogenic warming and vegetation change influence the fire system. This thesis adds to our knowledge of millennial-scale tundra fire-regimes by creating four new charcoal-based paleoecological records from lake sediment cores on the Alaskan North Slope. Statistical analyses of charcoal accumulation rate (CHAR # particles cm-2 yr-1) at three different size fractions were used to identify centennial-scale variability in biomass burned through time and identify individual fire events. These analyses were coupled with morphological identification and classification of charcoal particles to link charcoal production to hypothesized fuel source. The …

Gauge-Invariant Correlators In Quantum Gravity, Kenneth Ratliff

Dissertations - ALL

Recent successes in Euclidean Dynamical Triangulations (EDT) motivate the further comparison of lattice observables to predictions of general relativity (GR) treated as an effective quantum theory. A particularly promising observable is the two-point function of the scalar curvature, which can be straightforwardly computed on the lattice and which in principle can also be computed from the Einstein-Hilbert path integral. Any such comparison should be between manifestly gauge-invariant observables, and will require that the GR predictions be analytically continued in a gauge-invariant manner to the Euclidean signature of the lattice. In this thesis I present my work toward this goal, namely: …

Development And Application Of Small-Molecule Probes Targeting Ghrelin O-Acyltransferase, Jacob Moose

Dissertations - ALL

Ghrelin is a 28-amino acid peptide hormone that has wide-ranging physiological effects, including on metabolism, adipogenesis, insulin regulation, and addiction. Ghrelin offers an intriguing option for treatment of pathophysiologies related to these effects, as it requires a unique post-translational octanoyl modification to bind and activate its cognate receptor, growth hormone secretagogue 1a (GHSR). The enzyme responsible for this modification, ghrelin O-acyltransferase (GOAT) therefore offers the ability to modulate ghrelin signaling through inhibition of the maturation pathway. Due to a lack of structural or mechanistic information about GOAT, pharmaceutical development of molecules capable of GOAT inhibition has been desired, but few …

Enhancing Security And Robustness Of Contextual Human-Centric Sensing, Jingyu Xin

Dissertations - ALL

The rapid advancements in deep learning and smart hardware have accelerated the development of various automatic human-centric sensing applications. However, the intrusive nature of these sensing applications and the heterogeneity of sensory data pose challenges in real-world deployment. While performance is crucial, ensuring the security and robustness of these applications is equally imperative for their reliable operation. To tackle the challenges associated with security and robustness in human-centric sensing, this dissertation outlines two specific objectives: (1) mitigating false data injection attacks (FDIA) on sensing applications, and (2) establishing a generalized personalization framework for human sensing models. FDIA operates by injecting …

Multimode Metamaterial Ring Resonator As An Entangling Bus For Artificial Atoms, Tianna Carroll

Dissertations - ALL

Circuit quantum electrodynamics (cQED) systems with superconducting qubits coupled to linear microwave resonators are a prominent platform for realizing scalable quantum information processors. Combining cQED architectures with multimode resonators leads to a broad set of applications for performing analog quantum simulation, implementing dense quantum memory, and generating multimode entangled states between physically distant qubits. Microwave resonators in cQED are typically formed from distributed transmission lines that exhibit conventional dispersion with harmonic mode spacing; in such systems, usually only a single resonant mode can be strongly coupled to a qubit. Superconducting metamaterial resonators comprised of lumped circuit elements can be designed …

Numerical Invariants Of Cohen-Macaulay Local And Graded Rings, Richard Francis Bartels

Dissertations - ALL

We characterize different classes of Cohen-Macaulay local rings (R,m, k) with positive Krull di?mension in terms of MCM approximations of finitely-generated R-modules. Assume R has a canonical module. For each finitely-generated R-module M, Auslander’s δ?invariant δR(M) equals the rank of a maximal free direct summand of the minimal MCM approxi?mation XM of M. We have δR(R/m) = 1 if and only if R is a regular local ring. Auslander defined the index of R, denoted index(R), as the infimum of positive integers n such that δR(R/mn ) = 1. When R is Gorenstein, we have index(R) ≤ gℓℓ(R) < ∞, where gℓℓ(R) denotes the generalized Loewy length of R, the smallest positive integer n such that mn ⊆ xR for some system of parameters x for R. We call such a system of parameters a witness to the generalized Loewy length of R. In Chapter 3, we generalize a theorem of Ding, who proved that if R is Gorenstein with infinite residue field k and Cohen-Macaulay associated graded ring grm(R), then gℓℓ(R) = index(R). We prove that if R is a one-dimensional Cohen-Macaulay local ring with finite index and nonzerodivi?sor x of order t with grm(R)-regular initial form x ∗ , then gℓℓ(R) ≤ index(R) +t −1. We use this estimate to derive a formula for the generalized Loewy length of a one-dimensional hypersurface R = kJx, yK/(f). If z is a witness to gℓℓ(R) such that z ∗ is grm(R)-regular, then gℓℓ(R) = ordR(z)+e(R)−1, where e(R) denotes the Hilbert-Samuel multiplicity of R. We compute the generalized Loewy lengths of several families {Rn} ∞ n=1 of one-dimensional hypersurfaces over finite and infinite fields such that gℓℓ(Rn) = index(Rn) for all n ≥ 1 or gℓℓ(Rn) = index(Rn) + 1 for all n ≥ 1. Lastly, we study a graded version of the generalized Loewy length of a Noetherian local ring for Noetherian k-algebras (R,m, k), where k is an arbitrary field and m is the irrelevant ideal of R. This invariant is called the generalized graded length of R and denoted ggl(R). After determining bounds for ggl(R) in terms of gℓℓ(R) and the degrees of generators for R, we compute the generalized graded length of numerical semigroup rings. We also characterize witnesses to the generalized graded length of numerical semigroup rings for semigroups with two generators. In Chapter 4, we study criteria for when an MCM module over a Gorenstein complete local ring R is stably isomorphic to an MCM approximation of a finitely-generated R-module of some fixed positive codimension r. If this condition holds for an MCM R-module M, we say with Kato that M satisfies the SCr-condition. If this condition holds for every MCM R-module, we say that R satisfies the SCr-condition. Only the SC1- and SC2- conditions have been characterized for Gorenstein complete local rings R. Kato proved that R satisfies the SC1-condition if and only if R is a domain, and R satisfies the SC2-condition if and only if R is a UFD. For rings of dimension d ≥ 3 and 3 ≤ r ≤ d, we prove an inductive criterion for when an MCM R-module satisfies the SCr-condition when its first syzygy module Ω1 R (M) satisfies the SCr−1-condition. We use this criterion to prove the equivalence of the SCd- and SCd−1-conditions for Gorenstein complete local rings of dimension d ≥ 3 that remain UFDs when factoring out certain regular sequences of length d −2.

Investigating Holography Using Classical And Quantum Simulations, Goksu Can Toga

Dissertations - ALL

In this thesis, we aim to develop classical and quantum simulations to test holography. Holography can be thought of in its most basic form as a duality that relates a d + 1 dimensional theory to a d dimensional one and the most famous holographic correspondence is the AdS/CFT duality where d + 1 dimensional weakly coupled gravity theory is related to a d dimensional CFT. We start by developing lattice simulations for the N = 4 super Yang-Mills model and explore an improved supersymmetric lattice action showing that it is free of the lattice artifacts that plagued earlier lattice …

Directional Dopant Migration By ‘Atomic Trapping’ In Core/Multi-Shell Quantum Dots, Chun Chu

Dissertations - ALL

The study of transition metal ion-doped semiconductor nanocrystals (NCs) has attracted increasing attention due to their unique optical, electronic, and magnetic properties which sparked considerable interest towards a wide range of applications in material science, renewable energy and biological systems. Besides the size- and shape-dependent behavior, doped nanomaterials exhibit new and/or enhanced optical properties, which are sensitive to the dopant location or dopant distribution throughout the solid crystal lattice. Our work primarily focuses on understanding and elucidating the mechanism of dopant ion migration inside the NCs during post-synthetic treatments, such as shell passivation and high-temperature annealing. Mn(II) dopants migration behavior …

Overcoming Controls And Noise Challenges For High Power Interferometric Gravitational-Wave Detectors, Elenna Capote

Dissertations - ALL

In August 2017, the Advanced LIGO and Advanced Virgo detectors made the first coincident detection of gravitational waves from a binary neutron star merger, GW170817. This multi-messenger detection, measured with both gravitational wave detectors and electromagnetic telescopes, emphasized the ability of ground-based gravitational-wave detectors to make exciting astrophysical discoveries that revolutionize understanding of the universe. In this new era of gravitational-wave astronomy, high detector sensitivity and reliable operation are required to enable more of these exciting detections. Ground-based gravitational-wave observatories are generally limited in sensitivity at low frequency by technical noise, at mid frequency by coating thermal noise, and at …

Defects And Deformation In Passive And Active Structural Glasses, Julia Ann Giannini

Dissertations - ALL

Glasses and disordered granular media represent a class of materials that are quite familiar to us, from the glass in windows and phone screens, to piles of fruits, grains, and sand. Further, living and active systems such as cellular tissues, collections of robots, and even human crowds behave as disordered solids when they are gathered at high enough densities. Despite their ubiquity, there are still many behaviors of these amorphous systems that lack a full understanding. Contrasting crystalline solids, the thermodynamic, vibrational, energetic, and mechanical properties of glasses are not well-characterized by solid state theory. In the case of active …

On Multi-Sensor Adaptive Birth Theory For Labeled Random Finite Sets Tracking, Anthony Trezza

Dissertations - ALL

This dissertation provides a scalable, multi-sensor measurement adaptive track initiation technique for labeled random finite set filters. The lack of a well-defined, systematic approach is problematic for many applications, especially when fusing ambiguous sensor measurements. We begin by showing that a naive solution leads to an exponential number of newborn components in the number of sensors. An efficient solution is derived by formulating a ranked assignment truncation problem. A truncation criterion is established for a labeled multi-Bernoulli random finite set birth density that has a bounded L1 error in the generalized labeled multi-Bernoulli posterior density. This criterion is used to …

Exploring The Mandelbrot Set, James Shirley

Electronic Theses and Dissertations

The Mandelbrot set is a mathematical mystery. Finding its home somewhere be-
tween holomorphic dynamics and complex analysis, the Mandelbrot set showcases
its usefulness in fields across the many realms of math—ranging from physics to nu-
merical methods and even biology. While typically defined in terms of its bounded
sequences, this thesis intends to illuminate the Mandelbrot set as a type of param-
eterization of connectivity itself, specifically that of complex-valued rational maps
of the form z → z² + c. This fully illustrated guide to the Mandelbrot set merges
the worlds of intuition and theory with a series of …

Deformation Mapping And Modeling Of The Aleutian Volcanoes With Insar And Numerical Models, Jiahui Wang

Earth Sciences Theses and Dissertations

Surface deformation mapping is an essential component for comprehensive monitoring of volcanic activities, serving as a vital tool for discerning crucial insights into magma dynamics, storage, and migration for accurate hazard forecasting, assessment, and mitigation. However, monitoring of the volcanic deformation across the Aleutian volcanic arc is usually limited by the lack of terrestrial sensors deployed due to their remote locations and hostile environmental conditions, necessitating alternative methodologies for data acquisition and analysis.

My PhD study aims at precisely mapping the crustal deformation for the Aleutian volcanoes and tracking the evolution of the magmatic system with Interferometric Synthetic Aperture Radar …

The Geology And Geochemistry Of The Western Iron Ore Group Greenstone Belt, Singhbhum Craton, Eastern India, Jordan Wright

Earth Sciences Theses and Dissertations

This thesis presents new data on the origin of the Western Iron Ore Group (W-IOG), a Paleoarchean succession deposited on sialic rocks of the Singhbhum Craton. U-Pb ages from zircons from a tuff overlying the Lower Shales just below a banded iron formation (BIF) pin the age of the section to 3.39 Ga. Unconformably overlying the whole IOG section is the Darjing Group, which contains the Birtola Sandstone (on the basis of this work, now estimated to be 2.35 Ga). The lack of penetrative deformation and low-grade metamorphism makes these rocks excellent subjects for combined radiogenic and stable isotope studies. …

Investigating The Effects Of Suspended Algal Content, Dissolved Oxygen, And Temperature On A High-Frequency Acoustic Attenuation System In A Controlled Laboratory Environment, Noah Watson

Honors Theses

The Single Frequency Acoustic Attenuation System (SFAAS) has been developed at the National Center for Physical Acoustics (NCPA). This system uses acoustic methods to monitor fine suspended sediment concentration in streams. Site-specific calibrations are necessary for this system, and previous research has indicated that algal concentration or dissolved oxygen concentration of water may affect collected data. Temperature, dissolved oxygen concentration, and fluorescence, used as a proxy for algal concentration, were monitored during this system’s use, and calibrations were derived to account for the effect of each of these variables on acoustic measurements. It has been shown that temperature has a …

Timber And Tornadoes: A Journalistic View Of Mississippi's Escalating Climate Challenge, Alice Ann Hollingsworth, Alice Ann Hollingsworth

Honors Theses

Timber and Tornadoes: A Journalistic View of Mississippi’s Escalating Climate Challenges is a project which explores the impact of climate change on the state of Mississippi and its industries. Specific areas of interest were the recent onslaught of wind disasters including tornadic activity and hurricanes as well as the impact of weather events on the timber and forestry industries in the state. This project involved interviews of industry professionals as well as academic experts. In addition, interview questions and necessary supplemental context were developed using significant background research. Emphasizing the potential challenges that climate change will present for the state …

Climate Change In Mississippi: A Journalistic Exploration Of Education And Activism, Kala Nance

Honors Theses

Climate Change in Mississippi: A Journalistic Exploration of Education and Activism takes an investigative, journalistic approach toward climate change in Mississippi. Specifically, how education and awareness have a direct impact on Mississippi industries, people and legislation. The project explored the level of acknowledgement of climate change across the state, and how certain individuals used advocacy to encourage education about climate change to raise awareness of the severity of the situation. This project includes interviews with university professors and researchers, non-profit organizations, educational groups and working individuals in some of Mississippi’s largest areas of employment. Additionally, this project draws on research …

Manipulative, Dark, And Unethical Design Practices In Ui & Ux Design, Ryan Edward Brown

Honors Theses

This thesis examines the pervasive and detrimental effects of manipulative user interface and user experience design (UI/UX) practices on individuals and society. Focusing on three critical areas – accessibility, dark patterns, and polarization – the study employs a mixed-methods approach, combining findings from a comprehensive literature review, an analysis of specific design patterns and methods, and a survey of user experiences.
The literature review covers topics such as the importance of accessibility in design education, the prevalence of dark patterns in mobile and desktop sites, the role of personalization algorithms in shaping user experiences, and the formation of echo chambers …

Robust Prediction Of Charpy Toughness Of Additively Manufactured Kovar Using Deep Convolutional Neural Networks, Nathan R. Bianco

Mathematics & Statistics ETDs

Understanding the reason for mechanical failures of manufactured parts in their operating environments is critical to prevention of future failures. However, in-situ post-mortem evaluation of physical properties, such as fracture toughness, is time consuming and alters the condition of the material, leading to potentially misleading findings. In this study, additively manufactured test coupons were produced over a wide range of process conditions to test the impact toughness of a material. The Charpy V-Notch toughness was measured on over 200 samples alongside corresponding optical images of both sides of the fracture surface. Convolutional neural network models were trained to correlate fracture …

A Weather Radar Analysis Of The Effects Of The Albuquerque Urban Area On Thunderstorms From 2001 To 2020, Alexandra Jane Vivier

Geography ETDs

Urban areas have been found to affect the atmosphere locally through changes in emissions, thermal properties, the addition of moisture, and changes in airflow patterns. This study assessed the relationship between urban areas in central New Mexico and thunderstorm intensity and duration between 2001 and 2020. Weather radar data was used to derive thunderstorm events, as it is well-suited to fast-changing thunderstorm conditions. Regression analyses were used to determine the relationship between developed land cover and thunderstorm intensity and duration, while controlling for factors such as elevation, aspect, and near-surface temperatures. It was found that developed land cover was statistically …