Physical Sciences and Mathematics Commons^™

Simulation Study On Count Data Based On Double Poisson Distribution, Chao Ma

Theses and Dissertations

This thesis delves into the double Poisson distribution. Regression based on the double Poisson distribution, as proposed by Efron in 1986, offers an alternative approach that allows for more accurate regression models when dealing with discrete data that exhibit either over- or under-dispersion compared to the Poisson distribution. In this thesis, two methods of calculating the exact double Poisson density are compared: one utilizes the exact probability with the normalizing constant c(mu, theta) by definition or the “finite sum” method, while the other employs an approximation of the normalizing constant c(mu, theta). Furthermore, a simulation was …

Unraveling The Structure And Star Formation History Of Polar Ring Galaxies, Kyle Lackey

Theses and Dissertations

Polar ring galaxies (PRGs) are a fascinating subgroup of early-type galaxies (ETGs) consisting of a central host galaxy - typically E/S0 - surrounded by a ring of gas, dust and stars orbitting perpedicular to the major axis of that host. In order to estimate physical properties and origins of five such objects taken from Whitmore's 1990 PRC catalog, we conduct a photometric study in optical and infrared wavebands. Data are taken from SDSS, GMOS-S, HST-WFPC2, and SST-IRAC. Each object was decomposed into a host galaxy bulge, host galaxy disk, and polar ring, and each component was fit with a Sersic …

Automated Data-Flow Optimization For Digital Signal Processors, Madushan Thilina Abeysinghe

Theses and Dissertations

Digital signal processors (DSP), which are characterized by statically-scheduled Very-Long Instruction Word architectures and software-defined scratchpad memory, are currently the go-to processor type for low-power embedded vision systems, as exemplified by the DSP processors integrated into systems-on-chips from NVIDIA, Samsung, Qualcomm, Apple, and Texas Instruments. DSPs achieve performance by statically scheduling workloads, both in terms of data movement and instructions. We developed a method for scheduling buffer transactions across a data flow graph using data-driven performance models, yielding a 25% average reduction in execution time and a reduction of up to 85% DRAM utilization for randomly-generated data flow graphs. We …

New Techniques For Studying Ocean Eddy Dynamics In The Arabian Sea And The Gulf Of Mexico, Paul Andrew Ernst

Theses and Dissertations

Coherent vortices known as eddies are ubiquitous throughout the world’s oceans and are responsible for modulating regional climates via the transfer of heat, momentum, and salt. Two regions where eddies are particularly prominent are the Arabian Sea (AS) and the Gulf of Mexico (GoM). This dissertation advances the study of eddies in these regions by developing and employing new techniques in conjunction with remotely sensed data and high-resolution ocean models. These models focus particularly on lesser-studied eddy components at the subsurface and the submesoscale (below 25 km in radius).

The first component of this dissertation focuses on the Lakshadweep High …

The Control And Operation Of Optical Sensors For Environmental Monitoring With Microcontrollers As Data Acquisition And Processing Systems, Zechariah Kitzhaber

Theses and Dissertations

Phytoplankton are microscopic unicellular organisms, and they are ubiquitous in marine and freshwater environments across the globe. They play a critical role in primary production, carbon fixation, and O2 production through photosynthesis. Phytoplankton comprise an abundant variety of genera and species, and the taxonomic makeup of a community can be an important indicator of environmental health. Phytoplankton are spatially and taxonomically diverse; they change in size and cellular content throughout their lifetime, and they can also alter their pigmentation in response to environmental factors, so it is important to understand the variability in size and pigmentation between individuals of the …

Scene Text Detection And Recognition Via Discriminative Representation, Liang Zhao

Theses and Dissertations

Scene texts refer to arbitrary text presented in an image captured by a camera in the real world. The tasks of scene text detection and recognition from complex images play a crucial role in computer vision, with potential applications in scene understanding, information retrieval, robotics, autonomous driving, etc. Despite the notable progress made by existing deep-learning methods, achieving accurate text detection and recognition remains challenging for robust real-world applications. The challenges in scene text detection and recognition stem from: 1) diverse text shapes, fonts, colors, styles, layouts, etc.; 2) countless combinations of characters with unfixed attributes for complete detection, coupled …

Global Well-Posedness Of Nonlocal Differential Equations Arising From Traffic Flow, Thomas Joseph Hamori

Theses and Dissertations

Macroscopic traffic flow models describe the evolution of a function ρ(t, x), which represents the traffic density at time t and location x according to a differential equation (typically a conservation law). Numerous models have been introduced over the years which capture the phenomenon of shock formation in which the solution develops a discontinuity. This presents difficulties from the standpoint of mathematical analysis, necessitating the consideration of weak solutions. At the same time, this undesirable mathematical behavior corresponds to unsafe driving conditions on real roadways, in which the heaviness of traffic may vary abruptly and dramatically. This thesis introduces and …

Electronic Structure Investigation Of Photoswitch-Embedded Organic Frameworks And External Electric Field Effects On Carbon Dioxide, Austin Hill

Theses and Dissertations

Metal- and Covalent-Organic Frameworks (MOFs and COFs, respectively) are chemically versatile systems that have diverse applications, ranging from drug delivery to energy storage. This versatility is due to the highly tunable nature of organic frameworks, which utilize metal clusters, chemically diverse metals, and organic ligands. Researchers have recently demonstrated how MOFs and COFs can be remotely tuned through the use of photochromic organic linkers and light (Martin, et al., 2022). The implications of these findings are significant and have numerous applications, primarily in optical switching and energy storage. However, the photochromic mechanism within the organic framework must be investigated, which …

Assessing Multi-Annual Phytoplankton Community Compositions And Biomass Across Tidal Creek And Open Water Estuarine Habitats In South Carolina, Shannon Elizabeth Powers

Theses and Dissertations

The urbanization of coastal environments in recent decades has caused an accelerating increase in nutrient-rich runoff from the landscape. The presence of these excess nutrients in the aquatic environment can result in degradation of water quality and harmful algal blooms. In South Carolina (SC), coastal development continues to threaten the resiliency of salt marsh estuaries, especially in combination with other stressors like climate change and sea level rise. Estuaries are important nurseries and habitats for fisheries and ecotourism. The South Carolina Estuarine and Coastal Assessment Program (SCECAP) is an ongoing monitoring program that assesses the habitat condition along the coast …

Impaired Waters: New Treatments And Improved Methods For Pfas And Algae Toxins, Alexandria Forster

Theses and Dissertations

Per- and polyfluoroalkyl substances (PFAS) are high-profile environmental contaminants, many having long persistence in the environment and widespread presence in humans and wildlife. Following phase-out of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in North America and restrictions in Europe, PFAS replacements are now widely found in the environment. While liquid chromatography (LC)-mass spectrometry (MS) is typically used for measurement, much of the PFAS is missed. To more comprehensively capture organic fluorine, we developed sensitive and robust methods using activated carbon adsorption, solid phase extraction, and combustion ion chromatography (CIC) to measure total organic fluorine (TOF) in industrial wastewaters, river …

Feature Engineering For Grain Boundaries And Other Variable-Sized Atom Clusters, C. Braxton Owens

Theses and Dissertations

Obtaining microscopic structure-property relationships for grain boundaries are challenging because of the complex atomic structures that underlie their behavior. This has led to recent efforts to obtain these relationships with machine learning, but representing a grain boundary structure in a manner suitable for machine learning is not a trivial task. There are three key steps common to property prediction in grain boundaries and other variable-sized atom clustered structures. These are: (1) describe the atomic structure as a feature matrix, (2) transform the variable-sized feature matrices of different structures to a fixed length common to all structures, and (3) apply machine …

Wind-Carved Wonders: An Aerial Study Of Yardangs In The Puna, Argentina Using Drone And Satellite Imagery, Derek Gordon Ashliman

Theses and Dissertations

Yardangs, elongated landforms sculpted by wind erosion, are prominent features in the Campo de Piedra Pomez (CPP) region of the Puna-Altiplano Plateau, Argentina. This study explores their formation and evolution through the examination of a 6 km by 0.5 km area captured in 2019 and a 5 km by 0.5 km area in 2024. High-resolution drone imagery and satellite data were employed to classify and quantify yardangs, gravel, and underlying bedrock across a vast study area. The research reveals a variation in yardang distribution and morphology from northwest (windward) to southeast (leeward), noting a significant decrease in yardang and bedrock …

Dynamics Of Dissolved And Particulate Trace Metals In A Snowmelt-Dominated Stream, Provo River, Utah, Usa, Kendra Louise Caskey

Theses and Dissertations

Trace element concentrations vary substantially during snowmelt runoff, with changes in the dissolved versus particulate fractions potentially impacting their movement at the catchment scale. To investigate trace element behavior in a snowmelt dominated stream, we measured concentrations in different size fractions in the Provo River (northern Utah, USA). We sampled the river at three locations during water years 2016-2018 and 2021-2023 for trace metal and major ion concentrations. During the final year, we collected three fractions (unfiltered, <0.45 µm filtered, and <0.22 µm filtered) for trace metal chemistry and calculated the particulate concentration as the difference between the unfiltered and 0.45 µm fraction. Stream measurements included pH, discharge, turbidity, and fluorescent dissolved organic matter (fDOM). We also sampled water sources (soil water, ephemeral streams, and snowpack) to compare trace metal concentrations across the watershed with the stream. Trace metal (Al, Be, Fe, Pb) and rare earth element (REE +Y) concentrations had the highest particulate and dissolved concentrations during snowmelt runoff. In contrast, major cations were primarily found in the dissolved fraction with lowest concentrations during snowmelt runoff. Major cation and particulate metal concentrations increased from upstream to downstream. The increased trace metal and REE + Y concentrations during snowmelt relative to baseflow may be explained by increased discharge and associated increased turbidity and fDOM. A comparison with water sources suggests that dissolved and particulate trace metals in the stream are sourced from flushed soil water, as trace metal transport through the watershed is facilitated by suspended sediment and dissolved organic matter. For most of the trace metals and REE +Y, concentrations were similar in the <0.45 µm and <0.22 µm fractions. Yet Al tended to have higher concentrations in the <0.45 µm fraction, suggesting a colloidal form of Al between 0.22 µm and 0.45 µm may exist. Differences from upstream to downstream may be related to changes in pH, from ~7 at the upper site to ~8 at the lower sites, which would change sorption capacity, saturation indices, or speciation. Our study demonstrates that trace metal concentrations are variable during snowmelt as the metals interact with suspended particles or dissolved organic matter and are influenced by changing water chemistry, with implications for understanding water quality impairments in snowmelt-dominated streams.

Deep Learning For Source Localization In A Laboratory Tank, Corey Emerson Dobbs

Theses and Dissertations

Deep learning has been applied to underwater acoustics problems in many forms. One difficulty in applying deep learning techniques to ocean acoustics is the spatially and temporally varying environmental properties. Another challenge is the lack of labeled data for training large networks. The overall goal of this work is to develop deep learning approaches for source localization that can be adaptable to different conditions. In this work, a convolutional neural network was trained on acoustic data measured in a water tank, while the water was at room temperature, to predict source-receiver range. Tests were done to ascertain ideal quantities of …

Linking Geospatial Trends And Geochemical Fingerprints To Anthropogenic Phosphorus Dust Deposition In Subalpine Soils, Austen Michael Lambert

Theses and Dissertations

This study shows that fugitive emissions associated with the surface mining of phosphate rock are a significant phosphorus (P) source to surface soils in northeastern Utah. Phosphorus is a nonrenewable resource essential for all life. Anthropogenic alterations to the P-cycle have led to widespread P pollution, and the unsustainable management of P has led to the threat of global depletion of P resources. Thus, accounting for both natural and anthropogenic flow paths of P is essential for the conservation and pollution reduction of P. One such source of human alteration to the P-cycle is the mining of phosphate rock. Mining, …

The Cofactor Matrix For Optimized Normal Transformations & Real-Time Caustics And Refractions Using Signed Distance Fields, Dane William Christensen

Theses and Dissertations

This thesis contains two distinct manuscripts both focused on real-time rendering research; an abstract for each is provided: 1. We survey methods for mapping normal vectors to a transformed surface with emphasis on the cofactor matrix form. We demonstrate that the cofactor matrix uniquely and correctly supports matrix transformations that are rank deficient or have negative determinants, while also generalizing to operations such as rotation, scaling, translation, and shearing. We derive and demonstrate the completeness of this new convention in contrast to other approaches, while also establishing its computational efficiency benefits. 2. We present SDF volumes as an efficient datastructure …

A Sensitivity Equation Framework For Parameter Estimation In Dynamical Systems, Joshua Newey

Theses and Dissertations

We present a new framework for understanding parameter estimation in dynamical systems. The approach is developed within the modeling approach of continuous data assimilation. We outline the basic assumptions that lead to our derivation. Under these assumptions we show that the parameter estimation turns into a finite dimensional nonlinear optimization problem. We show that our derivation reproduces and extends the algorithm originally developed in [9]. We then implement these methods in three example systems: the Lorenz '63 model, the two-layer Lorenz '96 model, and the Kuramoto Sivashinsky equation. So as to remain sufficiently general, our derivations are largely formal; we …

Pretty Good State Transfer And Fractional Revival In Double Extended Star Graphs, Kellon G. Sandall

Theses and Dissertations

Much research has been done in the realm of quantum walks over networks of qubits. We primarily study a type of graph consisting of a path with two stars connected to the leaves which we call a Double Extended Star. We find that Pretty Good State Transfer can occur in many ways in a Double Extended Star and that Fractional Revival cannot occur in Double Extended Stars except when the length of the path within is one.

Extreme Ultraviolet And Xray Applications Of Carbon Nanotube Devices, Scott Olsen

Theses and Dissertations

The vacuum ultraviolet (VUV), extreme ultraviolet (EUV) and xray ranges of the electromagnetic spectrum have many unique properties and applications, such as medical treatment, photolithography, and astronomical observation. However, these applications require unique optical element designs, setups, and materials. carbon nanotubes (CNTs) are a fascinating material with thermal, mechanical, and chemical properties that may be beneficial for VUV, EUV, and xray applications. They are conductive, can be patterned into high aspect ratio structures, and are stable in high temperature vacuum. In this work, we report several carbon nanotube devices developed for the VUV, EUV, and xray range. These devices include …

Geological And Geophysical Model Of The Sand Wash Extensional Decollement, Utah, Brigham Louis Cardon

Theses and Dissertations

The Sand Wash Fault Zone (SWFZ) in the southern Uinta Basin is a significant extensional fault zone exhibiting complex deformation patterns. Our study integrates detailed structural analyses with a broader tectonic model to elucidate the tectonic evolution of the region. The SWFZ, extending over 34 km with a NW-SE strike, is underlain by an extensional decollement. Substantial deformation is observed in the upper layers, notably within the S2 sandstone of the Eocene Green River Formation. The deformation diminishes with depth, terminating at the oil-rich Mahogany oil shale zone, below which minimal deformation is observed. Our tectonic model, developed primarily through …

Using Neural Networks To Reconstruct Temperature From Fluorescent Data For Use In Bio-Microfluidics, Jacob G. Kullberg

Theses and Dissertations

It has been theorized that Quantum Dots (QD) can solve the temperature sensor issue with microfluidic devices. Quantum Dots are nano-sized semiconducting crystals with a radius of an excited electron-hole pair. When a QD is excited by a short wavelength light, the QD produces fluorescent light. As the temperature of the dot changes, the dot expands and shifts the fluorescent spectrum. Quantum Dots are small enough to be placed inside the microfluidic devices, and a spectrometer can measure the change in fluorescent data. This fluorescent data can be used to create fluorescent images corresponding to the QD temperature. These fluorescent …

Cellular Sorting Of The Dictyostelium Discoideum Slug, Erin Flowerday

Theses and Dissertations

Dictyostelium discoideum (Dd) cells are amoeba cells that feed on soil or plant leaf matter bacteria. They divide freely in the presence of food. When starved, cell division is ended, and cells transition from unicellular to multicellular organisms initiated by a chemoattractant, cyclic adenosine monophosphate (cAMP). This study intricately examines cellular sorting within the Dd slug, focusing on individual cell dynamics. Represented as oriented ellipsoids, these cells maintain constant volume through a viscoelastic structure. Applying force to specific semi-axes reveals predictable deformations, highlighting the relationship between force and deformation rate. Manipulating damping coefficients and spring constants uncovers insights into cell …

Investigating Cloth Sculpting For Simulation Control In Virtual Reality, Matthew S. Bishop

Theses and Dissertations

Artists require control and predictability over physically based simulations to create their required animation. This control can lead to reduced iteration time to get the desired simulation results. Controlling cloth simulations can require manual effort to create goal keyframes for control algorithms to match. Current techniques and research utilize a keyboard and mouse to create these goal keyframes. Other research has looked at using a virtual reality (VR) head-mounted display with controllers to improve the experience of completing similar animation tasks. However, we are not aware of any research that attempts to use VR as a tool to assist artists …

Mapping Urban Tree Canopy Using Publicly Available Satellite Data, Rosemary Mcguinness

Theses and Dissertations

This project addresses the need for accessible, cost-effective tools for quantifying spatial and temporal changes in tree canopy cover in urban areas. Urban tree canopy provides a wide range of ecosystem services, including lowering air temperatures, reducing pollution, and mitigating stormwater runoff. Cities around the world have placed the expansion of their urban forests at the center of their sustainability goals. Consistent and timely data on urban tree canopy is essential for urban greening initiatives to succeed. Existing methods of accessing information about urban tree canopy are highly technical, costly, and labor-intensive, while the freely available source of tree canopy …

Optimizing The Protein Yield Of The Collagen Mimetic Peptide: Col108, Fahmida Akter

Theses and Dissertations

Abstract

The fibril-forming collagen mimetic peptide Col108, produced in E. Coli, has shown potential for innovative biomaterial applications. However, further research is constrained by its limited yield. My study aims to enhance the experimental parameters and has successfully pinpointed rifampicin as an efficient method to boost the production of Col108.

Optimization Of Mass Spectrometry-Based Methods For Low-Input And Spatial Proteomics, Andikan Jones Nwosu

Theses and Dissertations

Eukaryotic cells are highly heterogeneous. These cells are arranged into different compartments, carrying out separate functions and facilitating biological processes. Proteins are the effector biomolecules targeted to subcellular locations that help fulfill specific tasks in living organisms. Spatial proteomics can help unravel molecularly how protein abundance and localization are altered in cells, which is not feasible in traditional bulk-scale proteomics. To achieve this, our lab has developed a miniaturized sample processing platform called nanoPOTS, reduced separation columns' inner diameter to increase ionization efficiency and concentrate analytes for mass spectrometers and optimized data acquisition modes for increasing proteome coverage in spatial …

Enumeration Of Level-K Hypertriangulations, Patrick J. Kaylor

Theses and Dissertations

Triangulations are a classical object in discrete and computational geometry that finds it uses in many other fields, including numerous applications. In this thesis we approach the question of enumerating all hypertriangulations of a point set, the family of tilings introduced by Olarte and Santos in 2022 as induced projections of hypersimplices. Unfortunately, the usual approach to enumeration of trinagulations using flips may not work for hypertriangulations as flip-connectivity is only conjectured for that family even in the two-dimensional case. As a result, we develop a DFS-based algorithm and present its Python implementation that enumerates all hypertriangulations of small point …

Synthesis And Characterization Of Medicinally Privileged Aza Heterocycles, Nneoma James

Theses and Dissertations

Four-membered cyclic amides, commonly known as β-lactams, have played a crucial role in drug discovery research since its discovery by Alexander Fleming in 1928 from Penicillium notatum. The β-lactam antibiotics are broadly effective against several bacterial infections through acylating the transpeptidase involved in cross-linking peptides to form peptidoglycan or periplasmic murein, which is a fundamental constituent of the bacterial cell wall for both the gram-positive (ten or more layers) and gram-negative (one or two layers) bacteria. Although for more than eight decades, β-lactams have been recognized as antibiotics, later, other medicinal activities of β-lactam derivatives have been reported, including lowering …

Chemical Investigation Of The Ethanol Extract Of Tillandsia Usneoides (Spanish Moss), Jakir Hossain

Theses and Dissertations

Tillandsia usneoides in epiphytic bromeliads takes up water through absorptive trichomes on the shoot surface under extreme environmental conditions. Although previous studies revealed the way by which T. usneoides absorbs water and prevents water loss, its water transport remains unclear. Uses of T. usneoides L. have been documented going back to pre-Columbian and late archaic societies. Between the 1800s and 1900s. T. usneoides was utilized in fruit packing and polish, among other industrial goods. In terms of medicine, tillandsia is well-known for treating leucorrhea, rheumatism, ulcers, hemorrhoids, and as an anti-diabetic, emetic, analgesic, purgative, antispasmodic, and diuretic. The chemical composition …

White Light Specular Reflection Data Augmentation For Polyp Detection, Jose Angel Nunez

Theses and Dissertations

Colorectal cancer is among the deadliest cancers, but fortunately, this type of cancer can be prevented. The best current method of prevention is via detecting the bad polyps in the colon in time. Furthermore, the best method we have available to detect these bad polyps is through colonoscopies. Even though a lot of lives have been saved via these methods, it is still not perfect because of human error. Integrating artificial intelligence into colonoscopy procedures is our next evolution in increasing our prevention of colorectal cancer. Polyp detectors are one of the tools brought by advancements in technology that may …