Physical Sciences and Mathematics Commons^™

Finding Torsion-Free Groups Which Do Not Have The Unique Product Property, Lindsay Jennae Soelberg

Theses and Dissertations

This thesis discusses the Kaplansky zero divisor conjecture. The conjecture states that a group ring of a torsion-free group over a field has no nonzero zero divisors. There are situations for which this conjecture is known to hold, such as linearly orderable groups, unique product groups, solvable groups, and elementary amenable groups. This paper considers the possibility that the conjecture is false and there is some counterexample in existence. The approach to searching for such a counterexample discussed here is to first find a torsion-free group that has subsets A and B such that AB has no unique product. We …

An Algorithm For Symbolic Computing Of Singular Limits Of Dynamical Systems, Dane Jordan Bjork

Theses and Dissertations

The manifold boundary approximation method, MBAM is a new technique used in approximating systems of equations using parameter reduction. This method and other approximation methods are introduced and described. Several current issues in performing MBAM are discussed in further detail. These issues significantly slow down the process of MBAM and create a barrier of entry for those wishing to use the method without a strong background in mathematics. A solution is proposed to automatically reparameterize models and evaluate specific types of variables approaching limits -- significantly speeding up the process of MBAM. An implementation of the solution is discussed.

Congruences For Fourier Coefficients Of Modular Functions Of Levels 2 And 4, Eric Brandon Moss

Theses and Dissertations

We give congruences modulo powers of 2 for the Fourier coefficients of certain level 2 modular functions with poles only at 0, answering a question posed by Andersen and Jenkins. The congruences involve a modulus that depends on the binary expansion of the modular form's order of vanishing at infinity. We also demonstrate congruences for Fourier coefficients of some level 4 modular functions.

Data Assimilation In The Boussinesq Approximation For Mantle Convection, Shane Alexander Mcquarrie

Theses and Dissertations

Many highly developed physical models poorly approximate actual physical systems due to natural random noise. For example, convection in the earth's mantle—a fundamental process for understanding the geochemical makeup of the earth's crust and the geologic history of the earth—exhibits chaotic behavior, so it is difficult to model accurately. In addition, it is impossible to directly measure temperature and fluid viscosity in the mantle, and any indirect measurements are not guaranteed to be highly accurate. Over the last 50 years, mathematicians have developed a rigorous framework for reconciling noisy observations with reasonable physical models, a technique called data assimilation. …

Mirror Symmetry For K3 Surfaces With Non-Symplectic Automorphism, Christopher James Bott

Theses and Dissertations

Mirror symmetry is the phenomenon, originally discovered by physicists, that Calabi-Yau manifolds come in dual pairs, with each member of the pair producing the same physics. Mathematicians studying enumerative geometry became interested in mirror symmetry around 1990, and since then, mirror symmetry has become a major research topic in pure mathematics. One important problem in mirror symmetry is that there may be several ways to construct a mirror dual for a Calabi-Yau manifold. Hence it is a natural question to ask: when two different mirror symmetry constructions apply, do they agree?We specifically consider two mirror symmetry constructions for K3 surfaces …

Measuring The Interaction And Cooperativity Between Ionic, Aromatic, And Nonpolar Amino Acids In Protein Structure, Mason Scott Smith

Theses and Dissertations

Protein folding studies have provided important insights about the key role of non-covalent interactions in protein structure and conformational stability. Some of these interactions include salt bridges, cation-π, and anion-Ï€ interactions. Understanding these interactions is crucial to developing methods for predicting protein secondary, tertiary, quaternary structure from primary sequence and understanding protein-protein interactions and protein-ligand interactions. Several studies have described how the interaction between two amino acid side chains have a substantial effect on protein structure and conformational stability. This is under the assumption that the interaction between the two amino acids is independent of surrounding interactions. We are interested …

Use Of Phase And Amplitude Gradient Estimation For Acoustic Source Characterization And Localization, Joseph Scott Lawrence

Theses and Dissertations

Energy-based acoustic quantities provide vital information about acoustic fields and the characterization of acoustic sources. Recently, the phase and amplitude gradient estimator (PAGE) method has been developed to reduce error and extend bandwidth of energy-based quantity estimates. To inform uses and applications of the method, analytical and experimental characterizations of the method are presented. Analytical PAGE method bias errors are compared with those of traditional estimation for two- and three-microphone one-dimensional probes. For a monopole field when phase unwrapping is possible, zero bias error is achieved for active intensity using three-microphone PAGE and for specific acoustic impedance using two-microphone PAGE. …

Image Source Modeling Of Time Reversal For Room Acoustics Applications, Michael Hunter Denison

Theses and Dissertations

Time Reversal (TR) is a technique that may be used to focus an acoustic signal at a particular point in space. While many variables contribute to the quality of TR focusing of sound in a particular room, the most important have been shown to be the number of sound sources, signal bandwidth and absorption properties of the medium [Ribay et al., J. Acoust. Soc. Am. 117(5), 2866-2872 (2005)]. However, the effect of room size on TR focusing has not been explored. Using the image source method algorithm proposed by Allen and Berkley [J. Allen and D. A. Berkley, J. Acoust. …

Strontium Isotopes-A Tracer For Dust And Flow Processes In An Alpine Catchment, Colin Andrus Hale

Theses and Dissertations

Stream chemistry changes in response to snowmelt, but does not typically reflect thechemistry of the snowpack. This suggests that flow processes between snowmelt and streamsystem, such as interactions with the soil and bedrock, have an important control on waterchemistry and highlight the complex flow pathways from the snowpack to stream. To investigateflow processes in the upper Provo River watershed, northern Utah, we sampled three sites on theriver ~20 times per year during 2016 and 2017. The sites, from highest elevations to lowest wereSoapstone, Woodland, and Hailstone, corresponding to locations of active stream gauges. Toidentify possible water sources to the stream …

Examining Multimorbidities Using Association Rule Learning, Kaylee Dudley

Undergraduate Honors Theses

All insurance companies, regardless of the kind of insurance they offer, do their best to predict the future by comparing current to historical information. Any statistically significant correlation, regardless of expectations and hidden factors, can help to actuarially model future behavior. Using deidentified data from over 6 million health insurance policies over one year, we looked for any significant groupings of medical issues. The medical issues are defined based on the commercial “Episode Treatment Groups” (ETGs) classification, and our claims contain 347 different ETGs. We performed different kinds of analysis, including Bayesian posterior cluster analysis, k-means cluster analysis, and association …

Application Of The Entropy Concept To Thermodynamics And Life Sciences: Evolution Parallels Thermodynamics, Cellulose Hydrolysis Thermodynamics, And Ordered And Disordered Vacancies Thermodynamics, Marko Popovic

Theses and Dissertations

Entropy, first introduced in thermodynamics, is used in a wide range of fields. Chapter 1 discusses some important theoretical and practical aspects of entropy: what is entropy, is it subjective or objective, and how to properly apply it to living organisms. Chapter 2 presents applications of entropy to evolution. Chapter 3 shows how cellulosic biofuel production can be improved. Chapter 4 shows how lattice vacancies influence the thermodynamic properties of materials. To determine the nature of thermodynamic entropy, Chapters 1 and 2 describe the roots, the conceptual history of entropy, as well as its path of development and application. From …

Evaluating The Usability Of Two-Factor Authentication, Kendall Ray Reese

Theses and Dissertations

Passwords are the dominant form of authentication on the web today. However,many users choose weak passwords and reuse the same password on multiple sites, thus increasing their vulnerability to having their credentials leaked or stolen. Two-factor authentication strengthens existing password authentication schemes against impersonation attacks and makes it more difficult for attackers to reuse stolen credentials on other websites. Despite the added security benefits of two-factor authentication, there are still many open questions about its usability. Many two-factor authentication systems in widespread usage today have not yet been subjected to adequate usability testing. Previous comparative studies have demonstrated significant differences …

Probabilistic Programming For Theory Of Mind For Autonomous Decision Making, Iris Rubi Seaman

Theses and Dissertations

As autonomous agents (such as unmanned aerial vehicles, or UAVs) become more ubiquitous, they are being used for increasingly complex tasks. Eventually, they will have to reason about the mental state of other agents, including those agents' beliefs, desires and goals – so-called Theory of Mind – and make decisions based on that reasoning. We describe increasingly complex theory of mind models of a UAV pursuing an intruder, and show that (1) there is a natural Bayesian formulation to reasoning about the uncertainty inherent in our estimate of another agent's mental state, and that (2) probabilistic programming is a natural …

Development Of Affinity Monoliths In 3d Printed Microfluidic Devices For Extraction Of Preterm Birth Biomarkers, Ellen Kelsey Parker

Theses and Dissertations

Preterm birth (PTB) is defined as birth before the 37th week of pregnancy and affects 15 million infants per year. Presently, there is no clinical test to determine PTB risk. A 3D printed microfluidic device is being developed as a clinical test for PTB risk via detection of a panel of biomarkers. A significant step is extraction of the PTB biomarkers from blood serum. In this work, I developed 3D printed microfluidic devices in which monoliths can be polymerized. Using the monolith as a solid support to attach antibody, I show that ferritin, one of the PTB biomarkers, can be …

Network Specializations, Symmetries, And Spectral Properties, Dallas C. Smith

Theses and Dissertations

In this dissertation, we introduce three techniques for network sciences. The first of these techniques is a series of new models for describing network growth. These models, called network specialization models, are built with the idea that networks grow by specializing the function of subnetworks. Using these models we create theoretical networks which exhibit well-known properties of real networks. We also demonstrate how the spectral properties are preserved as the models grow. The second technique we describe is a method for decomposing networks that contain automorphisms in a way that preserves the spectrum of the original graph. This method …

Mercury And Dissolved Organic Matter Dynamics During Snowmelt In A Montane Watershed, Provo River, Utah., Brian Noel Packer

Theses and Dissertations

Mercury (Hg) transport in streams is typically facilitated by dissolved organic matter (DOM), however, the dynamics of Hg and DOM during snowmelt in montane watersheds are poorly understood. Hg transport during snowmelt is widely recognized as a significant source of Hg to downstream lakes and reservoirs, such as Jordanelle Reservoir where fish consumption advisories are in effect due to elevated Hg concentrations in certain species of fish. For this study, total mercury (THg), methylmercury (MeHg), and DOM samples were collected at three sites in the upper Provo River, northern Utah, during the 2016 and 2017 water years. To evaluate Hg …

The Relationship Between Urban Tree Lai And Urban Heat, Amanda Sheepherd, Dr. Ryan Jensen

Journal of Undergraduate Research

It is well known that urban areas are warmer than the surrounding rural areas, with various negative (though sometimes not immediately perceived) consequences for urban residents and the environment. As the world’s human population becomes increasingly urban, methods of mitigating urban heat become more imperative to explore. Though not nearly as abundant as in many natural environments, trees are fairly common in urban areas and can be utilized to offset urban heat. Studying the cooling effects of trees on the surrounding areas can further our understanding of the relationship between trees and temperature. Leaf Area Index (LAI) is a specific …

Patterns Of The Past: Mountain Hemlock And Pacific Northwest Climate, Aaron Snow, Dr. Matthew Bekker

Journal of Undergraduate Research

In July, 2016, I had the opportunity to attend the North American Dendroecological Fieldweek (NADEF) at Mount Rainier National Park, Washington. NADEF organizes the attendees into five different groups to undergo specific research projects all having to do with tree rings. My group, the intro group, hiked to the southern side of the park, assembled a chronology of mountain hemlock trees (Tsuga mertensiana), and observed notable attributes of the collected data. Because the fieldweek lasted only seven days, our research was minimal, which was why I applied for an ORCA grant in order to take the research to …

Addressing The Regulator's Dilemma: A Self Drive Framework For Balancing Safety And Innovation, Craig Maughan

Brigham Young University Prelaw Review

Policymakers are tasked with creating regulations that responsibly oversee the growth and deployment of emerging technologies. I argue that the SELF DRIVE Act, currently being deliberated in Congress, offers one such intelligent regulatory structure for autonomous vehicles: it prioritizes public safety over adherence to outdated requirements, giving innovators greater freedom to field-test new designs. More importantly, I examine how key principles of the SELF DRIVE Act should be applied to other emerging technologies currently facing regulatory roadblock. Specifically, I suggest the drone industry be subject to regulatory changes that incentivize safety, allow exploration, and anticipate future growth. Such regulations allow …

Constraining Kura And South Caspian Basin Maikop Source Rock Stratigraphy, Deposition, And Timing Using Chemostratigraphy Of Redox-Sensitive Metals And Re-Os Geochronology, Alex M. Washburn

Theses and Dissertations

The Oligocene-Miocene Maikop Series in the South Caspian and Kura Basins is the key petroleum source rock for both offshore and onshore petroleum development in Azerbaijan. The Maikop is a thick (up to 3 km) succession of silty mudstones containing up to 15% total organic carbon (TOC), but is greatly lacking diagnostic microfaunal assemblages useful for dating and stratigraphically constraining the deposition of the mudstone. Current stratigraphic constraints relying on microfaunal assemblages, radiostratigraphy, and chemostratigraphy are robust, but key information is still missing. This study adds numerical age data to Maikop stratigraphy through Re-Os geochronology. Of five sample suites analyzed …

Subword Spotting And Its Applications, Brian Lafayette Davis

Theses and Dissertations

We propose subword spotting, a generalization of word spotting where the search is for groups of characters within words. We present a method for performing subword spotting based on state-of-the-art word spotting techniques and evaluate its performance at three granularitires (unigrams, bigrams and trigrams) on two datasets. We demonstrate three applications of subword spotting, though others may exist. The first is assisting human transcribers identify unrecognized characters by locating them in other words. The second is searching for suffixes directly in word images (suffix spotting). And the third is computer assisted transcription (semi-automated transcription). We investigate several variations of computer …

Subword Spotting And Its Applications, Brian Lafayette Davis

Theses and Dissertations

We propose subword spotting, a generalization of word spotting where the search is for groups of characters within words. We present a method for performing subword spotting based on state-of-the-art word spotting techniques and evaluate its performance at three granularitires (unigrams, bigrams and trigrams) on two datasets.We demonstrate three applications of subword spotting, though others may exist. The first is assisting human transcribers identify unrecognized characters by locating them in other words. The second is searching for suffixes directly in word images (suffix spotting). And the third is computer assisted transcription (semi-automated transcription). We investigate several variations of computer assisted …

End-To-End Full-Page Handwriting Recognition, Curtis Michael Wigington

Theses and Dissertations

Despite decades of research, offline handwriting recognition (HWR) of historical documents remains a challenging problem, which if solved could greatly improve the searchability of online cultural heritage archives. Historical documents are plagued with noise, degradation, ink bleed-through, overlapping strokes, variation in slope and slant of the writing, and inconsistent layouts. Often the documents in a collection have been written by thousands of authors, all of whom have significantly different writing styles. In order to better capture the variations in writing styles we introduce a novel data augmentation technique. This methods achieves state-of-the-art results on modern datasets written in English and …

Signal Structure For A Class Of Nonlinear Dynamic Systems, Meilan Jin

Theses and Dissertations

The signal structure is a partial structure representation for dynamic systems. It characterizes the causal relationship between manifest variables and is depicted in a weighted graph, where the weights are dynamic operators. Earlier work has defined signal structure for linear time-invariant systems through dynamical structure function. This thesis focuses on the search for the signal structure of nonlinear systems and proves that the signal structure reduces to the linear definition when the systems are linear. Specifically, this work: (1) Defines the complete computational structure for nonlinear systems. (2) Provides a process to find the complete computational structure given a state …

Adaptive Fluid Simulation Using A Linear Octree Structure, Sean A. Flynn

Theses and Dissertations

An Eulerian approach to fluid flow provides an efficient, stable paradigm for realistic fluid simulation. However, its traditional reliance on a fixed-resolution grid is not ideal for simulations that simultaneously exhibit both large and small-scale fluid phenomena. Octree-based fluid simulation approaches have provided the needed adaptivity, but the inherent weakness of a pointer-based tree structure has limited their effectiveness. We present a linear octree structure that provides a significant runtime speedup using these octree-based simulation algorithms. As memory prices continue to decline, we leverage additional memory when compared to traditional octree structures to provide this improvement. In addition to reducing …

Fitting Als Reflectance Data Using Python, R. Steven Turley

Faculty Publications

This article describes how to use the python refl library in https://bitbucket.org/steve_turley/reflectance-fitting to fit thin film reflectance data from the Advanced Light Source (ALS) at Lawrence Berkeley National Labs. It uses data taken for a thin film of aluminum capped by a thin film of aluminum fluoride on a silicon nitride substrate. The single fit in the example shown here shows the importance of taking into account the oxidation of the aluminum layer as part of the fit.

Blockchain: Technical Review, Evan D. Poff

Marriott Student Review

This review of blockchain technology accompanies the article "Strategic Implications of Blockchain."

Buzzwords, Evan D. Poff

Marriott Student Review

This feature will explain the following buzzwords:

• Blockchain
• Cryptocurrency
• Work-Life Integration
• Passive Equities
• Risk-Adjusted Returns

Dynamics For A Random Differential Equation: Invariant Manifolds, Foliations, And Smooth Conjugacy Between Center Manifolds, Junyilang Zhao

Theses and Dissertations

In this dissertation, we first prove that for a random differential equation with the multiplicative driving noise constructed from a Q-Wiener process and the Wiener shift, which is an approximation to a stochastic evolution equation, there exists a unique solution that generates a local dynamical system. There also exist a local center, unstable, stable, centerunstable, center-stable manifold, and a local stable foliation, an unstable foliation on the center-unstable manifold, and a stable foliation on the center-stable manifold, the smoothness of which depend on the vector fields of the equation. In the second half of the dissertation, we show that any …

A Geophysical And Geological Analysis Of A Regressive-Phase Lake Bonneville Deposit, Pilot Valley, Nv, Katelynn Marie Smith

Theses and Dissertations

Pilot Valley, located in the eastern Basin and Range, north of Wendover, UT, contains numerous shorelines and depositional remnants of late Pleistocene Lake Bonneville. These remnants present classic ground penetrating radar (GPR) targets due to their coherent stratification, low clay, low salinity, and low moisture content. Three-dimensional (3D) GPR imaging can resolve fine-scale stratigraphy of these deposits down to a few centimeters. While lake levels fluctuated due to flooding events, climatic changes were the dominant factor in controlling lake levels. In Pilot Valley, the paleowind entered from the northwest, with storms coming from the south, and circulated clockwise around the …