Physical Sciences and Mathematics Commons^™

Survival Analysis: An Exact Method For Rare Events, Kristina Reutzel

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Conventional asymptotic methods for survival analysis work well when sample sizes are at least moderately sufficient. When dealing with small sample sizes or rare events, the results from these methods have the potential to be inaccurate or misleading. To handle such data, an exact method is proposed and compared against two other methods: 1) the Cox proportional hazards model and 2) stratified logistic regression for discrete survival analysis data.

Investigating Mesospheric Mountain Waves And Oh Temperature Dynamics Over Chile, David G. Soward

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Atmospheric gravity waves (GW) occur throughout the atmosphere, propagating from copious sources in the lower atmosphere into the upper neutral atmosphere and ionosphere. There are many sources of GW, most of them are associated with strong weather disturbances which are highly transient in nature. Another source of GW are strong winds blowing over prominent mountains that generate mountain waves (MW.) An important property of all of these waves is that they propagate upwards, carrying large amounts of energy and momentum which can be deposited in the upper atmosphere as the waves saturate and break. The Andes Lidar Observatory (ALO) was …

Hazard Analysis Of A Segment Of Highway Sr-12 Through Bryce Canyon National Park, Southern Utah, Tomsen Reed

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Over 2.6 million people travel along highway SR-12, a National Scenic Byway, through Bryce Canyon in southern Utah each year. This highway is a major thoroughfare for tourists traveling to Bryce Canyon National Park, Grand Staircase-Escalante National Monument, and other scenic attractions. SR-12 is susceptible to rockfall and landslide hazards where it descends from the Paunsaugunt Plateau into Tropic Canyon, and these hazards have potential consequences of economic loss due to travel delays for tourists and commodities, and possible loss of life. Rockfall could have devastating effects at this location because of the traffic volume, sharp turns, low visibility, and …

A Thermochronometric, Microtextural, And Numerical Modeling Approach To Deciphering The Rock Record Of Deformation Processes In The Wasatch And Denali Fault Zones, Robert G. Mcdermott

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fault zones are the primary features that accommodate movement of Earth’s crust, resulting in the formation of mountain belts and damaging earthquakes. Rocks modified by faulting and brought to Earth’s surface by erosion are archives of the mechanical processes involved in earthquakes and(or) aseismic creep. Thermochronometry is a radioisotopic dating system primarily sensitive to temperature and offers a means to constrain dates and rates of thermal processes. Hematite is common in fault zones, amenable to (U-Th)/He (He) thermochronometry, and exhibits distinct microtextures diagnostic of fault zone mechanics. I apply hematite He thermochronometry and microtextural analyses with a suite of other …

Deep Q Learning Applied To Stock Trading, Agnibh Dasgupta

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Developing a strategy for stock trading is a vital task for investors. However, it is challenging to obtain an optimal strategy, given the complex and dynamic nature of the stock market. This thesis aims to explore the applications of Reinforcement Learning with the goal of maximizing returns from market investment, keeping in mind the human aspect of trading by utilizing stock prices represented as candlestick graphs. Furthermore, the algorithm studies public interest patterns in form of graphs extracted from Google Trends to make predictions. Deep Q learning has been used to train an agent based on fused images of stock …

Exact Generalized Voronoi Diagram Computation Using A Sweepline Algorithm, Daniel Marsden

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Voronoi Diagrams can provide useful spatial information. Little work has been done on computing exact Voronoi Diagrams when the sites are more complex than a point. We introduce a technique that measures the exact Generalized Voronoi Diagram from points, line segments and, connected lines including lines that connect to form simple polygons. Our technique is an extension of Fortune’s method. Our approach treats connected lines (or polygons) as a single site.

Water, Fish, And Fire: Interdisciplinary Research On Ecosystem Services And Climate Adaptation, Liana Prudencio

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ecosystem services, or benefits from the environment, are plentiful and vary from place to place. Human activities and climate change have impacted these services in every region of the world. This dissertation explores multiple ecosystem services, from water quality improvement to provisioning of fish and habitat, in multiple and international contexts. The first chapter synthesizes the literature on stormwater management and ecosystem services, finding that research at this intersection has provided many parcel-level studies and frameworks for implementing green infrastructure. The second chapter extends the stormwater management literature by quantifying the impacts of green infrastructure on water quantity and quality …

Delta Hedging Of Financial Options Using Reinforcement Learning And An Impossibility Hypothesis, Ronak Tali

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In this thesis we take a fresh perspective on delta hedging of financial options as undertaken by market makers. The current industry standard of delta hedging relies on the famous Black Scholes formulation that prescribes continuous time hedging in a way that allows the market maker to remain risk neutral at all times. But the Black Scholes formulation is a deterministic model that comes with several strict assumptions such as zero transaction costs, log normal distribution of the underlying stock prices, etc. In this paper we employ Reinforcement Learning to redesign the delta hedging problem in way that allows us …

Pre-Eruptive Evolution Of Izu-Bonin Boninite Melts: Mixing, Cooling, And Crystallization, Jesse L. Scholpp

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Subduction is the geologic process in which one tectonic plate moves beneath another as it sinks into the Earth’s mantle. Subduction initiation in the Izu-Bonin Marianas system is the result of a gravitational failure during which one tectonic plate (the Pacific plate) spontaneously sinks beneath another (the Philippne Sea plate). Fluids released by the sinking plate that caused the overlying mantle to melt by reducing its meltimg temperature, forming the Izu-Bonin Mariana island arc system.

The resulting melts initially have the chemical compositions that are rich in silica and magnesia, and highly depleted in other elements, refered to a boninite …

Job Satisfaction And Employee Turnover Determinants In Fortune 50 Companies: Insights From Employee Reviews From Indeed.Com, Bishal Sainju

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We explored 682176 employee reviews of Fortune 50 companies from Indeed.com using topic discovery techniques like Latent Dirichlet Allocation (LDA) and Structural Topic Modeling (STM) to identify salient aspects in employee reviews and automatically infer latent topics that tend to drive employee satisfaction. We also studied how various satisfaction factors could be related to employee turnover. We discovered important topics in the reviews, including Management and Leadership, Advancement Opportunity, Pay and Benefits, Work-Life Balance, and Culture, which we compare to the five Job Descriptive Index (JDI) facets. Both LDA and STM discovered well-separated and distinguishable topics. We also …

Acquisition, Processing, And Analysis Of Video, Audio And Meteorological Data In Multi-Sensor Electronic Beehive Monitoring, Sarbajit Mukherjee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In recent years, a widespread decline has been seen in honey bee population and this is widely attributed to colony collapse disorder. Hence, it is of utmost importance that a system is designed to gather relevant information. This will allow for a deeper understanding of the possible reasons behind the above phenomenon to aid in the design of suitable countermeasures.

Electronic Beehive Monitoring is one such way of gathering critical information regarding a colony’s health and behavior without invasive beehive inspections. In this dissertation, we have presented an electronic beehive monitoring system called BeePi that can be placed on top …

Micro Grid Control Optimization With Load And Solar Prediction, Shaju Saha

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Using renewable energy can save money and keep the environment cleaner. Installing a solar PV system is a one-time cost but it can generate energy for a lifetime. Solar PV does not generate carbon emissions while producing power. This thesis evaluates the value of being able to make accurate predictions in the use of solar energy. It uses predicted solar power and load for a system and a battery to store the energy for future use and calculates the operating cost or profit in several designed conditions. Various factors like a different place, tuning the capacity of sources, changing buy/sell …

Automation Of Feature Selection And Generation Of Optimal Feature Subsets For Beehive Audio Sample Classification, Aditya Bhouraskar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The last couple of decades have witnessed an abnormal phenomenon of reduction in the bee population, this is a serious matter of concern as three out of four crops available globally have honey bee as their sole pollinator causing significant economic losses and an unbalance in the ecosystem. There have been many theories about the cause of bee colony collapses such as parasites, pesticides and poor nutrition however conclusive evidence of this phenomenon is yet to be identified.

Human inspection of beehives requires precision. It takes an experienced beekeeper to determine the health of a hive by the sounds generated …

Effects Of The Radiation Belt On The Plasmasphere Distribution, Stefan Thonnard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study examines the interaction of plasma, ions and electrons created by Solar illumination in the Earth’s upper atmosphere, that travels along magnetic field lines filling the Plasmasphere, and the naturally occurring trapped particles known as the outer radiation belt. Although these two science disciplines have been largely worked independent of each other due the vast differences in the energy of the particles, recent satellite observations indicate a large population of particles with lower energy and greater mass also exist in the outer radiation belt. This study shows that during conditions of low solar output in an 11-year cycle, these …

Embedded-Atom-Method Modeling Of Alkali-Metal/Transition-Metal Interfaces, Jake D. Christensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Understanding the thermal properties of materials is essential to using those materials for technological advancement which can benefit civilization. For example, it has been proposed that essential components of tokamaks, devices which perform fusion, be made out of tungsten with a thin layer of lithium on the surface. To that end, this thesis seeks to calculate the thermal properties of a layer of alkali atoms, like lithium and sodium, on tungsten and molybdenum substrates. We use an Embedded Atom Method (EAM) model to perform our calculations. This type of model has been widely used to describe the interaction between atoms …

Classification Of Jacobian Elliptic Fibrations On A Special Family Of K3 Surfaces Of Picard Rank Sixteen, Thomas Hill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

K3 surfaces are an important tool used to understand the symmetries in physics that link different string theories, called string dualities. For example, heterotic string theory compactified on an elliptic curve describes a theory physically equivalent to (dual to) F-theory compactified on a K3 surface. In fact, M-theory, the type IIA string, the type IIB string, the Spin(32)/Z₂ heterotic string, and the E₈ x E₈ heterotic string are all related by compactification on Calabi-Yau manifolds.

We study a special family of K3 surfaces, namely a family of rank sixteen K3 surfaces polarized by the lattice H⊕E …

The Development And Use Of A Secondary Electron Yield Database For Spacecraft Charge Modeling, Phillip Lundgreen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Charge modeling of electron-solid interactions requires a detailed and accurate compilation of experimental data on which to base its physics and against which to test its predictions. Historically researchers used methods involving individual research or information taken from existing, vague, databases that were often found wanting. To streamline the charge modeling process, a collection of data has been assembled and categorized based upon surface morphology and contamination from various published sources and existing databases. The quality and quantity of the compilation vary widely with very little information offered with regards to surface conditions of various materials (contamination, morphology, etc. ...). …

Environmental Controls On Didymosphenia Geminata Bloom Formation, Lindsay Capito

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Climate change is causing rapid glacial recession and earlier snowmelt, which alter the physical and chemical properties of rivers. As a result, organisms at the base of the food web are responding in unforeseen ways. We use the nuisance algae D. geminata (Didymo) as a case study for how climate induced shifts in the timing of glacial and snowmelt runoff are affecting river ecosystems. We evaluated how shifts in the timing of nutrient concentrations and light availability affect nuisance blooms of Didymo in three complementary ways. These are, field studies across streams in various stages of glacial recession, weekly measurements …

Nato And The Ifrc: A Comparative Case Study, Abigail Kosiak

Undergraduate Honors Capstone Projects

This research analyzes the North Atlantic Treaty Organization's (NATO) Multinational Telemedicine System (MnTS) Project and works to answer five main questions:

1) What challenges did the NATO MnTS Project face that are directly related to the fact that the project included members from different countries and worked to create a system that operates across national borders?

2) How do these challenges compare to those faced by a non-governmental organization (NGO) like the International Federation of the Red Cross and Red Crescent Societies (IFRC)?

3) What successes has the IFRC had with its current operational model?

4) In what ways could …

Numerical Approximations Of Phase Field Equations With Physics Informed Neural Networks, Colby Wight

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Designing numerical algorithms for solving partial differential equations (PDEs) is one of the major research branches in applied and computational mathematics. Recently there has been some seminal work on solving PDEs using the deep neural networks. In particular, the Physics Informed Neural Network (PINN) has been shown to be effective in solving some classical partial differential equations. However, we find that this method is not sufficient in solving all types of equations and falls short in solving phase-field equations. In this thesis, we propose various techniques that add to the power of these networks. Mainly, we propose to embrace the …

Visualizing Effects Of Changing Base Level On Tributary Resources In Lake Powell Reservoir, Madeline Friend

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Lake Powell reservoir is the second-largest reservoir in the United States. As climate change reduces watershed runoff in the Colorado River Basin, questions arise about the management and even existence of Lake Powell. If lake levels continue to drop, what will the emerging canyon look like and what value will we assign it? Lake Powell traps all incoming fine sediment from the Colorado River, the San Juan River, and many smaller tributaries. What is the fate of this sediment under falling reservoir levels and how will it influence other resources? To support a robust public discourse, we provide an immersive …

Electron Emission And Transport Properties Database For Spacecraft Charging Models, Phil Lundgreen

Theses and Dissertations

Modeling the rate and likelihood of spacecraft charging during spacecraft mission is critical to determine mission length, proposed spacec­raft attitude, and spacecraft design. The focus of this work is the creation and utilization of a database of secondary electron yield (SEY) measurements for a host of materials to increase accuracy in spacecraft modeling. Traditional methods of SEY data selection for input into spacecraft charging codes typically include the use of compiled materials databases incorporated in charging codes or selecting values from a specific scientific study. The SEY database allows users to select data inputs based upon the details associated with …

Analyzing The Von Neumann Entropy Of Contact Networks, Thomas J. Brower

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

When modeling the spread of disease, ecologists use ecological or contact networks to model how species interact with their environment and one another. The structure of these networks can vary widely depending on the study, where the nodes of a network can be defined as individuals, groups, or locations among other things. With this wide range of definition and with the difficulty of collecting samples, it is difficult to capture every factor of every population. Thus ecologists are limited to creating smaller networks that both fit their budget as well as what is reasonable within the population of interest. With …

Methods In Modeling Wildlife Disease From Model Selection To Parameterization With Multi-Scale Data, Ian Mcgahan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effects of emerging wildlife diseases are global and profound, resulting in loss of human life, economic and agricultural impacts, declines in wildlife populations, and ecological disturbance. The spread of wildlife diseases can be viewed as the result of two simultaneous processes: spatial spread of wildlife populations and disease spread through a population. For many diseases these processes happen at different timescales, which is reflected in available data. These data come in two flavors: high-frequency, high-resolution telemetry data (e.g. GPS collar) and low-frequency, low-resolution presence-absence disease data. The multi-scale nature of these data makes analysis of such systems challenging. Mathematical …

A Stratospheric Approach To Diagnose The North American Winter Dipole, Henrik Panosyan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

It has been well established in the literature that the stratosphere is dynamically coupled with the troposphere during boreal winter. The North American Winter Dipole is comprised of an upper-tropospheric contrast between a ridge over western North America, and a trough over eastern North America. The variance of this circulation regime has increased in recent years, with its amplified states being associated with extremes ranging from drought and floods, to extreme cold air outbreaks. This study explores the stratospheric link to this extreme weather regime, in the hopes of ultimately improving the predictability of this regime on intraseasonal-to-seasonal timescales. We …

Geomorphic History Of The Grand Staircase Region Of The Colorado Plateau: Understanding Arroyo Cut-Fill Dynamics, Erosion Rates, And Wildfire, Kerry E. Riley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Most streams in the southwestern United States do not flow all year, and given their delicate balance of sediment and water flow, they are sensitive to climate change. At the turn of the 20th century, many streams in the Southwest rapidly incised into their floodplains, forming arroyos with a channel entrenched into near-vertical channel banks mostly composed of sand and mud. This dissertation investigates past changes in watersheds draining the Grand Staircase region in southern Utah with the goal of understanding how changes in climate and sediment influence these types of streams. Results show sediment supply is highly variable across …

Greening-Induced Runoff Loss In The Western United States, Xueyan Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study assessed how vegetation will influence long-term runoff trends across the western United States (western US) in the future. I used a land surface model with improved dynamic vegetation root processes to better quantify regional runoff trends across five regions (Upper and Lower Colorado, Great Basin, Pacific Northwest, and California). The model was driven by statistically downscaled and bias-corrected outputs from three global climate models under the Representative Concentration Pathway 4.5 and 8.5 scenarios. Vegetation greening dominated significant transpiration increases that contributed most to increasing evapotranspiration across the western US, especially during spring and summer. Consistent with these trends, …

Boron In The Pariette Wetlands, Uinta Basin, Ut, Palak Vasudeva

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Boron is a naturally occurring mineral in shale and coal beds formed in marine environments, as found in the Uinta Basin. Mining activity and the application of excess irrigation water on agricultural lands in the Pariette watershed lead to mobilization of B via surface run off. Water quality monitoring records from 2006- 2009 reported violations of Utah B standard for irrigation water 43-100% of the time, for water flowing through the Pariette Wetlands. This study aims to determine B distribution in abiotic (water, sediments) and biotic samples (macroinvertebrates, aquatic vegetation, fish, bird eggs), and to establish correlations between B concentrations …

Some Examples Of The Liouville Integrability Of The Banded Toda Flows, Zachary Youmans

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Toda lattice is a famous integrable system studied by Toda in the 1960s. One can study the Toda lattice using a matrix representation of the system. Previous results have shown that this matrix of dimension n with 1 band and n‚àí1 bands is Liouville integrable. In this paper, we lay the foundation for proving the general case of the Toda lattice, where we consider the matrix representation with dimension n and a partially filled lower triangular part. We call this the banded Toda flow. The main theorem is that the banded Toda flow up to dimension 10 is …

Nitrogen Fertilizer Needs Of First-Year Small Grains Following Alfalfa, Collin Pound

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wheat, barley, triticale, and oats, are small grains commonly grown as hay and grain following alfalfa in Utah and the Intermountain West, especially during drought years as they require less irrigation than corn. Several studies in many parts of the world have shown that first-year corn following alfalfa rarely needs nitrogen (N) fertilizer, yet relatively few have evaluated the N needs of small grains, especially small grains grown for hay. Objectives of this research were to determine whether N fertilizer is needed to economically optimize the yield and quality of first-year small grains following alfalfa, develop N guidelines, and whether …