Physical Sciences and Mathematics Commons^™

Stressor: An R Package For Benchmarking Machine Learning Models, Samuel A. Haycock

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many discipline specific researchers need a way to quickly compare the accuracy of their predictive models to other alternatives. However, many of these researchers are not experienced with multiple programming languages. Python has recently been the leader in machine learning functionality, which includes the PyCaret library that allows users to develop high-performing machine learning models with only a few lines of code. The goal of the stressor package is to help users of the R programming language access the advantages of PyCaret without having to learn Python. This allows the user to leverage R’s powerful data analysis workflows, while simultaneously …

The Derivation Of Sodium Density In The Mesosphere And Lower Thermosphere From The Na Lidar Photon Counting Profiles, Xiaoqi Xi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Derivation of Sodium (Na) number density from the Na lidar observations requires the in situ temperature and wind information because the absorption cross-section of the Na atom is a function of these dynamic parameters. The Na number density above ~ 110 km altitude was difficult to derive with the conventional algorithm, however. The standard output of the Na number density that utilizes the lidar-measured wind and temperature information falls short at ~ 110 km altitude and above due to the relatively large measurement uncertainties in the two critical parameters (low signal-to-noise ratio). Therefore, an innovative algorithm that may drive the …

Using Natural Language Processing To Quantify The Efficacy Of Language Simplification As A Communication Strategy, Brian Nalley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

People with communication disorders often experience difficulties being understood by unfamiliar listeners or in noisy environments. A common strategy for effectively communicating in these scenarios is to use simpler and more predictable language. Despite the prevalence of this strategy, there has been little to no research to date focused on the effectiveness of language simplification as a communication strategy. This study seeks to begin filling that gap by using natural language processing to determine whether speakers with early-stage Parkinson’s disease and age-matched neurotypical speakers are able to successfully simplify their language while still maintaining the original message.

Simplification was measured …

An Interval-Valued Random Forests, Paul Gaona Partida

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

There is a growing demand for the development of new statistical models and the refinement of established methods to accommodate different data structures. This need arises from the recognition that traditional statistics often assume the value of each observation to be precise, which may not hold true in many real-world scenarios. Factors such as the collection process and technological advancements can introduce imprecision and uncertainty into the data.

For example, consider data collected over a long period of time, where newer measurement tools may offer greater accuracy and provide more information than previous methods. In such cases, it becomes crucial …

Signatures Of Black Holes, Alexandra B. Chanson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In this defense I will describes three approaches to learn more about the relationship between the dynamics of black-holes and the distinctive signatures of a black hole systems: infinitesimal changes in the black hole background producing field excitations relating new fundamental black hole thermodynamic relations, mechanisms powering relativistic black hole jets and spontaneous symmetry breaking in five space-time dimensions, and physical signatures of black hole event horizons as conformal field theory duals (in both d=4,5 dimensional axisymmetric spacetimes).

Opening The Black Box: Soil Microbial Communities In Field-Based Plant-Soil Feedback Experiments, Julia Kate Aaronson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plant-soil feedback is a process through which plants modify the properties of their associated soils, affecting their growth. PSF can play a key role in regulating plant growth and communities including altering plant invasion, rarity, and abundance. However, our understanding of the soil organisms that drive these plant growth responses is limited. Most studies treat soils as a ‘black box’ and do little to reveal which specific microbes or microbial communities may be responsible. This chapter examines two recent large PSF field experiments conducted in Minnesota, USA, and Jena, Germany. These experiments revealed that plants altered their soils, changing subsequent …

Overcoming Barriers To Aquatic Plant Restoration: Addressing Gaps In Species Identification And Planting Techniques In The Intermountain West, Kate A. Sinnott

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aquatic ecosystems provide many critical and economically valuable benefits, including drinking water, food, recreational opportunities, and water supply for irrigation and agriculture. However, the health of these systems has been severely impacted by human activities such as pollution, land conversion, and introductions of harmful species. Restoring native aquatic plants can help reverse this damage and reestablish benefits, though it is not a common practice. With an objective to increase capacity for aquatic plant restoration in the Intermountain West, I identified and addressed two major barriers: 1) a lack of confidence in aquatic species identification among wetland professionals, and 2) underdeveloped …

Influence Of Hydrologic History On Nitrogen Cycling In Lake Sediments, Emily Jainarain

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water quality is declining in freshwater lakes around the world due to environmental change and anthropogenic activities that threaten the physical, ecological, and geochemical integrity of freshwater ecosystems. Excess N and P in lakes can cause eutrophication, a major driver of water quality impairment that leads to excessive algal growth, or harmful algal blooms (HABs), and poses risks to recreation, fisheries, and public drinking water. Water level fluctuations in lakes are expected to become more frequent and intense as climate change increases periods of drought and alters precipitation patterns, and fluctuations may stimulate biogeochemical reactions in littoral sediments that add …

Volatile Cycling And Metasomatism In Flat-Slab Subduction Zones Of The Central Andes, Coleman Hiett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Flat-slab subduction, where an oceanic plate subducts horizontally below a continental margin for hundreds of kilometers, is an enigmatic but prevalent tectonic configuration in which chemical cycling and alteration of the continental plate is poorly constrained. Geochemical investigations in regions of modern and ancient flat-slab subduction in the Central Andes afford an opportunity to study this process. Certain elements naturally occur with varying number of neutrons in their nuclei (isotopes), and measurements of isotope ratios within geologic materials inform on chemical sources and geologic processes. This research leverages stable isotope analyses and other geochemical tools to investigate volatiles and other …

Effects Of Soil Amendments On Water Quality And Hydrologic Properties In Low Impact Development Systems, Lily Wetterlin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Low impact development (LID) systems are practices that use natural elements, such as soils and vegetation, to absorb and filter stormwater to protect water quality and aquatic habitats. Many LID designs use native soils; however, urban soils typically have a limited potential for infiltrating and treating stormwater. Incorporation of soil amendments, such as compost and biochar, into LID soils can improve the physical properties of soil. However, soil amendments may increase or decrease pollutants in the water leaving the site. A comparison of the effects of different types and application rates of amendments on water quality is necessary to determine …

A Statewide Evaluation Of Fuel Treatment Effectiveness In Altering Wildfire Outcomes On Public Lands In Utah, Jamela Charmaine Thompson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fuel treatments are land management activities that reduce living and dead flammable materials on the landscape to mitigate undesirable wildfire behavior and effects. Common treatments in the western United States include mechanical methods such as thinning and mastication, prescribed burns, and chemical methods, such as herbicide application. Treatments usually have multiple objectives, including reducing fire intensity, protecting natural and cultural resources, slowing or disrupting a potential future fire’s path, supporting ecosystem health, and reestablishing low to mid severity fire cycles in ecosystems. Although treatments can potentially modify fire behavior and ecological health, they generally cannot prevent fires from igniting, eliminate …

A Mechanistic Examination Of Interspecific Competition Between Wild And Domestic Herbivores, Courtney Check

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Large herbivores, such as mule deer and cattle have similar life histories and likely compete for resources. However, quantifying the extent to which these species compete and the specific resources they compete for has proved challenging. My research examines if cattle influence deer abundance and behavior due to competition for forage, competition for shade, and/or by affecting the predation risk of deer. Using a grid of autonomous trail cameras, I was able to determine if cattle abundance influences local deer abundance in relation to specific resources and habitat features. Using GPS data from collared deer, I was also able to …

Physics-Guided Deep Learning For Solar Wind Modeling At L1 Point, Robert M. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Neural networks are adept at finding patterns that are too long and too small for humans to find in data. Usually, this power is used to generate predictions with greater accuracy than most alternative models. However, we can also use this power to understand more about the data we train these networks on. We do this by changing the data that the networks train on and the data they are tested on. This allows us to both control the maximum length of a pattern and to compare data between different groups, in our case, different solar cycles. This thesis is …

Proxy Voting Coordination Mechanisms: Determining How Agents Should Coordinate In A Continuous Preference Space, Michael D. Hegerhorst

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Illness, injury, and other impediments are common occurrences of everyday life. Such impediments prevent or deter voters from participating in important parts of the voting process, especially deliberation, bargaining, and the voting itself. Without participation, the results of the vote may change. There is a need to provide a system in which voters are still able to participate in important voting processes to ensure their vote is represented. We explore ‘proxy voting,’ a system in which voters are able to select another individual, or proxy, to vote on their behalf. By choosing a good proxy, a voter can still …

Comparative Study Of Clustering Techniques On Eye-Tracking In Dynamic 3d Virtual Environments, Scott Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Eye-tracking has been used for decades to understand how and why an individual focuses on particular objects, areas, and elements of space. A vast body of knowledge exists on how eye-tracking is measured. However, historically, eye-tracking has been predominately studied using 2D environments, with limited work in 3D environments. The purpose of this study is to identify which methods most accurately represent the areas that have captured the participant’s visual attention within a 3D dynamic environment. This will be completed by evaluating different clustering methods of fixations using a customized virtual reality tool that collects eye-tracking data. There exist several …

Comparing Commonly Used Aquatic Habitat Modeling Methods For Native Fishes, Eryn K. Turney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water resources are managed for a variety of human needs, including agriculture, industrial and municipal consumption, hydropower generation, and recreation. There has been a recent push to incorporate habitat needs of aquatic wildlife into water management models alongside these other uses, particularly as competition for limited water resources in a changing climate has reduced instream flow and contributed to declining native fish populations. Habitat models are used to estimate species distributions and differentiate between suitable and unsuitable habitat based on variables important to a given species, but are not usually incorporated into water management models. Because there are many ways …

Precise Determination Of Charge Distributions In Electron Irradiated Polymers Via Pulsed Electroacoustic Measurements With Applications To Spacecraft Charging, Zachary Gibson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Understanding how charge builds up and moves around in materials that are highly insulating, such as dielectrics, is important for many applications from power transmission to spacecraft charging. The leading cause of issues in spacecraft due to interactions with the space environment is spacecraft charging. That is, the accumulation of charge on insulating materials leads to arcing and sparking aboard the spacecraft. The most critical charging occurs due to electrons in a particular energy range of 10-50 keV. Electrons with these energies can travel 1’s to 10’s of microns into relevant materials. To measure where the charge is embedded and …

Generalizing Deep Learning Methods For Particle Tracing Using Transfer Learning, Shubham Gupta

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Particle tracing is a very important method for scientific visualization of vector fields, but it is computationally expensive. Deep learning can be used to speed up particle tracing, but existing deep learning models are domain-specific. In this work, we present a methodology to generalize the use of deep learning for particle tracing using transfer learning. We demonstrate the performance of our approach through a series of experimental studies that address the most common simulation design scenarios: varying time span, Reynolds number, and problem geometry. The results show that our methodology can be effectively used to generalize and accelerate the training …

Constrained Route Optimization With Fleet Considerations For Electrified Heavy-Duty Freight Vehicles, Zarin Subah Shamma

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Almost 75% of traffic-related emissions are caused by heavy-duty freight trucks and significantly impact neighborhoods, schools, and communities around shipping and distribution lines. With poor air quality and respiratory health, many children in at-risk and disadvantaged communities experience high rates of asthma, lower attendance in school, and lower concentration. This research creates to improve the impacts of heavy-duty electric freight by improving the route efficiency (in terms of energy, time, or route distance) of EV trucks. Our software and algorithms are tested in a simulation environment using data from several thousand fleet trucks operating in the Salt Lake City area. …

The Time-Dependent Ionospheric Model Using A Tec-Driven Servo: An Investigation Of The Capabilities And Limitations, Jenny Rebecca Whiteley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The ionosphere is a region of the atmosphere with a high density of electrons. These electrons affect the behavior of any electromagnetic wave that passes through the ionosphere. Communication and geolocation systems, such as traditional radio and Global Positioning Systems, depend on emitted electromagnetic signals being picked up by a receiver. The presence of the ionosphere affects the behavior of the signal and the quality of the service. Hence, the interactions between electromagnetic waves and the ionosphere provide a major motivation to understand, research, and successfully model and predict the ionosphere and its physical phenomena. This study focused on determining …

Big Fish And More Of Them: Salmonid Habitat Availability, Quality, And Use Across Multiple Scales Within A River-Reservoir System, John S. Mclaren V

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Reservoirs and their associated rivers provide water for agricultural and municipal uses, ecological benefits for fish and wildlife, and associated recreational activity. However, in the Greater Yellowstone Ecosystem climate change and population growth are putting pressure on water quality and supply, potentially damaging the unique and economically important coldwater trout habitat that these systems support. In this study, the author investigates the impact of changing water quality and supply on trout habitat quality, quantity, and selection to assist conservation goals in the Henry’s Fork Watershed in eastern Idaho. The study found that higher availability of cold-water refuge habitat in Island …

Statistical Graph Quality Analysis Of Utah State University Master Of Science Thesis Reports, Ragan Astle

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Graphical software packages have become increasingly popular in our modern world, but there are concerns within the statistical visualization field about the default settings provided by these packages, which can make it challenging to create good quality graphs that align with standard graph principles. In this thesis, we investigate whether the quality of graphs from Utah State University (USU) Plan A Master of Science (MS) thesis reports from the years 1930 to 2019 was affected by the rise of graphical software packages. We collected all data stored on the USU Digital Commons website since November 2021 to determine the specific …

A Generative Neural Network For Discovering Near Optimaldynamic Inductive Power Transfer Systems, Md Shain Shahid Chowdhury Oni

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An urgent need is to electrify transportation to lower carbon emissions into the atmosphere. Wireless charging makes electrical vehicles (EVs) more convenient and cheaper because energy is transferred to the vehicle without the need to plug it in. Dynamic wireless charging is particularly interesting, where the vehicle does not need to stop to receive the energy. This technology requires the EV and the roadway to include coils of wire, where the roadway coil is energized as the vehicle passes over it to induce an electrical current in the EV coil through electromagnetic induction. However, the problem of designing the two …

Evapotranspiration And Energy Balance Of Irrigated Urban Turfgrass, Matthew D. Miksch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water usage for irrigation is a big consumer of water resources in urban areas in Utah and other parts of the Intermountain Region of the Western United States. As populations continue to increase in these states, it is important to understand how much water is being used by urban landscapes in order to plan and manage future water resources. Evapotranspiration (ET), or the amount of water leaving a surface over a certain timeframe due to both transpiration from plants and evaporation from the soil, is a key variable in understanding how much water urban landscapes are really using to grow …

Regeneration Of Quaking Aspen And Understory Vegetation Change After Fire Risk Reduction Treatment, Allison M. Trudgeon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Quaking aspen (Populus tremuloides Michx.) is a keystone species that, when coexisting with conifers (i.e., seral aspen), often undergoes stand-replacing disturbances to sustain long term vigor. Historically, mixed-to-high severity fire reduced fuels and regenerated aspen, but such disturbances have become less common in recent decades. This has often led to high fuel loading, and many seral aspen stands are at now risk of an unpredictable, high-severity fire, posing a threat to development in the wildland-urban-interface. The lack of a commercial market for aspen, and the risk of conducting prescribed fire, means there are few alternate management options. This has …

Examining Political Discourse On Online 8kun And Reddit Forums, Braden Mindrum

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A recent example of political violence in the United States was that of the January 6, 2021, Capitol attack in connection with the certification of Joseph R. Biden’s victory over Donald J. Trump in the 2020 US presidential election. This thesis analyzes the events of January 6, 2021, through the lens of social media discourse. This thesis presents a workflow that acquired over 5 million 8kun and Reddit posts from various apolitical and political forums in the three months preceding and following the Capitol attack on January 6, 2021. Techniques from text analysis are then used to group forums according …

Recreational Fishing Participation In Utah: Comparing Active And Non-Active Angler Constraint Perceptions With The Use Of License Purchase Data, Will Rempel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As a leisure activity, recreational fishing provides numerous social, physical, and psychological benefits to its participants. It can also provide socioeconomic opportunities to specific communities, and as an outdoor activity can create support for natural fisheries resources and public lands. License and equipment taxes are also important funding mechanisms for state wildlife managers. Though fishing participation as a percentage of the population has overall decreased in the last century, there is a recent increase in fishing participation. However, participation dynamics result in a shifting cycle of entries, departures, and re-entries to the sport. In an effort to maintain participation and …

Daytime Versus Nighttime Sprinkler Irrigation Of Two Urban Crops In A Semi-Arid Climate At High-Elevation, Samikshya Pyakurel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nighttime irrigation scheduling is a longstanding water conservation approach to reduce evaporative losses in Utah's semi-arid, urban landscapes. However, residential demand now exceeds system capacity, and the efficiency of the practice has come under question. Therefore, the objectives of this study include: 1) quantify whether a water savings exists between day and night irrigation with a water balance and energy balance approach, and 2) analyze microclimate and crop quality effects to determine any changes to evaporative demand or plant stress by irrigation timing. In 2019, we established 12 field plots in North Logan, UT (41.77° N, -111.81° W, 1380 m …

A Frobenius-Schur Extension For Real Projective Representation, Levi Gagnon‐Ririe

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many problems in physics have explicit mathematical descriptions. This thesis aims to provide the mathematical tools for a particular problem in physics, that of Quantum Mechanical symmetries. In essence, we extend the known mathematics to a more general setting and provide a wider view of Real projective representation theory. The work done in this thesis contributes to the subfield of mathematics known as representation theory and to the subfield of physics concerned with time reversal symmetry.

Cross-Boundary Stewardship In Protected Area Centered Ecosystems: Perceptions Of Success And Characteristics Of Cooperative Engagement, Ryan D. Tarver

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The legal boundaries of protected areas, such as national parks are established and enforced by humans. Therefore, jurisdictional boundaries are ultimately have human meaning but not necessarily ecological relevance as natural phenomena such as watersheds and wildlife habitat often extend beyond a jurisdictional boundary. When considering the extent of natural system, we find that protected areas only make up part of a given ecosystem. The result is a large expanse of lands that fall under a various ownership types that include both publicly and privately designated tracts of land. This presents a management challenge when attempting to manage at the …