Digital Commons Network^™

Darboux Integrability Of Wave Maps Into 2-Dimensional Riemannian Manifolds, Robert Ream

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The harmonic map equations can be represented geometrically as an exterior differential system (EDS), ε. Using this representation we study the harmonic maps from 2D Minkowski space into 2D Riemannian manifolds. These are also known as wave maps. In this case, E is invariant under conformal transformations of Minkowski space. The quotient of ε by these conformal transformations, E/G, is an s=0 hyperbolic system.

The main result of our study is that the prolonged EDS, ε^(k), is Darboux integrable if and only if the prolonged quotient EDS, ε^(k+1), is Darboux integrable. We also find invariants determining …

Agent-Organized Network Coalition Formation, Levi L. Barton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis presents work based on modeling multi-agent coalition formation in an agent organized network. Agents choose which agents to connect with in the network. Tasks are periodically introduced into the network. Each task is defined by a set of skills that agents must fill. Agents form a coalition to complete a task by either joining an existing coalition a network neighbor belongs to, or by proposing a new coalition for a task no agents have proposed a coalition for. We introduce task patience and strategic task selection and show that they improve the number of successful coalitions agents form. …

Phenotypic Plasticity And The Post-Modern Synthesis: Integrating Evo-Devo And Quantitative Genetics In Theoretical And Empirical Studies, Alison G. Scoville

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mainstream evolutionary biology lacks a mature theory of phenotype. Following from the Modern Synthesis, researchers tend to assume an unrealistically simple mapping of genotype to phenotype, or else trust that the complexities of developmental architecture can be adequately captured by measuring trait variances and covariances. In contrast, the growing field of evolutionary developmental biology (evo-devo) explicitly examines the relationship between developmental architecture and evolutionary change, but lacks a rigorous quantitative and predictive framework. In my dissertation, I strive to integrate quantitative genetics and evo-devo, using both theoretical and empirical studies of plasticity. My first paper explores the effect of realistic …

Utah Middle-Level School Community Councils: An Evaluation Of Compliance, Processes, And Perceived Impact, Richard Jackson Nygaard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The historical perspective of schools in our democratic society provides a framework of tension between local parent and community control versus professional and state control of public school decisions. Today, federal and state requirements demand increased student achievement. The state of Utah requires each public school to have a school community council (SCC) that is responsible for the development of plans for school improvement. Limited funds are provided to each school community council through the School LAND Trust Program to assist in the implementation of the developed plans for the purpose of increased student achievement. Three Utah middlelevel school community …

Strides Towards Better Application Security, Sathyaraj Balasubramanian

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Static analysis tools analyze source code for vulnerabilities. However, these types of tools suffer from various problems that limit their effectiveness. This thesis examines these static analysis tools and suggests techniques for making them more efficient at detecting different types of vulnerabilities.

The thesis further analyzes possible causes for these vulnerabilities by examining the source code written by programmers of various categories. Finally, this thesis discusses solutions and techniques to improve general security awareness as well as the importance of secure coding among the students and software developers.

Optimal Irrigation Management For Sloping, Blocked-End Borders, Jorge Jose Escurra

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A robust mathematical model of one-dimensional flow for sloping, blocked-end border irrigation was developed using the four-point implicit method to solve the Saint-Venant equations, the volume-balance solution method, and the implementation of new algorithms to avoid numerical instability and solution divergence. The model has the capability of successfully simulating all surface irrigation phases in blocked-end borders for a range of inflow rates (0.01 - 0.05 m³/s per m), longitudinal slopes (up to 1.00%), and border lengths (100 - 500 m).

To achieve numerical stability over the specified parameter ranges, the model was divided into three parts: (1) advance-phase …

Distributed Control For Robotic Swarms Using Centroidal Voronoi Tessellations, Shelley Rounds

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis introduces a design combining an emerging area in robotics with a well established mathematical research topic: swarm intelligence and Voronoi tessellations, respectively. The main objective for this research is to design an economical and robust swarm system to achieve distributed control. This research combines swarm intelligence with Voronoi tessellations to localize a source and create formations. Extensive software coding must be implemented for this design, such as the development of a discrete centroidal Voronoi tessellation (CVT) algorithm.

The ultimate purpose of this research is to advance the existing Mobile Actuator and Sensor Network (MASnet) platform to eventually develop …

Student Achievement And Affective Traits In Electrical Engineering Laboratories Using Traditional And Computer-Based Instrumentation, Matthew D. Lammi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Distance education has the ability to transcend distance and time, reaching students anywhere at any time, particularly those underrepresented in engineering. Engineering is a practice-oriented profession requiring an interweaving of scientific theory and applied hands-on activities. Despite the need for distance education in engineering, few studies have systematically investigated the impact of student achievement and attitude in distance engineering laboratories. This quasi-experimental research addressed that need by studying the cognitive and affective domains of achievement in engineering laboratories while employing computer-based and traditional oscilloscopes. The students from two courses, electrical engineering for nonmajors and electronic fundamentals, were randomly assigned into …

Synthesis And Characterization Of Lactose-Amines With Respect To Oil-In-Water Emulsion Stability, Nidhi Garg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fatty amines (hexadecyl-amine) can be esterified to lactose via Schiff-base formation at temperatures of 60° C. Extending the time of the reaction results in a darker colored product due to the Maillard reaction. Due to the amphiphilic properties of the lactose-amines, the emulsion stabilization characteristics were investigated.

In this study, synthesis of lactose-amines was done at four different heating and cooling cycles from 4 to 24 hours. Lactose-amines processed for 24 hours and 12 hours of constant heating and cooling cycles are named as 24H and 12H, respectively. Lactose-amines 4H and 8H were processed for 4 and 8 hours of …

Decadal-Scale Changes On Coral Reefs In Quintana Roo, Mexico, Thaddeus Allen Nicholls

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In 1988 data on coral reef community composition were collected from two areas, Akumal and Chemuyil, Quintana Roo, Mexico, ranging from 5-35m depth. These areas were revisited in 2005 and data were collected by the same methods and at the same depths as in 1988. Data from 1988 and 2005 were compared to determine if the coral reefs had undergone significant changes, and what specific changes had occurred. Chi-square analysis determined that community composition data collected in 1988 are significantly different from data collected in 2005 at all sites and depths within the categories of corals, gorgonians, sponges, and macroalgae. …

The Effect Of Teacher Education Level, Teaching Experience, And Teaching Behaviors On Student Science Achievement, Danhui Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Previous literature leaves us unanswered questions about whether teaching behaviors mediate the relationship between teacher education level and experience with student science achievement. This study examined this question with 655 students from sixth to eighth grade and their 12 science teachers. Student science achievements were measured at the beginning and end of 2006-2007 school year. Given the cluster sampling of students nested in classrooms, which are nested in teachers, a two-level multilevel model was employed to disentangle the effects from teacher-level and student-level factors. Several findings were discovered in this study. Science teachers possessing of advanced degrees in science or …

A Comparison Of The Economic Profitability Of Specified Risk Management Alternatives For Intermountain West Farmers, Cody D. Bingham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this research is to provide quantitative and limited qualitative analysis for the United States Intermountain West on the economic effectiveness of risk management alternatives in an agricultural operation. This research is not meant to be an exhaustive comparison of every potential combination of alternatives and risk scenarios. Instead, specific parameters such as farm size, crops grown, risk attitudes and risk management strategies are set to guide the research and offer a basis of comparison.

This research evaluates several levels of coverage using Multiple Peril Crop Insurance, Crop Revenue Coverage Insurance, Adjusted Gross Revenue – Lite Insurance and …

The Adaptability Of Langmuir Probes To The Pico-Satellite Regime, Andrew Jay Auman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this thesis is to investigate whether it is feasible to use Langmuir probes on pico-satellites flying in low Earth orbit over mid- to low-latitude geographic regions. Following chapters on the expected ionospheric conditions and an overview of Langmuir probe theory, a chapter addressing the difficulties involved with pico-satellite Langmuir probes is presented. Also, the necessary satellite-to-probe surface area requirements in order to achieve confidence in pico-satellite Langmuir probe data, for the orbital regions of interest to this thesis, are stated.

Sedimentology, Stratigraphy, And Organic Geochemistry Of The Red Pine Shale, Uinta Mountains, Utah: A Prograding Deltaic System In A Mid-Neoproterozoic Interior Seaway, Caroline Amelia Myer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Red Pine Shale (RPS; ~1120m thick), uppermost formation of the Neoproterozoic Uinta Mountain Group, Utah, is an organic-rich sedimentary succession interpreted as a marine deltaic system that delivered immature sediment from the north that mixed with mature sediment from the east. Multiple data sets suggest regional climate and sea-level changes associated with changing organic-carbon burial rates.

Six facies were identified and represent wave-, tidal-, and river-influenced parts of the distal prodelta to delta front in a marine system. These include the shale facies and associated concretion facies (distal prodelta), the shale-sandstone facies (proximal prodelta to delta front), the slump …

Perceived Crowding And Visitor Support For Use Rationing: A Reanalysis Of Existing Data, Jascha M. Zeitlin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis presents a reanalysis of data collected between 1999 and 2006 by the Institute for Outdoor Recreation and Tourism (IORT) at Utah State University. These data concern a variety of outdoor recreation sites in Utah, Idaho, and South Dakota, and were collected via intercept, mail, and, to a very limited extent, telephone surveys. Survey instruments contained questions related to visitor perceptions of crowding, overall satisfaction, support for use limits/rationing, and estimates of use density, in addition to other conceptually related factors.

Analyses consisted of multiple regression models for both perceived crowding and visitor support for use limits dependent variables …

Hydrological Characterization Of A Riparian Vegetation Zone Using High Resolution Multi-Spectral Airborne Imagery, Osama Zaki Akasheh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Middle Rio Grande River (MRGR) is the main source of fresh water for the state of New Mexico. Located in an arid area with scarce local water resources, this has led to extensive diversions of river water to supply the high demand from municipalities and irrigated agricultural activities. The extensive water diversions over the last few decades have affected the composition of the native riparian vegetation by decreasing the area of cottonwood and coyote willow and increasing the spread of invasive species such as Tamarisk and Russian Olives, harmful to the river system, due to their high transpiration rates, …

Understanding Unfolding Change And The Value Of Strategic Unification In Recent Usu Information Technology Functional Realignment, Eric S. Hawley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This is a qualitative case study of the 2005-2008 Utah State University Information Technology reorganization from the perspective of key change advocates. The study identified and documented the unfolding change process involved in the reorganization in terms of dissatisfaction, executive changes, internal executive strategic planning, implementation and initial impacts, and continuous "in situ" strategic planning. The study also answered a set of supporting concluding questions indicating increased value to the institution in areas of customer service and confidence, organization, financial resources, planning and policy, security, and increased/improved services and service functions.

Effective Practices Of Project Lead The Way Partnership Teams, Cody J. Reutzel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to gather information from Project Lead The Way (PLTW) partnership team experts. This project follows the methodology of a modified Delphi study. A review of literature in the areas of curriculum development, pre-college engineering, and the Delphi research technique provided the background for the structure utilized. Top programs from across the country were questioned to identify and come to a consensus on top components essential to developing and utilizing a successful PLTW partnership team. The components were categorized into two lists: effective practices utilized to make a program successful and effective practices employed by …

Extending F10.7'S Time Resolution To Capture Solar Flare Phenomena, Ariel O. Acebal

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Solar ultraviolet (UV) radiation ionizes the neutral components in the atmosphere, which is partly responsible for the formation of the ionosphere, and contributes to heating of the atmosphere. Solar flares change the solar spectrum at times by several orders of magnitude. These changes modify the Earth's upper atmosphere, causing problems to communication systems and space operations, such as increased satellite drag. Unfortunately, solar UV measurements are limited since they can only be observed with space-based sensors. In order to work around this limitation, the solar radio emissions at a wavelength of 10.7 cm have been used as a proxy for …

Threat Perception As A Determinant Of Pro-Environmental Behaviors: Public Involvement In Air Pollution Abatement In Cache Valley, Utah, Joshua D. Marquit

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Threat perception related to environmental issues such as air pollution may be a determinant of pro-environmental behaviors. Among the potential threats of air pollution, include the perceived impacts on the psychological, social, and economic wellbeing of a community. Because of rapid increases in population growth, urbanization, and the mountainous landscapes, the American West is extremely susceptible to the adverse impacts of air pollution.

A secondary data analysis was conducted using data from the Air Quality Perception Survey conducted in Cache County, Utah. The survey focused on the public perception of air pollution in Cache County and perceived impact on personal …

Design Of Tunable Edge-Coupled Microstrip Bandpass Filters, Srinidhi V. Kaveri

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis is a study of tunability of edge-coupled filters. Microstrip edge-coupled bandpass filters are planar structures and have advantages such as easy design procedures and simple integration into circuits.

Three tuning techniques were implemented. The first technique involved the loading of one open end of each coupled into tunable capacitors. The second technique used a tunable resonator in series with the edge-coupled blocks. The final design made use of tunable feedback sections.

A detailed mathematical analysis of each design was performed. MATLAB code based on the analyses was written. The MATLAB simulations were compared to Agilent Advanced Design System …

Synthetic Complexes Of Relevance To Ni(Ii)-Containing Enzymes, Katarzyna Rudzka

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The work outlined herein presents an investigation of synthetic model complexes of relevance to the active sites of Ni(II)-containing enzymes, particularly urease, glyoxalase I, and acireductone dioxygenase. The research focuses on studying the structural and reactivity features of nickel complexes with biologically relevant substrates. The anion of acetohydroxamic acid is a well-known inhibitor of urease enzymes, including those isolated from Klebsiella aerogenes and Bacillus pasteurii. A precursor to the acetohydroxamate coordination in ureases is proposed to be an interaction between Ni(II) and acetohydroxamic acid. By using a novel supporting chelate ligand capable of secondary hydrogen bonding interactions a novel …

An Evolutionary Approach To Image Compression In The Discrete Cosine Transform Domain, Benjamin E. Banham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This paper examines the application of genetic programming to image compression while working in the frequency domain. Several methods utilized by JPEG encoding are applied to the image before utilizing a genetic programming system. Specifically, the discrete cosine transform (DCT) is applied to the original image, followed by the zig-zag scanning of DCT coefficients. The genetic programming system is finally applied to the one-dimensional array resulting from the zig-zag scan. The research takes an existing genetic programming system developed for the spatial domain and develops DCT domain functionality. The results from the DCT domain-based genetic programming system are compared with …

Safety-Focused Altruism: Valuing The Lives Of Others, Kevin Lee Brady

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The value of statistical life is an estimate of the monetary benefits of preventing an anonymous death. Society's willingness to pay to eliminate private health risks determines agencies' value-of-statistical-life estimates. Most estimates ignore society's willingness to pay to eliminate others' health risks. There are two possible reasons. First, altruism does not exist: Peter is not willing to pay to save Paul's life. The second possible reason is a bit more complicated. Certain economists argue that increasing benefit estimates to account for altruism involves double-counting.

The purpose of this thesis is to evaluate these possibilities. Accounting for altruism, it turns out, …

Identification Of Subsoil Compaction Using Electrical Conductivity And Spectral Data Across Varying Soil Moisture Regimes In Utah, Jay Murray Payne

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Subsoil compaction is a major yield limiting factor for most agricultural crops. Tillage is the most efficient method to quickly treat compacted subsoil, but it is also expensive, increases erosion, and accelerates nutrient cycling.

The use of real-time electrical conductivity (EC) and near-infrared (NIR) reflectance values to differentiate compacted areas from uncompacted areas was studied. This method has potential to reduce monetary and time investments inherent in traditional grid sampling and the resultant deep tillage of an entire field. EC and NIR reflectance are both very sensitive to spatial variability of soil attributes.

The objective of this research was to …

Measurement Of Fine Spatial Scale Ecohydrologic Gradients In A Pinyon-Juniper Ecosystem, Matthew David Madsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With the dramatic expansion of pinyon-juniper woodlands over the last century, improved understanding of how these woodlands modify infiltration properties is needed, in order for land managers to make informed decisions on how to best manage their specific resources. However, current methods for measuring soil infiltration are often limited by low sample sizes and high experimental error, due to constraints associated with remote, non agricultural settings. This thesis first presents a scheme for automating and calibrating two commercially available infiltrometers, which allows collection of a large number of precise unsaturated infiltration measurements in a relatively short period of time. Secondly, …

Conservation Implications Of Winter-Feeding Policies For Mule Deer In Utah, Chris C. Peterson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Policies regulating wildlife winter-feeding programs may have long-term impacts on conservation and future management of both target and non-target species. In 2000, the Utah Wildlife Board, upon reviewing input from a series of public regional meetings, adopted a Utah Big Game Winter-Feeding Policy. The Utah Division of Wildlife Resources used this policy to regulate winter-feeding programs for mule deer in northern Utah, 2001-2005. I monitored the program effects on mule deer biology, activity and migration, and winter browse utilization and productivity.

While feed rations generally compensated for protein and energy deficiencies, they may overlook mineral deficiencies. To determine if mule …

Small Sample Methods For The Analysis Of Clustered Binary Data, Lawrence J. Cook

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

There are several solutions for analysis of clustered binary data. However, the two most common tools in use today, generalized estimating equations and random effects or mixed models, rely heavily on asymptotic theory. However, in many situations, such as small or sparse samples, asymptotic assumptions may not be met. For this reason we explore the utility of the quadratic exponential model and conditional analysis to estimate the effect size of a trend parameter in small sample and sparse data settings. Further we explore the computational efficiency of two methods for conducting conditional analysis, the network algorithm and Markov chain Monte …

Impact Of Land-Applied Biosolids On Forage Quality And Water Movement During Rangeland Restoration Activities, Issaak R. Vasquez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The land application of biosolids to provide nutrients and organic matter is widely practiced in agricultural applications. However, the potential benefit of applying biosolids to disturbed rangelands has not been adequately evaluated. Thus the main goal of the current study was to evaluate the potential economic and environmental benefits of applying biosolids to disturbed rangeland with the main focus on evaluating the impact on forage quality and quantity as a function of biosolids type and application rate. Three types of biosolids (aerobically, anaerobically, and lime stabilized biosolids) were surface applied with no subsequent tilling at various loading rates (1, 5, …

A Causal-Comparative Model For The Examination Of An Online Teacher Professional Development Program For An Elementary Agricultural Literacy Curriculum, Clay L. Rasmussen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to determine the effectiveness of a teacher professional development program as measured by the extent that participants have continued to use lessons and materials up to three years after the professional development experience. The professional development program was delivered online and structured by five key characteristics of effective professional development.

Sixty-five participants of Food, Land, and People (FLP) professional development completed an online survey answering certain demographic variables and indicating the number of lessons and activities they had used from the FLP professional development. An implementation and continued use measurement model was …