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Hopping Conductivity And Charge Transport In Low Density Polyethylene, Jerilyn Brunson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The properties and behaviors of charge transport mechanisms in highly insulating polymers are investigated by measuring conduction currents through thin film samples of low density polyethylene (LDPE). Measurements were obtained using a constant voltage method with copper electrodes inside a chamber adapted for measurements under vacuum and over a wide range of temperatures and applied fields. Field-dependent behaviors, including Poole-Frenkel conduction, space charge limited current (SCLC), and Schottky charge injection, were investigated at constant temperature. These field-dependent mechanisms were found to predict incorrect values of the dielectric constant and the field dependence of conductivity in LDPE was not found to …

Intercomparison Of Prism And Daymet Temperature Interpolation From 1980 To 2003, Rebecca A. Scully

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As ecosystem modeling becomes increasingly integrated with Geographic Information Systems (GIS) there is a rise in demand for spatially and temporally continuous meteorological data. But in order to justify management decisions or to provide robust scientific insights, the accuracy of meteorological data used as model input must be thoroughly quantified. Current methods to create spatially continuous climate data from discrete weather station data include inverse distance weighting, geostatistical techniques such as kriging and splines, local regression models such as Parameter-Elevation Regression on Independent Slope Model (PRISM) and Daymet, and regional regression models. For the conterminous United States, PRISM and Daymet …

Altering Positive/Negative Interaction Ratios In Relationships Of Mothers And Young Children: A Preliminary Investigation, Andrew B. Armstrong

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Based on classic marital research of John Gottman, a popular notion exists that interpersonal relationships thrive when the number of positive interactions outweighs negative interactions by a ratio of five to one. Though many have given similar advice for parents and caregivers, Gottman's findings and methodology may not generalize to relationships of parents and young children. Were similar ratio findings to be validated for parent-child relationships, explicit ratio advice may be incorporated as a component of clinical practice (e.g., behavioral parent training). To begin investigating potential clinical implications, a project was conducted that examined mothers' ability to achieve prescribed ratios …

Field And Smog Chamber Studies Of Agricultural Emissions And Reaction Products, Derek J. Price

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Agricultural emissions are an important contributor to atmospheric aerosol. These emissions include nitrogen containing organic compounds, primarily as amines, which have not been well investigated to date. Although there have been several studies that have looked at the emission of gas phase amines, there are only a few studies that have focused on ambient amine-based aerosol. There have also only been a handful of smog chamber studies that have investigated amine aerosol chemistry. Kinetic studies have looked at the reactions of amines with OH and ozone. However, amine reactions with nitrate radical (NO₃) are not well understood. Several …

Cooperative Remote Sensing And Actuation Using Networked Unmanned Vehicles, Haiyang Chao

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation focuses on how to design and employ networked unmanned vehicles for remote sensing and distributed control purposes in the current information-rich world. The target scenarios are environmental or agricultural applications such as river/reservoir surveillance, wind profiling measurement, and monitoring/control of chemical leaks, etc. AggieAir, a small and low-cost unmanned aircraft system, is designed based on the remote sensing requirements from environmental monitoring missions. The state estimation problem and the advanced lateral flight controller design problem are further attacked focusing on the small unmanned aerial vehicle (UAV) platform. Then the UAV-based remote sensing problem is focused with further flight …

Analysis Of Ammonia And Volatile Organic Amine Emissions In A Confined Poultry Facility, Hanh Hong Thi Dinh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The National Air Emission Monitoring Study (NAEMS) project was funded by the Agricultural Air Research Council (AARC) to evaluate agricultural emissions nationwide. Utah State University (USU) is conducting a parallel study on agricultural emissions at a Cache Valley poultry facility. As part of this parallel study, samples of animal feed, eggs and animal waste were collected weekly from three manure barns (designated: manure barn, barn 4 - manure belt and barn 5 - high rise) from May 2008 to November 2009.

These samples were analyzed to determine ammonia content, total Kjeldahl nitrogen content and ammonia emission. The yearly average calculated …

Multivariate Bayesian Machine Learning Regression For Operation And Management Of Multiple Reservoir, Irrigation Canal, And River Systems, Andres M. Ticlavilca

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The principal objective of this dissertation is to develop Bayesian machine learning models for multiple reservoir, irrigation canal, and river system operation and management. These types of models are derived from the emerging area of machine learning theory; they are characterized by their ability to capture the underlying physics of the system simply by examination of the measured system inputs and outputs. They can be used to provide probabilistic predictions of system behavior using only historical data. The models were developed in the form of a multivariate relevance vector machine (MVRVM) that is based on a sparse Bayesian learning machine …

Expanding The Horizons Of Educational Pair Programming: A Methodological Review Of Pair Programming In Computer Science Education Research, Keith B. Rimington

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Educators and researchers continue to explore the benefits, real or imagined, of implementing pair programming as part of the computer science pedagogy. Current reviews of computer science educational research practices do not focus on educational pair programming. This thesis presents a review of the research methods used in recent educational pair programming research. The primary purpose of this review is to inform the ongoing dialogue about and to provide evidence-based recommendations for improving educational pair programming research.

Replicating the design of a previous computer science education methodological review, this study inspected a sample of 108 articles from a population of …

Kindergarten Teachers' Developmentally Appropriate Beliefs And Practices And Their Perceptions Of Children's Kindergarten Readiness: Comparing The Beginning And The End Of The School Year, Rachelle Ernest Wright

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study examined 180 matched pretest/posttest surveys of kindergarten teachers' perceptions of the transition children experienced upon kindergarten entry. Investigations of changes in the percentages of children perceived as not being ready for kindergarten and percentages of children who were rated as having had a very successful, moderately successful, or difficult transition from the pretest to the posttest were conducted. Additionally, changes in teachers' developmentally appropriate beliefs and practices from the beginning of the school year (pretest) to the end of the school year (posttest) were explored. Further analyses were conducted to find differences and associations between teacher and classroom …

Keeping Wetlands Wet: The Human Hydrology Of Wetlands In The Bear River Basin, Rebekah Downard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research seeks to understand how wetlands maintain a water supply in the Bear River Basin, where water is generally scarce. Research was conducted through semi-structured interviews with wetland and water experts in the basin and archival research of historical documents and water rights.

The U. S. Fish and Wildlife Service manages three refuges on the Bear River, and has obtained water rights portfolios for each. Holding water rights does not ensure that there will be water available for refuge wetlands. Instead, position in relation to other powerful water users is the most important factor in determining the security of …

Fatigue Life Analysis Of T-38 Aileron Lever Using A Continuum Damage Approach, James D. Gyllenskog

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In a recent investigation conducted by the United States Air Force, the mechanical failure of the aileron lever, manufactured from 2014-T6 aluminum, caused the fatal mishap of a T-38 trainer aircraft. In general the locations of cracks are unknown and must be determined by simulation. In this study we propose to use a continuum damage modeling approach to determine the degradation and damage in a material as the number of cycles of loading increases. This approach successfully predicts the location of crack initiation, propagation path, and propagation rate. A stress-based model in conjunction with the successive initiation technique is utilized. …

Electron-Induced Electron Yields Of Uncharged Insulating Materials, Ryan Carl Hoffmann

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Presented here are electron-induced electron yield measurements from high-resistivity, high-yield materials to support a model for the yield of uncharged insulators. These measurements are made using a low-fluence, pulsed electron beam and charge neutralization to minimize charge accumulation. They show charging induced changes in the total yield, as much as 75%, even for incident electron fluences of <3 fC/mm², when compared to an uncharged yield. The evolution of the yield as charge accumulates in the material is described in terms of electron recapture, based on the extended Chung and Everhart model of the electron emission spectrum and the dual dynamic …

Ecology And Seasonal Habitat Use Patterns Of Columbian Sharp-Tailed Grouse In Northern Utah, Ron D. Greer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Columbian sharp-tailed grouse (Tympanuchus phasianellus columbianus: hereafter sharp-tailed grouse) populations have been declining. These declines have been attributed to a number of factors, including habitat loss due to agriculture, habitat fragmentation, overgrazing by livestock, and the loss to fire.

To gather information about their status in northern Utah, I radio-marked sharp-tailed grouse in 2003 (n=15) and 2004 (n=20) in two research areas. The study areas were located on the south end of Cache County and in eastern Box Elder County. In the Cache study area, I monitored 7 males and 1 female in 2003, and 6 males and …

A Publish-Subscribe System For Data Replication And Synchronization Among Integrated Person-Centric Information Systems, Xiangbin Qiu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Synchronization of data across an integrated system of heterogeneous databases is a difficult but important task, especially in the context of integrating health care information throughout a region, state, or nation. This thesis describes the design and implementation of a data replication and synchronization tool, called the Sync Engine, which allows users to define custom data-sharing patterns and transformations for an integrated system of heterogeneous person-centric databases. This thesis also discusses the relationship between the Sync Engine's contributions and several relevant issues in the area of data integration and replication. The Sync Engine's design and implementation was validated by …

The Effects Of Pedagogical Agents On Mathematics Anxiety And Mathematics Learning, Quan Wei

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to investigate the impact of the mathematics anxiety treatment messages in a computer-based environment on ninth-grade students' mathematics anxiety and mathematics learning. The study also examined whether the impact of the treatment messages would be differentiated by learner's gender and by learner's prior mathematics anxiety levels (High vs. Medium vs. Low). Participants were 161 ninth-grade students, who took a required introductory algebra class in a public high school neighboring Utah State University. The learning environment was integrated with a pedagogical agent (animated human-like character) as a tutor. This study employed a pretest and posttest …

Transmitter Localization Using Autonomous Robotic Swarms, Joshua S. Adams

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this research is to design a proof of concept system that is capable of locating a hidden radio transmitter and to investigate methods of multi-agent formation control with a specific interest in the effectiveness of these methods on the overall objective of locating this transmitter. A system is proposed and developed in which autonomous agents work together to locate this transmitter and their responsiveness is analyzed while using formations based both on a behavioral system and a system derived from centroidal Voronoi tessellations. Many software adaptations to the existing MASnet program are required, as well as some …

Unraveling Conflicting Interpretations: A Reexamination Of The 1916 Report On Social Studies, C. Gregg Jorgensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study examines the 1916 Report on Social Studies in order to determine how it has been interpreted and regarded over time. The underlying question involved is "Which interpretation, or interpretations, most embodies the intent, goals, and purpose of the 1916 Committee"? Key members of the 1916 committee have been identified for extended research and analysis. One additional individual frequently quoted throughout the Report, John Dewey, has been included in this research on the 1916 committee. The design, format, and content of the 1916 Report on Social Studies was closely examined. This study dissected the three individual reports by time, …

Computer-Aided Detection Of Breast Cancer Using Ultrasound Images, Yanhui Guo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ultrasound imaging suffers from severe speckle noise. We propose a novel approach for speckle reduction using 2D homogeneity and directional average filters to remove speckle noise. We transform speckle noise into additive noise using a logarithm transformation. Texture information is employed to describe the speckle characteristics of the image. The homogeneity value is defined using texture information value, and the ultrasound image is transformed into a homogeneity domain from the gray domain. If the homogeneity value is high, the region is homogenous and has less speckle noise. Otherwise, the region is nonhomogenous, and speckle noise occurs. The threshold value is …

Analysis Of Square-Root Kalman Filters For Angles-Only Orbital Navigation And The Effects Of Sensor Accuracy On State Observability, Jason Knudsen Schmidt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Angles-only navigation is simple, robust, and well proven in many applications. However, it is sometimes ill-conditioned for orbital rendezvous and proximity operations because, without a direct range measurement, the distance to approaching satellites must be estimated by firing thrusters and observing the change in the target's bearing. Nevertheless, the simplicity of angles-only navigation gives it great appeal. The viability of this technique for relative navigation is examined by building a high-fidelity simulation and evaluating the sensitivity of the system to sensor errors. The relative performances of square-root filtering methods, including Potter, Carlson, and UD factorization filters, are compared to the …

Applying Information Visualization To Computer Security Applications, Robert Bruce Whitaker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis presents two phases of research in applying visualization to network security challenges. The first phase included discovering the most useful and powerful features in existing computer security visualizations and incorporating them into the AdviseAid visualization platform, an existing software package. The incorporation of such a complete feature set required novel resolution of software engineering, human factors, and computer graphics issues. We also designed additional novel features, such as plugin interfaces, allowing for rapid prototyping and experimentation with novel visualization features and capabilities. The second phase of the research focused on the development of novel visualization techniques themselves. These …

Stormwater Monitoring And Resident Behavior In A Semi-Arid Region, Jennifer Abraham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The combined effect of land-use alterations and introduced diffuse anthropogenic pollutants to the earth's surface in suburban/urban zones often sparks a decrease in stormwater quality in the area, and contributes to nonpoint source pollution in receiving waters. The ponds at the Utah Botanical Center (UBC) located in Kaysville, UT, regularly experience algal blooms, which in turn cause low dissolved oxygen levels in the waters, indicating high concentrations of inflowing pollutants. The goal of this thesis paper was to describe the findings from the water quality monitoring implemented at both the inlet and outlet of the UBC ponds in order to …

Development Of An Innovative Statewide Population Monitoring Program For Mule Deer, Heather H. Bernales

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Monitoring population trend and estimating vital demographic parameters are essential for effective management of a mule deer (Odocoileus hemionus) population. Because of financial constraints, many wildlife agencies use computer models to obtain indirect indices of population size and trend as an alternative to annual field-based estimates of population size. These models are based primarily on herd composition counts and harvest rates from hunter-harvest surveys, and are rarely field validated. I developed an alternative method for monitoring population dynamics of wintering populations of mule deer. I designed a hybrid monitoring program that combined annual vital rate monitoring to track changes in …

Critique Of A Wildlife Habitat Evaluation Method Applied To Residential Open Space, Sarah Rigard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To this date, little research has been done evaluating the quality of wildlife habitat provided by open space in residential areas. Quality wildlife habitat for the purposes of this study is defined as those areas which contain the physical and biological characteristics necessary to support native wildlife species of the region. This thesis critiqued a wildlife habitat assessment method used in a nationwide study of residential open space for the purpose of better understanding the research conducted by the study and to inform similar, future habitat evaluations of landscapes altered by human activity to accommodate residential land use. The methodology …

A Singular-Value-Based Semi-Fragile Watermarking Scheme For Image Content Authentication With Tampering Localization, Xing Xin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis presents a novel singular-value-based semi-fragile watermarking scheme for image content authentication with tampering localization. The proposed scheme first generates a secured watermark bit sequence by performing a logical "xor" operation on a content-based watermark and content-independent watermark, wherein the content-based watermark is generated by a singular-value-based watermark bit sequence that represents intrinsic algebraic image properties, and the content-independent watermark is generated by a private-key-based random watermark bit sequence. It next embeds the secure watermark in the approximation subband of each non-overlapping 4×4 block using the adaptive quantization method to generate the watermarked image. The image content authentication process …

The Effects Of Spruce Beetle (Coleoptera: Curculionidae: Scolytinae) On Fuels And Fire In Intermountain Spruce-Fir Forests, Carl Arik Jorgensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In spruce-fir forests, there are many biotic and abiotic disturbances that can alter stand structure and composition. Many of these disturbances can produce high percentages of tree mortality at different scales. Spruce beetle has been considered a devastating disturbance agent, capable of creating high levels of mortality that will alter fuel complexes that may affect fire behavior. For comparison, stand data were gathered in endemic (near Loa and Moab, UT), epidemic (near Loa and Fairview, UT), and post-epidemic (near Salina and Loa, UT) condition classes of spruce beetle activity. Generally, fine fuels were higher during the epidemic and returned to …

Decentralized Coordination Of Multiple Autonomous Vehicles, Yongcan Cao

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation focuses on the study of decentralized coordination algorithms of multiple autonomous vehicles. Here, the term decentralized coordination is used to refer to the behavior that a group of vehicles reaches the desired group behavior via local interaction. Research is conducted towards designing and analyzing distributed coordination algorithms to achieve desired group behavior in the presence of none, one, and multiple group reference states.

Decentralized coordination in the absence of any group reference state is a very active research topic in the systems and controls society. We first focus on studying decentralized coordination problems for both single-integrator kinematics and …

Maternal Effects In Transmission Of Self-Medicative Behavior From Mother To Offspring In Sheep, Udita Sanga

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mammals begin learning food preferences in utero and maternally mediated influences early in life help offspring develop their feeding habits. Mammals also learn by individual experience to ingest medicinal compounds such as polyethylene glycol (PEG), which attenuates the negative post-ingestive effects of tannins, a group of potentially toxic plant secondary compounds. The objective of this study was to investigate the transmission of acquired self-medicative behavior from mother to offspring using polyethylene glycol (PEG) as a medicine to relieve malaise caused by tannins. I hypothesized that: 1) mothers trained to associate the beneficial effects of PEG while consuming tannins will pass …

A Comparative Study To Identify Factors Affecting Adoption Of Soil And Water Conservation Practices Among Smallhold Farmers In The Njoro River Watershed Of Kenya, Steven P. Huckett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Natural resource conservation is important for human well-being, especially in fragile environments of developing countries. This study occurred in 2006 among 6,500 smallhold farmers residing along a 25-km segment of a heavily utilized river. Research objectives were to determine use and adoption constraints for 14 soil and water conservation practices (SWCPs). Farms were reportedly contributing to a decline in river water quality via soil erosion. Recent occupation of the upper watershed by immigrants magnified concerns that resource degradation could escalate. A multi-method approach incorporating quantitative surveys, qualitative interviews, and participant observation was used to interpret constraining factors within the biophysical …

Identifying And Understanding The Spatial Distribution Of Bobcat And Coyote Behavior, Ryan Radford Wilson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A common observation in animal space use studies is that animals do not use space uniformly, but rather use some areas of their home ranges and territories with much higher intensity than others. Numerous methods have been developed to estimate these "core areas"; however, all of the current methods available are based on arbitrary rules. Additionally, most studies do not attempt to understand what behavioral processes lead to the observed patterns of non-uniform space use. This study has four main objectives: 1) to develop an objective and more precise method for estimating core areas, 2) to understand the processes leading …

Goodness-Of-Fit And Change-Point Tests For Functional Data, Robertas Gabrys

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A test for independence and identical distribution of functional observations is proposed in this thesis. To reduce dimension, curves are projected on the most important functional principal components. Then a test statistic based on lagged cross--covariances of the resulting vectors is constructed. We show that this dimension reduction step introduces asymptotically negligible terms, i.e. the projections behave asymptotically as iid vector--valued observations. A complete asymptotic theory based on correlations of random matrices, functional principal component expansions, and Hilbert space techniques is developed. The test statistic has X²-square asymptotic null distribution.

Two inferential tests for error correlation in the …