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Electron Density And Electron Neutral Collision Frequency In The Ionosphere Using Plasma Impedance Probe Measurements On Sounding Rockets, Swadesh Patra

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Plasma Impedance Probe (PIP) is an RF-instrument that is used to measure plasma electron density and electron neutral collision Frequency. Radio Frequency probe techniques for the determination of plasma parameters are attractive especially because the RF response is not susceptible to spacecraft charging problems at frequencies above the electron plasma frequency where ion sheath effects are negligible. The work done in this thesis is presented as a compendium of two papers, the first paper dealing with PIP measurements on a sounding rocket mission and the second being a qualitative study of the effects of spacecraft aerodynamics on the impedance …

Teacher Educators' Computer Technology Integration At Utah State University, Jiayi Wan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this research is to develop a deep understanding of Utah State University teacher educators' perceptions and lived experience with computer technology integration. Ten methods course instructors in secondary education participated. Data were collected using the phenomenological research method: (1) conducting one-on-one in-depth interviews, (2) classroom observations of the four participants, and (3) examining artifacts, such as syllabi and presentation evaluation forms used by the participants.

The findings of this research show that the subjects regard computer technology as a powerful instructional tool. They also realize it is important to prepare preservice teachers with computer technology for their …

Soil Organic Carbon And Site Characteristics In Aspen And Evaluation Of The Potential Effects Of Conifer Encroachment On Soil Properties In Northern Utah, Mical K. Woldeselassie

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the Intermountain West, aspen (Populus tremuloides) has declined mainly due to a combination of successional processes, fire suppression and long-term use of ungulates which has led to replacement by conifers, sagebrush or other shrub communities. Conifer encroachment is believed to cause critical changes in the ecosystem properties. In order to understand the impacts of conifer encroachment on soil properties such as soil organic carbon (SOC) storage, soil morphology, and soil chemical properties, and the implications of such changes, it is very important to assess the soil properties under the two vegetation types. The objectives of this study …

A Geologic And Hydrochemical Investigation Of The Suitability Of Central Utah's Navajo Sandstone For The Disposal Of Saline Process Water And Co2, Kevin L. Randall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Salt water is produced from the Ferron Sandstone Member of the Mancos Shale in central Utah as part of the production of coalbed methane (CBM) and is disposed of by injection predominantly into the Navajo Sandstone between 4,500 feet to 7,300 feet and is considered to be a hazardous waste. Local government agencies are concerned about the potential impacts on shallow groundwater because of this disposal method.

Water samples were gathered from four shallow water-supply wells, and nine salt water disposal (SWD) wells to compare hydrochemistries as an indicator of potential mixing. Shallow water-supply wells are likely recharged by local …

Detecting Organic Molecules On The Surface Of Inorganic Dust Particles Using Aerosol Mass Spectrometry, Sileola B. Akinsiku

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Detection of organic molecules present on the surface of dust particles is important in homeland security, agriculture, and several other applications. The research presented reports the ability of the aerosol mass spectrometer (AMS) to detect molecules on the surface of dust particles without detecting the particle core.

Experiments were carried out to detect semi-volatile organic compounds adsorbed onto the surface of particulates without interference from the dust particle core. Methyl salicylate, oleic acid, and organophosphorus pesticides such as Malathion were detected on the surface of particles representative of dust-type materials. Zeolite powders were used as aerosol support, representative of a …

Speciation, Species Concepts, And Biogeography Illustrated By A Buckwheat Complex (Eriogonum Corymbosum), Mark W. Ellis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The focus of this research project is the complex of infraspecific taxa that make up the crisp-leaf buckwheat species Eriogonum corymbosum (Polygonaceae), which is distributed widely across southwestern North America. This complex provides an ideal taxonomic group for research into population relationships and speciation. To avoid unnecessary debates about taxonomic validity or contentious issues regarding appropriate species definitions, the historical evolution of the species concept is first reviewed in detail, demythologizing an often-assumed species problem. Following that review, the E. corymbosum complex is examined specifically.

Although eight varieties of E. corymbosum are currently recognized based on morphological characters, this group …

Optimal Candidate Generation In Spatial Co-Location Mining, Zhongshan Lin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Existing spatial co-location algorithms based on levels suffer from generating extra, nonclique candidate instances. Thus, they require cliqueness checking at every level. In this thesis, a novel, spatial co-location mining algorithm that automatically generates co-located spatial features without generating any nonclique candidates at any level is proposed. Subsequently, this algorithm generates fewer candidates than other existing level-wise, co-location algorithms without losing any pertinent information. The benefits of this algorithm have been clearly observed at early stages in the mining process.

A River Transformed: Historic Geomorphic Changes Of The Lower Rio Grande In The Big Bend Region Of Texas, Chihuahua, And Coahuila, David James Dean

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Over the last century, the construction and management of large dams and stream-flow diversions, and periodic drought have resulted in significant declines in stream flow of the lower Rio Grande in the Big Bend region. Reductions in mean annual flow and peak discharge have resulted in channel narrowing by the formation of vertically accreting inset floodplains. Narrowing has been temporarily interrupted by infrequent large dam releases greater than 1000 m³/s that have temporarily widened the channel; however, after each of these events, narrowing has resumed. Prior to 1942, floods of this magnitude occurred approximately once every 4 years …

Testing And Estimation For Functional Data With Applications To Magnetometer Records, Inga Maslova

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The functional linear model, Y_n = ψX_n + ε_n, with functional response and explanatory variables is considered. A simple test of the nullity of ψ based on the principal component decomposition is proposed. The test statistic has asymptotic chi-squared distribution, which is also an excellent approximation in finite samples. The methodology is applied to data from terrestrial magnetic observatories.

In recent years, the interaction of the auroral substorms with the equatorial and mid-latitude currents has been the subject of extensive research. We introduce a new statistical technique that allows us to test at a specified …

Modeling The Evolution Of Insect Phenology With Particular Reference To Mountain Pine Beetle, Brian P. Yurk

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Climate change is likely to disrupt the timing of developmental events (phenology) in insect populations in which development time is largely determined by temperature. Shifting phenology puts insects at risk of being exposed to seasonal weather extremes during sensitive life stages and losing synchrony with biotic resources. Additionally, warming may result in loss of developmental synchronization within a population, making it difficult to find mates or mount mass attacks against well-defended resources at low population densities. It is unknown whether genetic evolution of development time can occur rapidly enough to moderate these effects.

The work presented here is largely motivated …

Exploring The Spawning Dynamics And Identifying Limitations To The Early Life-History Survival Of An Important, Endemic Fish Species, Sara Elizabeth Seidel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

For many native, imperiled salmonid species, the prioritization of recovery and conservation efforts hinges upon the identification of a species most limiting life stage. The early life-history stage can be a limiting life stage for fish, and given the importance of the reproductive stage to overall persistence, there is a need to better understand the spawning ecology and early life history of many salmonids. The Logan River, in northern Utah, contains one of the largest metapopulations of imperiled Bonneville cutthroat trout (BCT) throughout the Bonneville Basin. Little research has evaluated the temporal and spatial distribution of BCT spawning nor quantified …

An Assessment Of Utah Resident Incentives And Disincentives For Use Of Opencourseware (Ocw), Anne Arendt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation examines Utah resident views of incentives and disincentives for use of OpenCourseWare (OCW) and how they fit into the theoretical framework of perceived innovation attributes established by Rogers. Rogers identified five categories of perceived innovation attributes, which include relative advantage, compatibility, complexity, trialability, and observability.

A survey instrument was developed using attributes that emerged from a Delphi technique with input from experts in the OCW field. The survey instrument was sent to 753 (n = 753) random individuals between 18 and 64 years of age throughout Utah based on information obtained from Alseco Data Group, LLC.

Results …

Surface Wave Propagation In A Dielectric Waveguide Loaded With An Anisotropic, Conductive, And Spatially Dispersive Substrate, Tushar Andriyas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis presents an analytical treatment of surface waves inside a dielectric slab loaded with a conductive and spatially dispersive semiconductor-like substrate. The work is primarily focused on the modelling of the substrate and getting the field solutions out from the Helmholtz equation. Appropriate boundary conditions have been used in order to get a unique dispersion relation. The surface wave modes are then extracted from the relation by using a root-searching algorithm, which in this work is the MATLAB Genetic Algorithm toolbox. Many different substrate configurations have been considered, starting from the very basic isotropic case to the most complex …

Covert Botnet Implementation And Defense Against Covert Botnets, Lokesh Babu Ramesh Babu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The advent of the Internet and its benevolent use has benefited mankind in private and business use alike. However, like any other technology, the Internet is often used for malevolent purposes. One such malevolent purpose is to attack computers using botnets. Botnets are stealthy, and the victims are typically unaware of the malicious activities and the resultant havoc they can cause. Computer security experts seek to combat the botnet menace. However, attackers come up with new botnet designs that exploit the weaknesses in existing defense mechanisms and, thus, continue to evade detection.

Therefore, it is necessary to analyze the weaknesses …

Evolution Of The Lower Cretaceous Chifeng Half-Graben Basins, Inner Mongolia, China, Scott Joshua Friedman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As a result of complex extensional tectonics in northeast China and southern portions of Mongolia, some workers have interpreted the Cretaceous Maanshan Uplift and associated Chifeng basins as metamorphic core complex. Previous work has relied solely upon kinematic indicators to determine the structural origin of these basins. To fully understand the creation of these basins, the sedimentiological record was analyzed in this study. The early Cretaceous sedimentary fill of these basins was analyzed to determine if it is synextensional in nature, and if so what manner of extension was in progress during that deposition.

The Chifeng basins are filled with …

An Evaluation Of Referral Patterns And Therapy Outcomes At A University Counseling Center: Analysis Of A Dialectical Behavior Skills Training Group, Eri Suzuki Bentley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was designed to answer two research questions. First, factors associated with placement decisions to three treatment modalities in a university counseling center were examined; the skills training group for dialectical behavior therapy plus individual therapy (DBT), the interpersonal process group plus individual therapy (IP), and individual therapy only (IND). Individual therapy in all three conditions did not follow a specific theoretical orientation. Of 203 participants (55 males, 148 females), 83 were in DBT, 53 were in IP, and 67 were in IND. Client information included demographic variables (e.g., age, gender) and clinical variables (i.e., diagnosis, and scores from …

Analysis Of Total Electron Content (Tec) Variations In The Low- And Middle-Latitude Ionosphere, Ja Soon Shim

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Detailed study of the spatial correlations of day-to-day ionospheric TEC variations on a global scale was performed for four 30-day-long periods in 2004 (January, March/April, June/July, September/October) using observations from more than 1000 ground-based GPS receivers. In order to obtain the spatial correlations, initially, the day-to-day variability was calculated by first mapping the observed slant TEC values for each 5-minute GPS ground receiver-satellite pair to the vertical and then differencing it with its corresponding value from the previous day. This resulted in more than 150 million values of day-to-day change in TEC (delta TEC). Next, statistics were performed on the …

Uncertainty Analysis For Land Surface Model Predictions: Application To The Simple Biosphere 3 And Noah Models At Tropical And Semiarid Locations, Joshua K. Roundy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Uncertainty in model predictions is associated with data, parameters, and model structure. The estimation of these contributions to uncertainty is a critical issue in hydrology. Using a variety of single and multiple criterion methods for sensitivity analysis and inverse modeling, the behaviors of two state-of-the-art land surface models, the Simple Biosphere Model 3 and Noah model, are analyzed. The different algorithms used for sensitivity and inverse modeling are analyzed and compared along with the performance of the land surface models. Generalized sensitivity and variance methods are used for the sensitivity analysis, including the Multi-Objective Generalized Sensitivity Analysis, the Extended Fourier …

Behavior Of Prestressed Concrete Bridge Girders, Franklin B. Angomas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

For this research, prestress losses were monitored in six HPC bridge girders. These measured losses were compared to predicted losses according to four sources. Prestress loss predictive methods considered for this research were: 1- AASHTO LRFD 2004, 2- AASHTO LRFD 2004 Refined, 3- AASHTO LRFD 2007, and 4- AASHTO LRFD Lump Sum method. On the other hand, the camber prediction methods used in the present research were: 1- Time dependent method described in NCHRP Report 496, 2- PCI multiplier method, and 3- Improved PCI Multiplier method. For the purpose of this research, long-term prestress losses were monitored in select girders …

The Effects Of Online Homework On Achievement And Self-Efficacy Of College Algebra Students, David Shane Brewer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study compared the effectiveness, in terms of mathematical achievement and mathematics self-efficacy, of online homework to textbook homework over an entire semester for 145 students enrolled in multiple sections of college algebra at a large community college. A quasi-experimental, posttest design was used to analyze the effect on mathematical achievement, as measured by a final exam. A pretest-posttest design was used to analyze the effect on mathematics self-efficacy, as measured by the Mathematics Self-efficacy Scale. The control group completed their homework using the textbook and the treatment group completed similar homework using an online homework system developed by the …

Investigations Of Variable Importance Measures Within Random Forests, Andrew C. Merrill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Random Forests (RF) (Breiman 2001; Breiman and Cutler 2004) is a completely nonparametric statistical learning procedure that may be used for regression analysis and. A feature of RF that is drawing a lot of attention is the novel algorithm that is used to evaluate the relative importance of the predictor/explanatory variables. Other machine learning algorithms for regression and classification, such as support vector machines and artificial neural networks (Hastie et al. 2009), exhibit high predictive accuracy but provide little insight into predictive power of individual variables. In contrast, the permutation algorithm of RF has already established a track record for …

Optimal Compost Rates For Organic Crop Production Based On A Decay Series, Jeffrey B. Endelman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

One of the more challenging aspects of organic farming is the development of an appropriate fertility plan, which may include crop rotation, cover crops, and/or soil amendments. When fertility is maintained by applying manure and/or compost, a pressing question is how much should be used. A framework was developed to address this question based on the idea of a decay series, which is a sequence of numbers quantifying the effects of compost on crop yield over a multi-year period. Prior research has focused on decay series expressed in nitrogen fertilizer equivalents. Given this information, I show how to calculate what …

Measurement And Modeling Of Reduced-Gravity Fluid Distribution And Transport In Unsaturated Porous Plant-Growth Media, Robert Heinse

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effect of reduced gravity on the balanced management of liquid, gaseous and ionic fluxes in unsaturated porous media remains a central challenge for plant-based bio-regenerative life support systems needed for long-duration space missions. This research investigated how shifting capillary and gravitational forces alter the sample-scale transport and distribution of fluids in mm-sized porous ceramic aggregates. Measurements in variably saturated media conducted on the International Space Station in microgravity (~1⋅10^-3 g_earth) and measurements during parabolic flight in variable gravity encompassing microgravity, terrestrial gravity and hypergravity (~1.8g_earth) were supported by numerical modeling based on fundamental, …

A Novel Authentication And Validation Mechanism For Analyzing Syslogs Forensically, Steena D.S. Monteiro

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research proposes a novel technique for authenticating and validating syslogs for forensic analysis. This technique uses a modification of the Needham Schroeder protocol, which uses nonces (numbers used only once) and public keys. Syslogs, which were developed from an event-logging perspective and not from an evidence-sustaining one, are system treasure maps that chart out and pinpoint attacks and attack attempts. Over the past few years, research on securing syslogs has yielded enhanced syslog protocols that focus on tamper prevention and detection. However, many of these protocols, though efficient from a security perspective, are inadequate when forensics comes into play. …

A C To Register Transfer Level Algorithm Using Structured Circuit Templates: A Case Study With Simulated Annealing, Jonathan D. Phillips

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A tool flow is presented for deriving simulated annealing accelerator circuits on a field programmable gate array (FPGA) from C source code by exploring architecture solutions that conform to a preset template through scheduling and mapping algorithms. A case study carried out on simulated annealing-based Autonomous Mission Planning and Scheduling (AMPS) software used for autonomous spacecraft systems is explained. The goal of the research is an automated method for the derivation of a hardware design that maximizes performance while minimizing the FPGA footprint. Results obtained are compared with a peer C to register transfer level (RTL) logic tool, a state-of-the-art …

Centering Pregnancy And Traditional Prenatal Care: A Comparison Of Health Practices, Kaylynn Shakespear

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Centering Pregnancy is an alternative method of providing prenatal care with increased education and social support with health assessment in a group setting. This study, a cross-sectional, correlational, convenience-sample design, sought to determine the difference between women who receive prenatal care in Centering Pregnancy prenatal care and those in traditional prenatal care in regards to health behaviors. Adult pregnant women (n = 125) were surveyed from at least 28 weeks gestation. The sample comprised primarily White low-income women. Using multiple linear regression, it was determined that women in Centering Pregnancy had significantly lower index health behavior scores compared with …

Are Delay Discounting, Probability Discounting, Time Perception, And Time Perspective Related? A Cross-Cultural Study Among Latino And White American Students, Ana Amelia L. Baumann Neves

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The present study aimed to evaluate (a) the extent to which different impulsivity measures would be related to each other and to a risk taking measure, (b) the extent to which impulsivity, risk taking, time perception and time perspective are related to each other, and (c) the extent to which these processes differ in Latino and White American students. Experiment I was conducted at Utah State University. One hundred and forty-three participants were exposed to the delay discounting, probability discounting and temporal bisection procedures, and answered the Barratt Impulsiveness Scale (BIS-11) and the Zimbardo Time Perspective Inventory (ZTPI). Results showed …

Automated Data Type Identification And Localization Using Statistical Analysis Data Identification, Sarah Jean Moody

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research presents a new and unique technique called SÁDI, statistical analysis data identification, for identifying the type of data on a digital device and its storage format based on data type, specifically the values of the bytes representing the data being examined. This research incorporates the automation required for specialized data identification tools to be useful and applicable in real-world applications. The SÁDI technique utilizes the byte values of the data stored on a digital storage device in such a way that the accuracy of the technique does not rely solely on the potentially misleading metadata information but rather …

Modeling The Electrodynamics Of The Low-Latitude Ionosphere, Christian Stephen Wohlwend

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The electrodynamics of the Earth's low-latitude ionosphere is dependent on the ionospheric conductivity and the thermospheric neutral density, temperature, and winds present. This two-part study focused on the gravity wave seeding mechanism of equatorial plasma depletions in the ionosphere and the associated equatorial spread F, as well as the differences between a two-dimensional flux tube integrated electrodynamics model and a three-dimensional model for the same time period. The gravity wave seeding study was based on a parameterization of a gravity wave perturbation using a background empirical thermosphere and a physics-based ionosphere for the case of 12 UT on 26 September …

Student Teachers' Beliefs And Practices About Developmentally Appropriate Practice For Infants And Toddlers, Trisha Haws

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to examine students’ beliefs and practices about developmentally appropriate practice with infants and toddlers. This study examined whether coursework in child development, combined with a lab experience engaging with children of the same age group, was related to developmentally appropriate beliefs and practices of student teachers. In particular, the study examined how coursework and practicum taken concurrently may have differed from taking the coursework alone. The relationships between descriptive data and student teachers’ developmentally appropriate beliefs and practices were also of interest.

A total of 390 college students participated in this study. These students …