Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Brigham Young University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1681 - 1710 of 8046

Full-Text Articles in Entire DC Network

Radio Frequency Interference Cancellation,Appraisal, Detection, And Correction, Michael J. Lambert Apr 2019

Radio Frequency Interference Cancellation,Appraisal, Detection, And Correction, Michael J. Lambert

Theses and Dissertations

Radio Astronomy, the study of distant objects in the radio spectrum, is set at defiance against all other users of the electromagnetic spectrum. Where traditional use would fill the electromagnetic spectrum with as much transmission and information as possible, Radio Astronomy would rather no man-made signals existed. Since that is not possible, they grumble and have to deal with unwanted transmissions impinging upon their instruments. I have demonstrated that subspace projection can remove these unwanted signals from Radio Astronomical data in post processing. I demonstrate it both on simulated data and on data taken from the Very Large Array radio …


Model Testing Of Soil Bacteria Population Dynamics, Adam Harlan Heninger Apr 2019

Model Testing Of Soil Bacteria Population Dynamics, Adam Harlan Heninger

Theses and Dissertations

This is one of the first time series studies of bacteria in soils supporting actively growing corn crops. Mathematically modeling bacteria population dynamics has the potential as a tool to more precisely assess the economic optimal nitrogen fertilizer rate for farmers. As a first step in this modeling effort, we examine the possibility that the bacteria population growth might be described by a dynamic model developed in the food sciences describing bacteria growth in food meant for human consumption. We make the assumption that air temperature above the soil can be used as an approximation for soil temperature. Also, because …


Hot Springs Inflow Controlled By The Damage Zone Of A Major Normal Fault, Steven Benjamin Godwin Apr 2019

Hot Springs Inflow Controlled By The Damage Zone Of A Major Normal Fault, Steven Benjamin Godwin

Theses and Dissertations

Spring water inflow is distinct at Pah Tempe Hot Springs (also known as Dixie Hot Springs) situated within the damage zone of the Hurricane Fault in Timpoweap Canyon in Hurricane, Utah. Excising of the footwall by the Virgin River has created Timpoweap Canyon and allowed an unusual opportunity to study the spring inflow in relation to the fault damage zone. While correlation of these springs with the damage zone and visible fracture patterns on the canyon wall has been made, no subsurface faulting has been imaged to verify connection to these visible fractures and spring inflows (Nelson et al., 2009). …


Exponential Stability Of Intrinsically Stable Dynamical Networks And Switched Networks With Time-Varying Time Delays, David Patrick Reber Apr 2019

Exponential Stability Of Intrinsically Stable Dynamical Networks And Switched Networks With Time-Varying Time Delays, David Patrick Reber

Theses and Dissertations

Dynamic processes on real-world networks are time-delayed due to finite processing speeds and the need to transmit data over nonzero distances. These time-delays often destabilize the network's dynamics, but are difficult to analyze because they increase the dimension of the network.We present results outlining an alternative means of analyzing these networks, by focusing analysis on the Lipschitz matrix of the relatively low-dimensional undelayed network. The key criteria, intrinsic stability, is computationally efficient to verify by use of the power method. We demonstrate applications from control theory and neural networks.


Regular Fibrations Over The Hawaiian Earring, Stewart Mason Mcginnis Apr 2019

Regular Fibrations Over The Hawaiian Earring, Stewart Mason Mcginnis

Theses and Dissertations

We present a family of fibrations over the Hawaiian earring that are inverse limits of regular covering spaces over the Hawaiian earring. These fibrations satisfy unique path lifting, and as such serve as a good extension of covering space theory in the case of nonsemi-locally simply connected spaces. We give a condition for when these fibrations are path-connected.


A Discovery Of Social Impact Categories For The Sustainable Design Of Engineered Products And Their Consideration By Industry Professionals, Andrew Taylor Pack Apr 2019

A Discovery Of Social Impact Categories For The Sustainable Design Of Engineered Products And Their Consideration By Industry Professionals, Andrew Taylor Pack

Theses and Dissertations

Sustainable design is often practiced and assessed through the consideration of three essential areas: economic sustainability, environmental sustainability, and social sustainability. For even the simplest of products, the complexities of these three areas and their trade-offs cause decision making transparency to be lost in most practical situations. Additionally, the models and tools available to consider social sustainability are severely underdeveloped. This thesis is separated into three parts: 1) a design tool to consider all three aspects of sustainability simultaneously, 2) a literature survey to characterize social impact as it relates to products, and 3) interviews with engineering professionals regarding how …


Uncovering One Teacher's Knowledge Of Arts Integration For Developing English Learners' Reading Comprehension: A Self-Study, Tina Ralinn Mcculloch Apr 2019

Uncovering One Teacher's Knowledge Of Arts Integration For Developing English Learners' Reading Comprehension: A Self-Study, Tina Ralinn Mcculloch

Theses and Dissertations

The purpose of this study was to explore what I, a general education classroom teacher, know about using arts integration to build English Learners (ELs) reading comprehension. As the primary researcher, I am a fifth-grade, general education teacher in an intermountain West, Title 1, urban school where the typical classroom contains over 50% EL students. The studys two other participants were Martha, the director of the universitys arts partnership, and Camilla, a fellow faculty member who integrates arts into her curriculum. This qualitative Self-Study of Teaching and Teacher Education Practice research methodology was utilized to uncover my knowledge of teaching …


A Content Analysis Of Scientific Practices In A Fourth-Grade Commercial Literacy Program, Hailey A. Oswald Apr 2019

A Content Analysis Of Scientific Practices In A Fourth-Grade Commercial Literacy Program, Hailey A. Oswald

Theses and Dissertations

Increasing science literacy among all students is a longstanding goal of science education. The most recent national attempt to improve science education, and thereby increase science literacy, came in the form of the Framework for K-12 Science Education and the Next Generation Science Standards, which include 3 dimensions: scientific and engineering practices, crosscutting concepts, and disciplinary core ideas. The purpose of this content analysis was to examine the alignment between 4 of the scientific practices (Asking Questions; Constructing Explanations; Engaging in Argument from Evidence; and Obtaining, Evaluating, and Communicating Information) and a widely used commercial literacy program, Reading Wonders, with …


After Https: Indicating Risk Instead Of Security, Matthew Wayne Holt Apr 2019

After Https: Indicating Risk Instead Of Security, Matthew Wayne Holt

Theses and Dissertations

Browser security indicators show warnings when sites load without HTTPS, but more malicious sites are using HTTPS to appear legitimate in browsers and deceive users. We explore a new approach to browser indicators that overcomes several limitations of existing indicators. First, we develop a high-level risk assessment framework to identify risky interactions and evaluate the utility of this approach through a survey. Next, we evaluate potential designs for a new risk indicator to communicate risk rather than security. Finally, we conduct a within-subjects user study to compare the risk indicator to existing security indicators by observing participant behavior and collecting …


Paternal Self-Efficacy: A Parenting Resilience Factor For Fathers With Depression, Mark Herrick Trahan, Kevin Shafer Mar 2019

Paternal Self-Efficacy: A Parenting Resilience Factor For Fathers With Depression, Mark Herrick Trahan, Kevin Shafer

Faculty Publications

Parental depression has a negative effect on child development including mental and physical health, language and development, and externalizing and internalizing behavior. This quantitative research study examined the relationship between paternal self-efficacy (PSE) and parenting behaviors often associated with paternal depression. Data from the Survey of Contemporary Fathers were used and responses from self-identified fathers (n = 1,156) on paternal involvement, warmth, harsh parenting practices, and parenting self-efficacy were analyzed to assess the association between depression and PSE on fathering behavior. Ordinary least squares regression analysis indicated that depression was associated with harsh parenting and parenting warmth, while parenting self-efficacy …


On The Persecution Of The Salvadoran People, Jacob Newman Mar 2019

On The Persecution Of The Salvadoran People, Jacob Newman

Undergraduate Honors Theses

El Salvador is the focal point of an American refugee crisis. This crisis owes its origins to protracted abuse and negligence suffered by the Salvadoran people. They are confronted with violence, apathy, and corruption in their homeland and throughout the international sphere. A complex system of harms has come to a concentrated fruition in the form of governments and gangs, histories and happenstance. The purpose of this thesis is, first, to document the persecution faced by Salvadorans and, second, argue that the conditions in El Salvador put many Salvadorans in need of asylum.


Investigating The Impact Of Taper And Aspect Ratio On A Stalling Wing Using A Corrected Vortex Lattice Method, Ryan Anderson Mar 2019

Investigating The Impact Of Taper And Aspect Ratio On A Stalling Wing Using A Corrected Vortex Lattice Method, Ryan Anderson

Undergraduate Honors Theses

The advent of new technologies such as eVTOL vehicles is exciting. The development of fast aerodynamics models incorporating stall is one small step on the road to realizing such concepts by improving the speed of design optimization algorithms. To this end, a modified vortex lattice model was developed based on one reported by dos Santos and Marques [4]. The model was validated against experimental data found in the literature. Making use of its stall capabilities, a sample study was performed to test for any coupling effect between aspect ratio and taper ratio. This was done by calculating the lift curve …


Computational Regiospecific Analysis Of Brain Lipidomic Profiles, Austin Ahlstrom Mar 2019

Computational Regiospecific Analysis Of Brain Lipidomic Profiles, Austin Ahlstrom

Undergraduate Honors Theses

Mass spectrometry provides an extensive data set that can prove unwieldy for practical analytical purposes. Applying programming and machine learning methods to automate region analysis in DESI mass spectrometry of mouse brain tissue can help direct and refine such an otherwise unusable data set. The results carry promise of faster, more reliable analysis of this type, and yield interesting insights into molecular characteristics of regions of interest within these brain samples. These results have significant implications in continued investigation of molecular processes in the brain, along with other aspects of mass spectrometry, collective analysis of biological molecules (i.e. omics), and …


"Where Was I?": Linguistic Reprocessing In Distracted Reading, Katrina Hillam Mar 2019

"Where Was I?": Linguistic Reprocessing In Distracted Reading, Katrina Hillam

Undergraduate Honors Theses

This thesis examines the impact of repeated auditory and task-oriented distractors on linguistic processing. Impact was measured through eye tracking software recording first fixation duration, gaze duration, and total time spent on distractor words. This study found consistent significant difference only in the total time category, suggesting that the processing stage most impacted by distraction is global context—our awareness of how a word fits in to the paragraph at large. Participants were skilled at regaining reading speed after distraction, showing no overall impairment for other processing levels. This phenomenon could be dangerous for student comprehension, as reading speed will be …


Does Family Communication Matter? Exploring Knowledge Of Breast Cancer Genetics In Cancer Families, Deborah Himes, Sarah H. Davis, Jane Lassetter Phd, Rn, Neil E. Peterson, Margaret F. Clayton, Wendy C. Birmingham, Anita Y. Kinney Mar 2019

Does Family Communication Matter? Exploring Knowledge Of Breast Cancer Genetics In Cancer Families, Deborah Himes, Sarah H. Davis, Jane Lassetter Phd, Rn, Neil E. Peterson, Margaret F. Clayton, Wendy C. Birmingham, Anita Y. Kinney

Faculty Publications

Purpose: Knowledge of breast cancer genetics is critical for those at increased hereditary risk who must make decisions about breast cancer screening options. This descriptive study explored theory-based relationships among cognitive and emotional variables related to knowledge of breast cancer genetics in cancer families. Methods: Participants included first-degree relatives of women with breast cancer who had received genetic counseling and testing. Study participants themselves did not have breast cancer and had not received genetic counseling or testing. Data were collected by telephone interviews and surveys. Variables analyzed included numeracy, health literacy, cancer-related distress, age, education, and the reported amount of …


Computationally Modeling The Trophic Cascade In Yellowstone National Park, Emily Menden Mar 2019

Computationally Modeling The Trophic Cascade In Yellowstone National Park, Emily Menden

Undergraduate Honors Theses

Many of the world’s ecosystems are facing species elimination (2). Whether this elimination is intentional or accidental, the consequences need to be understood in order to make better resource management decisions. Computational models can be helpful in making these management decisions. Yellowstone National Park gives ecologists a unique opportunity to study species elimination and reintroduction.

In the 1920s, wolves were extirpated from the Greater Yellowstone Area. The absence of wolves allowed the elk population to increase unbounded by a natural predator. Over the years, Yellowstone management took various measures to control the elk population. In the 1970s, the National Park …


Stochastic Modeling Reveals How Motor Protein And Filament Properties Affect Intermediate Filament Transport, J. C. Dallon, Cecil Leduc, Sandrine Etienne-Manneville, Stephanie Portet Mar 2019

Stochastic Modeling Reveals How Motor Protein And Filament Properties Affect Intermediate Filament Transport, J. C. Dallon, Cecil Leduc, Sandrine Etienne-Manneville, Stephanie Portet

Faculty Publications

Intermediate filaments are a key component of the cytoskeleton. Their trans- port along microtubules plays an essential role in the control of the shape and structural organization of cells. To identify the key parameters responsible for the control of intermediate filament transport, we generated a model of elastic filament transport by microtubule-associated dynein and kinesin. The model is also applicable to the transport of any elastically-coupled cargoes. We inves- tigate the effect of filament properties such as number of motor binding sites, length, and elasticity on motion of filaments. Additionally, we consider the ef- fect of motor properties, i.e. off …


Wasatch Front Atmospheric Deposition Reflects Regional Desert Dust And Local Anthropogenic Sources, Michael Max Goodman Mar 2019

Wasatch Front Atmospheric Deposition Reflects Regional Desert Dust And Local Anthropogenic Sources, Michael Max Goodman

Theses and Dissertations

Dust originating from dry lakes contributes harmful and toxic elements to downwind urban areas and mountain snowpack that is compounded by local contaminant inputs from anthropogenic sources. To evaluate dust contributions to an urban area from regional playas, we sampled playa dust sources, urban dust deposition, and snow dust deposition in central Utah, USA. Samples were analyzed for grain size, mineralogy, and chemistry. Bulk mineralogy between playa, urban, and snow dust samples was similar, with silicate, carbonate, and evaporite minerals. Grain size distribution between fine playa, urban, and snow dust particles was also similar. Elements found at high concentrations in …


Developing A Method To Identify Horizontal Curve Segments With High Crash Occurrences Using The Haf Algorithm, Joseph Stuart Browning Mar 2019

Developing A Method To Identify Horizontal Curve Segments With High Crash Occurrences Using The Haf Algorithm, Joseph Stuart Browning

Theses and Dissertations

Crashes occur every day on Utah’s roadways. Curves can be particularly dangerous as they require driver focus due to potentially unseen hazards. Often, crashes occur on curves due to poor curve geometry, a lack of warning signs, or poor surface conditions. This can create conditions in which vehicles are more prone to leave the roadway, and possibly roll over. These types of crashes are responsible for many severe injuries and a few fatalities each year, which could be prevented if these areas are identified. This highlights a need for identification of curves with high crash occurrences, particularly on a network-wide …


Total Synthesis Of Anticancer Agent Deoxypodophyllotoxin And Antiviral F4-4 Demonstrating The Utility Of The Intramolecular Styryl Diels-Alder (Isda) Reaction, Diana Isabel Saavedra Nova Mar 2019

Total Synthesis Of Anticancer Agent Deoxypodophyllotoxin And Antiviral F4-4 Demonstrating The Utility Of The Intramolecular Styryl Diels-Alder (Isda) Reaction, Diana Isabel Saavedra Nova

Theses and Dissertations

The intramolecular styryl Diels – Alder (ISDA) reaction is a rare and unique [4+2] cycloaddition with potential in the syntheses of polycycles. Its utility is based on the formation of two rings and one stereocenter in a single step, making it an efficient method for the construction of lignan-type natural product targets. Detailed mechanistic studies with complex esters and the application to natural product synthesis has been limited due to drawbacks including the loss of aromaticity, producing slow reactivity, a potentially problematic thermal [1,3]-hydrogen shift, and electronic mismatch related to the substituents on the aryl functional groups. In this research, …


Selective Catalysis By Polymer-Supported Ruthenium Nanoparticlesand New Ligand Design For Cooperative And Bimetallic Catalysis, Seyed Hadi Nazari Mar 2019

Selective Catalysis By Polymer-Supported Ruthenium Nanoparticlesand New Ligand Design For Cooperative And Bimetallic Catalysis, Seyed Hadi Nazari

Theses and Dissertations

The abstract is the summary of three different projects all centered around the generalidea of catalysis which is the general theme of research in the Michaelis laboratory. The firstproject focuses on development of a new heterogeneous catalyst for selective catalysis. In theMichaelis lab, we were interested in the potential of nanoparticle catalysts for regioselectivetransformations. We showed that polymer supported ruthenium nanoparticles performed as areliable catalyst for regioselective reduction of azide to amine. In our study of regioselectivereduction of multiple azide containing substrates, we observed that in presence of ourruthenium nanoparticle catalysts, the least sterically hindered azide group reduced to aminefunctional …


A Systematic Review Of Interventions For Implementation Fidelity For Academic Interventions, Emily Morgan Beecher Mar 2019

A Systematic Review Of Interventions For Implementation Fidelity For Academic Interventions, Emily Morgan Beecher

Theses and Dissertations

To address students’ academic and behavioral needs, schools are held accountable for implementing effective evidence–based interventions. An important relationship exists between implementation fidelity and the effectiveness of interventions. The purpose of this systematic review was to identify and evaluate the evidence of interventions to improve the implementation fidelity of academic interventions and to evaluate the quality of the existing research with a focus on the quality of the research on the most successful interventions. A total of 13 studies met the inclusion criteria. Each study was coded based on a quality of evidence coding protocol and the findings were then …


Strain Path Effect On Austenite Transformation And Ductility In Tbf 1180 Steel, Parker Kenneth Gibbs Mar 2019

Strain Path Effect On Austenite Transformation And Ductility In Tbf 1180 Steel, Parker Kenneth Gibbs

Theses and Dissertations

TBF 1180 steel was studied under various conditions focusing on the correlation of ductility and amount of retained austenite. Samples were prepared from sheet stock and then strained using limiting dome height tooling (LDH), a standard uniaxial test frame, and a tensile stage for use in an electron microscope. The steel was observed in plane, biaxial, and uniaxial strain to determine its effect on retained austenite transformation and ultimately, ductility. Retained austenite was observed using a scanning electron microscope (SEM) equipped with an electron backscatter detector (EBSD) to distinguish the different phases present. Initial austenite levels were around 5% by …


Applications Of Pattern Recognition Entropy (Pre) And Informatics To Data Analysis, Shiladitya Chatterjee Mar 2019

Applications Of Pattern Recognition Entropy (Pre) And Informatics To Data Analysis, Shiladitya Chatterjee

Theses and Dissertations

The primary focus of my work is the application of informatics methods to the fields of materials science and analytical chemistry. The statistical analysis of data has become increasingly important in understanding the properties of materials and analytes. Statistical methods like principal component analysis (PCA) and multivariate curve resolution (MCR) are widely used for analysis in chemistry and other fields given their ability to categorize spectra in an unsupervised way. PCA is relatively easy to apply and has appealing mathematical properties. However, the results can be challenging to interpret, even for experienced users. In contrast, MCR results can be more …


Analog Adaptive Calibration For Arbitrary Phased Array Configuration, Mark William Nielson Mar 2019

Analog Adaptive Calibration For Arbitrary Phased Array Configuration, Mark William Nielson

Theses and Dissertations

The development of phased array antenna systems requires considerable resources and time. Due to this constraint, the Naval Air Command (NAVAIR) needs a phased array that can be physically reconfigured to meet the demands of multiple missions without added development time or cost. This work develops and demonstrates a solution to this problem by implementing an adaptive calibration approach to the development of electronically steerable antennas (ESAs). In contrast to previous analog adaptive beamformer systems, this system allows for an arbitrary antenna configuration with a variable number of antenna elements and locations. A simulation model of arbitrary phased array configurations …


Who Says Women Can't Be Computer Programmers, Ashley Mckenzie Feb 2019

Who Says Women Can't Be Computer Programmers, Ashley Mckenzie

Children's Book and Media Review

No abstract provided.


Developable Mechanisms On Developable Surfaces, Todd G. Nelson, Trent K. Zimmerman, Robert J. Lang, Spencer P. Magleby, Larry L. Howell Feb 2019

Developable Mechanisms On Developable Surfaces, Todd G. Nelson, Trent K. Zimmerman, Robert J. Lang, Spencer P. Magleby, Larry L. Howell

Faculty Publications

The trend toward smaller mechanism footprints and volumes, while maintaining the ability to perform complex tasks, presents the opportunity for exploration of hypercompact mechanical systems integrated with curved surfaces. Developable surfaces are shapes that a flat sheet can take without tearing or stretching, and they represent a wide range of manufactured surfaces. This work introduces “developable mechanisms” as devices that emerge from or conform to developable surfaces. They are made possible by aligning hinge axes with developable surface ruling lines to enable mobility. Because rigid-link motion depends on the relative orientation of hinge axes and not link geometry, links can …


Model Predictive Automatic Control Of Sucker Rod Pump System With Simulation Case Study, Brigham Hansen, Brandon Tolbert, Cory Vernon, John Hedengren Feb 2019

Model Predictive Automatic Control Of Sucker Rod Pump System With Simulation Case Study, Brigham Hansen, Brandon Tolbert, Cory Vernon, John Hedengren

Faculty Publications

This work enables accelerated fluid recovery in oil and gas reservoirs by automatically controlling fluid height and bottomhole pressure in wells. Several literature studies show significant increase in recovered oil by determining a target bottomhole pressure but rarely consider how to control to that value. This work enables those benefits by maintaining bottomhole pressure or fluid height. Moving Horizon Estimation (MHE) determines uncertain well parameters using only common surface measurements. A Model Predictive Controller (MPC) adjusts the stroking speed of a sucker rod pump to maintain fluid height. Pump boundary conditions are simulated with Mathematical Programs with Complementarity Constraints (MPCCs) …


Emergence Of Collective Behaviors In Hub-Based Colonies Using Grammatical Evolution And Behavior Trees, Aadesh Neupane Feb 2019

Emergence Of Collective Behaviors In Hub-Based Colonies Using Grammatical Evolution And Behavior Trees, Aadesh Neupane

Theses and Dissertations

Animals such as bees, ants, birds, fish, and others are able to efficiently perform complex coordinated tasks like foraging, nest-selection, flocking and escaping predators without centralized control or coordination. These complex collective behaviors are the result of emergence. Conventionally, mimicking these collective behaviors with robots requires researchers to study actual behaviors, derive mathematical models, and implement these models as algorithms. Since the conventional approach is very time consuming and cumbersome, this thesis uses an emergence-based method for the efficient evolution of collective behaviors. Our method, Grammatical Evolution algorithm for Evolution of Swarm bEhaviors (GEESE), is based on Grammatical Evolution (GE) …


Schur Rings Over Infinite Groups, Cache Porter Dexter Feb 2019

Schur Rings Over Infinite Groups, Cache Porter Dexter

Theses and Dissertations

A Schur ring is a subring of the group algebra with a basis that is formed by a partition of the group. These subrings were initially used to study finite permutation groups, and classifications of Schur rings over various finite groups have been studied. Here we investigate Schur rings over various infinite groups, including free groups. We classify Schur rings over the infinite cyclic group.