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Articles 541 - 570 of 2906

Full-Text Articles in Physical Sciences and Mathematics

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.


Multi-Instrument Surface Characterization Of Display Glass, Cody Vic Cushman Apr 2019

Multi-Instrument Surface Characterization Of Display Glass, Cody Vic Cushman

Theses and Dissertations

Flat panel displays (FPDs) are microfabricated devices that are often fabricated on specialized glass substrates known as display glass. The surface chemistry of the outer few nanometers of display glass can have an important influence on FPD performance and yield. Dsiplay glass surface characterization is difficult because (i) display glass surface composition varies significantly from its bulk composition; (ii) high-surface area forms of glass, such as fibers and powders, may not have the same surface composition as melt-formed planar surfaces, and (iii) the surface composition of display glass may be altered through exposure to chemical treatments commonly used during flat …


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). …


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.


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 …


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 …


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 …


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 …


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.


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) …


Using Coherence To Improve The Calculation Of Active Acoustic Intensity With The Phase And Amplitude Gradient Estimator Method, Mylan Ray Cook Jan 2019

Using Coherence To Improve The Calculation Of Active Acoustic Intensity With The Phase And Amplitude Gradient Estimator Method, Mylan Ray Cook

Theses and Dissertations

Coherence, which gives the similarity of signals received at two microphone locations, can be a powerful tool for calculating acoustic quantities, particularly active acoustic intensity. To calculate active acoustic intensity, a multi-microphone probe is often used, and therefore coherence between all microphone pairs on the probe can be obtained. The phase and amplitude gradient estimator (PAGE) method can be used to calculate intensity, and is well suited for many situations. There are limitations to this method—such as multiple sources or contaminating noise in the sound field—which can cause significant error. When there are multiple sources or contaminating noise present, the …


Y2O3 Optical Constants Between 5 Nm And 50 Nm, Joseph B. Muhlestein, Benjamin D. Smith, Margaret Miles, Stephanie M. Thomas, Anthony Willey, David D. Allred, R. Steven Turley Jan 2019

Y2O3 Optical Constants Between 5 Nm And 50 Nm, Joseph B. Muhlestein, Benjamin D. Smith, Margaret Miles, Stephanie M. Thomas, Anthony Willey, David D. Allred, R. Steven Turley

Faculty Publications

We report optical constants of e-beam evaporated yttrium oxide Y2O3 thin films as determined from angle-dependent reflectance measurements at wavelengths from 5 to 50 nm. Samples were measured using synchrotron radiation at the Advanced Light Source. The experimental reflectance data were fit to obtain values for the index of refraction and thin film roughness. We compare our computed constants with those of previous researchers and those computed using the independent atom approximation from the CXRO website. We found that the index of refraction near 36 nm is much lower than previous data from Tomiki as reported by …


The Security Layer, Mark Thomas O'Neill Jan 2019

The Security Layer, Mark Thomas O'Neill

Theses and Dissertations

Transport Layer Security (TLS) is a vital component to the security ecosystem and the most popular security protocol used on the Internet today. Despite the strengths of the protocol, numerous vulnerabilities result from its improper use in practice. Some of these vulnerabilities arise from weaknesses in authentication, from the rigidity of the trusted authority system to the complexities of client certificates. Others result from the misuse of TLS by developers, who misuse complicated TLS libraries, improperly validate server certificates, employ outdated cipher suites, or deploy other features insecurely. To make matters worse, system administrators and users are powerless to fix …


Fine-Grained Topic Models Using Anchor Words, Jeffrey A. Lund Dec 2018

Fine-Grained Topic Models Using Anchor Words, Jeffrey A. Lund

Theses and Dissertations

Topic modeling is an effective tool for analyzing the thematic content of large collections of text. However, traditional probabilistic topic modeling is limited to a small number of topics (typically no more than hundreds). We introduce fine-grained topic models, which have large numbers of nuanced and specific topics. We demonstrate that fine-grained topic models enable use cases not currently possible with current topic modeling techniques, including an automatic cross-referencing task in which short passages of text are linked to other topically related passages. We do so by leveraging anchor methods, a recent class of topic model based on non-negative matrix …


Evaluating An Educational Cybersecurity Playable Case Study, Tanner West Johnson Dec 2018

Evaluating An Educational Cybersecurity Playable Case Study, Tanner West Johnson

Theses and Dissertations

The realities of cyberattacks have become more and more prevalent in the world today. Due to the growing number of these attacks, the need for highly trained individuals has also increased. Because of a shortage of qualified candidates for these positions, there is an increasing need for cybersecurity education within high schools and universities. In this thesis, I discuss the development and evaluation of Cybermatics, an educational simulation, or playable case study, designed to help students learn and develop skills within the cybersecurity discipline.

This playable case study was designed to allow students to gain an understanding of the field …


Designing Cybersecurity Competitions In The Cloud: A Framework And Feasibility Study, Chandler Ryan Newby Dec 2018

Designing Cybersecurity Competitions In The Cloud: A Framework And Feasibility Study, Chandler Ryan Newby

Theses and Dissertations

Cybersecurity is an ever-expanding field. In order to stay current, training, development, and constant learning are necessary. One of these training methods has historically been competitions. Cybersecurity competitions provide a method for competitors to experience firsthand cybersecurity concepts and situations. These experiences can help build interest in, and improve skills in, cybersecurity.

While there are diverse types of cybersecurity competitions, most are run with on-premise hardware, often centralized at a specific location, and are usually limited in scope by available hardware. This research focuses on the possibility of running cybersecurity competitions, specifically CCDC style competitions, in a public cloud environment. …


Nonlinear Optical Characterization Of Solids, Alex Farnsworth Dec 2018

Nonlinear Optical Characterization Of Solids, Alex Farnsworth

Undergraduate Honors Theses

Vibrational Sum Frequency Generation (VSFG) and the similar Second Harmonic Generation (SHG) are both classified as nonlinear optical phenomena, with the hallmark trait being that the input and output frequencies are different. Both of these systems are remarkable tools due to their surface specific nature. Still, there is much that is not known about the response from these systems, especially the nonresonant SFG response. We have worked to better understand SFG signal, specifically the nonresonant temporal profile. We have also collected results that call into question some underlying assumptions about time-based suppression methods when working with single crystal substrates.

As …


User Attitudes About Duo Two-Factor Authentication At Byu, Jonathan Dutson Dec 2018

User Attitudes About Duo Two-Factor Authentication At Byu, Jonathan Dutson

Undergraduate Honors Theses

Simple password-based authentication provides insufficient protection against increasingly common incidents of online identity theft and data loss. Although two-factor authentication (2FA) provides users with increased protection against attackers, users have mixed feelings about the usability of 2FA. We surveyed the students, faculty, and staff of Brigham Young University (BYU) to measure user sentiment about DUO Security, the 2FA system adopted by BYU in 2017. We find that most users consider DUO to be annoying, and about half of those surveyed expressed a preference for authentication without using a second-factor. About half of all participants reported at least one instance of …


Toward Real-Time Flip Fluid Simulation Through Machine Learning Approximations, Javid Kennon Pack Dec 2018

Toward Real-Time Flip Fluid Simulation Through Machine Learning Approximations, Javid Kennon Pack

Theses and Dissertations

Fluids in computer generated imagery can add an impressive amount of realism to a scene, but are particularly time-consuming to simulate. In an attempt to run fluid simulations in real-time, recent efforts have attempted to simulate fluids by using machine learning techniques to approximate the movement of fluids. We explore utilizing machine learning to simulate fluids while also integrating the Fluid-Implicit-Particle (FLIP) simulation method into machine learning fluid simulation approaches.


Security Analysis And Recommendations For Coniks As A Pki Solution For Mobile Apps, George Bradley Spendlove Dec 2018

Security Analysis And Recommendations For Coniks As A Pki Solution For Mobile Apps, George Bradley Spendlove

Theses and Dissertations

Secure mobile apps, including end-to-end encrypted messaging apps such as Whats-App and Signal, are increasingly popular today. These apps require trust in a centralized key directory to automatically exchange the public keys used to secure user communication. This trust may be abused by malicious, subpoenaed, or compromised directories. A public key infrastructure (PKI) solution that requires less trust would increase the security of these commonly used apps.CONIKS is a recent PKI proposal that features transparent key directories which publish auditable digests of the public keys they present to queriers. By monitoring its key every time a new digest is published, …


Improving The Quality Of Neural Machine Translation Using Terminology Injection, Duane K. Dougal Dec 2018

Improving The Quality Of Neural Machine Translation Using Terminology Injection, Duane K. Dougal

Theses and Dissertations

Most organizations use an increasing number of domain- or organization-specific words and phrases. A translation process, whether human or automated, must also be able to accurately and efficiently use these specific multilingual terminology collections. However, comparatively little has been done to explore the use of vetted terminology as an input to machine translation (MT) for improved results. In fact, no single established process currently exists to integrate terminology into MT as a general practice, and especially no established process for neural machine translation (NMT) exists to ensure that the translation of individual terms is consistent with an approved terminology collection. …


Endocytosis As An Additional Mechanism Of Glucose Transport To The Hexose Transporter In Trypanosoma Brucei, Jongsu Choi Dec 2018

Endocytosis As An Additional Mechanism Of Glucose Transport To The Hexose Transporter In Trypanosoma Brucei, Jongsu Choi

Theses and Dissertations

Trypanosoma brucei is an extracellular kineotoplastid parasite that causes human African trypanosomiasis (HAT), also known as sleeping sickness. As trypanosomes undergo vector to host transition, heavy transcriptional adaptation such as metabolic shift to glycolysis and upregulated endocytosis occurs. Specifically, glycolysis in the infectious stage becomes the sole source of energy production; thus, the glucose transport mechanism in T. brucei provides one of the most promising therapeutic targets for development of new drugs to treat HAT. Despite an established trypanosome hexose transporter (THT) model for glucose transport across the plasma membrane, there remains gaps in the detailed mechanism of glucose transport …


Penetration Depth Variation In Atomic Layer Deposition On Multiwalled Carbon Nanotube Forests, David Alan Kane Dec 2018

Penetration Depth Variation In Atomic Layer Deposition On Multiwalled Carbon Nanotube Forests, David Alan Kane

Theses and Dissertations

Atomic Layer Deposition (ALD) of Al2O3 on tall multiwalled carbon nanotube forests shows concentration variation with the depth in the form of discrete steps. While ALD is capable of extremely conformal deposition in high aspect ratio structures, decreasing penetration depth has been observed over multiple thermal ALD cycles on 1.3 mm tall multiwalled carbon nanotube forests. SEM imaging with Energy Dispersive X-ray Spectroscopy elemental analysis shows steps of decreasing intensity corresponding to decreasing concentrations of Al2O3. A study of these steps suggests that they are produced by a combination of diffusion limited delivery of precursors with increasing precursor adsorption site …


Discovery Of Paleotsunami Deposits Along Eastern Sunda Arc: Potential For Megathrust Earthquakes In Bali, Hanif Ibadurrahman Sulaeman Dec 2018

Discovery Of Paleotsunami Deposits Along Eastern Sunda Arc: Potential For Megathrust Earthquakes In Bali, Hanif Ibadurrahman Sulaeman

Theses and Dissertations

Several laterally extensive candidate tsunami deposits are preserved along coastlines facing the eastern Java Trench, indicating it has experienced mega-thrust earthquakes in the past. We investigated 37 coastal sites in Bali, Lombok, Sumba and Timor islands, many of which preserve course sand and pebble layers that overlie sharp basal contacts with scour marks into the mud, fine upward in grain size, and have bimodal grain size distributions. Other unique features are the common occurrence of marine fossils and concentrations of heavy minerals. The occurrence of these high-energy deposits interlayered with clay-rich units indicates the coarse clastics are anomalous because they …


Flow Adaptive Video Object Segmentation, Fanqing Lin Dec 2018

Flow Adaptive Video Object Segmentation, Fanqing Lin

Theses and Dissertations

We tackle the task of semi-supervised video object segmentation, i.e, pixel-level object classification of the images in video sequences using very limited ground truth training data of its corresponding video. Recently introduced online adaptation of convolutional neural networks for video object segmentation (OnAVOS) has achieved good results by pretraining the network, fine-tuning on the first frame and training the network at test time using its approximate prediction as newly obtained ground truth. We propose Flow Adaptive Video Object Segmentation (FAVOS) that refines the generated adaptive ground truth for online updates and utilizes temporal consistency between video frames with the help …


Discovery Of Paleotsunami Deposits Along Eastern Sunda Arc: Potential For Megathrust Earthquakes In Bali, Hanif Ibadurrahman Sulaeman Dec 2018

Discovery Of Paleotsunami Deposits Along Eastern Sunda Arc: Potential For Megathrust Earthquakes In Bali, Hanif Ibadurrahman Sulaeman

Theses and Dissertations

Several laterally extensive candidate tsunami deposits are preserved along coastlines facing the eastern Java Trench, indicating it has experienced mega-thrust earthquakes in the past. We investigated 37 coastal sites in Bali, Lombok, Sumba and Timor islands, many of which preserve course sand and pebble layers that overlie sharp basal contacts with scour marks into the mud, fine upward in grain size, and have bimodal grain size distributions. Other unique features are the common occurrence of marine fossils and concentrations of heavy minerals. The occurrence of these high-energy deposits interlayered with clay-rich units indicates the coarse clastics are anomalous because they …


Cake Cam: Take Your Photo And Be In It Too, Candice Lynn Davis Dec 2018

Cake Cam: Take Your Photo And Be In It Too, Candice Lynn Davis

Theses and Dissertations

In this thesis we explore a different kind of computer-mediated collaboration (CMC) in which two people collaborate to perform a single task in a time-sensitive asymmetric situation wherein one person is more invested in the outcome than the other is. Our conjecture is that interactive computing can quickly communicate intent, which may help mediate time-sensitive asymmetric tasks between two people. We explore this idea specifically in the context of asking a stranger to take one's picture at a tourist site. Consider a tourist handing a cell phone to a complete stranger and asking the stranger to take the tourist's picture …