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Articles 1 - 30 of 2075

Full-Text Articles in Physical Sciences and Mathematics

Characterizing Equivalence And Correctness Properties Of Dynamic Mode Decomposition And Subspace Identification Algorithms, Samuel Gregory Neff Apr 2022

Characterizing Equivalence And Correctness Properties Of Dynamic Mode Decomposition And Subspace Identification Algorithms, Samuel Gregory Neff

Theses and Dissertations

We examine the related nature of two identification algorithms, subspace identification (SID) and Dynamic Mode Decomposition (DMD), and their correctness properties over a broad range of problems. This investigation begins by noting the strong relationship between the two algorithms, both drawing significantly on the pseudoinverse calculation using singular value decomposition, and ultimately revealing that DMD can be viewed as a substep of SID. We then perform extensive computational studies, characterizing the performance of SID on problems of various model orders and noise levels. Specifically, we generate 10,000 random systems for each model order and noise level, calculating the average ...


How Failures Cascade In Software Systems, Barbara W. Chamberlin Apr 2022

How Failures Cascade In Software Systems, Barbara W. Chamberlin

Theses and Dissertations

Cascading failures involve a failure in one system component that triggers failures in successive system components, potentially leading to system wide failures. While frequently used fault tolerant techniques can reduce the severity and the frequency of such failures, they continue to occur in practice. To better understand how failures cascade, we have conducted a qualitative analysis of 55 cascading failures, described in 26 publicly available incident reports. Through this analysis we have identified 16 types of cascading mechanisms (organized into eight categories) that capture the nature of the system interactions that contribute to cascading failures. We also discuss three themes ...


A Permutation-Based Confidence Distribution For Rare-Event Meta-Analysis, Travis Andersen Apr 2022

A Permutation-Based Confidence Distribution For Rare-Event Meta-Analysis, Travis Andersen

Theses and Dissertations

Confidence distributions (CDs), which provide evidence across all levels of significance, are receiving increasing attention, especially in meta-analysis. Meta-analyses allow independent study results to be combined to produce one overall conclusion and are particularly useful in public health and medicine. For studies with binary outcomes that are rare, many traditional meta-analysis methods often fail (Sutton et al. 2002; Efthimiou 2018; Liu et al. 2018; Liu 2019; Hunter and Schmidt 2000; Kontopantelis et al. 2013). Zabriskie et al. (2021b) develop a permutation-based method to analyze such data when study treatment effects vary beyond what is expected by chance. In this work ...


The Perception Of At-Risk Students On Caring Student-Teacher Relationships And Its Impact On Their Productive Disposition, Brittany Hopper Apr 2022

The Perception Of At-Risk Students On Caring Student-Teacher Relationships And Its Impact On Their Productive Disposition, Brittany Hopper

Theses and Dissertations

The importance of a positive, caring relationship with students in the classroom is under-researched in mathematics education. Research shows that a positive student-teacher relationship can have many long-term positive results for the student. Many of these results directly impact a student's productive disposition towards mathematics. At-risk students are in greater need of positive relationships and an increase in productive disposition. Using Joan Tronto's (1993) elements of care, I examine the student perspective of these kinds of relationships and how the student sees development of their own productive disposition.


A Multidimensional Convolutional Bootstrapping Method For The Analysis Of Degradation Data, Jared M. Clark Apr 2022

A Multidimensional Convolutional Bootstrapping Method For The Analysis Of Degradation Data, Jared M. Clark

Theses and Dissertations

While Monte Carlo methods for bootstrapping are typically easy to implement, they can be quite time intensive. This work aims to extend an established convolutional method of bootstrapping to work when convolutions in two or more dimensions are required. The convolutional method relies on efficient computational tools rather than Monte Carlo simulation which can greatly reduce the computation time. The proposed method is particularly well suited for the analysis of degradation data when the data are not collected on time intervals of equal length. The convolutional bootstrapping method is typically much faster than the Monte Carlo bootstrap and can be ...


Accurate Band Energies Of Metals With Quadratic Integration, Jeremy John Jorgensen Apr 2022

Accurate Band Energies Of Metals With Quadratic Integration, Jeremy John Jorgensen

Theses and Dissertations

Materials play an important role in society. Historically, and even at present, materials have been discovered by trial and error, and many of the most useful materials have been discovered by chance. The high-throughput approach aims to remove (as much as possible) chance and guesswork at the experimental level by filtering out materials candidates that are not predicted to exist. Many successes have been recorded. In the high-throughput approach to materials discovery, machined-learned models of materials are created from databases of theoretical materials. These databases are the result of millions of density-functional-theory (DFT) simulations. The size and accuracy of the ...


Inhibition Of Cell Adhesion And Actin Localization During Migration Upon Protective Antigen Mutant Ligand Binding To The Capillary Morphogenesis Gene 2, Sai Lun Lee Apr 2022

Inhibition Of Cell Adhesion And Actin Localization During Migration Upon Protective Antigen Mutant Ligand Binding To The Capillary Morphogenesis Gene 2, Sai Lun Lee

Theses and Dissertations

Capillary Morphogenesis Gene 2 protein (CMG2) is a type 1 transmembrane receptor known as the anthrax toxin receptor 2 (ANTXR2). While it is documented that the cell surface receptor CMG2 mediates anthrax toxin entry into the cell via endocytosis, the physiological role of CMG2 is not well understood. Others have suggested that CMG2 may have a role in mediating ECM homeostasis and angiogenesis. Additionally, both anthrax protective antigen (PA) and a furin protease-resistant mutant, PASSSR, inhibit corneal neovascularization in a mouse model, and interestingly PASSSR has a greater affinity to CMG2 receptor. PASSSRalso has a more potent antiangiogenic effect than ...


Physics-Guided Machine Learning In Ocean Acoustics Using Fisher Information, Michael Craig Mortenson Apr 2022

Physics-Guided Machine Learning In Ocean Acoustics Using Fisher Information, Michael Craig Mortenson

Theses and Dissertations

Waterborne acoustic signals carry information about the ocean environment. Ocean geoacoustic inversion is the task of estimating environmental parameters from received acoustic signals by matching the measured sound with the predictions of a physics-based model. A lower bound on the uncertainty associated with environmental parameter estimates, the Cramér-Rao bound, can be calculated from the Fisher information, which is dependent on derivatives of a physics-based model. Physics-based preconditioners circumvent the need for variable step sizes when computing numerical derivatives. This work explores the feasibility of using a neural network to perform geoacoustic inversion for environmental parameters and their associated uncertainties from ...


“If I Could Do This, I Feel Anyone Could:” The Design And Evaluation Of A Two-Factor Authentication Manager, Garrett D. Smith Apr 2022

“If I Could Do This, I Feel Anyone Could:” The Design And Evaluation Of A Two-Factor Authentication Manager, Garrett D. Smith

Theses and Dissertations

Two-factor authentication (2FA) is a strong defense against account compromise. However, usability studies reveal challenges with 2FA setup. The process to manually setup and remove 2FA methods differs across websites. We present a system design for a 2FA manager to automatically setup and remove 2FA methods. Potential benefits are reduced time, fewer mistakes, consistent terminology, a single workflow for users to learn, and the ability to rapidly transition to a new 2FA method—e.g., when replacing a lost 2FA method. We create two proof-of-concept implementations of our design, one as a browser extension and one integrated as a feature ...


Using Connections To Make Predictions On Dynamic Networks, Rebecca Dorff Jones Apr 2022

Using Connections To Make Predictions On Dynamic Networks, Rebecca Dorff Jones

Theses and Dissertations

Networks are sets of objects that are connected in some way and appear abundantly in nature, sociology, and technology. For many centuries, network theory focused on static networks, which are networks that do not change. However, since all networks transform over time, static networks have limited applications. By comparison, dynamic networks model how connections between objects change over time. In this work, we will explore how connections in dynamic networks change and how we can leverage these changes to make predictions about future iterations of networks. We will do this by first considering the link prediction problem, using either Katz ...


Statistical Properties Of 2d Navier-Stokes Equations Driven By Quasi-Periodic Force And Degenerate Noise, Rongchang Liu Apr 2022

Statistical Properties Of 2d Navier-Stokes Equations Driven By Quasi-Periodic Force And Degenerate Noise, Rongchang Liu

Theses and Dissertations

We consider the incompressible 2D Navier-Stokes equations on the torus driven by a deterministic time quasi-periodic force and a noise that is white in time and extremely degenerate in Fourier space. We show that the asymptotic statistical behavior is characterized by a uniquely ergodic and exponentially mixing quasi-periodic invariant measure. The result is true for any value of the viscosity ν > 0. By utilizing this quasi-periodic invariant measure, we show the strong law of large numbers and central limit theorem for the continuous time inhomogeneous solution processes. Estimates of the corresponding rate of convergence are also obtained, which is the ...


Stabilizing Controlled Systems In The Presence Of Time-Delays, Isaac Becker Pardo Apr 2022

Stabilizing Controlled Systems In The Presence Of Time-Delays, Isaac Becker Pardo

Theses and Dissertations

A dynamical system's state evolves over time, and when the system stays near a particular state this state is known as a stable state of the system. Through control methods, dynamical systems can be manipulated such that virtually any state can be made stable. Although most real systems evolve continuously in time the application of digital control methods to these systems is inherently discrete. States are sampled (with sensors) and fed back into the system in discrete-time to determine the input needed to control the continuous system. Additionally, dynamical systems often experience time delays. Some examples of time delays ...


Computationally Assisted Nmr Crystallography: A Path To Unusually High-Resolution Crystal Structures, Luther Wang Apr 2022

Computationally Assisted Nmr Crystallography: A Path To Unusually High-Resolution Crystal Structures, Luther Wang

Theses and Dissertations

Crystallography has traditionally been studied by diffraction methods involving X ray or neutron radiation. These methods have some limitations, from requiring the substance under study to form single crystals to the limited ability of X rays to locate hydrogen atoms. While neutron radiation can characterize hydrogens, it is expensive, not readily available and has its own particular limits on resolution. It this dissertation, it is demonstrated that NMR is extraordinarily sensitive to atomic positions, with variations of mere tens of femtometers creating statistically distinguishable chemical shift changes. To date, no other means of measurement can detect structural changes at this ...


Gas Phase Structure Characterization Of Host-Guest Systems Using Ion Mobility Spectrometry, Jamir Shrestha Apr 2022

Gas Phase Structure Characterization Of Host-Guest Systems Using Ion Mobility Spectrometry, Jamir Shrestha

Theses and Dissertations

This dissertation focuses on the investigation of gas-phase characteristics of cucurbituril host-guest systems using ion mobility spectrometry (IMS) and related techniques. Collision cross-sections (CCS) of alkylammonium complexes of cucurbit[n]uril (CB[n]) are measured to understand the allosteric interactions that induce conformational changes in the complex in the presence of metal cations on one of the portals of the cucurbit[6]uril (CB[6]) host. Cationic species on one CB[6] rim sterically force longer linear alkylammonium guests out of the cucurbituril cavity during complex formation. Similarly, rigid cucurbituril-metal complexes were studied using IMS to demonstrate the effect of ...


Atg9a And Atg13 Cooperate To Drive Basal Autophagy, Daniel Morgan Poole Apr 2022

Atg9a And Atg13 Cooperate To Drive Basal Autophagy, Daniel Morgan Poole

Theses and Dissertations

Autophagy, as the name suggests, is a cellular process of self-eating in which cytoplasmic debris is engulfed by a double membrane vesicle dubbed the autophagosome and is ultimately degraded and recycled by proteases in the lysosome. The process is initiated by a group of core ATG proteins, including a multi-pass transmembrane protein called ATG9A. Although ATG9A has been shown to be essential for both stress induced and basal autophagy, its mechanism and interaction network remain largely illusive. Our current study employs BioID proteomics to identify a network of interactors, including regulators of membrane fusion and vesicle trafficking, such as TRAPP ...


Musical Phrase Segmentation Via Grammatical Induction, Reed James Perkins Apr 2022

Musical Phrase Segmentation Via Grammatical Induction, Reed James Perkins

Theses and Dissertations

Procedural generation algorithms can infer rules based on a dataset of examples when each example is made up of labeled components. Unfortunately, musical sequences resist potential inclusion in these kinds of datasets because they lack explicit structural semantics. In order to algorithmically transform a musical sequence into a sequence of labeled components, a segmentation process is needed. We outline a solution to the challenge of musical phrase segmentation that uses grammatical induction algorithms, a class of algorithms which infer a context-free grammar from an input sequence. We study five different grammatical induction algorithms on three different datasets, one of which ...


Datadescription-Detection Of Sulfur Dioxide By Broadband Cavity-Enhanced Absorption Spectroscopy (Bbceas), Ryan Thalman, Nitish Bhardwaj, Callum Flowerday, Jaron C. Hansen Apr 2022

Datadescription-Detection Of Sulfur Dioxide By Broadband Cavity-Enhanced Absorption Spectroscopy (Bbceas), Ryan Thalman, Nitish Bhardwaj, Callum Flowerday, Jaron C. Hansen

ScholarsArchive Data

Files archived include the following:

Figure1.txt This file contains all the data used to make Figure 1 in the paper.

Figure4.txt This file contains all the data used to make Figure 4 in the paper.

Figure5.txt This file contains all the data used to make Figure 5 in the paper.

Figure6.txt This file contains all the data used to make Figure 6 in the paper.

Figure7.txt This file contains the code, written in Igor, that was used to generate this figure.

Figure8.txt This file contains all the data used to make Figure 8 in ...


Enhancing The Opportunities For Adults With Autism To Find Jobs Using A Job-Matching Algorithm, Joseph T. Bills Apr 2022

Enhancing The Opportunities For Adults With Autism To Find Jobs Using A Job-Matching Algorithm, Joseph T. Bills

Theses and Dissertations

Adults with autism face many difficulties when finding employment, such as struggling with interviews and needing accommodating environments for sensory issues. However, autistic adults also have unique skills to contribute to the workplace that companies have recently started to seek after, such as close attention to detail and trustworthiness. To work around these difficulties and help companies find the talent they are looking for we have developed a job-matching system. Our system is based around the stable matching of the Gale-Shapley algorithm to match autistic adults with employers after estimating how both adults with autism and employers would rank the ...


Identification Of Sources Of Air Pollution Using Novel Analytical Techniques And Instruments, Nitish Bhardwaj Mar 2022

Identification Of Sources Of Air Pollution Using Novel Analytical Techniques And Instruments, Nitish Bhardwaj

Theses and Dissertations

This dissertation is a collection of studies that investigates the issue of air pollution in the field of environmental chemistry. My thesis consists of research works done to measure the concentration of particulate matter (PM) and gas-phase species in ambient air. High concentrations of PM is a significant problem in Utah and in other regions of the world. Particles having an aerodynamic diameter of 2.5 micrometers and smaller play a crucial role in air pollution and pose serious health risks when inhaled. PM is composed of both organic and inorganic components. The organic fraction in PM ranges from 10-90 ...


Confronting Barriers To Human-Robot Cooperation: Balancing Efficiency And Risk In Machine Behavior, Tim Whiting Mar 2022

Confronting Barriers To Human-Robot Cooperation: Balancing Efficiency And Risk In Machine Behavior, Tim Whiting

Theses and Dissertations

In strategically rich settings in which machines and people do not fully share the same preferences, machines must learn to cooperate and compromise with people to establish mutually successful relationships. However, designing machines that effectively cooperate with people in these settings is difficult due to a variety of technical and psychological challenges. To better understand these challenges, we conducted a series of user studies in which we investigated human-human, robot-robot, and human-robot cooperation in a simple, yet strategically rich, resource-sharing scenario called the Block Dilemma, a game in which players must balance fairness, efficiency, and risk. While both human-human and ...


Symbolic Semantic Memory In Transformer Language Models, Robert Kenneth Morain Mar 2022

Symbolic Semantic Memory In Transformer Language Models, Robert Kenneth Morain

Theses and Dissertations

This paper demonstrates how transformer language models can be improved by giving them access to relevant structured data extracted from a knowledge base. The knowledge base preparation process and modifications to transformer models are explained. We evaluate these methods on language modeling and question answering tasks. These results show that even simple additional knowledge augmentation leads to a reduction in validation loss by 73%. These methods also significantly outperform common ways of improving language models such as increasing the model size or adding more data.


Polymer Coated Urea Microplastics: Urban Landscape, C. J. Seely, B. T. Geary, B. G. Hopkins Mar 2022

Polymer Coated Urea Microplastics: Urban Landscape, C. J. Seely, B. T. Geary, B. G. Hopkins

Library/Life Sciences Undergraduate Poster Competition 2022

  • Polymer Coated Urea (PCU) is an effective fertilizer.
  • Microplastics, from a wide range of waste materials, pollute water bodies.
  • One potential source of microplastics are from PCU fertilizers if the coatings are transported overland into water bodies.
  • Various urban landscape systems vary in the potential for surface runoff.


Material Characterization Using Nuclear Magnetic Resonance, Giovanna Marcella Pope Feb 2022

Material Characterization Using Nuclear Magnetic Resonance, Giovanna Marcella Pope

Theses and Dissertations

Nuclear magnetic resonance techniques can provide highly accurate information about the local environment of both liquid and solid samples. In the first half of this dissertation research, solid state NMR has provided experimental evidence for turbostratic disorder in layered covalent organic solids. Additionally, comparison with candidate structures allowed a proposed correction to the accepted structure of Covalent Organic Framework-5. The second half of the dissertation work emphasized liquid NMR spectroscopy applied to doped iron oxides (IOs). In particular, the effect of IOs on water proton T2 relaxation times were determined as a measure of contrast agent efficacy. Both types of ...


Kemar Hats Head Orientation Directivity, Samuel D. Bellows, Timothy W. Leishman Jan 2022

Kemar Hats Head Orientation Directivity, Samuel D. Bellows, Timothy W. Leishman

Directivity

No abstract provided.


Pentagonal Extensions Of The Rationals Ramified At A Single Prime, Pablo Miguel Rodriguez Dec 2021

Pentagonal Extensions Of The Rationals Ramified At A Single Prime, Pablo Miguel Rodriguez

Theses and Dissertations

In this thesis, we define a certain group of order 160, which we call a hyperpentagonal group, and we prove that every totally real D5-extension of the rationals ramified at only one prime is contained in a hyperpentagonal extension of the rationals. This generalizes a result of Doud and Childers (originally conjectured by Wong) that every totally real S3 extension of the rationals ramified at only one prime is contained in an S4 extension.


An Analysis Of Two Photometric Redshift Methods And Their Uses For Finding Void Galaxies, Rochelle J. Steele Dec 2021

An Analysis Of Two Photometric Redshift Methods And Their Uses For Finding Void Galaxies, Rochelle J. Steele

Theses and Dissertations

An extensive survey of extragalactic objects with accurate distances is difficult to perform. Distance at that scale is commonly found with redshift and most easily identified with spectroscopic observations, which are time intensive. This is especially a concern when surveying for the elusive, possibly non-existent dwarf galaxies in the centers of voids, whose light would be so faint that a spectroscopic survey to find them would be unreasonably time consuming. Photometric methods to calculate redshift could provide a much quicker way to find distance, but the photometric methods used thus far are characterized by large errors that make them unusable ...


Using Facies Analysis And Reservoir Characterization Of The Albian-Cenomanian Nanushuk Formation To Assist In Better Understanding Interactions Between Shoreface, Deltaic, And Fluvial Systems On The North Slope, Alaska, Andrea Smoot Dec 2021

Using Facies Analysis And Reservoir Characterization Of The Albian-Cenomanian Nanushuk Formation To Assist In Better Understanding Interactions Between Shoreface, Deltaic, And Fluvial Systems On The North Slope, Alaska, Andrea Smoot

Theses and Dissertations

The Albian-Cenomanian Nanushuk Formation located on the North Slope of Alaska is the result of fluvial, deltaic, and shoreface processes and has been the focus of recent petroleum exploration activity in the Colville Basin. The Nanushuk and underlying Torok formations together contain an estimated 8.7 billion barrels of oil and 25 trillion cubic feet of natural gas reserves within the resource-rich North Slope. The Nanushuk Formation is composed of sediment sourced from the Chukotka Peninsula to the west and deposited axially within the Colville Basin. High sedimentation rates led to rapid progradation of shoreface and deltaic systems, which effectively ...


Deep Parameter Selection For Classic Computer Vision Applications, Michael Whitney Dec 2021

Deep Parameter Selection For Classic Computer Vision Applications, Michael Whitney

Theses and Dissertations

A trend in computer vision today is to retire older, so-called "classic'' methods in favor of ones based on deep neural networks. This has led to tremendous improvements in many areas, but for some problems deep neural solutions may not yet exist or be of practical application. For this and other reasons, classic methods are still widely used in a variety of applications. This paper explores the possibility of using deep neural networks to improve these older methods instead of replace them. In particular, it addresses the issue of parameter selection in these algorithms by using a neural network to ...


Minimizer Of A Free Boundary Problem, Mingyan Zhao Dec 2021

Minimizer Of A Free Boundary Problem, Mingyan Zhao

Theses and Dissertations

We study a free boundary problem with initial data given on three-dimensional cones. In particular, we study when the free boundary is allowed to pass through the vertex of the cone, which depends on the cone’s slope, determined by a parameter c. With a mix of analytical and computational methods, we show that the free boundary may pass through the vertex of the cone when c ≤ 0.43.


Modeling A Human Family Network, Rebecca Jo Flores Dec 2021

Modeling A Human Family Network, Rebecca Jo Flores

Theses and Dissertations

We propose a model that generates a family network based on real-world family network data. We use this model to study the extent to which distances to union and the number of children characterize family networks. To determine how accurate our model is we use persistent homology to identify and compare the structure of our modeled family networks to real-world family networks. To accomplish this, we introduce the notion of a network's persistence curve, which encodes the network's set of persistence intervals. Using the bottleneck distance allows us to measure the difference in the homological structure between any ...