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Articles 571 - 600 of 2906

Full-Text Articles in Physical Sciences and Mathematics

Normally Supportive Sublattices Of Crystallographic Space Groups, Miles A. Clemens Dec 2018

Normally Supportive Sublattices Of Crystallographic Space Groups, Miles A. Clemens

Theses and Dissertations

Normal subgroups can be thought of as the primary building blocks for decomposing mathematicalgroups into quotient groups. The properties of the resulting quotient groups are oftenused to determine properties of the group itself. This thesis considers normal subgroups of threedimensionalcrystallographic space groups that are themselves three-dimensional crystallographicspace groups; for convenience, we refer to such a subgroup as a csg-normal subgroup. We identifypractical restrictions on csg-normal subgroups that facilitate their tabulation. First, the point groupof an csg-normal subgroup must be a normal subgroup of the crystallographic point group of thespace group, which we refer to for convenience as a cpg-normal subgroup. …

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The Use Of Tissue And Serum ”˜Omics' Methods To Characterize Disease, Ying Ding Dec 2018

The Use Of Tissue And Serum ”˜Omics' Methods To Characterize Disease, Ying Ding

Theses and Dissertations

Preeclampsia (PE) is a multisystem disorder that contributes to maternal and fetal mortality and morbidity worldwide. It is characterized by de-novo hypertension and proteinuria or other maternal organ damage after 20 weeks of gestation. Evidence suggested that endogenous digitalis-like factor (EDLF) contributes to the pathogenesis of PE, and that the potential source of EDLF is the placenta. EDLF can inhibit the sodium pump (SP) specifically and may lead to hypertension, it has also been associated with hypoxia, oxidative stress and other abnormalitites present in PE.We studied whether normal human placenta responded to SP inhibition casued by EDLF with a change …

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The Bird And The Fish: Motion Field-Based Frame Interpolation In The Context Of A Story, Thomas Sterling Ellsworth Dec 2018

The Bird And The Fish: Motion Field-Based Frame Interpolation In The Context Of A Story, Thomas Sterling Ellsworth

Theses and Dissertations

Animating by hand can be a long and challenging process in part because of the necessity of drawing every frame by hand. 3D animation media minimize this problem with the use of automatically interpolated frames, but despite significant research no universally acceptable techniques have been demonstrated for 2 dimensional interpolation. In this paper we explore computer-assisted optimizations to the animation pipeline. Specifically, we utilize 3D motion fields to create more realistic in-between frames for sets of 2D ``key frames.'' We demonstrate our method by using it to create 2D special effects for a 30-second clip of an animated short film.

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Usable Security And Privacy For Secure Messaging Applications, Elham Vaziripour Dec 2018

Usable Security And Privacy For Secure Messaging Applications, Elham Vaziripour

Theses and Dissertations

The threat of government and corporate surveillance around the world, as well as the publicity surrounding major cybersecurity attacks, have increased interest in secure and private end-to-end communications. In response to this demand, numerous secure messaging applications have been developed in recent years. These applications have been welcomed and publically used not just by political activists and journalists but by everyday users as well. Most of these popular secure messaging applications are usable because they hide many of the details of how encryption is provided. The strength of the security properties of these applications relies on the authentication ceremony, wherein …

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Divisibility Properties Of Coefficients Of Modular Functions Of Genus Zero Levels, Merrill Warnick Nov 2018

Divisibility Properties Of Coefficients Of Modular Functions Of Genus Zero Levels, Merrill Warnick

Undergraduate Honors Theses

We prove divisibility results for the Fourier coefficients of canonical basis elements for the spaces of weakly holomorphic modular forms of weight 0 and levels 6, 10, 12, 18 with poles only at the cusp at infinity. In addition, we show that these Fourier coefficients satisfy Zagier duality in all weights, and give a general formula for the generating functions of such canonical bases for all genus zero levels. These results originally appeared in a paper of the same title that was accepted by the journal Integers, and was authored by the present author, with Paul Jenkins and Vicki

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Writing And Designing A Chapter On Mercury And Pluto For The Textbook Exploring The Planets (Explanet.Info), Braxton Clark Spilker Nov 2018

Writing And Designing A Chapter On Mercury And Pluto For The Textbook Exploring The Planets (Explanet.Info), Braxton Clark Spilker

Theses and Dissertations

Exploring the Planets (http://explanet.info) is a free online college textbook covering thebasic concepts of planetary science emphasizing the character and evolution of the planetarybodies in the Solar System. The latest edition (3rd edition) was published online in 2007 by EricH Christiansen. Since the release of the third edition, two important planetary missions havebeen completed: MESSENGER (to Mercury) and New Horizons (to Pluto). These missionsprovided new information and fundamental insights into these planetary bodies, which have notyet been included in Exploring the Planets. The modern results based on recent investigations ofMercury and Pluto are critical for our understanding of the nature …

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Netlight: Cloud Baked Indirect Illumination, Nathan Andrew Zabriskie Nov 2018

Netlight: Cloud Baked Indirect Illumination, Nathan Andrew Zabriskie

Theses and Dissertations

Indirect lighting drastically increases the realism of rendered scenes but it has traditionally been very expensive to calculate. This has long precluded its use in real-time rendering applications such as video games which have mere milliseconds to respond to user input and produce a final image. As hardware power continues to increase, however, some recently developed algorithms have started to bring real-time indirect lighting closer to reality. Of specific interest to this paper, cloud-based rendering systems add indirect lighting to real-time scenes by splitting the rendering pipeline between a server and one or more connected clients. However, thus far they …

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Clean Indices Of Common Rings, Benjamin L. Schoonmaker Nov 2018

Clean Indices Of Common Rings, Benjamin L. Schoonmaker

Theses and Dissertations

Lee and Zhou introduced the clean index of rings in 2004. Motivated by this work, Basnet and Bhattacharyya introduced both the weak clean index of rings and the nil clean index of rings and Cimpean and Danchev introduced the weakly nil clean index of rings. In this work, we calculate each of these indices for the rings ℤ/nℤ and matrix rings with entries in ℤ/nℤ. A generalized index is also introduced.

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Using Machine Learning To Accurately Predict Ambient Soundscapes From Limited Data Sets, Katrina Lynn Pedersen Oct 2018

Using Machine Learning To Accurately Predict Ambient Soundscapes From Limited Data Sets, Katrina Lynn Pedersen

Theses and Dissertations

The ability to accurately characterize the soundscape, or combination of sounds, of diverse geographic areas has many practical implications. Interested parties include the United States military and the National Park Service, but applications also exist in areas such as public health, ecology, community and social justice noise analyses, and real estate. I use an ensemble of machine learning models to predict ambient sound levels throughout the contiguous United States. Our data set consists of 607 training sites, where various acoustic metrics, such as overall daytime L50 levels and one-third octave frequency band levels, have been obtained. I have data for …

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Certificate Revocation Table: Leveraging Locality Of Reference In Web Requests To Improve Tls Certificate Revocation, Luke Austin Dickinson Oct 2018

Certificate Revocation Table: Leveraging Locality Of Reference In Web Requests To Improve Tls Certificate Revocation, Luke Austin Dickinson

Theses and Dissertations

X.509 certificate revocation defends against man-in-the-middle attacks involving a compromised certificate. Certificate revocation strategies face scalability, effectiveness, and deployment challenges as HTTPS adoption rates have soared. We propose Certificate Revocation Table (CRT), a new revocation strategy that is competitive with or exceeds alternative state-of-the-art solutions in effectiveness, efficiency, certificate growth scalability, mass revocation event scalability, revocation timeliness, privacy, and deployment requirements. The CRT periodically checks the revocation status of X.509 certificates recently used by an organization, such as clients on a university's private network. By prechecking the revocation status of each certificate the client is likely to use, the client …

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A Quantitative Study Of The Deployment Of The Sender Policy Framework, Eunice Zsu Tan Oct 2018

A Quantitative Study Of The Deployment Of The Sender Policy Framework, Eunice Zsu Tan

Theses and Dissertations

Email has become a standard form of communication between businesses. With the prevalent use of email as a form of communication between businesses and customers, phishing emails have emerged as a popular social engineering approach. With phishing, attackers trick users into divulging their personal information through email spoofing. Thus, it is imperative to verify the sender of an email. Anti-spoofing mechanisms such as the Sender Policy Framework (SPF) have been developed as the first line of defense against spoofing by validating the source of an email as well as the presenting options of how to handle emails that fail to …

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Development And Use Of Lipidomics And Proteomics Methods To Identify And Measure Pro-Survival Metabolic Pathways In Cancer, Monique Merilyn Speirs Oct 2018

Development And Use Of Lipidomics And Proteomics Methods To Identify And Measure Pro-Survival Metabolic Pathways In Cancer, Monique Merilyn Speirs

Theses and Dissertations

Throughout society’s continual war against cancer, we have attempted pharmacological intervention only to find that tumors develop modes of resistance. It is well known that genetics play an integral role in cancer. Technological advances have greatly improved our ability to study cancer biochemistry beyond the genome by measuring changes in the expression and activity of RNA, proteins, and lipids in experimental models and human patients. As our techniques and technology to perform cancer research progresses, it is becoming more evident that cancer cells develop stress tolerance mechanisms at multiple levels within the central dogma, including altering mRNA expression, enzyme concentrations, …

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Fully Convolutional Neural Networks For Pixel Classification In Historical Document Images, Seth Andrew Stewart Oct 2018

Fully Convolutional Neural Networks For Pixel Classification In Historical Document Images, Seth Andrew Stewart

Theses and Dissertations

We use a Fully Convolutional Neural Network (FCNN) to classify pixels in historical document images, enabling the extraction of high-quality, pixel-precise and semantically consistent layers of masked content. We also analyze a dataset of hand-labeled historical form images of unprecedented detail and complexity. The semantic categories we consider in this new dataset include handwriting, machine-printed text, dotted and solid lines, and stamps. Segmentation of document images into distinct layers allows handwriting, machine print, and other content to be processed and recognized discriminatively, and therefore more intelligently than might be possible with content-unaware methods. We show that an efficient FCNN with …

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Fully Convolutional Neural Networks For Pixel Classification In Historical Document Images, Seth Andrew Stewart Oct 2018

Fully Convolutional Neural Networks For Pixel Classification In Historical Document Images, Seth Andrew Stewart

Theses and Dissertations

We use a Fully Convolutional Neural Network (FCNN) to classify pixels in historical document images, enabling the extraction of high-quality, pixel-precise and semantically consistent layers of masked content. We also analyze a dataset of hand-labeled historical form images of unprecedented detail and complexity. The semantic categories we consider in this new dataset include handwriting, machine-printed text, dotted and solid lines, and stamps. Segmentation of document images into distinct layers allows handwriting, machine print, and other content to be processed and recognized discriminatively, and therefore more intelligently than might be possible with content-unaware methods. We show that an efficient FCNN with …

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Using Aviris And Machine Learning To Map And Discriminate Bull Kelp And Giant Kelp Along The Pacific Coast Of The United States, Tanner Thompson, Dr. Ryan Jensen Sep 2018

Using Aviris And Machine Learning To Map And Discriminate Bull Kelp And Giant Kelp Along The Pacific Coast Of The United States, Tanner Thompson, Dr. Ryan Jensen

Journal of Undergraduate Research

Kelp forests provide food and shelter for many organisms, and they are an important part of coastal ecosystems throughout the world. Along the Pacific coast of the United States, kelp forests are made up of two species of kelp: bull kelp (Nereocystis Leutkana) and giant kelp (Macrocystis Pyrifera). While similar, these two species are physiologically and structurally different.

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Linear Least Squares Curve Fitting, R. Steven Turley Sep 2018

Linear Least Squares Curve Fitting, R. Steven Turley

Faculty Publications

This article is a review of the theory and practice behind linear least squares curve fitting. It outlines how to find the optimal parameters to match experimental data with theory and how to estimate the uncertainty in those parameters. The article demonstrates and validates these calculations in Excel, MATLAB, Mathematica, Python, and Julia.

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Fitting Parameter Uncertainties In Least Squares Fitting, R. Steven Turley Sep 2018

Fitting Parameter Uncertainties In Least Squares Fitting, R. Steven Turley

Faculty Publications

This article review the theory and practice of computing uncertainties in the fit parameters in least squares fits. It shows how to estimate the uncertainties and gives some numerical examples in Julia of their use. Examples are given and validated for both linear and nonlinear fits.

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Polynomial Fitting, R. Steven Turley Sep 2018

Polynomial Fitting, R. Steven Turley

Faculty Publications

This article reviews the theory and some good practice for fitting polynomials to data. I show by theory and example why fitting using a basis of orthogonal polynomials rather than monomials is desirable. I also show how to scale the independent variable for a more stable fit. I also demonstrate how to compute the uncertainty in the fit parameters. Finally, I discuss regression analysis: how to determine whether adding an additional term to the fit is justified.

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Cubic Interpolation With Irregularly-Spaced Points In Julia 1.4, R. Steven Turley Aug 2018

Cubic Interpolation With Irregularly-Spaced Points In Julia 1.4, R. Steven Turley

Faculty Publications

This article shows how to interpolate between regularly- or irregularly-spaced points in Julia 1.4. It has derivations of the theory behind cubic splines, and piece-wise cubic hermite polynomial interpolation. The spline interpolants are continuous and have continuous first and second derivatives. The hermite polynomial interpolants are continuous and have continuous first derivatives. Three techniques are implemented to determine the slope at the data points for the interpolation (knots). One uses the average slope of the neighboring segments. Another use the quadratic polynomial passing through the point and its two neighbors. The third, PCHIP, is similar to the first method, but …

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Fluorescent Labeling Of Antibiotic Resistant Bacteria Model Dna, Janice Darko Aug 2018

Fluorescent Labeling Of Antibiotic Resistant Bacteria Model Dna, Janice Darko

Theses and Dissertations

Global threats to treatment of bacterial infections due to antibiotic resistance (AR) have been on the rise in recent years. Current diagnostic tests identify bacteria by using blood culture, which takes more than 24 hours. This study focuses on the fluorescent labeling of DNA derived from bacterial AR genes (KPC & VIM) and other model DNAs using oligreen dye (OG) and molecular beacons (MB). A NanoDrop 3300 fluorospectrometer was used to take fluorescence measurements. Linear dynamic range and labeling efficiency were dependent on the following optimized conditions: dilution factor of OG (200 fold), buffer (20 mM Tris HCl, pH 8), …

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Model Predictive Linear Control With Successive Linearization, Jesse Robert Friedbaum Aug 2018

Model Predictive Linear Control With Successive Linearization, Jesse Robert Friedbaum

Theses and Dissertations

Robots have been a revolutionizing force in manufacturing in the 20th and 21st century but have proven too dangerous around humans to be used in many other fields including medicine. We describe a new control algorithm for robots developed by the Brigham Young University Robotics and Dynamics and Robotics Laboratory that has shown potential to make robots less dangerous to humans and suitable to work in more applications. We analyze the computational complexity of this algorithm and find that it could be a feasible control for even the most complicated robots. We also show conditions for a system which guarantee …

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Model Predictive Linear Control With Successive Linearization, Jesse Robert Friedbaum Aug 2018

Model Predictive Linear Control With Successive Linearization, Jesse Robert Friedbaum

Theses and Dissertations

Robots have been a revolutionizing force in manufacturing in the 20th and 21st century but have proven too dangerous around humans to be used in many other fields including medicine. We describe a new control algorithm for robots developed by the Brigham Young University Robotics and Dynamics and Robotics Laboratory that has shown potential to make robots less dangerous to humans and suitable to work in more applications. We analyze the computational complexity of this algorithm and find that it could be a feasible control for even the most complicated robots. We also show conditions for a system which guarantee …

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Synthesis And Determination Of The Local Structure And Phase Evolution Of Unique Boehmite-Derived Mesoporous Doped Aluminas, Ying Zhang Aug 2018

Synthesis And Determination Of The Local Structure And Phase Evolution Of Unique Boehmite-Derived Mesoporous Doped Aluminas, Ying Zhang

Theses and Dissertations

Mesoporous alumina (Al2O3) in the gamma (γ) phase is widely used as a support in catalytic applications because of its high surface area, large pore volume, acid-base characteristics, and thermal stability. To improve the thermal stability of gamma alumina, dopants such as lanthanum, magnesium, zirconia, and silica are often introduced. Current laboratory-based methods for synthesizing gamma alumina generally involve 10-15 steps and/or use toxic, expensive surfactants and solvents. Industrial methods, while simpler, lack control of pore properties and surface chemistry. In contrast, we have developed an innovative solvent deficient, one-step method that is able to synthesize a wide range of …

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Implementation And Optimization Of Time Reversal For Use In Nondestructive Evaluation Of Stress Corrosion Cracking, Sarah Marie Young Aug 2018

Implementation And Optimization Of Time Reversal For Use In Nondestructive Evaluation Of Stress Corrosion Cracking, Sarah Marie Young

Theses and Dissertations

The time reversal (TR) process manipulates a system's impulse response in order to focus a peak of acoustic energy at a specific location in space and time. This technique has been implemented in both fluid and solid media for purposes ranging from communications to source localization. This thesis will examine both the implementation and processing of TR for nondestructive evaluation in steel, specializing in nonlinear detection methods. A series of steel samples are inspected for stress corrosion cracking (SCC) using TR focusing to excite nonlinearities inherent in cracks. It is determined that SCC exists in the expected regions of the …

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Time-Domain Characterization Of Nonlinear Propagation In Military Aircraft Jet Noise, Brent Owen Reichman Jul 2018

Time-Domain Characterization Of Nonlinear Propagation In Military Aircraft Jet Noise, Brent Owen Reichman

Theses and Dissertations

Nonlinear propagation and shock formation are shown in noise radiated from full-scale military jet aircraft. Perception of sound is not only affected by the overall sound pressure level of the noise, but also characteristics of the sound itself. In the case of jet noise, acoustic shocks within the waveforms result in a characteristic commonly referred to as"crackle." The origin of shocks in the far-field of jet noise is shown to be through nonlinear propagation. Metrics characterizing the shock content of a waveform are explained and given physical significance, then applied to jet noise at various distances and engine conditions to …

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Euclidean Domains, Vandy Jade Tombs Jul 2018

Euclidean Domains, Vandy Jade Tombs

Theses and Dissertations

In the usual definition of a Euclidean domain, a ring has a norm function whose codomain is the positive integers. It was noticed by Motzkin in 1949 that the codomain could be replaced by any well-ordered set. This motivated the study of transfinite Euclidean domains in which the codomain of the norm function is replaced by the class of ordinals. We prove that there exists a (transfinitely valued) Euclidean Domain with Euclidean order type for every indecomposable ordinal. Modifying the construction, we prove that there exists a Euclidean Domain with no multiplicative norm. Following a definition of Clark and Murty, …

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The Arithmetic Of Modular Grids, Grant Steven Molnar Jul 2018

The Arithmetic Of Modular Grids, Grant Steven Molnar

Theses and Dissertations

Let Mk(∞) (Gamma, nu) denote the space of weight k weakly holomorphic weight modular forms with poles only at the cusp (∞), and let widehat Mk(∞) (Gamma, nu) subseteq Mk(∞) (Gamma, nu) denote the space of weight k weakly holomorphic modular forms in Mk(∞) (Gamma, nu) which vanish at every cusp other than (∞). We construct canonical bases for these spaces in terms of Maass--Poincaré series, and show that the coefficients of these bases satisfy Zagier duality.

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Machine Learning For Inspired, Structured, Lyrical Music Composition, Paul Mark Bodily Jul 2018

Machine Learning For Inspired, Structured, Lyrical Music Composition, Paul Mark Bodily

Theses and Dissertations

Computational creativity has been called the "final frontier" of artificial intelligence due to the difficulty inherent in defining and implementing creativity in computational systems. Despite this difficulty computer creativity is becoming a more significant part of our everyday lives, in particular music. This is observed in the prevalence of music recommendation systems, co-creational music software packages, smart playlists, and procedurally-generated video games. Significant progress can be seen in the advances in industrial applications such as Spotify, Pandora, Apple Music, etc., but several problems persist. Of more general interest, however, is the question of whether or not computers can exhibit autonomous …

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Ion Friction At Small Values Of The Coulomb Logarithm, Robert Tucker Sprenkle Jul 2018

Ion Friction At Small Values Of The Coulomb Logarithm, Robert Tucker Sprenkle

Theses and Dissertations

We create a dual-species ultracold neutral plasma (UNP) by photo-ionizing Yb and Ca atoms in a dual-species magneto-optical trap. Unlike single-species UNP expansion, these plasmas are well outside of the collisionless (Vlasov) approximation. We observe the mutual interaction of the Yb and Ca ions by measuring the velocity distribution for each ion species separately. We model the expansion using a fluid code including ion-ion friction and compare with experimental results to obtain a value of the Coulomb logarithm of Λ= 0.04.

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Adding Limit Points To Bass-Serre Graphs Of Groups, Alexander Jin Shumway Jul 2018

Adding Limit Points To Bass-Serre Graphs Of Groups, Alexander Jin Shumway

Theses and Dissertations

We give a brief overview of Bass-Serre theory and introduce a method of adding a limit point to graphs of groups. We explore a basic example of this method, and find that while the fundamental theorem of Bass-Serre theory no longer applies in this case we still recover a group action on a covering space of sorts with a subgroup isomorphic to the fundamental group of our new base space with added limit point. We also quantify how much larger the fundamental group of a graph of groups becomes after this construction, and discuss the effects of adding and identifying …

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