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

Physical Sciences and Mathematics Commons™

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

Brigham Young University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1231 - 1260 of 3436

Full-Text Articles in Physical Sciences and Mathematics

The Use Of Object-Oriented Programming Concepts For Documenting A Model Ensemble, Georgii A. Alexandrov Jun 2014

The Use Of Object-Oriented Programming Concepts For Documenting A Model Ensemble, Georgii A. Alexandrov

International Congress on Environmental Modelling and Software

The spread of cloud computing services gives community modelling a reasonable opportunity to become a reality in scientific research. However, even if models will be deployed in clouds, and model codes will be open for re-use, there will be little progress in community modelling in the lack of consensus standards for model documentation. This paper is to discuss a conceptual framework for developing such standards. The proposed conceptual framework is based on the idea that a new model is often a modification of an old one, and hence, the similarities between the models of the same environmental process could be …

Go to article

Overcoming The Obstacles Of Motion Capture, Matthew Asanuma, Brent Adams Jun 2014

Overcoming The Obstacles Of Motion Capture, Matthew Asanuma, Brent Adams

Journal of Undergraduate Research

Facial motion capture is used to capture the intimate and subtle motions of the facial features and apply them to a digital character’s face. Animation for the character, Davy Jones, in the Pirates of the Caribbean movies was achieved using this technique. In Overcoming the Obstacles of Motion Capture, I’ve tried to develop a relatively low-cost, yet high-performing technique suitable for a target market of students and independent artists.

Go to article

Sand Sea Extents And Sediment Volumes On Titan From Dune Parameters, Karl D. Arnold Jun 2014

Sand Sea Extents And Sediment Volumes On Titan From Dune Parameters, Karl D. Arnold

Theses and Dissertations

Linear dunes are one of the most abundant and important features on the surface of Titan. We present a model for estimating the volume of dune sediment using the area coverage of Titan's sand seas along with dune widths, spacings, and heights. This helps to reveal local sediment transport and deposition. We refine global dune area estimates from Cassini SAR (Synthetic Aperture RADAR) of 20 million km2 or 24 ± 3% of Titan's surface based on ~50% Cassini RADAR global coverage. Additionally, the global area of sand seas is estimated from a joint analysis of Cassini SAR and ISS (Imaging …

Go to article

Trustworthy, Useful Languages For Probabilistic Modeling And Inference, Neil B. Toronto Jun 2014

Trustworthy, Useful Languages For Probabilistic Modeling And Inference, Neil B. Toronto

Theses and Dissertations

The ideals of exact modeling, and of putting off approximations as long as possible, make Bayesian practice both successful and difficult. Languages for modeling probabilistic processes, whose implementations answer questions about them under asserted conditions, promise to ease much of the difficulty. Unfortunately, very few of these languages have mathematical specifications. This makes them difficult to trust: there is no way to distinguish between an implementation error and a feature, and there is no standard by which to prove optimizations correct. Further, because the languages are based on the incomplete theories of probability typically used in Bayesian practice, they place …

Go to article

Along Strike Variability Of Thrust-Fault Vergence, Scott Royal Greenhalgh Jun 2014

Along Strike Variability Of Thrust-Fault Vergence, Scott Royal Greenhalgh

Theses and Dissertations

The kinematic evolution and along-strike variation in contractional deformation in overthrust belts are poorly understood, especially in three dimensions. The Sevier-age Cordilleran overthrust belt of southwestern Wyoming, with its abundance of subsurface data, provides an ideal laboratory to study how this deformation varies along the strike of the belt. We have performed a detailed structural interpretation of dual vergent thrusts based on a 3D seismic survey along the Wyoming salient of the Cordilleran overthrust belt (Big Piney-LaBarge field). The complex evolution of the thrust faults that parallel the overthrust belt is demonstrated by the switching of the direction of thrust …

Go to article

Hölder Extensions For Non-Standard Fractal Koch Curves, Joshua Taylor Fetbrandt Jun 2014

Hölder Extensions For Non-Standard Fractal Koch Curves, Joshua Taylor Fetbrandt

Theses and Dissertations

Let K be a non-standard fractal Koch curve with contraction factor α. Assume α is of the form α = 2+1/m for some m ∈ N and that K is embedded in a larger domain Ω. Further suppose that u is any Hölder continuous function on K. Then for each such m ∈ N and iteration n ≥ 0, we construct a bounded linear operator Πn which extends u from the prefractal Koch curve Kn into the whole of Ω. Unfortunately, our sequence of extension functions Πnu are not bounded in norm in the limit because the upper bound is …

Go to article

A New Geophysical Strategy For Measuring The Thickness Of The Critical Zone, Johnathan R. Yaede Jun 2014

A New Geophysical Strategy For Measuring The Thickness Of The Critical Zone, Johnathan R. Yaede

Theses and Dissertations

Estimates of the depth and variation of lateritic weathering profiles are especially important in tropical areas such as Oahu, HI. Shear-wave velocity data were obtained by a new application of Multi-channel Analysis of Surface Waves (MASW) to map the base of the critical zone, to show variations in the LWP, and to derive weathering rates. The MASW technique proved highly capable of imaging the base of the critical zone, confirmed by lithological well data and direct field measurements. Profile thickness can be obtained without drilling, which has applications in engineering and geochemical studies. The measured rate of advance of the …

Go to article

Application Sharing From Mobile Devices With A Collaborative Shared Display, Richard S. Shurtz Jun 2014

Application Sharing From Mobile Devices With A Collaborative Shared Display, Richard S. Shurtz

Theses and Dissertations

With the increasing ubiquity of smartphones, tablets, and large pixel-rich displays, there are many exciting new possibilities for using these devices for collaborative work. While there already exist hardware and software that support communication and interaction between mobile devices and shared displays, application sharing in these scenarios is still limited and inflexible. We present a new method of application sharing which allows collaborators to download clips or snapshots of each other's applications. These snapshots can be used to re-launch and resume the shared application back to the state it was in when it was shared. We have built a system …

Go to article

Facies Analysis, Sequence Stratigraphy And Paleogeography Of The Middle Jurassic (Callovian) Entrada Sandstone: Traps, Tectonics, And Analog, George R. Jennings Iii Jun 2014

Facies Analysis, Sequence Stratigraphy And Paleogeography Of The Middle Jurassic (Callovian) Entrada Sandstone: Traps, Tectonics, And Analog, George R. Jennings Iii

Theses and Dissertations

The late Middle Jurassic (Callovian) Entrada Sandstone has been divided into two general facies associations consisting primarily of eolian sandstones in eastern Utah and "muddy" redbeds in central Utah. Sedimentary structures within the redbed portion are explained by the interfingering of inland sabkha, alluvial, and eolian depositional systems. A complete succession from the most basinward facies to the most terrestrial facies in the Entrada Sandstone consists of inland sabkha facies overlain by either alluvial or eolian facies. Where both alluvial and eolian facies interfinger, alluvial facies overlain by eolian facies is considered a normal succession. Sequence boundaries, often identified by …

Go to article

Musical Motif Discovery In Non-Musical Media, Daniel S. Johnson Jun 2014

Musical Motif Discovery In Non-Musical Media, Daniel S. Johnson

Theses and Dissertations

Many music composition algorithms attempt to compose music in a particular style. The resulting music is often impressive and indistinguishable from the style of the training data, but it tends to lack significant innovation. In an effort to increase innovation in the selection of pitches and rhythms, we present a system that discovers musical motifs by coupling machine learning techniques with an inspirational component. The inspirational component allows for the discovery of musical motifs that are unlikely to be produced by a generative model, while the machine learning component harnesses innovation. Candidate motifs are extracted from non-musical media such as …

Go to article

The Bell Springs Formation: Characterization And Correlationof Upper Triassic Strata In Northeast Utah, Skyler Bart May Jun 2014

The Bell Springs Formation: Characterization And Correlationof Upper Triassic Strata In Northeast Utah, Skyler Bart May

Theses and Dissertations

Upper Triassic strata that lie between the Chinle Formation and Nugget Sandstone along the south flank of the Uinta Mountains in northeastern Utah are distinctive. In the past, these rocks have been lumped together with the overlying or underlying units. These strata are equivalent to the Bell Springs Member of the Nugget Sandstone as defined in Wyoming and perhaps to the Rock Point Formation of the Chinle Formation near the Four Corners region. In this study, these rocks will be called the Bell Springs Formation following the usage of Lucas (1993) in Wyoming. The unit is regionally mappable in northeastern …

Go to article

Convolutions And Convex Combinations Of Harmonic Mappings Of The Disk, Zachary M. Boyd Jun 2014

Convolutions And Convex Combinations Of Harmonic Mappings Of The Disk, Zachary M. Boyd

Theses and Dissertations

Let f_1, f_2 be univalent harmonic mappings of some planar domain D into the complex plane C. This thesis contains results concerning conditions under which the convolution f_1 ∗ f_2 or the convex combination tf_1 + (1 − t)f_2 is univalent. This is a long-standing problem, and I provide several partial solutions. I also include applications to minimal surfaces.

Go to article

Application Of An Isogeometric Boundary Element Method To The Calculation Of Acoustic Radiation Modes And Their Efficiencies, Candice Marie Humpherys Jun 2014

Application Of An Isogeometric Boundary Element Method To The Calculation Of Acoustic Radiation Modes And Their Efficiencies, Candice Marie Humpherys

Theses and Dissertations

In contrast to the structural modes, which describe the physical motion of vibrating structures, acoustic radiation modes describe the radiated sound power. Radiation modes are beneficial in active noise control because reducing an efficiently radiating radiation mode guarantees the reduction of radiated sound power. Much work has been done to calculate the radiation modes for simple geometries, where analytic solutions are available. In this work, isogeometric analysis (IGA) is used to provide a tool capable of analyzing the radiation modes of arbitrarily complex geometries. IGA offers increased accuracy and efficiency by using basis functions generated from Non-Uniform Rational B-Splines (NURBS) …

Go to article

Discovery Of Novel Serum Biomarkers For Diagnosing And Staging Alzheimer's Disease, Dipti Jigar Shah Jun 2014

Discovery Of Novel Serum Biomarkers For Diagnosing And Staging Alzheimer's Disease, Dipti Jigar Shah

Theses and Dissertations

Discovery of Novel Serum Biomarkers for Diagnosing and Staging Alzheimer’s DiseaseDipti Jigar ShahDepartment of Chemistry and Biochemistry, BYUDoctor of PhilosophyAlzheimer’s disease (AD) is an untreatable neurologic disease affecting more than 5 million Americans, most over 60 years of age. Protein plaques and neurofibrillary tangles typify AD brain pathology and are thought to cause the progressive dementia and brain shrinkage observed in AD. Currently there are no methods to diagnose the disease at a time before damage becomes irreversible.Biochemical tests for AD using cerebrospinal fluid analysis or neuroimaging are not yet sufficiently sensitive and specific, and they are invasive. This points …

Go to article

A New Public-Key Cryptosystem, Christopher James Hettinger Jun 2014

A New Public-Key Cryptosystem, Christopher James Hettinger

Theses and Dissertations

Public key cryptosystems offer important advantages over symmetric methods, but the most important such systems rely on the difficulty of integer factorization (or the related discrete logarithm problem). Advances in quantum computing threaten to render such systems useless. In addition, public-key systems tend to be slower than symmetric systems because of their use of number-theoretic algorithms. I propose a new public key system which may be secure against both classical and quantum attacks, while remaining simple and very fast. The system's action is best described in terms of linear algebra, while its security is more naturally explained in the context …

Go to article

Elucidation And Improvement Of Algorithms For Mass Spectrometry Isotope Trace Detection, Robert Anthony Smith May 2014

Elucidation And Improvement Of Algorithms For Mass Spectrometry Isotope Trace Detection, Robert Anthony Smith

Theses and Dissertations

Mass spectrometry facilitates cutting edge advancements in many fields. Although instrumentation has advanced dramatically in the last 100 years, data processing algorithms have not kept pace. Without sensitive and accurate signal segmentation algorithms, the utility of mass spectrometry is limited. In this dissertation, we provide an overview and analysis of mass spectrometry data processing. A tutorial to ease the learning curve for those outside the field is provided. We draw attention to the lack of critical evaluation in the field and describe the resulting effects, including a glut of algorithm contributions of questionable novel contribution. To facilitate increased critical evaluation, …

Go to article

The First 40ar/39ar Ages And Tephrochronologic Framework For The Jurassic Entrada Sandstone In Central Utah, Toby S. Dossett May 2014

The First 40ar/39ar Ages And Tephrochronologic Framework For The Jurassic Entrada Sandstone In Central Utah, Toby S. Dossett

Theses and Dissertations

The first 40Ar/39Ar ages of the Middle Jurassic Entrada Sandstone were derived from tephra beds found in central Utah. Eight air fall ash beds in the Entrada Sandstone, with 40Ar/39Ar biotite ages ranging from 168.1 ± 0.2 to 160.8 ± 0.2 Ma, help to establish the age of Entrada deposition. They were also used to create the first chronostratigraphic divisions within the mudstone-dominated Entrada Sandstone. Statistical cluster analysis of chemical data from electron microprobe analyses of phenocrysts were used as a second line of evidence to test absolute age and stratigraphic correlations. The first direct correlations of two distinct air …

Go to article

Characterization Of Cretaceous Chalk Microporosity Related To Depositional Texture: Based Upon Study Of The Upper Cretaceous Niobrara Formation, Denver-Julesburg Basin, Colorado And Wyoming, P D. Pahnke May 2014

Characterization Of Cretaceous Chalk Microporosity Related To Depositional Texture: Based Upon Study Of The Upper Cretaceous Niobrara Formation, Denver-Julesburg Basin, Colorado And Wyoming, P D. Pahnke

Theses and Dissertations

Prompted by increased interest in understanding microporosity, recent efforts at describing and classifying pore types in mudstones have focused primarily on siliceous, gas producing unconventional reservoirs with little attention being paid to carbonate, mixed oil-and-gas producers. The Niobrara Formation in the Denver-Julesburg Basin is a self-sourced resource play producing oil and natural gas from low permeability chalks. Key reservoir lithologies consist of chalk, chalky marl and marl. These lithologies contain flattened chalk fecal pellets which play a significant role in providing porosity. Integration of depositional fabric with pore-type distribution emphasizes the unique textural and depositional nature of chalk and provides …

Go to article

Algebraic And Combinatorial Properties Of Schur Rings Over Cyclic Groups, Andrew F. Misseldine May 2014

Algebraic And Combinatorial Properties Of Schur Rings Over Cyclic Groups, Andrew F. Misseldine

Theses and Dissertations

In this dissertation, we explore the nature of Schur rings over finite cyclic groups, both algebraically and combinatorially. We provide a survey of many fundamental properties and constructions of Schur rings over arbitrary finite groups. After specializing to the case of cyclic groups, we provide an extensive treatment of the idempotents of Schur rings and a description for the complete set of primitive idempotents. We also use Galois theory to provide a classification theorem of Schur rings over cyclic groups similar to a theorem of Leung and Man and use this classification to provide a formula for the number of …

Go to article

Psychoacoustic Effects Of High-Resolution Directivity Measurements On Room Modeling Auralizations, Nathan Eyring, Dr. Timothy Leishman Apr 2014

Psychoacoustic Effects Of High-Resolution Directivity Measurements On Room Modeling Auralizations, Nathan Eyring, Dr. Timothy Leishman

Journal of Undergraduate Research

Over the past years research has been conducted to understand how sound radiates from musical instruments. This has been done by recording a sphere of 2664 data points around a player through the process of many repetitions. This sphere is called the instrument’s directivity This data can be input into room modeling software to predict how an instrument will sound in any given location even before it is built. However there is the legitimate question of whether or not there this new data will change how room model sounds, and if someone listening would care. This research was an attempt …

Go to article

Phase-Correlation And Propagation Analysis Of Near-Field Military Jet Noise, Jazz Myres, Dr. Kent Gee Apr 2014

Phase-Correlation And Propagation Analysis Of Near-Field Military Jet Noise, Jazz Myres, Dr. Kent Gee

Journal of Undergraduate Research

According to the Office of Naval Research (ONR), the United States Department of Veteran Affairs spent over $1 billion dollars on military hearing loss compensation in 2010 alone1. A major cause of hearing loss is exposure to high Sound Pressure Levels, which are caused by military aircraft. These severe levels and high risks are what motivate the overarching goal of all jet noise research: to attenuate the sound impact and reduce the risk of hearing loss. My research project helps this overall purpose by characterizing jet noise and innovating more complete methods of jet noise study. The purpose of this …

Go to article

Development Of A Data Reduction Pipeline For The Rovor Observatory, Thayne Mccombs, Dr. Joseph Ward Moody Apr 2014

Development Of A Data Reduction Pipeline For The Rovor Observatory, Thayne Mccombs, Dr. Joseph Ward Moody

Journal of Undergraduate Research

The ROVOR observatory is a robotic, remotely controlled telescope in Delta, Utah. Since it is remotely controlled and semi-automated, it produces a very large amount of raw data. Unfortunately it took much longer to process and analyze the data than to acquire it, and, therefore, we had a backlog of over two years of data that was waiting to be processed. This delay in analyzing data was detrimental to monitoring projects because without the analysis of recent data it is difficult to determine the most interesting targets to observe.

Go to article

Magnetic Symmetry-Mode Analysis Of La0.5 Ca0.5 Mno3, Eric Gibbs, Dr. Branton Campell Apr 2014

Magnetic Symmetry-Mode Analysis Of La0.5 Ca0.5 Mno3, Eric Gibbs, Dr. Branton Campell

Journal of Undergraduate Research

This project focuses on solving magnetic crystal structures using symmetry-mode analysis (SMA). A crystal is an arrangement of atoms in a repeating spatial pattern with the smallest repeating unit being known as the unit cell. A magnetic crystal contains atoms with a non-zero magnetic moment. A magnetic crystal’s unit cell repeats both the atomic and magnetic structure of the crystal. Neutron diffraction is a common method for studying magnetic crystals as the diffraction pattern can be used to determine the arrangement of atoms and magnetic moments within the unit cell.

Go to article

Developing Microwave-Generated Hydrogen Atoms As A Reducing Agent For Tungsten Atomic Layer Deposition, Jason Kyle Anderson, Dr. David Allred Apr 2014

Developing Microwave-Generated Hydrogen Atoms As A Reducing Agent For Tungsten Atomic Layer Deposition, Jason Kyle Anderson, Dr. David Allred

Journal of Undergraduate Research

Traditional micro fabrication processes are confined to a small subset of possible materials due to limitations on etching and are confined to low aspect ratio fabrication due to limits in both etching and stability of thicker film deposition processes.

Go to article

Generation Of A Low Velocity Controlled Beam Of Sr Ions, Jarom Jackson, Dr. Dallin Durfee Apr 2014

Generation Of A Low Velocity Controlled Beam Of Sr Ions, Jarom Jackson, Dr. Dallin Durfee

Journal of Undergraduate Research

The purpose of this project was to produce a slow controlled beam of Strontium (Sr) ions. This is a key step in a proposed experiment to build an ion interferometer capable of measuring electric fields to a degree of sensitivity that has never been done before. This device will be useful in conducting a number of new experiments and will help test and push the boundaries of modern electromagnetic theory.

Go to article

Modeling Supernovae Light Curves: A Vital Step Toward Photometric Classification, Brittany Spencer, Dr. Shane Reese Apr 2014

Modeling Supernovae Light Curves: A Vital Step Toward Photometric Classification, Brittany Spencer, Dr. Shane Reese

Journal of Undergraduate Research

Type Ia supernovae play a critical role in understanding the nature of the evolving universe. The Dark Energy Survey is currently investigating the expansion rate of the universe, with the intent to gain insight into the nature of dark energy. One of their primary measures of expansion is Type Ia supernovae (DES Projects, 2011). Due to this type of supernova’s uniformity in formation, most supernova of this type explode to approximately the same absolute brightness (Goobar, 2011).

Go to article

Asset Returns From A Distance-Based Random Partition Model, Richard D. Payne, David B. Dahl, Brian M. Hartman Apr 2014

Asset Returns From A Distance-Based Random Partition Model, Richard D. Payne, David B. Dahl, Brian M. Hartman

Journal of Undergraduate Research

When pricing an insurance product, many factors a ect market returns. Policyholder behavior (lapses, mortality, morbidity, etc.), policy riders (guarantees, look-backs, ratchets, etc.), industry and government forces (competition and regulation), among others can all depend on the asset returns and a ect the total risk exposure from the market. In these complicated settings, an analytical solution is often unavailable and the asset returns will need to be simulated. Regime- switching models are important in nance and actuarial science because they are often successful in simulating asset returns. These models t the complicated nature of market risk exposure more e ectively …

Go to article

A Bayesian Nonparametric Approach To Hyperspectral Data Analysis, Jessica Seeger, Dr. Candace Berrett Apr 2014

A Bayesian Nonparametric Approach To Hyperspectral Data Analysis, Jessica Seeger, Dr. Candace Berrett

Journal of Undergraduate Research

Hyperspectral imaging (HSI) is a technology that provides a dense set of previously un- available data{o ering the opportunity for use in a variety of applications such as food safety, ecology, and non-proliferation research. HSI stores measurements across three dimen- sions (two-dimensional space and the electromagnetic spectrum), resulting in large, three- dimensional data cubes. This additional amount of information can be used to identify materials in the images remotely. However, due to the many possibilities for measurement and other errors, it is hard to distinguish between the signal (the material spectra) and these sources of noise. We combine a known …

Go to article

Kir2.1 Effects On Craniofacial And Limb Development In Knockout Mice, Joy Williams, Dr. Emily Bates Apr 2014

Kir2.1 Effects On Craniofacial And Limb Development In Knockout Mice, Joy Williams, Dr. Emily Bates

Journal of Undergraduate Research

Birth defects arise because of both genetic and environmental factors. Children with genetic alteration of the inwardly-rectifying potassium ion channel Kir2.1 channel have heart arrhythmias, impaired cognitive function, and facial and limb abnormalities. Children that suffer from Fetal Alcohol Syndrome have cognitive and social development problems, heart defects, and facial abnormalities—including small eyes, small head, small upper jaw, and a small upper lip1. Kir2.1 is bound and blocked by alcohol2 and thus we predicted that it is the molecular target of Fetal Alcohol Syndrome. We designed experiments to determine how Kir2.1 is required during development and found that within 14 …

Go to article

The Use Of Alpha-1-Antitrypsin (Aat) In The Downregulation Of Nuclear Factor Kappa-Light-Chain-Enhancer Of Activated B Cells (Nf-Κb) As A Treatment For Acquired Immunodeficiency Syndrome (Aids), Aaron Mcbride, Dr. Gregory F. Burton Apr 2014

The Use Of Alpha-1-Antitrypsin (Aat) In The Downregulation Of Nuclear Factor Kappa-Light-Chain-Enhancer Of Activated B Cells (Nf-Κb) As A Treatment For Acquired Immunodeficiency Syndrome (Aids), Aaron Mcbride, Dr. Gregory F. Burton

Journal of Undergraduate Research

Current Human Immunodeficiency Virus (HIV) treatment is greatly hindered due to viral reservoirs throughout the body prolonging and perpetuating infection.i Large stores of HIV exist in the follicular dendritic cell (FDC) microenvironment, located primarily in the lymph nodes and spleen. Free-floating virus has a half-life of less than two hours; however, FDC-trapped virus has a half-life of over eight weeks and can be rescued in its infectious state longer than nine months after the initial infection,ii showing the role of FDCs as an HIV reservoir.iii Studies in the Gregory Burton laboratory focus on the interactions between HIV, FDCs, and CD4+ …

Go to article

First Prev Next Last