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 1441 - 1470 of 2906

Full-Text Articles in Physical Sciences and Mathematics

A General Framework For Interactive Television News, Benjamin Bart Sellers Jul 2012

A General Framework For Interactive Television News, Benjamin Bart Sellers

Theses and Dissertations

We design a complete interactive television news system. We develop a news production system that allows for the creation of flexible, content-rich interactive news. This system embraces a general creation process to interactive news that is built on top of a newscast model that evolves from and conforms with the current production newscast model. It allows for content sharing and content reuse. We also create an interactive news viewing system that adapts well to a living room environment. It contains several interactive features designed to give the viewer control and allow them to watch the news when, where, and how …

Go to article

Methods Of Music Classification And Transcription, Jonathan Peter Baker Jul 2012

Methods Of Music Classification And Transcription, Jonathan Peter Baker

Theses and Dissertations

We begin with an overview of some signal processing terms and topics relevant to music analysis including facts about human sound perception. We then discuss common objectives of music analysis and existing methods for accomplishing them. We conclude with an introduction to a new method of automatically transcribing a piece of music from a digital audio signal.

Go to article

A Maple Program For Computing Landau-Ginzburg A- And B-Models And An Exploration Of Mirror Symmetry, Evan D. Merrell Jul 2012

A Maple Program For Computing Landau-Ginzburg A- And B-Models And An Exploration Of Mirror Symmetry, Evan D. Merrell

Theses and Dissertations

Mirror symmetry has been a significant area of research for geometry and physics for over two decades. Berglund and Hubsch proposed that for a certain family of singularities W, the so called "transposed" singularity WT should be the mirror partner of W. cite{BH} The techniques for constructing the orbifold LG models to test this conjecture were developed by FJR in cite{FJR} with a cohomological field theory generalized from the study of r-spin curves. The duality of LG A- and B-models became more elaborate when Krawitz cite{Krawitz} generalized the Intriligator-Vafa orbifold B-model to include contributions from more than one sector.This thesis …

Go to article

Temporal Trends In West Antarctic Accumulation Rates: Evidence From Observed And Simulated Records, Landon Kelly Burgener Jul 2012

Temporal Trends In West Antarctic Accumulation Rates: Evidence From Observed And Simulated Records, Landon Kelly Burgener

Theses and Dissertations

Reconstructed snow accumulation rate observations from five new firn cores show a statistically significant negative trend in accumulation rates over the past four decades across the central West Antarctic ice sheet. A negative temporal trend in accumulation is unexpected in light of rising surface temperatures and simulations run by GCMs. Both the magnitude of the mean accumulation rates and the range of interannual variability observed in the new records compares favorably to older records, suggesting that the new accumulation rate records may serve as a regional proxy for recent temporal trends in West Antarctic accumulation rates. The observed negative trend …

Go to article

Detection Likelihood Maps For Wilderness Search And Rescue: Assisting Search By Utilizing Searcher Gps Track Logs, Michael Thomas Roscheck Jul 2012

Detection Likelihood Maps For Wilderness Search And Rescue: Assisting Search By Utilizing Searcher Gps Track Logs, Michael Thomas Roscheck

Theses and Dissertations

Every year there are numerous cases of individuals becoming lost in remote wilderness environments. Principles of search theory have become a foundation for developing more efficient and successful search and rescue methods. Measurements can be taken that describe how easily a search object is to detect. These estimates allow the calculation of the probability of detection—the probability that an object would have been detected if in the area. This value only provides information about the search area as a whole; it does not provide details about which portions were searched more thoroughly than others. Ground searchers often carry portable …

Go to article

Total Character Groups, Chelsea Lorraine Kennedy Jul 2012

Total Character Groups, Chelsea Lorraine Kennedy

Theses and Dissertations

The total character of a finite group G is the sum of the irreducible characters of G. When the total character of a finite group can be written as a monic polynomial with integer coefficients in an irreducible character of G, we say that G is a total character group. In this thesis we examine the total character of the dicyclic group of order 4n, the non-abelian groups of order p^3, and the symmetric group on n elements for all n ≥ 1. The dicyclic group of order 4n is a total character group precisely when n is congruent to …

Go to article

The Synthesis And Structural Characterization Of Metal Oxide Nanoparticles Having Catalytic Applications, Stacey Janel Smith Jul 2012

The Synthesis And Structural Characterization Of Metal Oxide Nanoparticles Having Catalytic Applications, Stacey Janel Smith

Theses and Dissertations

Nanotechnology is blossoming into one of the premiere technologies of this century, but the key to its progress lies in developing more efficient nanosynthesis methods. Variations in synthetic technique, however, can cause variations in size, structure, and surface characteristics, thereby altering the physical properties and functionality of the particles. Careful structural characterizations are thus essential for understanding the properties and appropriate applications for particles produced by new synthetic techniques.In this work, a new ‘solvent-deficient’ method is presented for the synthesis of an unprecedentedly wide range of metal oxide nanomaterials including at least one metal oxide from each group in Groups …

Go to article

Unknotting Tunnels Of Hyperbolic Tunnel Number N Manifolds, Stephan Daniel Burton Jul 2012

Unknotting Tunnels Of Hyperbolic Tunnel Number N Manifolds, Stephan Daniel Burton

Theses and Dissertations

Adams conjectured that unknotting tunnels of tunnel number 1 manifolds are always isotopic to a geodesic. We generalize this question to tunnel number n manifolds. We find that there exist complete hyperbolic structures and a choice of spine of a compression body with genus 1 negative boundary and genus n ≥ 3 outer boundary for which (n−2) edges of the spine self-intersect. We use this to show that there exist finite volume one-cusped hyperbolic manifolds with a system of n tunnels for which (n−1) of the tunnels are homotopic to geodesics arbitrarily close to self-intersecting. This gives evidence that the …

Go to article

K-S-Rings, Emma Louise Turner Jul 2012

K-S-Rings, Emma Louise Turner

Theses and Dissertations

For a finite group G we study certain rings called k-S-rings, one for each non-negative integer k, where the 1-S-ring is the centralizer ring of G. These rings have the property that the (k+1)-S-ring determines the k-S-ring. We show that the 4-S-ring determines G when G is any group with finite classes. We show that the 3-S-ring determines G for any finite group G, thus giving an answer to a question of Brauer. We show the 2-characters defined by Frobenius and the extended 2-characters of Ken Johnson are characters of representations of the 2-S-ring of G. We find the character …

Go to article

An Applied Investigation Of Gaussian Markov Random Fields, Jessica Lyn Olsen Jun 2012

An Applied Investigation Of Gaussian Markov Random Fields, Jessica Lyn Olsen

Theses and Dissertations

Recently, Bayesian methods have become the essence of modern statistics, specifically, the ability to incorporate hierarchical models. In particular, correlated data, such as the data found in spatial and temporal applications, have benefited greatly from the development and application of Bayesian statistics. One particular application of Bayesian modeling is Gaussian Markov Random Fields. These methods have proven to be very useful in providing a framework for correlated data. I will demonstrate the power of GMRFs by applying this method to two sets of data; a set of temporal data involving car accidents in the UK and a set of spatial …

Go to article

Xprime-Em: Eliciting Expert Prior Information For Motif Exploration Using The Expectation-Maximization Algorithm, Wei Zhou Jun 2012

Xprime-Em: Eliciting Expert Prior Information For Motif Exploration Using The Expectation-Maximization Algorithm, Wei Zhou

Theses and Dissertations

Understanding the possible mechanisms of gene transcription regulation is a primary challenge for current molecular biologists. Identifying transcription factor binding sites (TFBSs), also called DNA motifs, is an important step in understanding these mechanisms. Furthermore, many human diseases are attributed to mutations in TFBSs, which makes identifying those DNA motifs significant for disease treatment. Uncertainty and variations in specific nucleotides of TFBSs present difficulties for DNA motif searching. In this project, we present an algorithm, XPRIME-EM (Eliciting EXpert PRior Information for Motif Exploration using the Expectation-Maximization Algorithm), which can discover known and de novo (unknown) DNA motifs simultaneously from a …

Go to article

Technique And Cue Selection For Graphical Presentation Of Generic Hyperdimensional Data, Lee Mont Howard Jun 2012

Technique And Cue Selection For Graphical Presentation Of Generic Hyperdimensional Data, Lee Mont Howard

Theses and Dissertations

The process of visualizing n-D data presents the user with four problems: finding a hyperdimensional graphics package capable of rendering n-D data, finding a suitable presentation technique supported by the package that allows insight to be gained, using the provided user interface to interact with the presentation technique to explore the information in the data, and finding a way to share the information gained with others. Many graphics packages have been written to solve the first problem. However, existing packages do not sufficiently solve the other three problems. A hyperdimensional graphics package that sufficiently solves all these problems simplifies the …

Go to article

Analysis And Design Tools For Structured Feedback Systems, Anurag Rai Jun 2012

Analysis And Design Tools For Structured Feedback Systems, Anurag Rai

Theses and Dissertations

As we begin to analyze and construct extremely complex systems, a theory for understanding and designing the underlying architecture becomes very important. To move in the direction of a precise theory of architecture, this thesis will provide some concrete tools to analyze and design complex systems with a given network structure. The first main result of this thesis analyzes the vulnerability of a system and shows that a system's vulnerability depends on its network structure. We will consider destabilization attacks acting on a single link in a system's logical interconnection structure. The concept of a vulnerable link is characterized and …

Go to article

Spread Option Pricing With Stochastic Interest Rate, Yi Luo Jun 2012

Spread Option Pricing With Stochastic Interest Rate, Yi Luo

Theses and Dissertations

In this dissertation, we investigate the spread option pricing problem with stochastic interest rate. First, we will review the basic concept and theories of stochastic calculus, give an introduction of spread options and provide some examples of spread options in different markets. We will also review the market efficiency theory, arbitrage and assumptions that are commonly used in mathematical finance. In Chapter 3, we will review existing spread pricing models and term-structure models such as Vasicek Mode, and the Heath-Jarrow-Morton framework. In Chapter 4, we will use the martingale approach to derive a partial differential equation for the price of …

Go to article

Persistence And Foliation Theory And Their Application To Geometric Singular Perturbation, Ji Li Jun 2012

Persistence And Foliation Theory And Their Application To Geometric Singular Perturbation, Ji Li

Theses and Dissertations

Persistence problem of compact invariant manifold under random perturbation is considered in this dissertation. Under uniformly small random perturbation and the condition of normal hyperbolicity, the original invariant manifold persists and becomes a random invariant manifold. The random counterpart has random local stable and unstable manifolds. They could be invariantly foliated thanks to the normal hyperbolicity. Those underlie an extension of the geometric singular perturbation theory to the random case which means the slow manifold persists and becomes a random manifold so that the local global structure near the slow manifold persists under singular perturbation. A normal form for a …

Go to article

New Computational Techniques In Fjrw Theory With Applications To Landau Ginzburg Mirror Symmetry, Amanda Francis Jun 2012

New Computational Techniques In Fjrw Theory With Applications To Landau Ginzburg Mirror Symmetry, Amanda Francis

Theses and Dissertations

Mirror symmetry is a phenomenon from physics that has inspired a lot of interesting mathematics. In the Landau-Ginzburg setting, we have two constructions, the A and B models, which are created based on a choice of an affine singularity with a group of symmetries. Both models are vector spaces equipped with multiplication and a pairing (making them Frobenius algebras), and they are also Frobenius manifolds. We give a result relating stabilization of singularities in classical singularity to its counterpart in the Landau-Ginzburg setting. The A model comes from so-called FJRW theory and can be de fined up to a full …

Go to article

Diagonal Entry Restrictions In Minimum Rank Matrices, And The Inverse Inertia And Eigenvalue Problems For Graphs, Curtis G. Nelson Jun 2012

Diagonal Entry Restrictions In Minimum Rank Matrices, And The Inverse Inertia And Eigenvalue Problems For Graphs, Curtis G. Nelson

Theses and Dissertations

Let F be a field, let G be an undirected graph on n vertices, and let SF(G) be the set of all F-valued symmetric n x n matrices whose nonzero off-diagonal entries occur in exactly the positions corresponding to the edges of G. Let MRF(G) be defined as the set of matrices in SF(G) whose rank achieves the minimum of the ranks of matrices in SF(G). We develop techniques involving Z-hat, a process termed nil forcing, and induced subgraphs, that can determine when diagonal entries corresponding to specific vertices of G must be zero or nonzero for all matrices in …

Go to article

Estimation Of The Effects Of Parental Measures On Child Aggression Using Structural Equation Modeling, Jordan Daniel Pyper Jun 2012

Estimation Of The Effects Of Parental Measures On Child Aggression Using Structural Equation Modeling, Jordan Daniel Pyper

Theses and Dissertations

A child's parents are the primary source of knowledge and learned behaviors for developing children, and the benefits or repercussions of certain parental practices can be long lasting. Although parenting practices affect behavioral outcomes for children, families tend to be diverse in their circumstances and needs. Research attempting to ascertain cause and effect relationships between parental influences and child behavior can be difficult due to the complex nature of family dynamics and the intricacies of real life. Structural equation modeling (SEM) is an appropriate method for this research as it is able to account for the complicated nature of child-parent …

Go to article

Active Noise Control Of A Centrifugal Fan Mounted In A Mock Laptop Enclosure, John J. Esplin Jun 2012

Active Noise Control Of A Centrifugal Fan Mounted In A Mock Laptop Enclosure, John J. Esplin

Theses and Dissertations

Noise from information technology (IT) equipment is a significant problem in today's modern society. Active Noise Control (ANC) has shown promise in reducing the effect of IT fan noise on users. Though ANC has been applied to axial fans (such as those found in desktop computers), it has not been applied to centrifugal fans, such as those found in laptop computers. This work applies an ANC method to a centrifugal fan mounted in a mock laptop enclosure. This method is applied in four steps. First, secondary sources are placed in the vicinity of the fan. Second, an accurate model of …

Go to article

Weak Cayley Table Isomorphisms, Long Pham Bao Nguyen Jun 2012

Weak Cayley Table Isomorphisms, Long Pham Bao Nguyen

Theses and Dissertations

We investigate weak Cayley table isomorphisms, a generalization of group isomorphisms. Suppose G and H are groups. A bijective map phi : G to H is a weak Cayley table isomorphism if it satisfies two conditions:(1) If x is conjugate to y, then phi(x) is conjugate to phi(y); (2) For all x, y in G, phi(xy) is conjugate to phi(x)phi(y).If there exists a weak Cayley table isomorphism between two groups, then we say that the two groups have the same weak Cayley table.This dissertation has two main goals. First, we wish to find sufficient conditions under which two groups have …

Go to article

Advancing The Effectiveness Of Non-Linear Dimensionality Reduction Techniques, Michael S. Gashler May 2012

Advancing The Effectiveness Of Non-Linear Dimensionality Reduction Techniques, Michael S. Gashler

Theses and Dissertations

Data that is represented with high dimensionality presents a computational complexity challenge for many existing algorithms. Limiting dimensionality by discarding attributes is sometimes a poor solution to this problem because significant high-level concepts may be encoded in the data across many or all of the attributes. Non-linear dimensionality reduction (NLDR) techniques have been successful with many problems at minimizing dimensionality while preserving intrinsic high-level concepts that are encoded with varying combinations of attributes. Unfortunately, many challenges remain with existing NLDR techniques, including excessive computational requirements, an inability to benefit from prior knowledge, and an inability to handle certain difficult conditions …

Go to article

Support Vector Machines For Classification And Imputation, Spencer David Rogers May 2012

Support Vector Machines For Classification And Imputation, Spencer David Rogers

Theses and Dissertations

Support vector machines (SVMs) are a powerful tool for classification problems. SVMs have only been developed in the last 20 years with the availability of cheap and abundant computing power. SVMs are a non-statistical approach and make no assumptions about the distribution of the data. Here support vector machines are applied to a classic data set from the machine learning literature and the out-of-sample misclassification rates are compared to other classification methods. Finally, an algorithm for using support vector machines to address the difficulty in imputing missing categorical data is proposed and its performance is demonstrated under three different scenarios …

Go to article

Improving The Effectiveness Of Machine-Assisted Annotation, Paul L. Felt May 2012

Improving The Effectiveness Of Machine-Assisted Annotation, Paul L. Felt

Theses and Dissertations

Annotated textual corpora are an essential language resource, facilitating manual search and discovery as well as supporting supervised Natural Language Processing (NLP) techniques designed to accomplishing a variety of useful tasks. However, manual annotation of large textual corpora can be cost-prohibitive, especially for rare and under-resourced languages. For this reason, developers of annotated corpora often attempt to reduce annotation cost by offering annotators various forms of machine assistance intended to increase annotator speed and accuracy. This thesis contributes to the field of annotated corpus development by providing tools and methodologies for empirically evaluating the effectiveness of machine assistance techniques. This …

Go to article

Refining Vibrationally-Resonant Sum Frequency Generation Spectroscopy For Studies Of Interfacial Interactions, Alexander D. Curtis May 2012

Refining Vibrationally-Resonant Sum Frequency Generation Spectroscopy For Studies Of Interfacial Interactions, Alexander D. Curtis

Theses and Dissertations

Many phenomena of interest to science and engineering occur at interfaces; however, access to, or discrimination of, interfacial interactions has been challenging, especially at buried interfaces. Vibrationally resonant sum-frequency generation (VR-SFG) spectroscopy is a powerful tool for investigating the molecular structure of free or buried interfaces, but spectral analysis has relied on many assumptions. To claim accurate new insights, practitioners must be able to make unique determinations from the data without experimental artifacts affecting the final results. For example, two independent and overlapping studies for the polystyrene/air interface were carried out, but reported different surface structures. Initially, this difference was …

Go to article

Species Identification And Strain Attribution With Unassembled Sequencing Data, Owen Eric Francis Apr 2012

Species Identification And Strain Attribution With Unassembled Sequencing Data, Owen Eric Francis

Theses and Dissertations

Emerging sequencing approaches have revolutionized the way we can collect DNA sequence data for applications in bioforensics and biosurveillance. In this research, we present an approach to construct a database of known biological agents and use this database to develop a statistical framework to analyze raw reads from next-generation sequence data for species identification and strain attribution. Our method capitalizes on a Bayesian statistical framework that accommodates information on sequence quality, mapping quality and provides posterior probabilities of matches to a known database of target genomes. Importantly, our approach also incorporates the possibility that multiple species can be present in …

Go to article

Hitters Vs. Pitchers: A Comparison Of Fantasy Baseball Player Performances Using Hierarchical Bayesian Models, Scott D. Huddleston Apr 2012

Hitters Vs. Pitchers: A Comparison Of Fantasy Baseball Player Performances Using Hierarchical Bayesian Models, Scott D. Huddleston

Theses and Dissertations

In recent years, fantasy baseball has seen an explosion in popularity. Major League Baseball, with its long, storied history and the enormous quantity of data available, naturally lends itself to the modern-day recreational activity known as fantasy baseball. Fantasy baseball is a game in which participants manage an imaginary roster of real players and compete against one another using those players' real-life statistics to score points. Early forms of fantasy baseball began in the early 1960s, but beginning in the 1990s, the sport was revolutionized due to the advent of powerful computers and the Internet. The data used in this …

Go to article

Using An Experimental Mixture Design To Identify Experimental Regions With High Probability Of Creating A Homogeneous Monolithic Column Capable Of Flow, Charles C. Willden Apr 2012

Using An Experimental Mixture Design To Identify Experimental Regions With High Probability Of Creating A Homogeneous Monolithic Column Capable Of Flow, Charles C. Willden

Theses and Dissertations

Graduate students in the Brigham Young University Chemistry Department are working to develop a filtering device that can be used to separate substances into their constituent parts. The device consists of a monomer and water mixture that is polymerized into a monolith inside of a capillary. The ideal monolith is completely solid with interconnected pores that are small enough to cause the constituent parts to pass through the capillary at different rates, effectively separating the substance. Although the end objective is to minimize pore sizes, it is necessary to first identify an experimental region where any combination of input variables …

Go to article

Performance Evaluation Of Optimal Rate Allocation Models For Wireless Networks, Ryan Michael Padilla Apr 2012

Performance Evaluation Of Optimal Rate Allocation Models For Wireless Networks, Ryan Michael Padilla

Theses and Dissertations

Convex programming is used in wireless networks to optimize the sending or receiving rates of links or flows in a network. This kind of optimization problem is formulated into a rate allocation problem, where each node in the network will distributively solve the convex problem and all links or flows will converge to their optimal rate. The objective function and constraints of these problems are represented in a simplified model of contention, interference, and sending or receiving rates. The Partial Interference model is an optimal rate allocation model for use in wireless mesh networks that has been shown to be …

Go to article

Automated Fingertip Detection, Joseph G. Butler Apr 2012

Automated Fingertip Detection, Joseph G. Butler

Theses and Dissertations

One of the oldest biometrics that has been used to uniquely identify a person is their fingerprint. Recent developments in research on fingerprint collection have made it possible to collect fingerprint data from a stand-off digital image. Each of the techniques developed so far have relied on either a very controlled capture environment to ensure only a single fingertip is collected or manual cropping of the image down to the fingertip. The main body of the research focuses on extracting the fingerprint itself. If fingerprint collection via digital image is ever to be fielded in the real world on such …

Go to article

Wifu Transport: A User-Level Protocol Framework, Randall Jay Buck Apr 2012

Wifu Transport: A User-Level Protocol Framework, Randall Jay Buck

Theses and Dissertations

It is well known that the transport layer protocol TCP has low throughput and is unfair in wireless mesh networks. Transport layer solutions for mesh networks have been primarily validated using simulations with simplified assumptions about the wireless network. The WiFu Transport framework complements simulator results by allowing developers to easily create and experiment with transport layer protocols on live networks. We provide a user-space solution that is flexible and promotes code reuse while maintaining high performance and scalability. To validate WiFu Transport we use it to build WiFu TCP, a decomposed Tahoe solution that preserves TCP semantics. Furthermore, we …

Go to article

First Prev Next Last