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

Digital Commons Network™

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

Brigham Young University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 5131 - 5160 of 8053

Full-Text Articles in Entire DC Network

Carbon Coated Tellurium For Optical Data Storage, Jonathan D. Abbott Dec 2009

Carbon Coated Tellurium For Optical Data Storage, Jonathan D. Abbott

Theses and Dissertations

A highly durable optical disk has been developed for data archiving. This optical disk uses tellurium as the write layer and carbon as a dielectric and oxidation prevention layer. The sandwich style CTeC film was deposited on polycarbonate and silicon substrates by plasma sputtering. These films were then characterized with SEM, TEM, EELS, ellipsometry, ToF-SIMS, etc, and were tested for writability and longevity. Results show the films were uniform in physical structure, are stable, and able to form permanent pits. Data was written to a disk and successfully read back in a commercial DVD drive.


Measured Optical Constants Of Copper From 10 Nm To 35 Nm, David D. Allred, Nicole Brimhall, Nicholas Herrick, Justin Peatross, R. Steven Turley, Michael Ware Dec 2009

Measured Optical Constants Of Copper From 10 Nm To 35 Nm, David D. Allred, Nicole Brimhall, Nicholas Herrick, Justin Peatross, R. Steven Turley, Michael Ware

Faculty Publications

We use laser high-order harmonics and a polarization-ratioreflectance technique to determine the optical constants of copper and oxidized copper in the wavelength range 10-35 nm. This measurement resolves previously conflicting data sets, where disagreement on optical constants of copper in the extreme ultraviolet most likely arises from inadvertent oxidation of samples before measurement.


Progress Toward The Total Synthesis Of Lyconadin A, Yu Zhang Dec 2009

Progress Toward The Total Synthesis Of Lyconadin A, Yu Zhang

Theses and Dissertations

Lyconadin A is a pentacyclic Lycopodium alkaloid isolated from the club moss Lycopodium complanatum with antitumor properties. We have developed a novel 7-exo/6-exo acyl radical cascade cyclization as a method of making the bicyclo[5.4.0]undecane ring system of lyconadin A. The model products are trans-fused ring systems, while a cis-fused ring system is needed in lyconadin A. We have discovered a method to convert the trans-fused model cascade cyclization product into the desired cis isomer. Based on Donohoe's pyridone synthesis, we developed a method for the construction of 5-alkyl and 3,5-dialkyl-6-carbomethoxy-2-pyridones, the former of which …


Analysis Of Electromagnetic And Seismic Geophysical Methods For Investigating Shallow Sub-Surface Hydrogeology, Eric M. Parks Dec 2009

Analysis Of Electromagnetic And Seismic Geophysical Methods For Investigating Shallow Sub-Surface Hydrogeology, Eric M. Parks

Theses and Dissertations

An integrated electromagnetic (EM) and seismic geophysical study was performed to evaluate non-invasive approaches to estimate depth to shallow groundwater in arid environments with elevated soil salinity where the installation of piezometers would be impractical or prohibited. Both methods were tested in two study areas (semi-arid and arid respectively), one in Palmyra, Utah, USA near the shore of Utah Lake where groundwater is shallow and unconfined in relatively homogeneous lacustrine sediments. The other area is Carson Slough, Nevada, USA near Ash Meadows National Wildlife Refuge in Amargosa Valley. The area is underlain by valley fill, with generally variable shallow depths …


The Ecological Importance Of Extrinsic And Intrinsic Drivers Of Animal Movement, Josh Earl Rasmussen Dec 2009

The Ecological Importance Of Extrinsic And Intrinsic Drivers Of Animal Movement, Josh Earl Rasmussen

Theses and Dissertations

The movement of individuals is foundational to many ecological processes. For example, the movement of an organism from one place to another alters population density at both sites and has potential for affecting the genetic dynamics within the new population. Individual movement events may be in synchrony with overall trends in populations, e.g. spawning migrations, or may be atypical (asynchronous). This latter movement type can affect population and metapopulation dynamics, depending on its prevalence within a population. Nevertheless, given the complexity of interactions, the causative factors of movement are understood vaguely, much less for aquatic organisms. Drivers of movement are …


Influence Of Cardiac Output On Oxygen Uptake Kinetics, Crystelle Kiyoko Grant Dec 2009

Influence Of Cardiac Output On Oxygen Uptake Kinetics, Crystelle Kiyoko Grant

Theses and Dissertations

The purpose of this study was to evaluate increased cardiac output (Q) on oxygen kinetics at exercise intensities above and below the lactate threshold (LT). We hypothesized the increase in Q using head-out water immersion (HOI) while treadmill running would reduce the rate constant of the fast component and reduce the amplitude of the slow component of oxygen kinetics compared with land treadmill running. Subjects (n=10) performed two 6 min exercise bouts at a 15% below and above the LT on a land and underwater treadmill following rest. A single exponential equation [VO2(t) = VO2(b) + A1•(1-e-t/TC1] was used to …


Interactive Football Summarization, Brandon B. Moon Dec 2009

Interactive Football Summarization, Brandon B. Moon

Theses and Dissertations

Football fans do not have the time to watch every game in its entirety and need an effective solution that summarizes them the story of the game. Human-generated summaries are often too short, requiring time and resources to create. We utilize the advantages of Interactive TV to create an automatic football summarization service that is cohesive, provides context, covers the necessary plays, and is concise. First, we construct a degree of interest function that ranks each play based on detailed, play-by-play game events as well as viewing statistics collected from an interactive viewing environment. This allows us to select the …


Bisecting Document Clustering Using Model-Based Methods, Aaron Samuel Davis Dec 2009

Bisecting Document Clustering Using Model-Based Methods, Aaron Samuel Davis

Theses and Dissertations

We all have access to large collections of digital text documents, which are useful only if we can make sense of them all and distill important information from them. Good document clustering algorithms that organize such information automatically in meaningful ways can make a difference in how effective we are at using that information. In this paper we use model-based document clustering algorithms as a base for bisecting methods in order to identify increasingly cohesive clusters from larger, more diverse clusters. We specifically use the EM algorithm and Gibbs Sampling on a mixture of multinomials as the base clustering algorithms …


Studies On The Performance And Impact Of Channel Estimation In Mimo And Ofdm Systems, Michael David Larsen Dec 2009

Studies On The Performance And Impact Of Channel Estimation In Mimo And Ofdm Systems, Michael David Larsen

Theses and Dissertations

The need for reliable, high-throughput, mobile wireless communication technologies has never been greater as increases in the demand for on-the-go access to information, entertainment, and other electronic services continues. Two such technologies, which are at the forefront of current research efforts, are orthogonal frequency division multiplexing (OFDM) and multiple-input multiple-output (MIMO) systems, their union being known simply as MIMO-OFDM. The successful performance of these technologies depends upon the availability of accurate information concerning the wireless communication channel. In this dissertation, several issues related to quality of this channel state information (CSI) are studied. Specifically, the first part of this dissertation …


Fused Visible And Infrared Video For Use In Wilderness Search And Rescue, Dennis Eggett, Michael A. Goodrich, Bryan S. Morse, Nathan Rasmussen Dec 2009

Fused Visible And Infrared Video For Use In Wilderness Search And Rescue, Dennis Eggett, Michael A. Goodrich, Bryan S. Morse, Nathan Rasmussen

Faculty Publications

Mini Unmanned Aerial Vehicles (mUAVs) have the potential to assist Wilderness Search and Rescue groups by providing a bird’s eye view of the search area. This paper proposes a method for augmenting visible-spectrum searching with infrared sensing in order to make use of thermal search clues. It details a method for combining the color and heat information from these two modalities into a single fused display to reduce needed screen space for remote field use. To align the video frames for fusion, a method for simultaneously pre-calibrating the intrinsic and extrinsic parameters of the cameras and their mount using a …


Noninvasive Estimation Of Pulmonary Artery Pressure Using Heart Sound Analysis, Aaron W. Dennis Dec 2009

Noninvasive Estimation Of Pulmonary Artery Pressure Using Heart Sound Analysis, Aaron W. Dennis

Theses and Dissertations

Right-heart catheterization is the most accurate method for estimating pulmonary artery pressure (PAP). Because it is an invasive procedure it is expensive, exposes patients to the risk of infection, and is not suited for long-term monitoring situations. Medical researchers have shown that PAP influences the characteristics of heart sounds. This suggests that heart sound analysis is a potential noninvasive solution to the PAP estimation problem. This thesis describes the development of a prototype system, called PAPEr, which estimates PAP noninvasively using heart sound analysis. PAPEr uses patient data with machine learning algorithms to build models of how PAP affects heart …


An Adaptive Bayesian Approach To Dose-Response Modeling, Thomas J. Leininger Dec 2009

An Adaptive Bayesian Approach To Dose-Response Modeling, Thomas J. Leininger

Theses and Dissertations

Clinical drug trials are costly and time-consuming. Bayesian methods alleviate the inefficiencies in the testing process while providing user-friendly probabilistic inference and predictions from the sampled posterior distributions, saving resources, time, and money. We propose a dynamic linear model to estimate the mean response at each dose level, borrowing strength across dose levels. Our model permits nonmonotonicity of the dose-response relationship, facilitating precise modeling of a wider array of dose-response relationships (including the possibility of toxicity). In addition, we incorporate an adaptive approach to the design of the clinical trial, which allows for interim decisions and assignment to doses based …


Facilitating The Generalization Of Social Skills With Bibliotherapy And Positive Peer Reporting, Angelina C. Krieger Dec 2009

Facilitating The Generalization Of Social Skills With Bibliotherapy And Positive Peer Reporting, Angelina C. Krieger

Theses and Dissertations

Social competence is needed for interaction among peers, teachers, and families in order for children to be successful in school. Children enter school with various levels of social competence. Social skills training is an effective method for building social skills; however, many programs fail to generalize these skills across settings and time. This study investigated the effects of a social skills training intervention for first and second grade students with emotional and behavioral problems. The intervention blended direct instruction, role-plays, and children's literature, with peers supporting both the acquisition and generalization of the social skills through positive peer reporting (PPR) …


Open Access Fiber To The Home Networking, Roger E. Timmerman Dec 2009

Open Access Fiber To The Home Networking, Roger E. Timmerman

Theses and Dissertations

The concept of open-access networks appeals to communities that want to invest in and improve their access to modern telecommunications services. By investing in, or building their own open-access telecommunications networks, communities can create an environment where several telecommunications service providers can co-exist on a common open-access infrastructure. This model promotes innovation and competition among several smaller service providers rather than having a monopoly or oligopoly from those companies that can afford the investment of infrastructure in the community. This research provides an analysis of two large open-access fiber-to-the-home networks in Utah to determine a set of recommendations and best-practices …


Gpu-Accelerated Hierarchical Dense Correspondence For Real-Time Aerial Video Processing, Stephen Cluff, Bryan S. Morse, Jonathan D. Cohen, Mark Duchaineau Dec 2009

Gpu-Accelerated Hierarchical Dense Correspondence For Real-Time Aerial Video Processing, Stephen Cluff, Bryan S. Morse, Jonathan D. Cohen, Mark Duchaineau

Faculty Publications

Video from aerial surveillance can provide a rich source of data for many applications and can be enhanced for display and analysis through such methods as mosaic construction, super-resolution, and mover detection. All of these methods require accurate frame-to-frame registration, which for live use must be performed in real time. In many situations, scene parallax may make alignment using global transformations impossible or error-prone, limiting the performance of subsequent processing and applications. For these cases, dense (per-pixel) correspondence is required, but this can be computationally prohibitive. This paper presents a hierarchical dense correspondence algorithm designed for implementation on graphics processing …


Has The Marital Time Cost Of Parenting Changed Over Time?, Jeffrey P. Dew Dec 2009

Has The Marital Time Cost Of Parenting Changed Over Time?, Jeffrey P. Dew

Faculty Publications

Qualitative and quantitative research has suggested that married couples handle the increasing demands of intensive parenting norms and work expectations by reducing spousal time (e.g., the time that spouses spend alone with each other). Using nationally representative time-diary data, this study examined whether married individuals with children at home lost more spousal time in the years 1975–2003 than individuals without children at home. The analyses showed that on average married individuals have reduced their spousal time by 50 minutes a day. Contrary to expectations, however, individuals with minor children at home had lower time declines than individuals without children. The …


Using Operator Teams For Supervisory Control, Jonathan M. Whetten Nov 2009

Using Operator Teams For Supervisory Control, Jonathan M. Whetten

Theses and Dissertations

Robots and other automated systems have potential use in many different fields. As the scope of robot applications that robots are used for increases, there is a growing desire to have human operators manage multiple robots. Typical methods of enabling operators to multi-task in this way involve some combination of user interfaces that support human cognition and advanced robot autonomy. Our research explores a complementary method of managing multiple robots by utilizing operator teams. The evidence suggests that for appropriate task scenarios, two cooperating operators can be more than twice as effective as one operator working alone.


Impact Of Large Gravity Loads On Buckling Restrained Braced Frame Performance, Mark Thurgood Matthews Nov 2009

Impact Of Large Gravity Loads On Buckling Restrained Braced Frame Performance, Mark Thurgood Matthews

Theses and Dissertations

The Buckling Restrained Braced Frame (BRBF) is used in steel structures as a lateral load resisting system for seismic events. In typical design procedure the impact of gravity loads acting on BRBFs is neglected and the beams and columns of the structure are designed to resist all gravity loads. In actuality BRBFs are supporting portions of gravity loads acting on the structure which may be changing the overall performance of BRBFs. The purpose of this study is to determine the impact of large gravity loads on BRBF performance. This is done using finite element analysis to test two different structures …


Vision-Based Precision Landings Of A Tailsitter Uav, Paul Travis Millet Nov 2009

Vision-Based Precision Landings Of A Tailsitter Uav, Paul Travis Millet

Theses and Dissertations

We present a method of performing precision landings of a vertical take-off and landing (VTOL) unmanned air vehicle (UAV) with the use of an onboard vision sensor and information about the aircraft's orientation and altitude above ground level (AGL). A method for calculating the 3-dimensional location of the UAV relative to a ground target of interest is presented as well as a navigational controller to position the UAV above the target. A method is also presented to prevent the UAV from moving in a way that will cause the ground target of interest to go out of view of the …


Beauty, Ugliness, And Meaning: A Study Of Difficult Beauty, Christine Anne Palmer Nov 2009

Beauty, Ugliness, And Meaning: A Study Of Difficult Beauty, Christine Anne Palmer

Theses and Dissertations

The emergence of modern art, and subsequently contemporary art, has brought with it a deep-rooted deliberation of the definition of beauty and its role in the realm of art. Unlike many representational artworks, contemporary art less often contains a beauty that is readily available on the surface of an artwork- an easy beauty. Instead, it often possesses a beauty that requires substantial reasoning and understanding- a difficult beauty. Just as the definition of beauty has and will continue to be culturally and historically changing, so must our methodological and pedagogical practices in regards to beauty and Aesthetics. As Art Educators, …


Dinosaurian Faunas Of The Cedar Mountain Formation And La-Icp-Ms Detrital Zircon Ages For Three Stratigraphic Sections, Hirotsugu Mori Nov 2009

Dinosaurian Faunas Of The Cedar Mountain Formation And La-Icp-Ms Detrital Zircon Ages For Three Stratigraphic Sections, Hirotsugu Mori

Theses and Dissertations

The Cedar Mountain Formation contains the most diverse record of Early Cretaceous dinosaurs in the western hemisphere. However, analyses of its faunas have been hindered because 1) most taxa are based on incomplete/fragmentary materials or incomplete descriptions, 2) most sites and some horizons preserve few taxa, and 3) the stratigraphy and geochronology are poorly understood. To help resolve these stratigraphic and correlation problems U-Pb LA-ICP-MS detrital zircon ages were obtained at significant sites and horizons. These dates indicate all sites at or near the base of the formation are no older than 122 to 124 Ma, thus all basal stratigraphic …


Automated Calibration Of The Gssha Watershed Model: A Look At Accuracy And Viability For Routine Hydrologic Modeling, Kayson M. Shurtz Nov 2009

Automated Calibration Of The Gssha Watershed Model: A Look At Accuracy And Viability For Routine Hydrologic Modeling, Kayson M. Shurtz

Theses and Dissertations

The goal of hydrologic models is to accurately predict a future event of a given magnitude. Historic data are often used to calibrate models to increase their ability to forecast accurately. The GSSHA model is a distributed model that uses physical parameters and physics based computations to compute water flow from cell to cell based on a 2 dimensional grid. The goal of calibration is to obtain good estimates for the actual parameters of the watershed. These parameters should then transfer to other storm events of different magnitudes more easily than an empirical model. In conducting this research three watersheds …


You Don't Know Jack: The Dynamics Of Mormon Religious/Ethnic Identity, Michael R. Cope Nov 2009

You Don't Know Jack: The Dynamics Of Mormon Religious/Ethnic Identity, Michael R. Cope

Theses and Dissertations

For much of human existence identity was ascribed based on the group one was born into. In such cultures all aspects of social life were fused into one incontrovertible identity: group identity. However as modern mindsets took root individuals began to shift the foundation of meaning and identity away from the fixed focal point of the group to one of personal preference. In response to this modern trend many groups began to intensify the maintenance of group identity as paramount in the lives of group members. Hammond and Warner (1993) assert that a powerful mechanism for sustaining group identity is …


Hokua – A Wavelet Method For Audio Fingerprinting, Steven S. Lutz Nov 2009

Hokua – A Wavelet Method For Audio Fingerprinting, Steven S. Lutz

Theses and Dissertations

In recent years, multimedia identification has become important as the volume of digital media has dramatically increased. With music files, one method of identification is audio fingerprinting. The underlying method for most algorithms is the Fourier transform. However, due to a lack of temporal resolution, these algorithms rely on the short-time Fourier transform. We propose an audio fingerprinting algorithm that uses a wavelet transform, which has good temporal resolution. In this thesis, we examine the basics of certain topics that are needed in understanding audio fingerprinting techniques. We also look at a brief history of work done in this field. …


An Empirical Study Of Instance Hardness, Michael Reed Smith Nov 2009

An Empirical Study Of Instance Hardness, Michael Reed Smith

Theses and Dissertations

Most widely accepted measures of performance for learning algorithms, such as accuracy and area under the ROC curve, provide information about behavior at the data set level. They say nothing about which instances are misclassified, whether two learning algorithms with the same classification accuracy on a data set misclassify the same instances, or whether there are instances misclassified by all learning algorithms. These questions about behavior at the instance level motivate our empirical analysis of instance hardness, a measure of expected classification accuracy for an instance. We analyze the classification of 57 data sets using 9 learning algorithms. Of …


Growth And Geodesics Of Thompson's Group F, Jennifer L. Schofield Nov 2009

Growth And Geodesics Of Thompson's Group F, Jennifer L. Schofield

Theses and Dissertations

In this paper our goal is to describe how to find the growth of Thompson's group F with generators a and b. Also, by studying elements through pipe systems, we describe how adding a third generator c affects geodesic length. We model the growth of Thompson's group F by producing a grammar for reduced pairs of trees based on Blake Fordham's tree structure. Then we change this grammar into a system of equations that describes the growth of Thompson's group F and simplify. To complete our second goal, we present and discuss a computer program that has led to some …


Synthesis And Evaluation Of N6,5'-Bis-Ureido-5'-Amino-5'-Deoxyadenosine Derivatives: Novel Nucleosides With Antiproliferative And Protein Kinase Binding Activities, Marcelio Oliveira Nov 2009

Synthesis And Evaluation Of N6,5'-Bis-Ureido-5'-Amino-5'-Deoxyadenosine Derivatives: Novel Nucleosides With Antiproliferative And Protein Kinase Binding Activities, Marcelio Oliveira

Theses and Dissertations

A new series of N6,5'-bis-ureido-5'-amino-5'-deoxyadenosine derivatives was prepared and evaluated for anticancer activities using the NCI 60 panel of human cancers. Certain of the derivatives showed promising activities (low micromolar GI50's) against several of the representative cancers. These included cell lines from the following general cell types in the NCI 60: Leukemia, Breast, Central Nervous System, Non-Small Cell Lung, Ovarian, Prostate, Renal, and Colon cancers. Select compounds were also screened for their affinities for protein kinases. The synthesis of the compounds was straightforward and involved N6 acylation with arylisocyanates, preceded by activation and nucleophilic substitution of the 5'-position to give …


Feature-Based Interactive Terrain Sketching, Daniel B. Adams Nov 2009

Feature-Based Interactive Terrain Sketching, Daniel B. Adams

Theses and Dissertations

Procedural generation techniques are able to quickly and cheaply produce large areas of terrain. However, these techniques produce results that are not easily directable and often require artists to edit the results by hand to achieve the desired layout. This paper proposes a sketch-based system for controlling fractal terrain that allows for a wide variety of terrain feature types. Artists sketch features rather than constrained points or elevations. The system is interactive, provides quick on-demand previews of the terrain, and allows for iterative design modifications. Interaction between features is handled in a realistic fashion. An arbitrary vertex insertion order midpoint …


A La-Icpms Sr Isotope And Trace Element Study Of Plagioclase And Clinopyroxene Of The Higganum Dike, Connecticut: Determining The Magma Source Of The Central Atlantic Magmatic Province, Caprise Steadman Harper Nov 2009

A La-Icpms Sr Isotope And Trace Element Study Of Plagioclase And Clinopyroxene Of The Higganum Dike, Connecticut: Determining The Magma Source Of The Central Atlantic Magmatic Province, Caprise Steadman Harper

Theses and Dissertations

The Higganum dike of Connecticut is one of the earliest basaltic dikes of the Central Atlantic Magmatic province and is geochemically representative of the widespread low-Ti basaltic lavas (~1 wt % TiO2) that make up the majority of the province in North America. Liquid compositions calculated from Cr-rich clinopyroxene cores from the Higganum dike are significantly more primitive than the bulk rock with average Mg# s of 0.63 compared to the Higganum dike which has Mg #'s ~ 0.55. However, the negative Nb and positive Pb anomalies that are seen in trace element patterns of the low-Ti group are also …


Parameter Estimation For The Lognormal Distribution, Brenda Faith Ginos Nov 2009

Parameter Estimation For The Lognormal Distribution, Brenda Faith Ginos

Theses and Dissertations

The lognormal distribution is useful in modeling continuous random variables which are greater than or equal to zero. Example scenarios in which the lognormal distribution is used include, among many others: in medicine, latent periods of infectious diseases; in environmental science, the distribution of particles, chemicals, and organisms in the environment; in linguistics, the number of letters per word and the number of words per sentence; and in economics, age of marriage, farm size, and income. The lognormal distribution is also useful in modeling data which would be considered normally distributed except for the fact that it may be more …