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2010

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Articles 3451 - 3480 of 8620

Full-Text Articles in Physical Sciences and Mathematics

A Study Of The Effective Interfacial Tension Between Miscible Fluids By Spinning Drop Tensiometer And Microfluidics, Gloria Dollie Viner May 2010

A Study Of The Effective Interfacial Tension Between Miscible Fluids By Spinning Drop Tensiometer And Microfluidics, Gloria Dollie Viner

Dissertations

A miscible system is a system in which two fluids can completely dissolve in one another. A sharp concentration gradient can be observed in miscible systems. We studied the concentration gradient or miscible interface between IBA (isobutyric acid) and water, a miscible system near a consulate point (close to the system’s upper critical solution temperature [UCST]). The original hypothesis was that the sharp concentration gradient of IBA/water was due to barodiffusion, a diffusion effect driven by pressure. We tested this hypothesis by studying IBA/water at five different rotation rates and three different temperatures. At 20 oC, increasing rotation acceleration from …


Some Classification Results For Hadamard Matrices Of Order 6, William Lee Tune May 2010

Some Classification Results For Hadamard Matrices Of Order 6, William Lee Tune

Chancellor’s Honors Program Projects

No abstract provided.


Observation Of A Nonaxisymmetric Magnetohydrodynamic Self-Organized State, C. D. Cothran, Michael R. Brown, T. Gray, M. J. Schaffer, G. Marklin, Vyacheslav S. Lukin , '00 May 2010

Observation Of A Nonaxisymmetric Magnetohydrodynamic Self-Organized State, C. D. Cothran, Michael R. Brown, T. Gray, M. J. Schaffer, G. Marklin, Vyacheslav S. Lukin , '00

Physics & Astronomy Faculty Works

A nonaxisymmetric stable magnetohydrodynamic(MHD) equilibrium within a prolate cylindrical conducting boundary has been produced experimentally at Swarthmore Spheromak Experiment (SSX) [M. R. Brown et al., Phys. Plasmas6, 1717 (1999)]. It has m=1toroidal symmetry, helical distortion, and flat λ profile. Each of these observed characteristics are in agreement with the magnetically relaxed minimum magnetic energy Taylor state. The Taylor state is computed using the methods described by A. Bondeson et al. [Phys. Fluids24, 1682 (1981)] and by J. M. Finn et al. [Phys. Fluids24, 1336 (1981)] and is compared in detail to the measured internal magnetic structure. The lifetime of this …


Substrate Dependent Buffer-Layer Assisted Growth Of Nanoclusters, Jan Honolka, Violetta Sessi, Jian Zhang, Simon Hertenberger, Axel Enders, Klaus Kern May 2010

Substrate Dependent Buffer-Layer Assisted Growth Of Nanoclusters, Jan Honolka, Violetta Sessi, Jian Zhang, Simon Hertenberger, Axel Enders, Klaus Kern

Axel Enders Publications

The role of the substrate on the morphology of nanometer size clusters fabricated by buffer layer assisted growth (BLAG) was studied using scanning tunneling microscopy. Clusters of Fe and Co were deposited on Ag(111), Cu(100), Rh(111), and Pt(111) surfaces using identical BLAG parameters, which are temperature, as well as metal and buffer layer coverage. Semi-hemispherical clusters are found on Ag(111) and Cu(100), while flat monolayer high islands are observed on Rh(111) and Pt(111) due to complete wetting. The results of this study are in agreement with the common notion that BLAG is useful to deposit clusters of virtually any material …


Personalization By Website Transformation: Theory And Practice, Saverio Perugini May 2010

Personalization By Website Transformation: Theory And Practice, Saverio Perugini

Computer Science Faculty Publications

We present an analysis of a progressive series of out-of-turn transformations on a hierarchical website to personalize a user’s interaction with the site. We formalize the transformation in graph-theoretic terms and describe a toolkit we built that enumerates all of the traversals enabled by every possible complete series of these transformations in any site and computes a variety of metrics while simulating each traversal therein to qualify the relationship between a site’s structure and the cumulative effect of support for the transformation in a site. We employed this toolkit in two websites. The results indicate that the transformation enables users …


Sat-Based Answer Set Programming, Yuliya Lierler May 2010

Sat-Based Answer Set Programming, Yuliya Lierler

Computer Science Faculty Publications

Answer set programming (ASP) is a declarative programming paradigm oriented towards difficult combinatorial search problems. Syntactically, ASP programs look like Prolog programs, but solutions are represented in ASP by sets of atoms, and not by substitutions, as in Prolog. Answer set systems, such as SMODELS, SMODELSCC, and DLV, compute answer sets of a given program in the sense of the answer set (stable model) semantics. This is different from the functionality of Prolog systems, which determine when a given query is true relative to a given logic program. ASP has been applied to many areas of science and technology, from …


Vegetation Trends On A Waste Rock Repository Cap In The Northern Black Hills, Andrew C. Korth, Gary E. Larson, Lan Xu, Thomas E. Schumacher May 2010

Vegetation Trends On A Waste Rock Repository Cap In The Northern Black Hills, Andrew C. Korth, Gary E. Larson, Lan Xu, Thomas E. Schumacher

The Prairie Naturalist

We assessed successional trends, long-term vegetation sustainability, and soil surface protection during the 2005-2007 growing seasons on the 32-ha Ruby Gulch Waste Rock Repository cap. The cap consisted of 150 cm of rock and soil covering a polyethylene membrane which in turn covered mining waste rock in order to prevent leaching of heavy metals and acidic water into streams. Following construction in 2003, a contractor applied a grass-forb seed mixture to provide soil-surface protection especially for steeply sloped portions of the cap. In 2005, we established 56, 1-m2 plots, and 20, 20-m transects to annually measure canopy cover, basal …


Beyond Alpha: Lower Bounds For The Reliability Of Tests, Nol Bendermacher May 2010

Beyond Alpha: Lower Bounds For The Reliability Of Tests, Nol Bendermacher

Journal of Modern Applied Statistical Methods

The most common lower bound to the reliability of a test is Cronbach’s alpha. However, several lower bounds exist that are definitely better, that is, higher than alpha. An overview is given as well as an algorithm to find the best: the greatest lower bound.


Assessing Classification Bias In Latent Class Analysis: Comparing Resubstitution And Leave-One-Out Methods, Marc H. Kroopnick, Jinsong Chen, Jaehwa Choi, C. Mitchell Dayton May 2010

Assessing Classification Bias In Latent Class Analysis: Comparing Resubstitution And Leave-One-Out Methods, Marc H. Kroopnick, Jinsong Chen, Jaehwa Choi, C. Mitchell Dayton

Journal of Modern Applied Statistical Methods

This Monte Carlo simulation study assessed the degree of classification success associated with resubstitution methods in latent class analysis (LCA) and compared those results to those of the leaveone- out (L-O-O) method for computing classification success. Specifically, this study considered a latent class model with two classes, dichotomous manifest variables, restricted conditional probabilities for each latent class and relatively small sample sizes. The performance of resubstitution and L-O-O methods on the lambda classification index was assessed by examining the degree of bias.


A New Biased Estimator Derived From Principal Component Regression Estimator, Set Foong Ng, Heng Chin Low, Soon Hoe Quah May 2010

A New Biased Estimator Derived From Principal Component Regression Estimator, Set Foong Ng, Heng Chin Low, Soon Hoe Quah

Journal of Modern Applied Statistical Methods

A new biased estimator obtained by combining the Principal Component Regression Estimator and the special case of Liu-type estimator is proposed. The properties of the new estimator are derived and comparisons between the new estimator and other estimators in terms of mean squared error are presented.


Symmetry Plus Quasi Uniform Association Model And Its Orthogonal Decomposition For Square Contingency Tables, Kouji Yamamoto, Sadao Tomizawa May 2010

Symmetry Plus Quasi Uniform Association Model And Its Orthogonal Decomposition For Square Contingency Tables, Kouji Yamamoto, Sadao Tomizawa

Journal of Modern Applied Statistical Methods

A model is proposed having the structure of both symmetry and quasi-uniform association (SQU model) and provides a decomposition of the SQU model. It is also shown with examples that the test statistic for goodness-of-fit of the SQU model is asymptotically equivalent to the sum of those for the decomposed models.


Optimal Meter Placement By Reconciliation Conventional Measurements And Phasor Measurement Units (Pmus), Reza Kaihani, Ali Reza Seifi May 2010

Optimal Meter Placement By Reconciliation Conventional Measurements And Phasor Measurement Units (Pmus), Reza Kaihani, Ali Reza Seifi

Journal of Modern Applied Statistical Methods

The success of state estimation depends on the number, type and location of the established meters and RTUs on the system. A new method by incorporating conventional measurements and New Technology of Phasor Measurement Units (PMU) is proposed. Conventional meters (power injection and power flow measurements) are allocated in order to reduce the number of meters, RTUs, critical measurements, critical sets and leverage points, and also to improve the numerical stability of equations; a genetic algorithm is used for optimization. A second step involves adding PMUs in areas in which it is expected that the accuracy of state estimation will …


Toward A Synthesis Of Conservation And Animal Welfare Science, David Fraser May 2010

Toward A Synthesis Of Conservation And Animal Welfare Science, David Fraser

Conservation Biology and Animal Welfare Collection

Conservation biology and animal welfare science are multidisciplinary fields of research that address social concerns about animals. Conservation biology focuses on wild animals, works at the level of populations, ecological systems and genetic types, and deals with threats to biodiversity and ecological integrity. Animal welfare science typically focuses on captive (often domestic) animals, works at the level of individuals and groups, and deals with threats to the animals’ health and quality of life. However, there are many areas of existing or potential overlap: (i) many real-life problems, such as environmental contamination, urban development and transportation, create problems for animals that …


Field And Smog Chamber Studies Of Agricultural Emissions And Reaction Products, Derek J. Price May 2010

Field And Smog Chamber Studies Of Agricultural Emissions And Reaction Products, Derek J. Price

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Agricultural emissions are an important contributor to atmospheric aerosol. These emissions include nitrogen containing organic compounds, primarily as amines, which have not been well investigated to date. Although there have been several studies that have looked at the emission of gas phase amines, there are only a few studies that have focused on ambient amine-based aerosol. There have also only been a handful of smog chamber studies that have investigated amine aerosol chemistry. Kinetic studies have looked at the reactions of amines with OH and ozone. However, amine reactions with nitrate radical (NO3) are not well understood. Several …


How Anthocyanin Mutants Respond To Stress: The Need To Distinguish Between Stress Tolerance And Maximal Vigour, Eric J. Von Wettberg, Maureen L. Stanton, Justen B. Whittall May 2010

How Anthocyanin Mutants Respond To Stress: The Need To Distinguish Between Stress Tolerance And Maximal Vigour, Eric J. Von Wettberg, Maureen L. Stanton, Justen B. Whittall

College of Agriculture and Life Sciences Faculty Publications

Background: Anthocyanins are produced by plants in response to diverse stresses. Mutants that block the anthocyanin biosynthetic pathway (ABP) at various steps can easily be compared across numerous abiotic stresses. Hypothesis: Anthocyanins or their precursors are required for stress tolerance. Thus, ABP loss-of-function mutants should have proportionately lower fitness than wildtype plants under stress, compared with benign conditions. In contrast, a decrease in maximal vigour - the general capacity for growth and fecundity - should be most pronounced under benign conditions that allow luxuriant growth by the most vigorous genotypes. Tests: Determine whether, under stressful conditions, ABP loss-of-function mutants have …


High-Resolution Holocene Alluvial Chronostratigraphy At Archaeological Sites In Eastern Grand Canyon, Arizona, Erin Margaret Tainer May 2010

High-Resolution Holocene Alluvial Chronostratigraphy At Archaeological Sites In Eastern Grand Canyon, Arizona, Erin Margaret Tainer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Understanding the nature of Colorado River deposits in Grand Canyon helps reveal how the river responds to changes in its Colorado Plateau tributaries and Rocky Mountain headwaters. This study focused on Holocene alluvial deposits associated with archaeological sites excavated near Ninemile Draw in Glen Canyon and at Tanner Bar in eastern Grand Canyon. Two previously-developed conceptual models of deposition were tested based on previous work. Previous researchers have suggested that Holocene alluvial deposits in Grand Canyon are a series of inset aggradational packages that correlate to valley fills and arroyo-cutting cycles in Colorado Plateau tributaries and are laterally consistent throughout …


Hopping Conductivity And Charge Transport In Low Density Polyethylene, Jerilyn Brunson May 2010

Hopping Conductivity And Charge Transport In Low Density Polyethylene, Jerilyn Brunson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The properties and behaviors of charge transport mechanisms in highly insulating polymers are investigated by measuring conduction currents through thin film samples of low density polyethylene (LDPE). Measurements were obtained using a constant voltage method with copper electrodes inside a chamber adapted for measurements under vacuum and over a wide range of temperatures and applied fields. Field-dependent behaviors, including Poole-Frenkel conduction, space charge limited current (SCLC), and Schottky charge injection, were investigated at constant temperature. These field-dependent mechanisms were found to predict incorrect values of the dielectric constant and the field dependence of conductivity in LDPE was not found to …


Intercomparison Of Prism And Daymet Temperature Interpolation From 1980 To 2003, Rebecca A. Scully May 2010

Intercomparison Of Prism And Daymet Temperature Interpolation From 1980 To 2003, Rebecca A. Scully

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As ecosystem modeling becomes increasingly integrated with Geographic Information Systems (GIS) there is a rise in demand for spatially and temporally continuous meteorological data. But in order to justify management decisions or to provide robust scientific insights, the accuracy of meteorological data used as model input must be thoroughly quantified. Current methods to create spatially continuous climate data from discrete weather station data include inverse distance weighting, geostatistical techniques such as kriging and splines, local regression models such as Parameter-Elevation Regression on Independent Slope Model (PRISM) and Daymet, and regional regression models. For the conterminous United States, PRISM and Daymet …


Ecology And Seasonal Habitat Use Patterns Of Columbian Sharp-Tailed Grouse In Northern Utah, Ron D. Greer May 2010

Ecology And Seasonal Habitat Use Patterns Of Columbian Sharp-Tailed Grouse In Northern Utah, Ron D. Greer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Columbian sharp-tailed grouse (Tympanuchus phasianellus columbianus: hereafter sharp-tailed grouse) populations have been declining. These declines have been attributed to a number of factors, including habitat loss due to agriculture, habitat fragmentation, overgrazing by livestock, and the loss to fire.

To gather information about their status in northern Utah, I radio-marked sharp-tailed grouse in 2003 (n=15) and 2004 (n=20) in two research areas. The study areas were located on the south end of Cache County and in eastern Box Elder County. In the Cache study area, I monitored 7 males and 1 female in 2003, and 6 males and …


Computer-Aided Detection Of Breast Cancer Using Ultrasound Images, Yanhui Guo May 2010

Computer-Aided Detection Of Breast Cancer Using Ultrasound Images, Yanhui Guo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ultrasound imaging suffers from severe speckle noise. We propose a novel approach for speckle reduction using 2D homogeneity and directional average filters to remove speckle noise. We transform speckle noise into additive noise using a logarithm transformation. Texture information is employed to describe the speckle characteristics of the image. The homogeneity value is defined using texture information value, and the ultrasound image is transformed into a homogeneity domain from the gray domain. If the homogeneity value is high, the region is homogenous and has less speckle noise. Otherwise, the region is nonhomogenous, and speckle noise occurs. The threshold value is …


Critique Of A Wildlife Habitat Evaluation Method Applied To Residential Open Space, Sarah Rigard May 2010

Critique Of A Wildlife Habitat Evaluation Method Applied To Residential Open Space, Sarah Rigard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To this date, little research has been done evaluating the quality of wildlife habitat provided by open space in residential areas. Quality wildlife habitat for the purposes of this study is defined as those areas which contain the physical and biological characteristics necessary to support native wildlife species of the region. This thesis critiqued a wildlife habitat assessment method used in a nationwide study of residential open space for the purpose of better understanding the research conducted by the study and to inform similar, future habitat evaluations of landscapes altered by human activity to accommodate residential land use. The methodology …


A Singular-Value-Based Semi-Fragile Watermarking Scheme For Image Content Authentication With Tampering Localization, Xing Xin May 2010

A Singular-Value-Based Semi-Fragile Watermarking Scheme For Image Content Authentication With Tampering Localization, Xing Xin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis presents a novel singular-value-based semi-fragile watermarking scheme for image content authentication with tampering localization. The proposed scheme first generates a secured watermark bit sequence by performing a logical "xor" operation on a content-based watermark and content-independent watermark, wherein the content-based watermark is generated by a singular-value-based watermark bit sequence that represents intrinsic algebraic image properties, and the content-independent watermark is generated by a private-key-based random watermark bit sequence. It next embeds the secure watermark in the approximation subband of each non-overlapping 4×4 block using the adaptive quantization method to generate the watermarked image. The image content authentication process …


The Effects Of Spruce Beetle (Coleoptera: Curculionidae: Scolytinae) On Fuels And Fire In Intermountain Spruce-Fir Forests, Carl Arik Jorgensen May 2010

The Effects Of Spruce Beetle (Coleoptera: Curculionidae: Scolytinae) On Fuels And Fire In Intermountain Spruce-Fir Forests, Carl Arik Jorgensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In spruce-fir forests, there are many biotic and abiotic disturbances that can alter stand structure and composition. Many of these disturbances can produce high percentages of tree mortality at different scales. Spruce beetle has been considered a devastating disturbance agent, capable of creating high levels of mortality that will alter fuel complexes that may affect fire behavior. For comparison, stand data were gathered in endemic (near Loa and Moab, UT), epidemic (near Loa and Fairview, UT), and post-epidemic (near Salina and Loa, UT) condition classes of spruce beetle activity. Generally, fine fuels were higher during the epidemic and returned to …


A Comparative Study To Identify Factors Affecting Adoption Of Soil And Water Conservation Practices Among Smallhold Farmers In The Njoro River Watershed Of Kenya, Steven P. Huckett May 2010

A Comparative Study To Identify Factors Affecting Adoption Of Soil And Water Conservation Practices Among Smallhold Farmers In The Njoro River Watershed Of Kenya, Steven P. Huckett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Natural resource conservation is important for human well-being, especially in fragile environments of developing countries. This study occurred in 2006 among 6,500 smallhold farmers residing along a 25-km segment of a heavily utilized river. Research objectives were to determine use and adoption constraints for 14 soil and water conservation practices (SWCPs). Farms were reportedly contributing to a decline in river water quality via soil erosion. Recent occupation of the upper watershed by immigrants magnified concerns that resource degradation could escalate. A multi-method approach incorporating quantitative surveys, qualitative interviews, and participant observation was used to interpret constraining factors within the biophysical …


Goodness-Of-Fit And Change-Point Tests For Functional Data, Robertas Gabrys May 2010

Goodness-Of-Fit And Change-Point Tests For Functional Data, Robertas Gabrys

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A test for independence and identical distribution of functional observations is proposed in this thesis. To reduce dimension, curves are projected on the most important functional principal components. Then a test statistic based on lagged cross--covariances of the resulting vectors is constructed. We show that this dimension reduction step introduces asymptotically negligible terms, i.e. the projections behave asymptotically as iid vector--valued observations. A complete asymptotic theory based on correlations of random matrices, functional principal component expansions, and Hilbert space techniques is developed. The test statistic has X2-square asymptotic null distribution.

Two inferential tests for error correlation in the …


Pulsed-Laser Excited Photothermal Study Of Glasses And Nanoliter Cylindrical Sample Cell Based On Thermal Lens Spectroscopy, Prakash Raj Joshi May 2010

Pulsed-Laser Excited Photothermal Study Of Glasses And Nanoliter Cylindrical Sample Cell Based On Thermal Lens Spectroscopy, Prakash Raj Joshi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The research in this dissertation presents Pulsed-Laser Excited photothermal studies of optical glasses and cylindrical sample cell.

First, a study of a photothermal lens experiment and the finite element analysis modeling for commercial colored glass filters is done. The ideal situation of a semiinfinite cylinder approximate model used to describe the photothermal lens experiment requires the boundary condition that there is no transfer of heat from the glass to surrounding when the glass is excited with a laser. The finite element analysis modeling for photothermal signal with coupling heat with surrounding shows the thermal heat transfer between the glass surface …


The Effect Of Explicit Timing On Math Performance Using Interspersal Assignments With Students With Mild/Moderate Disabilities, Fangjuan Hou May 2010

The Effect Of Explicit Timing On Math Performance Using Interspersal Assignments With Students With Mild/Moderate Disabilities, Fangjuan Hou

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Explicit timing and interspersal assignments have been validated as effective methods to facilitate students' math practice. However, no researchers have explored the combinative effect of these two methods. In Study 1, we extended the literature by comparing the effect of explicit timing with interspersal assignments, and interspersal assignments without timing. Generally, participants' rate of digits correct on easy and hard addition problems was higher during the explicit timing condition than during the untimed condition. However, the participants' rate of digits correct decreased after initial implementation of the explicit timing condition.

Motivation plays a crucial role in maintaining performance levels and …


Examination Of Deformation In Crystalline Rock From Strike-Slip Faults In Two Locations, Southern California, David H. Forand May 2010

Examination Of Deformation In Crystalline Rock From Strike-Slip Faults In Two Locations, Southern California, David H. Forand

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Damage zones adjacent to or associated with faults are important to the geologic community because of their implications to hazards and their ability to preserve evidence for, and show history of, slip, fluid flow, and deformation associated with large strike-slip faults. We examine two fault zones in southern California where fault zone damage is expressed. We revisit the drilled crystalline core from the Cajon Pass California drill hole, 4 km northeast of the San Andreas fault (SAF), and 1 km north of the Cleghorn fault, to perform a systematic structural analysis of deformation and alteration associated with strike-slip faulting at …


Classical Foundations For A Quantum Theory Of Time In A Two-Dimensional Spacetime, Nathan Thomas Carruth May 2010

Classical Foundations For A Quantum Theory Of Time In A Two-Dimensional Spacetime, Nathan Thomas Carruth

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We consider the set of all spacelike embeddings of the circle S1 into a spacetime R1 × S1 with a metric globally conformal to the Minkowski metric. We identify this set and the group of conformal isometries of this spacetime as quotients of semidirect products involving diffeomorphism groups and give a transitive action of the conformal group on the set of spacelike embeddings. We provide results showing that the group of conformal isometries is a topological group and that its action on the set of spacelike embeddings is continuous. Finally, we point out some directions for future research.


Dancing With Heretics: Essays On Orthodoxy, Questioning And Faith, Darren M. Edwards May 2010

Dancing With Heretics: Essays On Orthodoxy, Questioning And Faith, Darren M. Edwards

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

While much has been written about the conflicts, supposed or actual, between logic and faith, science and religion, few accounts of the personal turmoil these conflicts can cause exist. Likewise, many of these nonfiction accounts are written from a distinctly polarized place leaning either to science or faith.

In this thesis, I mix research and history with memoir and a sense of poetry to explore my personal experience with this conflict. At its outset, I hoped for this project to capture my struggle as an orthodox member of The Church of Jesus Christ of Latter-day Saints (LDS) in dealing with …