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2007

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Articles 61 - 90 of 6758

Full-Text Articles in Physical Sciences and Mathematics

From Twisted Supersymmetry To Orbifold Lattices, Simon Catterall Dec 2007

From Twisted Supersymmetry To Orbifold Lattices, Simon Catterall

Physics - All Scholarship

We show how to derive the supersymmetric orbifold lattices of Cohen et al. \cite{Cohen:2003xe,Cohen:2003qw} and Kaplan et al. \cite{Kaplan:2005ta} by direct discretization of an appropriate twisted supersymmetric Yang-Mills theory. We examine in detail the four supercharge two dimensional theory and the theory with sixteen supercharges in four dimensions. The continuum limit of the latter theory is the well known Marcus twist of {\cal N}=4 Yang-Mills. The lattice models are gauge invariant and possess one exact supersymmetry at non-zero lattice spacing.


Existence And Nonexistence Results For A Class Of Quasilinear Elliptic Systems, Said El Manouni Dec 2007

Existence And Nonexistence Results For A Class Of Quasilinear Elliptic Systems, Said El Manouni

Mathematics and System Engineering Faculty Publications

Using variational methods, we prove the existence and nonexistence of positive solutions for a class of -Laplacian systems with a parameter.


Post-Breeding Habitat Use By Adult Boreal Toads (Bufo Boreas) After Wildfire In Glacier National Park, Usa, C. Gregory Guscio, Blake R. Hossack, Lisa A. Eby, Paul Stephen Corn Dec 2007

Post-Breeding Habitat Use By Adult Boreal Toads (Bufo Boreas) After Wildfire In Glacier National Park, Usa, C. Gregory Guscio, Blake R. Hossack, Lisa A. Eby, Paul Stephen Corn

United States Geological Survey: Staff Publications

Effects of wildfire on amphibians are complex, and some species may benefit from the severe disturbance of stand-replacing fire. Boreal Toads (Bufo boreas boreas) in Glacier National Park, Montana, USA increased in occurrence after fires in 2001 and 2003. We used radio telemetry to track adult B. boreas in a mosaic of terrestrial habitats with different burn severities to better understand factors related to the post-fire pulse in breeding activity. Toads used severely burned habitats more than expected and partially burned habitats less than expected. No toads were relocated in unburned habitat, but little of the study area …


Wildfire Effects On Water Temperature And Selection Of Breeding Sites By The Boreal Toad (Bufo Boreas) In Seasonal Wetlands, Blake R. Hossack, Paul Stephen Corn Dec 2007

Wildfire Effects On Water Temperature And Selection Of Breeding Sites By The Boreal Toad (Bufo Boreas) In Seasonal Wetlands, Blake R. Hossack, Paul Stephen Corn

United States Geological Survey: Staff Publications

Disturbances can significantly affect the thermal regime and community structure of wetlands. We investigated the effect of a wildfire on water temperature of seasonal, montane wetlands after documenting the colonization of recently burned wetlands by the Boreal Toad (Bufo boreas boreas). We compared the daily mean temperature, daily maximum temperature, and accumulated growing degree·days measured on the north shore of three classes of wetlands: unburned wetlands, burned wetlands that were colonized by breeding toads, and burned wetlands that were not colonized. We hypothesized that toads colonized burned wetlands because they were warmer than unburned wetlands and selected specific …


A Unified Framework For Solving Multiagent Task Assignment Problems, Kevin Cousin Dec 2007

A Unified Framework For Solving Multiagent Task Assignment Problems, Kevin Cousin

Theses and Dissertations

Multiagent task assignment problem descriptors do not fully represent the complex interactions in a multiagent domain, and algorithmic solutions vary widely depending on how the domain is represented. This issue is compounded as related research fields contain descriptors that similarly describe multiagent task assignment problems, including complex domain interactions, but generally do not provide the mechanisms needed to solve the multiagent aspect of task assignment. This research presents a unified approach to representing and solving the multiagent task assignment problem for complex problem domains. Ideas central to multiagent task allocation, project scheduling, constraint satisfaction, and coalition formation are combined to …


Total Depletion Of Hg° In The Upper Troposphere-Lower Stratosphere, R. Talbot, Huiting Mao, Jack E. Dibb, M A. Avery Dec 2007

Total Depletion Of Hg° In The Upper Troposphere-Lower Stratosphere, R. Talbot, Huiting Mao, Jack E. Dibb, M A. Avery

Earth Sciences

Our current understanding of atmospheric mercury lacks fundamental details. Gas phase elemental mercury (Hg°) was measured aboard the NASA DC-8 research aircraft during the Intercontinental Chemical Transport Experiment-Phase B (INTEX-B) conducted in spring 2006 over the North Pacific. Our data confirm efficient chemical cycling of Hg° in the tropopause region and show that it is strongly anti-correlated with O3 there, yielding a tropospheric-stratospheric mixing curve of ∼−0.20 ppqv Hg°/ppbv O3. In addition, we found frequent total depletion of Hg° in upper tropospheric (8–12 km) air masses impacted by stratospheric influence. When O3 mixing ratios were >300 …


Packings And Coverings Of Various Complete Digraphs With The Orientations Of A 4-Cycle., Melody Elaine Cooper Dec 2007

Packings And Coverings Of Various Complete Digraphs With The Orientations Of A 4-Cycle., Melody Elaine Cooper

Electronic Theses and Dissertations

There are four orientations of cycles on four vertices. Necessary and sufficient conditions are given for covering complete directed digraphs Dv, packing and covering complete bipartite digraphs, Dm,n, and packing and covering the complete digraph on v vertices with hole of size w, D(v,w), with three of the orientations of a 4-cycle, including C4, X, and Y.


Decomposition, Packings And Coverings Of Complete Digraphs With A Transitive-Triple And A Pendant Arc., Janice Gail Lewenczuk Dec 2007

Decomposition, Packings And Coverings Of Complete Digraphs With A Transitive-Triple And A Pendant Arc., Janice Gail Lewenczuk

Electronic Theses and Dissertations

In the study of design theory, there are eight orientations of the complete graph on three vertices with a pendant edge, K3∪{e}. Two of these are the 3-circuit with a pendant arc and the other six are transitive triples with a pendant arc. Necessary and sufficient conditions are given for decompositions, packings and coverings of the complete digraph with each of the six transitive triples with a pendant arc.


Examining Significant Differences Of Gunshot Residue Patterns Using Same Make And Model Of Firearms In Forensic Distance Determination Tests., Heather Lewey Dec 2007

Examining Significant Differences Of Gunshot Residue Patterns Using Same Make And Model Of Firearms In Forensic Distance Determination Tests., Heather Lewey

Electronic Theses and Dissertations

In many cases of crimes involving a firearm, police investigators need to know how far the firearm was held from the victim when it was discharged. Knowing this distance, vital questions regarding the re-construction of the crime scene can be known. Often, the original firearm used in commission of a suspected crime is not available for testing or is damaged. Crime laboratories require the original firearm in order to conduct distance determination tests. However, no empirical research has ever been conducted to determine if same make and model firearms produce different results in distance determination testing. It was the purpose …


Probability And Statistics For Third Through Fifth Grade Classrooms., Melissa Taylor Mckinnon Dec 2007

Probability And Statistics For Third Through Fifth Grade Classrooms., Melissa Taylor Mckinnon

Electronic Theses and Dissertations

This document contains a variety of lesson plans that can be readily used by a teacher of intermediate students. This thesis contains two units in Probability and one unit in Statistics. Any educator can supplement this document with any curriculum to teach lessons from vocabulary to concept.


New Technique For Imputing Missing Item Responses For An Ordinal Variable: Using Tennessee Youth Risk Behavior Survey As An Example., Andaleeb Abrar Ahmed Dec 2007

New Technique For Imputing Missing Item Responses For An Ordinal Variable: Using Tennessee Youth Risk Behavior Survey As An Example., Andaleeb Abrar Ahmed

Electronic Theses and Dissertations

Surveys ordinarily ask questions in an ordinal scale and often result in missing data. We suggest a regression based technique for imputing missing ordinal data. Multilevel cumulative logit model was used with an assumption that observed responses of certain key variables can serve as covariate in predicting missing item responses of an ordinal variable. Individual predicted probabilities at each response level were obtained. Average individual predicted probabilities for each response level were used to randomly impute the missing responses using a uniform distribution. Finally, likelihood ratio chi square statistics was used to compare the imputed and observed distributions. Two other …


Self-Management Of Type 2 Diabetes In Appalachina Women., Melissa Joy Magness Dec 2007

Self-Management Of Type 2 Diabetes In Appalachina Women., Melissa Joy Magness

Electronic Theses and Dissertations

Gender, minority, and regional-related disparities have been documented in diabetes management. Self-efficacy, the belief in one's ability to carry out the actions mandated by a task, has been identified as a key predictor in glycemic control; however, it has not been investigated in rural, female populations. This cross-sectional, correlation investigation examined the relationships among self-efficacy, depression, and diabetes self-care management in women living in Appalachia with type 2 diabetes. Using Bandura's Social Cognitive Theory, 85 women ages ≥ 21 with type 2 diabetes for a minimum of 6 months who were residents in Appalachia completed the 1) Diabetes Self-Efficacy Scale, …


Chromatic Number Of The Alphabet Overlap Graph, G(2, K , K-2)., Jerry Brent Farley Dec 2007

Chromatic Number Of The Alphabet Overlap Graph, G(2, K , K-2)., Jerry Brent Farley

Electronic Theses and Dissertations

A graph G(a, k, t) is called an alphabet overlap graph where a, k, and t are positive integers such that 0 ≤ t < k and the vertex set V of G is defined as, V = {v : v = (v1v2...vk); vi ∊ {1, 2, ..., a}, (1 ≤ i ≤ k)}. That is, each vertex, v, is a word of length k over an alphabet of size a. There exists an edge between two vertices u, …


Study Of The Decay BS0DS(*)DS(*), V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration Dec 2007

Study Of The Decay BS0 → DS(*)DS(*), V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration

Kenneth Bloom Publications

We report a study of the decay Bs0Ds(*)Ds(*) using a data sample corresponding to 1.3 fb-1 of integrated luminosity collected by the D0 experiment in 2002–2006 during run II of the Fermilab Tevatron collider. One Ds(*) meson was partially reconstructed in the decay Ds→ φμν, and the other Ds(*) meson was identified using the decay Ds→ φπ where no attempt was made to distinguish Ds and Ds(*) states. For the branching fraction Br(Bs0Ds …


Settling For Limited Privacy: How Much Does It Help?, Anna M. Shubina Dec 2007

Settling For Limited Privacy: How Much Does It Help?, Anna M. Shubina

Dartmouth College Ph.D Dissertations

This thesis explores practical and theoretical aspects of several privacy-providing technologies, including tools for anonymous web-browsing, verifiable electronic voting schemes, and private information retrieval from databases. State-of-art privacy-providing schemes are frequently impractical for implementational reasons or for sheer information-theoretical reasons due to the amount of information that needs to be transmitted. We have been researching the question of whether relaxing the requirements on such schemes, in particular settling for imperfect but sufficient in real-world situations privacy, as opposed to perfect privacy, may be helpful in producing more practical or more efficient schemes. This thesis presents three results. The first result …


2007 Fall Engr333/Biol354 Project Final Report, 2007 Fall Engr333, 2007 Fall Biol354 Dec 2007

2007 Fall Engr333/Biol354 Project Final Report, 2007 Fall Engr333, 2007 Fall Biol354

ENGR 333

The students of Calvin College’s Engineering 333 and Biology 354 classes were given the task of determining “What would it take to make Calvin College Carbon Neutral?” At first glance, it would not appear that classes on Advanced Thermal System Design and Investigations in Plant Ecology would have much in common. However, the biology and engineering students comprising these classes banded together to tackle the problem. Coming to a satisfactory conclusion would require:

  • Creating an inventory of Green House Gas (GHG) emissions and sequestration potential
  • Coming up with detailed solutions to achieve Carbon Neutrality
  • Working out a practical schedule to …


Study Of The Reproducibility Of Proteomics Methods And Variability Of Fruit Fly Proteomes., Thomas Franklin Culwell Dec 2007

Study Of The Reproducibility Of Proteomics Methods And Variability Of Fruit Fly Proteomes., Thomas Franklin Culwell

Theses and Dissertations

The reliability of biomarker discovery by means of proteomics has been called into question. It was speculated that "background noise" variation resulting from differences in preparation and handling of samples and proteome dynamics may mask subtle, yet important, differences due to the biological condition. Little is understood about complex proteomes and their variability. A critical aspect of proteomic biomarker research that is largely unexplored is the comparative reproducibility of certain methods such as two-dimensional gel electrophoresis and liquid chromatography/mass spectrometry. In particular, with liquid chromatography/mass spectrometry, it is not known whether variability in peptide quantitation is dependent on any of …


Nirt: Developing A Nanoscale Sensing Device For Measuring The Supply Of Iron To Phytoplankton In Marine Systems, Mark L. Wells, Karen Orcutt, D. Whitney King, Carl Tripp Dec 2007

Nirt: Developing A Nanoscale Sensing Device For Measuring The Supply Of Iron To Phytoplankton In Marine Systems, Mark L. Wells, Karen Orcutt, D. Whitney King, Carl Tripp

University of Maine Office of Research Administration: Grant Reports

There is increasing evidence that Fe has a singularly unique role in marine ecosystems, both regulating total phytoplankton production in high nitrate, low chlorophyll regions of the world, and influencing the predominant composition of the phytoplankton assemblages found in others. It is remarkable then that there is no agreement about how to define biologically available Fe, in contrast to the macronutrients nitrogen, phosphorous or silicon. Current attempts to attain predictive insights to how ocean ecosystems will influence the magnitude of climate change are blocked in large part by this question, along with an extreme shortage of data on Fe distributions …


Existence Of Positive Definite Noncoercive Sums Of Squares, Gregory C. Verchota Dec 2007

Existence Of Positive Definite Noncoercive Sums Of Squares, Gregory C. Verchota

Mathematics - All Scholarship

Positive definite forms

f 2 R[x1, . . . , xn] which are sums of squares of forms of R[x1, . . . , xn] are constructed to have the additional property that the members of any collection of forms whose squares sum to f must share a nontrivial complex root in Cn.


Numerics Of Stochastic Systems With Memory (Mittag-Leffler Institute Seminar), Salah-Eldin A. Mohammed Dec 2007

Numerics Of Stochastic Systems With Memory (Mittag-Leffler Institute Seminar), Salah-Eldin A. Mohammed

Miscellaneous (presentations, translations, interviews, etc)

No abstract provided.


Pyridinium Bis-Retinoids A2-Dopamine And A2-Cadaverine: Implications In Age-Related Macular Degeneration And Cancer, Mckenzie Ruth Pew Dec 2007

Pyridinium Bis-Retinoids A2-Dopamine And A2-Cadaverine: Implications In Age-Related Macular Degeneration And Cancer, Mckenzie Ruth Pew

Theses and Dissertations

Age-related macular degeneration (AMD) is the leading cause of blindness in the United States of America. The pyridinium bis-retinoid A2-ethanolamine (A2E) has been implicated to play a role in AMD. We have observed novel pyridinium bis-retinoids through melanolipofuscin and human RPE extractions that may also play a role in the pathology of AMD. We have begun the construction of an amino-retinoid library in order to identify these ocular compounds. The compounds from the amino-retinoid library are also used in a targeted and triggered drug delivery system for treating cancer. Folic acid is coupled with the amino-retinoids to specifically target cancer …


Iron Sequestration In Lake Sediments From Artificial Hypolimnetic Oxygenation: Richard B. Russell Reservoir, Amanda Elrod Dec 2007

Iron Sequestration In Lake Sediments From Artificial Hypolimnetic Oxygenation: Richard B. Russell Reservoir, Amanda Elrod

All Theses

The Upper Savannah River watershed has numerous impoundments, and the three largest hydroelectric reservoirs, from north to south, are Hartwell, Richard B. Russell, and J. Strom Thurmond Lakes. During the summer months, these reservoirs undergo thermal and chemical stratification, which results in the formation of cool, hypoxic/anoxic hypolimnia and warm, oxic epilimnion. To maintain fisheries habitat, the United States Army Corps of Engineers operates a hypolimnetic oxygenation system in the forebay of Richard B. Russell Lake. The purpose of this system is to improve the water quality of the releases from Richard B. Russell Dam by maintaining a dissolved oxygen …


A Hybrid Multi-Robot Control Architecture, Daylond J. Hooper Dec 2007

A Hybrid Multi-Robot Control Architecture, Daylond J. Hooper

Theses and Dissertations

Multi-robot systems provide system redundancy and enhanced capability versus single robot systems. Implementations of these systems are varied, each with specific design approaches geared towards an application domain. Some traditional single robot control architectures have been expanded for multi-robot systems, but these expansions predominantly focus on the addition of communication capabilities. Both design approaches are application specific and limit the generalizability of the system. This work presents a redesign of a common single robot architecture in order to provide a more sophisticated multi-robot system. The single robot architecture chosen for application is the Three Layer Architecture (TLA). The primary strength …


Estimating Sensitivity And Specificity From A Phase 2 Biomarker Study That Allows For Early Termination, Margaret S. Pepe Phd Dec 2007

Estimating Sensitivity And Specificity From A Phase 2 Biomarker Study That Allows For Early Termination, Margaret S. Pepe Phd

UW Biostatistics Working Paper Series

Development of a disease screening biomarker involves several phases. In phase 2 its sensitivity and specificity is compared with established thresholds for minimally acceptable performance. Since we anticipate that most candidate markers will not prove to be useful and availability of specimens and funding is limited, early termination of a study is appropriate if accumulating data indicate that the marker is inadequate. Yet, for markers that complete phase 2, we seek estimates of sensitivity and specificity to proceed with the design of subsequent phase 3 studies.

We suggest early stopping criteria and estimation procedures that adjust for bias caused by …


Summary Of Trapping Regulations For Fur Harvesting In The United States, Gordon Batcheller, Furbearer Conservation Technical Work Group Dec 2007

Summary Of Trapping Regulations For Fur Harvesting In The United States, Gordon Batcheller, Furbearer Conservation Technical Work Group

Other Publications in Wildlife Management

A “Summary of Trapping Regulations for Fur Harvesting in the United States and Canada” was originally conducted by the International Association of Fish and Wildlife Agencies Fur Resources Technical Subcommittee in 1995. Over the last decade trapping devices and methods, as well as the regulations that guide them have undergone changes. The summary data of furbearer trapping regulations contained in this report were gathered during the summer/fall of 2007 in an effort to capture those regulation changes and report the current conditions and restrictions within existing laws for the harvest of 26 species of furbearers by regulated trapping throughout the …


Perceiving A Corridor With Ctfm Ultrasonic Sensing, S. M. Antoun, Phillip J. Mckerrow Dec 2007

Perceiving A Corridor With Ctfm Ultrasonic Sensing, S. M. Antoun, Phillip J. Mckerrow

Faculty of Informatics - Papers (Archive)

When deprived of sight humans adapt and use other senses for navigation. Most rely on touch (long cane), but some use auditory perception. We have observed a blind teenager echolocating using sounds (clicks) he makes with his mouth. More commonly, an ultrasonic sensor is used as a navigational aid to scan the path and environment. The echoes blind people perceive are interpreted by each individual to form an auditory scene where clear paths and obstacles are identified. With this information, the blind user threads his/her way safely through the space scanned. The work we describe here seeks to mimic a …


Mathematical Sciences News, Georgia Southern University Dec 2007

Mathematical Sciences News, Georgia Southern University

Department of Mathematical Sciences News (2007-2021)

  • Putnam Competition


The General Relativistic Infinite Plane, Preston Jones, Gerardo Muñoz, Michael Ragsdale, Douglas Singleton Dec 2007

The General Relativistic Infinite Plane, Preston Jones, Gerardo Muñoz, Michael Ragsdale, Douglas Singleton

Publications

Uniform fields are one of the simplest and most pedagogically useful examples in introductory courses on electrostatics or Newtonian gravity. In general relativity there have been several proposals as to what constitutes a uniform field. In this article we examine two metrics that can be considered the general relativistic version of the infinite plane with finite mass per unit area. The first metric is the 4D version of the 5D “brane” world models which are the starting point for many current research papers. The second case is the cosmological domain wall metric. We examine to what extent these different metrics …


Electron Beam Characterization Of Carbon Nanostructures, Eric Samuel Mandell Dec 2007

Electron Beam Characterization Of Carbon Nanostructures, Eric Samuel Mandell

Dissertations

Atom-thick carbon nanostructures represent a class of novel materials that are of interest to those studying carbon's role in fossil fuel, hydrogen storage, scaled-down electronics, and other nanotechnology. Electron microscope images of "edge-on" graphene sheets show linear image features due to the projected potential of the sheets. Here, intensity profiles along these linear features can measure the curvature of the sheet, as well as the shape of the sheet (i.e. hexagonal, triangular). Also, electron diffraction powder profiles calculated for triangular graphene sheet shapes show a broadening of the low-frequency edge of diffraction rings, in comparison to those calculated for hexagonal …


Rendering Principal Direction Contour Lines With Oriented Textures, Kelly Gallagher Dec 2007

Rendering Principal Direction Contour Lines With Oriented Textures, Kelly Gallagher

All Theses

In this paper we explore the use of contour lines in computer graphics as a means of conveying shape to the end-user. Contour lines provide an alternative to traditional realistic rendering styles and may even provide a more appropriate visualization for certain situations. For our images, contour line orientation is established in accordance with principal curvature directions.
We present a method for rendering a texture, oriented in the principal curvature direction, across a traditionally-modeled geometric surface that effectively forms suggestive contour lines to enhance the visualization of that surface. We further extend the method to create animated contour textures, wherein …