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Articles 176431 - 176460 of 293102

Full-Text Articles in Physical Sciences and Mathematics

The Effects Of Evapotranspiration Upon Recharge Using The Stable Isotopes Of Oxygen And Hydrogen In The Carbonate Aquifers Of The Cumberland Plateau In Southeast Kentucky, Lee J. Florea Nov 2011

The Effects Of Evapotranspiration Upon Recharge Using The Stable Isotopes Of Oxygen And Hydrogen In The Carbonate Aquifers Of The Cumberland Plateau In Southeast Kentucky, Lee J. Florea

Lee J Florea, PhD, P.G.

In this brief manuscript, we consider the variation of the stable isotopes of oxygen, δ18O, and hydrogen, δ2H, in samples collected during 2010 and 2011 from precipitation and shallow groundwater along the Cumberland Plateau of southeast Kentucky. These data from the 1,900-ha Redmond Creek karst aquifer lend insight into the source and timing of recharge to shallow groundwater in the epigenic karst of the U.S midcontinent. Specifically, we find that only 43% of precipitation remains as potential recharge after accounting for evapotranspiration, and 85% of this potential recharge occurs during only four two-week sampling periods. The isotopic composition of precipitation …


Testing For Improvement In Prediction Model Performance, Margaret S. Pepe Phd, Kathleen F. Kerr Phd, Gary Longton, Zheyu Wang Phd Nov 2011

Testing For Improvement In Prediction Model Performance, Margaret S. Pepe Phd, Kathleen F. Kerr Phd, Gary Longton, Zheyu Wang Phd

Margaret S Pepe PhD

New methodology has been proposed in recent years for evaluating the improvement in prediction performance gained by adding a new predictor, Y, to a risk model containing a set of baseline predictors, X, for a binary outcome D. We prove theoretically that null hypotheses concerning no improvement in performance are equivalent to the simple null hypothesis that the coefficient for Y is zero in the risk model, P(D=1|X,Y). Therefore, testing for improvement in prediction performance is redundant if Y has already been shown to be a risk factor. We investigate properties of tests through simulation studies, focusing on the change …


Revisiting Two-Step Forbush Decreases, Andrew P. Jordan, Harlan E. Spence, J. B. Blake, D. N. A. Shaul Nov 2011

Revisiting Two-Step Forbush Decreases, Andrew P. Jordan, Harlan E. Spence, J. B. Blake, D. N. A. Shaul

Physics & Astronomy

Interplanetary coronal mass ejections (ICMEs) and their shocks can sweep out galactic cosmic rays (GCRs), thus creating Forbush decreases (FDs). The traditional model of FDs predicts that an ICME and its shock decrease the GCR intensity in a two-step profile. This model, however, has been the focus of little testing. Thus, our goal is to discover whether a passing ICME and its shock inevitably lead to a two-step FD, as predicted by the model. We use cosmic ray data from 14 neutron monitors and, when possible, high time resolution GCR data from the spacecraft International Gamma Ray Astrophysical Laboratory (INTEGRAL). …


The Fierce Green Fire: Vol. 2 Issue 12, Wofford College Environmental Studies Program Nov 2011

The Fierce Green Fire: Vol. 2 Issue 12, Wofford College Environmental Studies Program

The Fierce Green Fire

No abstract provided.


Nondestructive Electrothermal Detection Of Corrosion, Brittany Ambeau, Harris Enniss, Stefan Schnake Nov 2011

Nondestructive Electrothermal Detection Of Corrosion, Brittany Ambeau, Harris Enniss, Stefan Schnake

Mathematical Sciences Technical Reports (MSTR)

Nondestructive testing and imaging plays an important role in many industries, e.g., the monitoring and maintenance of corrosion in aircraft. The general technique is to input energy in some form into an object, observe the object’s response, and from this input-output information determine the internal structure. New techniques are always being explored, and recently there has been much interest in methods that use multiple forms of energy. In this vein, we examine a new technique for imaging corrosion or material loss in an object by combining electrical and thermal measurements on some accessible portion of the object’s outer boundary. The …


Simone: Building An Sid Detector For Space Weather Monitoring, Daniel Everding Nov 2011

Simone: Building An Sid Detector For Space Weather Monitoring, Daniel Everding

Honors Capstone Projects and Theses

No abstract provided.


Investigating Turbulence Transport In The Heliosphere, Lauren Kahre Nov 2011

Investigating Turbulence Transport In The Heliosphere, Lauren Kahre

Honors Capstone Projects and Theses

No abstract provided.


Variational Approach For Fractional Diffusion-Wave Equations On Cantor Sets, Guo-Cheng Wu, Kai-Teng Wu Nov 2011

Variational Approach For Fractional Diffusion-Wave Equations On Cantor Sets, Guo-Cheng Wu, Kai-Teng Wu

G.C. Wu

The fractional variational iteration method is used to investigate the diffusion-wave problem on Cantor sets. The approximate solution is obtained in forms of fractional differentiable functions


Fast Parallel Machine Learning Algorithms For Large Datasets Using Graphic Processing Unit, Qi Li Nov 2011

Fast Parallel Machine Learning Algorithms For Large Datasets Using Graphic Processing Unit, Qi Li

Theses and Dissertations

This dissertation deals with developing parallel processing algorithms for Graphic Processing Unit (GPU) in order to solve machine learning problems for large datasets. In particular, it contributes to the development of fast GPU based algorithms for calculating distance (i.e. similarity, affinity, closeness) matrix. It also presents the algorithm and implementation of a fast parallel Support Vector Machine (SVM) using GPU. These application tools are developed using Compute Unified Device Architecture (CUDA), which is a popular software framework for General Purpose Computing using GPU (GPGPU). Distance calculation is the core part of all machine learning algorithms because the closer the query …


Spatial And Temporal Variations In The Air-Sea Carbon Dioxide Fluxes Of Florida Bay, Christopher Michael Dufore Nov 2011

Spatial And Temporal Variations In The Air-Sea Carbon Dioxide Fluxes Of Florida Bay, Christopher Michael Dufore

USF Tampa Graduate Theses and Dissertations

The flux of CO2 between the ocean and the atmosphere is an important measure in determining local, global, and regional, as well as short term and long term carbon budgets. In this study, air-sea CO2 fluxes measured using a floating chamber were used to examine the spatial and temporal variability of CO2 fluxes in Florida Bay. Measurements of dissolved inorganic carbon and total alkalinity obtained concurrently with chamber measurements of CO2 flux allowed calculation of ΔpCO2 from flux measurements obtained at zero wind velocity. Floating chamber measurements of ΔpCO2 were subsequently coupled with wind speed data to provide a simple …


An Analysis Of User-Centric Identity Technology Trends, Openid's First Act, Peter Motykowski Nov 2011

An Analysis Of User-Centric Identity Technology Trends, Openid's First Act, Peter Motykowski

Regis University Student Publications (comprehensive collection)

Identity technologies within Internet applications have evolved at an aggressive pace over the past decade. As a result, a variety of user-centric identity management technologies are available on the Internet today. The user-centric identity technology realm has become a fragmented ecosystem of standards, techniques, and technical approaches to identity management. A symptom of this fragmentation is the sluggish adoption of user-centric identity technologies by Internet users. A study titled, An Analysis of User-Centric Identity Technology Trends, OpenID"â„¢s First Act, aims to reveal identity technology adoption patterns of users that engage in the use of Internet applications secured by an authentication …


Fast Spheroidal Weathering With Colluvium Deposition, Mckay T. Farley Nov 2011

Fast Spheroidal Weathering With Colluvium Deposition, Mckay T. Farley

Theses and Dissertations

It can be difficult to quickly and easily create realistic sandstone terrain. Film makers often need to generate realistic terrain for establishing the setting of their film. Many methods have been created which address terrain generation. One such method is using heightmaps which encode height as a gray-value in a 2d image. Most terrain generation techniques don't admit concavities such as overhangs and arches. We present an algorithm that operates on a voxel grid for creating 3d terrain. Our algorithm uses curvature estimation to weather away the terrain. We speed up our method using a caching mechanism that stores the …


Electronic Editing Of Anglo-Saxon Texts, George K. Thiruvathukal, Allen J. Frantzen Nov 2011

Electronic Editing Of Anglo-Saxon Texts, George K. Thiruvathukal, Allen J. Frantzen

George K. Thiruvathukal

Poster presentation/demonstration at the first Chicago Colloquium on Digital Humanities about editing of Old English texts and the Anglo-Saxon project.


A Model-Driven Approach To Job/Task Composition In Cluster Computing, Yogesh Kanitkar, Konstantin Läufer, Neeraj Mehta, George K. Thiruvathukal Nov 2011

A Model-Driven Approach To Job/Task Composition In Cluster Computing, Yogesh Kanitkar, Konstantin Läufer, Neeraj Mehta, George K. Thiruvathukal

George K. Thiruvathukal

In the general area of high-performance computing, object-oriented methods have gone largely unnoticed. In contrast, the Computational Neighborhood (CN), a framework for parallel and distributed computing with a focus on cluster computing, was designed from ground up to be object-oriented. This paper describes how we have successfully used UML in the following model-driven, generative approach to job/task composition in CN. We model CN jobs using activity diagrams in any modeling tool with support for XMI, an XML-based external representation of UML models. We then export the activity diagrams and use our XSLT-based tool to transform the resulting XMI representation to …


Web 2.0 Publishing And Happy 1.0, Computing Now!, George Thiruvathukal Nov 2011

Web 2.0 Publishing And Happy 1.0, Computing Now!, George Thiruvathukal

George K. Thiruvathukal

In this special issue, we take a look at Web 2.0 and publishing and extend a special happy first birthday greeting to Computing Now, the online member engagement initiative of the IEEE Computer Society.


Pdc Modules For Every Level: A Comprehensive Model For Incorporating Pdc Topics Into The Existing Undergraduate Curriculum, Konstantin Läufer, Chandra N. Sekharan, George K. Thiruvathukal Nov 2011

Pdc Modules For Every Level: A Comprehensive Model For Incorporating Pdc Topics Into The Existing Undergraduate Curriculum, Konstantin Läufer, Chandra N. Sekharan, George K. Thiruvathukal

George K. Thiruvathukal

We propose to give a half-hour presentation on incorporating PDC topics into our existing undergraduate computer science curriculum. We first describe our experience with single-course and cross-curricular undergraduate PDC education since 1997. We then provide details about our proposed model for incorporating PDC topics into our undergraduate curriculum. To this end, we have distilled a set of consistent, regularly offered and required three-week core and advanced PDC modules from our previously offered PDC content.


Novel Architectures And Accelerators, George Thiruvathukal Nov 2011

Novel Architectures And Accelerators, George Thiruvathukal

George K. Thiruvathukal

Computing Now special issue on novel architectures (GPGPU, FPGA, etc.)


Using Lectinmicroarrays To Identify Regulatory Mechanisms For Mammalian Glycosylation, John F. Rakus Nov 2011

Using Lectinmicroarrays To Identify Regulatory Mechanisms For Mammalian Glycosylation, John F. Rakus

Chemistry Faculty Research

Glycosylation involves the post-translational addition of carbohydrates to protein molecules and is an intricate and indispensable biochemical process. Study of this complicated network of interactions is hindered by the lack of a coding template analogous to the genetic code, and by the vast structural complexity inherent to carbohydrate polymers. We use lectins (non-enzymatic carbohydrate-binding proteins of non-immunological origin) as microarray probes to identify carbohydrate features expressed on cellular surfaces. Specifically, we utilized lectin microarray technology to investigate the differences in carbohydrates expressed by the cell lines of the Nation Cancer Institute’s NCI-60 panel. Our investigation identified tissue-specific expression differences in …


Exploration And Comparison Of Methods For Combining Population- And Family-Based Genetic Association Using The Genetic Analysis Workshop 17 Mini-Exome, David W. Fardo, Anthony R. Druen, Jinze Liu, Lucia Mirea, Claire Infante-Rivard, Patrick Breheny Nov 2011

Exploration And Comparison Of Methods For Combining Population- And Family-Based Genetic Association Using The Genetic Analysis Workshop 17 Mini-Exome, David W. Fardo, Anthony R. Druen, Jinze Liu, Lucia Mirea, Claire Infante-Rivard, Patrick Breheny

Biostatistics Faculty Publications

We examine the performance of various methods for combining family- and population-based genetic association data. Several approaches have been proposed for situations in which information is collected from both a subset of unrelated subjects and a subset of family members. Analyzing these samples separately is known to be inefficient, and it is important to determine the scenarios for which differing methods perform well. Others have investigated this question; however, no extensive simulations have been conducted, nor have these methods been applied to mini-exome-style data such as that provided by Genetic Analysis Workshop 17. We quantify the empirical power and false-positive …


Retired A Stars And Their Companions. Vii. 18 New Jovian Planets, John Asher Johnson, Christian Clanton, Andrew W. Howard, Brendan P. Bowler, Gregory W. Henry, Geoffrey W. Marcy, Justin R. Crepp, Michael Endl, William D. Cochran, Phillip J. Macqueen, Jason T. Wright, Howard Isaacson Nov 2011

Retired A Stars And Their Companions. Vii. 18 New Jovian Planets, John Asher Johnson, Christian Clanton, Andrew W. Howard, Brendan P. Bowler, Gregory W. Henry, Geoffrey W. Marcy, Justin R. Crepp, Michael Endl, William D. Cochran, Phillip J. Macqueen, Jason T. Wright, Howard Isaacson

Information Systems and Engineering Management Research Publications

We report the detection of 18 Jovian planets discovered as part of our Doppler survey of subgiant stars at Keck Observatory, with follow-up Doppler and photometric observations made at McDonald and Fairborn Observatories, respectively. The host stars have masses 0.927 ⩽ M⋆/M☉ ⩽ 1.95, radii 2.5 ⩽ R⋆/R☉ ⩽ 8.7, and metallicities −0.46 ⩽ [Fe/H] ⩽+0.30. The planets have minimum masses 0.9 MJup ⩽ MPsin i ≲ 13 MJup and semimajor axes a ⩾ 0.76 AU. These detections represent a 50% increase in the number of planets known to orbit stars more massive than 1.5 M☉ and provide valuable additional …


Absolute Properties Of The Highly Eccentric, Solar-Type Eclipsing Binary Hd 74057, James R. Sowell, Gregory W. Henry, Francis C. Fekel Nov 2011

Absolute Properties Of The Highly Eccentric, Solar-Type Eclipsing Binary Hd 74057, James R. Sowell, Gregory W. Henry, Francis C. Fekel

Information Systems and Engineering Management Research Publications

We have obtained Strömgren b and y differential photometric observations of the solar-type eclipsing binary HD 74057 plus follow-up high-resolution, red wavelength spectroscopic observations. The system has an orbital period of 31.2198 days, a high eccentricity of 0.47, and is seen almost exactly edge on with an inclination of 89fdg8. The two main-sequence G0 stars are nearly identical in all physical characteristics. We used the Wilson–Devinney program to obtain a simultaneous solution of our photometric and spectroscopic observations. The resulting masses of the components are M1 = 1.138 ± 0.003 M☉ and M2 = 1.131 ± 0.003 M☉, and the …


Reactivity Of Dimethylplatinum (Ii) Complexes, Muhieddine A. Safa Nov 2011

Reactivity Of Dimethylplatinum (Ii) Complexes, Muhieddine A. Safa

Electronic Thesis and Dissertation Repository

This thesis describes a study of dimethylplatinum(II) and dimethylplatinum(IV) complexes containing bidentate nitrogen donor ligands. This work deals with oxidative addition, and reductive elimination chemistry, and it focuses on synthesis, characterization, and reaction mechanisms in studies of these complexes.

The compound [PtMe2(bpe)], bpe = 1,2-bis(2-pyridyl)ethane, is easily oxidized to give octahedral organoplatinum(IV) complexes and the subsequent chemistry is profoundly influenced by the accompanying strain induced in the 7-membered Pt(bpe) chelate ring. On reaction of [PtMe2(bpe)] with HCl, the initial product [PtHClMe2(bpe)] undergoes reductive elimination of methane to form [PtClMe(bpe)]. In contrast, methyl …


Agile Innovation Management, Arcot Desai Narasimhalu Nov 2011

Agile Innovation Management, Arcot Desai Narasimhalu

Research Collection School Of Computing and Information Systems

The volume and velocity of innovations are on the increase resulting in increased pressures on every company for attaining, retaining and increasing its market leadership. Many companies need to retool their innovation management processes to address two agility related objectives in order to survive and grow in such a rapidly changing innovation environment. The first objective would be the ability to assemble an innovation team within the shortest possible time. This can only be satisfied by companies that are capable of forming innovation teams rather quickly. The related second objective would be to reduce the I2M (Idea to Market) cycle …


Gravity Wave Characteristics From Oh Airglow Imager Over Maui, Alan Z. Liu, Xian Lu, Zhenhua Li, Gary R. Swenson, Steven Franke Nov 2011

Gravity Wave Characteristics From Oh Airglow Imager Over Maui, Alan Z. Liu, Xian Lu, Zhenhua Li, Gary R. Swenson, Steven Franke

Alan Z Liu

No abstract provided.


A Geochemical Analysis: Application Of A Chelating Agent On Potential Asr Reactive Aggregates, Jennifer N. Garcia Nov 2011

A Geochemical Analysis: Application Of A Chelating Agent On Potential Asr Reactive Aggregates, Jennifer N. Garcia

Geosciences Theses

Alkali Silica Reaction (ASR) is a deleterious, expansive reaction in concrete. Several ASTM methods test potential aggregates for ASR risk. One method uses NaOH digestion, followed by spectroscopic methods, to estimate the amount of reactive silica present in an aggregate. NaOH, however, can digest both crystalline (i.e. quartz) and non-crystalline (e.g. opal), or poorly crystalline silica, potentially yielding falsely high estimates of reactive silica. Studies in soil and plant sciences have used Tiron, an alkaline chelating agent (C6H4S2O8Na2), as a method of digesting opaline silica for spectroscopic analysis. Here we …


Dipole-Dipole Interaction Between Rubidium Rydberg Atoms, Emily Altiere, Donald P. Fahey, Michael W. Noel, Rachel J. Smith, Thomas J. Carroll Nov 2011

Dipole-Dipole Interaction Between Rubidium Rydberg Atoms, Emily Altiere, Donald P. Fahey, Michael W. Noel, Rachel J. Smith, Thomas J. Carroll

Physics and Astronomy Faculty Publications

Ultracold Rydberg atoms in a static electric field can exchange energy via the dipole-dipole interaction. The Stark effect shifts the energy levels of the atoms which tunes the energy exchange into resonance at specific values of the electric field (F¨orster resonances). We excite rubidium atoms to Rydberg states by focusing either a 480 nm beam from a tunable dye laser or a pair of diode lasers into a magneto-optical trap. The trap lies at the center of a configuration of electrodes. We scan the electric field by controlling the voltage on the electrodes while measuring the fraction of atoms that …


Examining The Effects Of Recycling Education On The Knowledge, Attitudes, And Behaviors Of Elementary School Students, Hannah Williams '12 Nov 2011

Examining The Effects Of Recycling Education On The Knowledge, Attitudes, And Behaviors Of Elementary School Students, Hannah Williams '12

Outstanding Senior Seminar Papers

In order to promote environmental sustainability, the Unit 5 School District in McLean County, Illinois has recognized the need to increase recycling rates within the district. As a part of the efforts to encourage recycling in Unit 5 schools, this study considers the barriers that may prevent the effective implementation of environmental education programs in school curricula, as well as the elements that contribute to the success of these programs. Furthermore, this study examines the effects of recycling educational programs on the knowledge, attitudes, and behaviors of second and third grade students at Fox Creek Elementary School in Bloomington, Illinois. …


Dipole-Dipole Interaction Between Rubidium Rydberg Atoms, Emily Altiere, Donald Fahey, Michael Noel, Rachel J. Smith, Thomas J. Carroll Nov 2011

Dipole-Dipole Interaction Between Rubidium Rydberg Atoms, Emily Altiere, Donald Fahey, Michael Noel, Rachel J. Smith, Thomas J. Carroll

Physics Faculty Research and Scholarship

Ultracold Rydberg atoms in a static electric field can exchange energy via the dipole-dipole interaction. The Stark effect shifts the energy levels of the atoms which tunes the energy exchange into resonance at specific values of the electric field (Forster resonances). We excite rubidium atoms to Rydberg states by focusing either a 480 nm beam from a tunable dye laser or a pair of diode lasers into a magneto-optical trap. The trap lies at the center of a configuration of electrodes. We scan the electric field by controlling the voltage on the electrodes while measuring the fraction of atoms that …


Unusual Electron Transfer Rate Effects Due To Pyridyl Ring Substituents And Trace Group Viii B Hexacyano Complexes As Added Salts, Faisal Mehmood Nov 2011

Unusual Electron Transfer Rate Effects Due To Pyridyl Ring Substituents And Trace Group Viii B Hexacyano Complexes As Added Salts, Faisal Mehmood

Master's Theses

The rates of pseudo-self-exchange electron transfer reactions between [(NH3)5RuIIL]2+ and [(NH3)5RuIIIL’]3+ at reactant concentrations of 1.0 х 10-4 M (where L, L’ = substituted pyridines) and the reaction between [(NH3)5RuIIPy]2+ and [(NH3)5RuIII3FPy]2+ at different reactant concentrations in the presence of various salts added were studied by using the stopped-flow kinetic spectroscopy. Marcus theory rate vs. driving force plots yielded distinct families of lines depending on whether a 3- or 4- …


Multiple Dark-Bright Solitons In Atomic Bose-Einstein Condensates, D. Yan, J. J. Chang, C. Hamner, Panos Kevrekidis, P. Engels, V. Achilleos, D. J. Frantzeskakis, R. Carretero-Gonz´Alez, P. Schmelcher Nov 2011

Multiple Dark-Bright Solitons In Atomic Bose-Einstein Condensates, D. Yan, J. J. Chang, C. Hamner, Panos Kevrekidis, P. Engels, V. Achilleos, D. J. Frantzeskakis, R. Carretero-Gonz´Alez, P. Schmelcher

Panos Kevrekidis

Motivated by recent experimental results, we present a systematic theoretical analysis of dark-bright-soliton interactions and multiple-dark-bright-soliton complexes in atomic two-component Bose-Einstein condensates. We study analytically the interactions between two dark-bright solitons in a homogeneous condensate and then extend our considerations to the presence of the trap. We illustrate the existence of robust stationary dark-bright-soliton “molecules,” composed of two or more solitons, which are formed due to the competition of the interaction forces between the dark- and bright-soliton components and the trap force. Our analysis is based on an effective equation of motion, derived for the distance between two dark-bright solitons. …