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2004

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Articles 3031 - 3060 of 4447

Full-Text Articles in Physical Sciences and Mathematics

History Of Greater Sage-Grouse In The Dakotas: Distribution And Population Trends, Joe T. Smith, Lester D. Flake, Kenneth F. Higgins, Gerald D. Kobriger Jan 2004

History Of Greater Sage-Grouse In The Dakotas: Distribution And Population Trends, Joe T. Smith, Lester D. Flake, Kenneth F. Higgins, Gerald D. Kobriger

United States Geological Survey: Staff Publications

The greater sage-grouse (Centrocercus urophasianus) has declined throughout its range and its status is of major concern to federal, state, and provincial wildlife agencies. We collected information on current and historical greater sage-grouse distribution and lek activity in western North and South Dakota. A steady decline in lek attendance by males occurred over the entire recorded period in North Dakota (1951-2002) and South Dakota (1972-2002). There was no apparent change in numbers of known active leks due to discovery of new leks, but there was an abandonment of regions once occupied by active leks.

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Mineralogical Maturity In Dunefields Of North America, Africa And Australia, Daniel R. Muhs Jan 2004

Mineralogical Maturity In Dunefields Of North America, Africa And Australia, Daniel R. Muhs

United States Geological Survey: Staff Publications

Studies of dunefields in central and western North America show that mineralogical maturity can provide new insights into the origin and evolution of aeolian sand bodies. Many of the world’s great sand seas in Africa, Asia and Australia are quartz-dominated and thus can be considered to be mineralogically mature. The Algodones (California) and Parker (Arizona) dunes in the southwestern United States are also mature, but have inherited a high degree of mineralogical maturity from quartz-rich sedimentary rocks drained by the Colorado River. In Libya, sediments of the Zallaf sand sea, which are almost pure quartz, may have originated in a …

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Testing Density-Dependent Groundwater Models: Two-Dimensional Steady State Unstable Convection In Infinite, Finite And Inclined Porous Layers, Douglas Weatherill, Craig T. Simmons, Clifford I. Voss, Neville I. Robinson Jan 2004

Testing Density-Dependent Groundwater Models: Two-Dimensional Steady State Unstable Convection In Infinite, Finite And Inclined Porous Layers, Douglas Weatherill, Craig T. Simmons, Clifford I. Voss, Neville I. Robinson

United States Geological Survey: Staff Publications

This study proposes the use of several problems of unstable steady state convection with variable fluid density in a porous layer of infinite horizontal extent as two-dimensional (2-D) test cases for density-dependent groundwater flow and solute transport simulators. Unlike existing density-dependent model benchmarks, these problems have well-defined stability criteria that are determined analytically. These analytical stability indicators can be compared with numerical model results to test the ability of a code to accurately simulate buoyancy driven flow and diffusion. The basic analytical solution is for a horizontally infinite fluid-filled porous layer in which fluid density decreases with depth. The proposed …

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Complete Angular Distribution Measurements Of Two-Body Deuteron Photodisintegration Between 0.5 And 3 Gev, H. Bagdasaryan, H. Bektasoglu, G. E. Dodge, T. A. Forest, C. E. Hyde-Wright, A. Klein, A. V. Klimenko, S. E. Kuhn, F. Sabatié, S. Stepanyan, L. B. Weinstein, J. Yun, Et Al., The Clas Collaboration Jan 2004

Complete Angular Distribution Measurements Of Two-Body Deuteron Photodisintegration Between 0.5 And 3 Gev, H. Bagdasaryan, H. Bektasoglu, G. E. Dodge, T. A. Forest, C. E. Hyde-Wright, A. Klein, A. V. Klimenko, S. E. Kuhn, F. Sabatié, S. Stepanyan, L. B. Weinstein, J. Yun, Et Al., The Clas Collaboration

Physics Faculty Publications

Nearly complete angular distributions of the two-body deuteron photodisintegration differential cross section have been measured using the CEBAF Large Acceptance Spectrometer detector and the tagged photon beam at the Thomas Jefferson National Accelerator Facility. The data cover photon energies between 0.5 and 3.0 GeV and center-of-mass proton scattering angles 10°–160°. The data show a persistent forward-backward angle asymmetry over the explored energy range, and are well described by the nonperturbative quark gluon string model.

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Experimental Determination Of The Evolution Of The Bjorken Integral At Low Q², A. Deur, P. Bosted, V. Burkert, G. Cates, J.P. Chen, Seonho Choi, D. Crabb, C.W. De Jager, R. De Vita, G.E. Dodge, R. Fatemi, T.A. Forest, F. Garibaldi, R. Gilman, E. W. Hughes, X. Jiang, W. Korsch, S. E. Kuhn, W. Melnitchouk, Z.-E. Meziani, R. Minehart, A.V. Skabelin, K. Slifer, M. Taiuti, J. Yun Jan 2004

Experimental Determination Of The Evolution Of The Bjorken Integral At Low Q², A. Deur, P. Bosted, V. Burkert, G. Cates, J.P. Chen, Seonho Choi, D. Crabb, C.W. De Jager, R. De Vita, G.E. Dodge, R. Fatemi, T.A. Forest, F. Garibaldi, R. Gilman, E. W. Hughes, X. Jiang, W. Korsch, S. E. Kuhn, W. Melnitchouk, Z.-E. Meziani, R. Minehart, A.V. Skabelin, K. Slifer, M. Taiuti, J. Yun

Physics Faculty Publications

We extract the Bjorken integral 𝚪1p-n in the range 0.17 < Q2 <1.10 GeV2 from inclusive scattering of polarized electrons by polarized protons, deuterons, and 3He, for the region in which the integral is dominated by nucleon resonances. These data bridge the domains of the hadronic and partonic descriptions of the nucleon. In combination with earlier measurements at higher Q2, we extract the nonsinglet twist-4 matrix element f2.

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Measurement Of The Electric Form Factor Of The Neutron At Q² = 0.5 And 1.0 Gev²/C², Jefferson Lab E93-026 Collaboration, G. Warren, F. Wesselmann, H. Zhu, A. Klimenko, S. E. Kuhn, L. Yuan, J. Yun, B. Zihlmann, Et Al. Jan 2004

Measurement Of The Electric Form Factor Of The Neutron At Q² = 0.5 And 1.0 Gev²/C², Jefferson Lab E93-026 Collaboration, G. Warren, F. Wesselmann, H. Zhu, A. Klimenko, S. E. Kuhn, L. Yuan, J. Yun, B. Zihlmann, Et Al.

Physics Faculty Publications

The electric form factor of the neutron was determined from measurements of the →d( →e, e'n)p reaction for quasielastic kinematics. Polarized electrons were scattered off a polarized deuterated ammonia (15ND3) target in which the deuteron polarization was perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons in a large solid angle detector. We find GnE =0.0526 ± 0.0033(stat) ± 0.0026(sys) and 0.0454 ± 0.0054 ± 0.0037 at Q2=0.5 and 1.0 (GeV/c)2, respectively.

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Unique Electron Polarimeter Analyzing Power Comparison And Precision Spin-Based Energy Measurement, J. M. Grames, C. K. Sinclair, J. Mitchell, E. Chudakov, H. Fenker, A. Freyberger, D. W. Higinbotham, M. Poelker, M. Steigerwald, M. Tiefenback, Vipuli Dharmawardane Jan 2004

Unique Electron Polarimeter Analyzing Power Comparison And Precision Spin-Based Energy Measurement, J. M. Grames, C. K. Sinclair, J. Mitchell, E. Chudakov, H. Fenker, A. Freyberger, D. W. Higinbotham, M. Poelker, M. Steigerwald, M. Tiefenback, Vipuli Dharmawardane

Physics Faculty Publications

Precision measurements of the relative analyzing powers of five electron beam polarimeters, based on Compton, Moller, and Mott scattering, have been performed using the CEBAF accelerator at the Thomas Jefferson National Accelerator Facility ( Jefferson Laboratory). A Wien filter in the 100 keV beam line of the injector was used to vary the electron spin orientation exiting the injector. High statistical precision measurements of the scattering asymmetry as a function of the spin orientation were made with each polarimeter. Since each polarimeter receives beam with the same magnitude of polarization, these asymmetry measurements permit a high statistical precision comparison of …

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Ua56/1 Fact Book, Wku Institutional Research Jan 2004

Ua56/1 Fact Book, Wku Institutional Research

WKU Archives Records

Statistical and demographic profile of WKU.

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Bohmian Dynamics On Subspaces Using Linearized Quantum Force, V. A. Rassolov, Sophya V. Garashchuk Jan 2004

Bohmian Dynamics On Subspaces Using Linearized Quantum Force, V. A. Rassolov, Sophya V. Garashchuk

Faculty Publications

In the de Broglie–Bohm formulation of quantum mechanics the time-dependent Schrödinger equation is solved in terms of quantum trajectories evolving under the influence of quantum and classical potentials. For a practical implementation that scales favorably with system size and is accurate for semiclassical systems, we use approximate quantum potentials. Recently, we have shown that optimization of the nonclassical component of the momentum operator in terms of fitting functions leads to the energy-conserving approximate quantum potential. In particular, linear fitting functions give the exact time evolution of a Gaussian wave packet in a locally quadratic potential and can describe the dominant …

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Geminal Model Chemistry Ii. Perturbative Corrections, V. A. Rassolov, F. Xu, Sophya V. Garashchuk Jan 2004

Geminal Model Chemistry Ii. Perturbative Corrections, V. A. Rassolov, F. Xu, Sophya V. Garashchuk

Faculty Publications

We introduce and investigate a chemical model based on perturbative corrections to the product of singlet-type strongly orthogonal geminals wave function. Two specific points are addressed (i) Overall chemical accuracy of such a model with perturbative corrections at a leading order; (ii) Quality of strong orthogonality approximation of geminals in diverse chemical systems. We use the Epstein–Nesbet form of perturbation theory and show that its known shortcomings disappear when it is used with the reference Hamiltonian based on strongly orthogonal geminals. Application of this model to various chemical systems reveals that strongly orthogonal geminals are well suited for chemical models, …

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Reference Soils Of South-Western Australia, W M. Mcarthur, Australian Society Of Soil Science W.A. Branch., Department Of Agriculture And Food Jan 2004

Reference Soils Of South-Western Australia, W M. Mcarthur, Australian Society Of Soil Science W.A. Branch., Department Of Agriculture And Food

Books & book chapters

First printed 1991, Reprinted 2004

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Terminal Moraine Remnants Of The Trail Creek Glacier Northeast Of Sun Valley, Idaho, Eric L. Rothwell, Spencer H. Wood Jan 2004

Terminal Moraine Remnants Of The Trail Creek Glacier Northeast Of Sun Valley, Idaho, Eric L. Rothwell, Spencer H. Wood

Geosciences Faculty Publications and Presentations

This optional excursion is 8 miles on paved road from the center of Ketchum (Main Street and Sun Valley Road traffic light), northeast through Sun Valley along the Trail Creek Road (fig. 1). A short walk of 10 minutes takes you to the crests of two moraines of very different ages. Here we view and discuss calcareous soils developed into the deposits, the pretty weathering-rinds developed on the sandstone cobbles, and ages of Pinedale and Bull Lake advances. During the Quaternary, an extensive system of mountain glaciers accumulated in the Pioneer and Boulder Mountains and flowed down valleys emanating from …

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Fire And Ice In Central Idaho: Modern And Holocene Fires, Debris Flows, And Climate In The Payette River Basin, And Quaternary And Glacial Geology In The Sawtooth Mountains, Jennifer L. Pierce, Grant A. Meyer, Glenn D. Thackray, Spencer H. Wood, Kari Lundeen, Jennifer A. Borgert, Eric Rothwell Jan 2004

Fire And Ice In Central Idaho: Modern And Holocene Fires, Debris Flows, And Climate In The Payette River Basin, And Quaternary And Glacial Geology In The Sawtooth Mountains, Jennifer L. Pierce, Grant A. Meyer, Glenn D. Thackray, Spencer H. Wood, Kari Lundeen, Jennifer A. Borgert, Eric Rothwell

Geosciences Faculty Publications and Presentations

This 2-day trip will highlight recent fire and storm-related debris flows in the Payette River region, Holocene records of fires and fire-related sedimentation events preserved in alluvial fan stratigraphic sequences, and geomorphology and geology of alpine glaciations in the spectacular Sawtooth Mountains and Stanley Basin of central Idaho. Storm events and associated scour following recent fires in the South Fork Payette basin have exposed Holocene fire-related debris-flow deposits, flood sediments, and other alluvial fan-building deposits that yield insights into Holocene environmental change. Moraine characteristics and sediment cores from the southeastern Sawtooth Mountains and Stanley Basin provide evidence of late Pleistocene …

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Magnetic Granulometry Of Igneous And Metasedimentary Rocks From Northern Graham Land, Antarctic Peninsula, Stefanie A. Brachfeld, Anne Grunow, Emily Youcha Jan 2004

Magnetic Granulometry Of Igneous And Metasedimentary Rocks From Northern Graham Land, Antarctic Peninsula, Stefanie A. Brachfeld, Anne Grunow, Emily Youcha

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

No abstract provided.

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Application Of Pyrolysis-Gc/Ms For Rapid Assessment Of Organic Contamination In Sediments From Barcelona Harbor, Michael A. Kruge, Albert Permanyer Jan 2004

Application Of Pyrolysis-Gc/Ms For Rapid Assessment Of Organic Contamination In Sediments From Barcelona Harbor, Michael A. Kruge, Albert Permanyer

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Pyrolysis-GC/MS is advantageous as a tool for rapid sediment contamination assessment because of the small sample size required, minimal sample preparation, and its ability to detect a wide variety of organic pollutants as well as naturally-occurring biological materials. Py-GC/MS was applied, together with determination of organic carbon, and major and minor element concentrations, to evaluate potentially contaminated sediments in the port of Barcelona (Spain) and the adjacent Llobregat River delta. Detected contaminant markers, most evident in the Old Port (Port Vell) area, included hopanes and alkylated PAHs (petroleum), sterenes (sewage), C16-C19 phenylalkanes (detergents) and parent …

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Superionicity In Na3Po4: A Molecular Dynamics Simulation, Wei-Guo Yin, Jianjun Liu, Chun-Gang Duan, Wai-Ning Mei, Robert W. Smith, John R. Hardy Jan 2004

Superionicity In Na3Po4: A Molecular Dynamics Simulation, Wei-Guo Yin, Jianjun Liu, Chun-Gang Duan, Wai-Ning Mei, Robert W. Smith, John R. Hardy

Physics Faculty Publications

Fast ionic conduction in solid Na3PO4 is studied by use of molecular dynamics simulation based on the modified Lu-Hardy approach. We obtain reasonable agreement with experiment for the structural transition and diffusion of the sodium ions. All the sodium ions are found to contribute comparably to the high ionic conductivity. The results of the simulation are discussed in terms of the relative magnitude of the two proposed transport mechanisms: percolation and paddle-wheel. It appears to us that the percolation mechanism dominates the sodium diffusion.

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Rectification Of Thermal Fluctuations In Ideal Gases, Alejandro Garcia, P. Meurs, C. Van De Broeck Jan 2004

Rectification Of Thermal Fluctuations In Ideal Gases, Alejandro Garcia, P. Meurs, C. Van De Broeck

Alejandro Garcia

We calculate the systematic average speed of the adiabatic piston and a thermal Brownian motor, introduced by C. Van den Broeck, R. Kawai and P. Meurs [Phys. Rev. Lett. 93, 090601 (2004)], by an expansion of the Boltzmann equation and compare with the exact numerical solution.

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Lanthanide Spectroscopic Studies Of The Dinuclear And Mg(Ii)-Dependent Pvuii Restriction Endonuclease, Gilles Muller, L. M. Bowen, J. P. Riehl, C. M. Dupureur Jan 2004

Lanthanide Spectroscopic Studies Of The Dinuclear And Mg(Ii)-Dependent Pvuii Restriction Endonuclease, Gilles Muller, L. M. Bowen, J. P. Riehl, C. M. Dupureur

Gilles Muller

Type II restriction enzymes are homodimeric systems that bind four to eight base pair palindromic recognition sequences of DNA and catalyze metal ion-dependent phosphodiester cleavage. While Mg(II) is required for cleavage in these enzymes, in some systems Ca(II) promotes avid substrate binding and sequence discrimination. These properties make them useful model systems for understanding the roles of alkaline earth metal ions in nucleic acid processing. We have previously shown that two Ca(II) ions stimulate DNA binding by PvuII endonuclease and that the trivalent lanthanide ions Tb(III) and Eu(III) support subnanomolar DNA binding in this system. Here we capitalize on this …

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The Transformation Engine, Bruno Degazio Jan 2004

The Transformation Engine, Bruno Degazio

Publications and Scholarship

The Transformation Engine is a software music composition system for the Macintosh computer, based on a hierarchical model of musical structure derived from the theories of Heinrich Schenker. It implements processes of musical transformation in real time, i.e. Schenkerian prolongations (“composing-out”) can be executed while the user listens to a high performance MIDI rendering of the music. The Transformation Engine also employs technical devices derived from the musical theories of Joseph Schillinger. The software has been used for algorithmic composition using planetary position data and chaotic processes as drivers for musical transformations. It also has applications to traditional forms of …

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The Faith Factor: New Testament Cosmology In Its Historical Context, Keith A. Burton Jan 2004

The Faith Factor: New Testament Cosmology In Its Historical Context, Keith A. Burton

Journal of the Adventist Theological Society

No abstract provided.

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On The Transferability Of The Spcal Water Model To Biomolecular Simulation, Alice Glaettli, Chris Oostenbrink, Xavier Daura, Daan Geerke, Haibo Yu, Wilfred Van Gunsteren Jan 2004

On The Transferability Of The Spcal Water Model To Biomolecular Simulation, Alice Glaettli, Chris Oostenbrink, Xavier Daura, Daan Geerke, Haibo Yu, Wilfred Van Gunsteren

Faculty of Science - Papers (Archive)

We investigated the performance of the recently developed SPC/L model for liquid water, as a pure liquid, in binary mixtures with DMSO, and as a solvent model in a peptide folding simulation. Additionally, in order to test the compatibility with the GROMOS biomolecular force field, free energies of hydration of a set of representative compounds were computed. The results are compared to those for the well established SPC water model, which is generally used as a solvent model in conjunction with the GROMOS force field already for more than two decades. It turns out that as a pure liquid and …

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Protecting Group Effects On The Efficiency Of The Ruthenium-Catalyzed Alder-Ene Reaction, Joseph Hartley, Stephen G. Pyne Jan 2004

Protecting Group Effects On The Efficiency Of The Ruthenium-Catalyzed Alder-Ene Reaction, Joseph Hartley, Stephen G. Pyne

Faculty of Science - Papers (Archive)

The efficiency of the ruthenium-catalysed Alder-ene reaction of hydroxy alkenes depends heavily on the nature of the O-protecting groups employed as well as the length of the carbon spacer between the hydroxy and alkene group.

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Methods Of Online Grocery Shopping: Linking And Searching, Mark B. Freeman Jan 2004

Methods Of Online Grocery Shopping: Linking And Searching, Mark B. Freeman

Faculty of Informatics - Papers (Archive)

There are two dominant methods for locating information or goods on websites and online systems: searching and linking. Most previous research on searching and linking methods has focused on generic websites dedicated to locating information, such as Yahoo, rather than the searching and linking mechanisms used in specific applications, such as online shopping. In contrast, this study assessed the searching and linking metaphors inherent in online grocery stores, where each website must provide efficient tools for locating products if they are to be successful e-commerce websites. Worldwide grocery sites were judged against a checklist of advanced search features, and the …

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Lessons Learned From The Practice Of Mobile Health Application Development, Ping Yu, H. Yu Jan 2004

Lessons Learned From The Practice Of Mobile Health Application Development, Ping Yu, H. Yu

Faculty of Informatics - Papers (Archive)

This fast abstract briefly discusses lessons learned in terms of how to overcome limitations of PDA devices, effectively capture requirements for mobile health application development and effectively reengineer a desktop application on PDA. The limitation of PDA devices includes: (1) small screen size, which limits text-based data entry, reporting and browsing; (2) limited storage space and slow processing, which requires effective and efficient coding generation; (3) security limitations and inadequate third party application support, which poses challenge for application development. The corresponding strategies addressing the above challenges are: (1) providing check box, radio button, drop down list, text field, combo …

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A Distributed Server Architecture For Providing Immersive Audio Communication To Massively Multiplayer Online Games, C. D. Nguyen, Farzad Safaei, P. Boustead Jan 2004

A Distributed Server Architecture For Providing Immersive Audio Communication To Massively Multiplayer Online Games, C. D. Nguyen, Farzad Safaei, P. Boustead

Faculty of Informatics - Papers (Archive)

This paper investigates the assignment of audio mixing operations to a geographically distributed set of servers to provide an immersive audio communication environment for massively multiplayer online games. The immersive audio communication service enables each avatar to hear a realistic audio mix of the conversations in its audible range. There are three primary delivery architectures for this service, namely, peer-to-peer, central server and distributed servers. We focus on the distributed server architecture, which partitions the virtual world into regions or locales and then assigns the computation associated with the creation of audio scenes for all avatars in each locale to …

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On The Provision Of Immersive Audio Communication To Massively Multi-Player Online Games, C. D. Nguyen, Farzad Safaei, D. Platt Jan 2004

On The Provision Of Immersive Audio Communication To Massively Multi-Player Online Games, C. D. Nguyen, Farzad Safaei, D. Platt

Faculty of Informatics - Papers (Archive)

This paper discusses issues in providing immersive audio communication to massively multi-player online games (MMOG). We focus on network and server architectures for creating immersive audio scenes for game clients. We examine advantages and limitations of several architectures, including central server, distributed servers, and peer-to-peer architectures. We focus on a dynamic centralized server architecture which is suitable for the current MMOG in terms of sealability at end users and resource efficiency. We propose algorithms to optimize the performance of a centralized server. Finally, a simulation study is carried out to evaluate the performance of our proposed centralized server architecture and …

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Nonlinear Sigma Model For Odd-Frequency Triplet Superconductivity In Superconductor/Ferromagnet Structures, J E. Bunder, K B. Efetov Jan 2004

Nonlinear Sigma Model For Odd-Frequency Triplet Superconductivity In Superconductor/Ferromagnet Structures, J E. Bunder, K B. Efetov

Faculty of Informatics - Papers (Archive)

No abstract provided.

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Data Management For Large Scale Power Quality Surveys, Murray-Luke Peard, Sean T. Elphick, Victor W. Smith, Victor J. Gosbell, D A. Robinson Jan 2004

Data Management For Large Scale Power Quality Surveys, Murray-Luke Peard, Sean T. Elphick, Victor W. Smith, Victor J. Gosbell, D A. Robinson

Faculty of Informatics - Papers (Archive)

For large scale power quality surveys, the management of the large amount of data generated is a major issue. This paper presents solutions to three main areas of data management, viz. a data interchange format, database design and data processing. Consideration of these issues has come about as a result of the Long Term National Power Quality Survey currently being conducted by the University of Wollongong, and reference is made to that specific application for illustrative purposes.

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Q-Pod: Deployable And Scalable End System Support For Enabling Qos In Legacy Enterprise Systems, Asad Khan Awan, Kihong Park Jan 2004

Q-Pod: Deployable And Scalable End System Support For Enabling Qos In Legacy Enterprise Systems, Asad Khan Awan, Kihong Park

Department of Computer Science Technical Reports

No abstract provided.

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Combinatorial Identities Deriving From The N-Th Power Of A 2 X 2 Matrix, James Mclaughlin Jan 2004

Combinatorial Identities Deriving From The N-Th Power Of A 2 X 2 Matrix, James Mclaughlin

Mathematics Faculty Publications

In this paper we give a new formula for the n-th power of a 2 × 2 matrix. More precisely, we prove the following: Let A = (a b c d) be an arbitrary 2 × 2 matrix, T = a + d its trace, D = ad − bc its determinant and define yn : = b X n/2c i=0 (n − i i )T n−2i (−D) i . Then, for n ≥ 1, A n = (yn − d yn−1 b yn−1 c yn−1 yn − a yn−1) . We use this formula together with an existing formula …

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