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Performance Surface Prediction For Wan-Based Clusters, Mark J. Clement, J. Kelly Flanagan, Glenn M. Judd, Bryan S. Morse, Joy L. Peterson Jan 1999

Performance Surface Prediction For Wan-Based Clusters, Mark J. Clement, J. Kelly Flanagan, Glenn M. Judd, Bryan S. Morse, Joy L. Peterson

Faculty Publications

The last five years have been a period of exponential growth in the number of machines connected to the Internet and the speed at which these machines communicate. The infrastructure is now in place to consider a nationwide cluster of workstations as a viable parallel processing platform. In order to achieve acceptable performance on this kind of a machine, performance prediction tools must provide information on where to place computational objects. Incorrect object placement can result in poor performance and congestion in the network. This research develops a new paradigm for predicting performance in the Wide Area Network (WAN) based …

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Some Aspects Of The Adsorption Of A Lennard-Jones Gas On A Rough Surface, Douglas Henderson, Pawel Bryk, Stefan Sokolowski Jan 1999

Some Aspects Of The Adsorption Of A Lennard-Jones Gas On A Rough Surface, Douglas Henderson, Pawel Bryk, Stefan Sokolowski

Faculty Publications

We study the adsorption, including wetting, of a Lennard-Jones gas on a rough surface consisting of rough layer on a smooth substrate with which the gas interacts via a 9-3 potential. The rough layer is two molecular diameters thick and consists of a disordered quenched matrix of hard spheres. As well as interacting with the other matrix spheres by the hard-sphere potential, the matrix molecules interact with the gas molecules by the hard-sphere potential. Hence, on average, the degree to which the gas molecules can approach the substrate depends only on the density of the matrix layer. The density of …

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Balancing Interests And Maximizing Rights In Envrionmental Law, Tseming Yang Jan 1999

Balancing Interests And Maximizing Rights In Envrionmental Law, Tseming Yang

Faculty Publications

No abstract provided.

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Historical Essays On Meteorology, 1919-1995, Theodore S. Feldman Jan 1999

Historical Essays On Meteorology, 1919-1995, Theodore S. Feldman

Faculty Publications

No abstract provided.

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Importance Of Convection And Damping On Rates Of Convergence For The Lax-Wendroff Method, Joseph Kolibal Jan 1999

Importance Of Convection And Damping On Rates Of Convergence For The Lax-Wendroff Method, Joseph Kolibal

Faculty Publications

It is well known that in solving steady state problems using hyperbolic time-stepping methods the intent is to drive the transients to zero as quickly as possible. In this paper the convergence to steady state of the Lax-Wendroff method applied to solving the equations of gas dynamics is analyzed for the Laval nozzle problem by comparing the relative rates of damping and convection using a linearized eigenmode analysis. This analysis is developed for the simpler isenthalpic system and then extended to the full Euler equations. Finally, this allows a comparison between these systems. For both models, useful analytical information can …

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Period-Doubling Behavior In Frontal Polymerization Of Multifunctional Acrylates, Jonathan Masere, Felicia Stewart, Timothy Meehan, John A. Pojman Jan 1999

Period-Doubling Behavior In Frontal Polymerization Of Multifunctional Acrylates, Jonathan Masere, Felicia Stewart, Timothy Meehan, John A. Pojman

Faculty Publications

Front dynamics in the frontal polymerization of two multifunctional acrylate monomers, 1,6-hexanediol diacrylate (HDDA) and trimethylolpropane ethoxylate triacrylate (TMPTA), with Lupersol 231 [1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane] as the initiator, are studied. In most frontal polymerization systems, the dynamics are associated with a planar front propagating through the sample. However, in some cases, front behavior can be altered: the front becomes nonplanar characterized by complex patterns like spin modes and pulsations. To determine how these periodic and aperiodic modes arise, reactant solutions consisting of HDDA diluted with diethyl phthalate (DEP) and TMPTA diluted with dimethyl sulfoxide (DMSO) were used in the study. In the …

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Overview: Nonlinear Dynamics Related To Polymeric Systems, Irving R. Epstein, John A. Pojman Jan 1999

Overview: Nonlinear Dynamics Related To Polymeric Systems, Irving R. Epstein, John A. Pojman

Faculty Publications

No abstract provided.

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Thickness Of Knots, R. A. Litherland, J. Simon, O. Durumeric, E. Rawdon Jan 1999

Thickness Of Knots, R. A. Litherland, J. Simon, O. Durumeric, E. Rawdon

Faculty Publications

Classical knot theory studies one-dimensional filaments; in this paper we model knots as more physically "real", e.g., made of some "rope" with nonzero thickness. A motivating question is: How much length of unit radius rope is needed to tie a nontrivial knot? For a smooth knot K, the "injectivity radius" R(K) is the supremum of radii of embedded tubular neighborhoods. The "thickness" of K, a new measure of knot complexity, is the ratio of R(K) to arc-length. We relate thickness to curvature, self-distance, distortion, and (for knot types) edge-number. © 1999 Elsevier Science B.V. All rights reserved.

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Image Segmentation With A Finite Element Method, Blaise Bourdin Jan 1999

Image Segmentation With A Finite Element Method, Blaise Bourdin

Faculty Publications

The Mumford-Shah functional for image segmentation is an original approach of the image segmentation problem, based on a minimal energy criterion. Its minimization can be seen as a free discontinuity problem and is based on Γ-convergence and bounded variation functions theories. Some new regularization results, make possible to imagine a finite element resolution method. In a first time, the Mumford-Shah functional is introduced and some existing results are quoted. Then, a discrete formulation for the Mumford-Shah problem is proposed and its Γ-convergence is proved. Finally, some numerical results, computed from both artificial and real images are presented and discussed.

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The Condition Number Of The Schur Complement In Domain Decomposition, Susanne C. Brenner Jan 1999

The Condition Number Of The Schur Complement In Domain Decomposition, Susanne C. Brenner

Faculty Publications

It is shown that for elliptic boundary value problems of order 2m the condition number of the Schur complement matrix that appears in nonoverlapping domain decomposition methods is of order d h , where d measures the diameters of the subdomains and h is the mesh size of the triangulation. The result holds for both conforming and nonconforming finite elements. -1 -2m+1

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Balancing Domain Decomposition For Nonconforming Plate Elements, Susanne C. Brenner, Li Yeng Sung Jan 1999

Balancing Domain Decomposition For Nonconforming Plate Elements, Susanne C. Brenner, Li Yeng Sung

Faculty Publications

In this paper the balancing domain decomposition method is extended to nonconforming plate elements. The condition number of the preconditioned system is shown to be bounded by C[1 + ln(H/h)] , where H measures the diameters of the subdomains, h is the mesh size of the triangulation, and the constant C is independent of H, h and the number of subdomains. 2

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Close-Limit Approximation To Neutron Star Collisions, Gabrielle D. Allen, Jorge A. Pullin Jan 1999

Close-Limit Approximation To Neutron Star Collisions, Gabrielle D. Allen, Jorge A. Pullin

Faculty Publications

We develop a close-limit approximation to the head-on collision of two neutron stars similar to that used to treat the merger of black hole binaries. This approximation can serve as a useful benchmark test for future fully non-linear studies. For neutron star binaries, the close-limit approximation involves assuming that the merged object can be approximated as a perturbed, stable neutron star during the ring-down phase of the coalescence. We introduce a prescription for the construction of initial data sets, discuss the physical plausibility of the various assumptions involved, and briefly investigate the character of the gravitational radiation produced during the …

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An Overview Of Canonical Quantum Gravity, Jorge Pullin Jan 1999

An Overview Of Canonical Quantum Gravity, Jorge Pullin

Faculty Publications

This paper presents a brief review of current results on the canonical quantization of general relativity using Ashtekar's variables and loop quantization.

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The Close Limit Of Colliding Black Holes: An Update, Jorge Pullin Jan 1999

The Close Limit Of Colliding Black Holes: An Update, Jorge Pullin

Faculty Publications

This is the writeup of the talk I gave at the Yukawa International Symposium at Kyoto, Japan on June 29, 1999. The talk summarizes the present status of the close limit approximation for colliding black holes.

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Semiclassical Calculation Of Cumulative Reaction Probabilities, David J. Tannor, Sophya V. Garashchuk Jan 1999

Semiclassical Calculation Of Cumulative Reaction Probabilities, David J. Tannor, Sophya V. Garashchuk

Faculty Publications

Calculation of chemical reaction rates lies at the very core of theoretical chemistry. The essential dynamical quantity which determines the reaction rate is the energy-dependent cumulative reaction probability, N(E), whose Boltzmann average gives the thermal rate constant, k(T). Converged quantum mechanical calculations of N(E) remain a challenge even for three- and four-atom systems, and a longstanding goal of theoreticians has been to calculate N(E) accurately and efficiently using semiclassical methods. In this article we present a variety of methods for achieving this goal, by combining semiclassical initial value …

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Policy And Science: A Review Essay Of Wilson’S Consilience: The Unity Of Knowledge, Thomas E. Geu Jan 1999

Policy And Science: A Review Essay Of Wilson’S Consilience: The Unity Of Knowledge, Thomas E. Geu

Faculty Publications

No abstract provided.

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Minor-Equivalence For Infinite Graphs, Bogdan Oporowski Jan 1999

Minor-Equivalence For Infinite Graphs, Bogdan Oporowski

Faculty Publications

Two graphs are minor-equivalent if each is isomorphic to a minor of the other. In this paper, we give structural characterizations of the minor equivalence classes of the infinite full grid GZ×L and of the infinite half-grid GZ×N. A corollary of these results states that every minor of GZ×z that has a minor isomorphic to GZ×N is minor-equivalent to one of GZ×Z or GZ×N. © 1999 Elsevier Science B.V. All rights reserved.

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Analysis Of A Lithium/Thionyl Chloride Battery Under Moderate-Rate Discharge, Mukul Jain, Ganesan Nagasubramanian, Rudolph G. Jungst, John W. Weidner Jan 1999

Analysis Of A Lithium/Thionyl Chloride Battery Under Moderate-Rate Discharge, Mukul Jain, Ganesan Nagasubramanian, Rudolph G. Jungst, John W. Weidner

Faculty Publications

A one-dimensional mathematical model of a spirally wound lithium/thionyl chloride primary battery is developed and used for parameter estimation and design studies. The model formulation is based on the fundamental conservation laws using porous electrode theory and concentrated solution theory. The model is used to estimate the transference number, the diffusion coefficient, and the kinetic parameters for the reactions at the anode and the cathode as a function of temperature. These parameters are obtained by fitting the simulated capacity and average cell voltage to experimental data over a wide range of temperatures (–55 to 49°C) and discharge loads (10-250 ). …

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Database Protection In A Digital World, Mary Maureen Brown, Robert M. Bryan, John M. Conley Jan 1999

Database Protection In A Digital World, Mary Maureen Brown, Robert M. Bryan, John M. Conley

Faculty Publications

No abstract provided.

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A Matrix-Based Approach To Global Locality Optimization, Mahmut Kandemir, Alok Choudhary, J. Ramanujam, Prith Banerjee Jan 1999

A Matrix-Based Approach To Global Locality Optimization, Mahmut Kandemir, Alok Choudhary, J. Ramanujam, Prith Banerjee

Faculty Publications

Global locality optimization is a technique for improving the cache performance of a sequence of loop nests through a combination of loop and data layout transformations. Pure loop transformations are restricted by data dependencies and may not be very successful in optimizing imperfectly nested loops and explicitly parallelized programs. Although pure data transformations are not constrained by data dependencies, the impact of a data transformation on an array might be program-wide; that is, it can affect all the references to that array in all the loop nests. Therefore, in this paper we argue for an integrated approach that employs both …

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Material Balance Modification In One-Dimensional Modeling Of Porous Electrodes, Mukul Jain, John W. Weidner Jan 1999

Material Balance Modification In One-Dimensional Modeling Of Porous Electrodes, Mukul Jain, John W. Weidner

Faculty Publications

The material balance used previously in one-dimensional mathematical models of porous electrodes is invalid when there is a non-zero volume change associated with the reaction. It is shown here how the material balance should be modified either to account for a loss in volume, or to account for an inflow of electrolyte from the header into the active pores. A one-dimensional mathematical model is used to illustrate the effect of this correction on the prediction of the delivered capacity and the electrolyte concentration in a lithium/thionyl chloride primary battery.

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A Mathematical Model Of An Electrochemical Capacitor With Double-Layer And Faradaic Processes, Chuan Lin, James A. Ritter, Branko N. Popov, Ralph E. White Jan 1999

A Mathematical Model Of An Electrochemical Capacitor With Double-Layer And Faradaic Processes, Chuan Lin, James A. Ritter, Branko N. Popov, Ralph E. White

Faculty Publications

A mathematical model of an electrochemical capacitor with hydrous ruthenium oxide (RuO2·xH2O) electrodes including both double-layer and surface faradaic processes is developed to predict the behavior of the capacitor under conditions of galvanostatic charge and discharge. The effect of RuO2·xH2O particle size is studied and shows that the smaller the particles the better the performance because of the increased surface area per unit volume or mass. The model also predicts that the faradaic process increases significantly the energy per unit volume of the capacitor for power densities of …

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A Mathematical Model For Electroless Copper Deposition On Planar Substrates, M. Ramasubramanian, Branko N. Popov, Ralph E. White, K. S. Chen Jan 1999

A Mathematical Model For Electroless Copper Deposition On Planar Substrates, M. Ramasubramanian, Branko N. Popov, Ralph E. White, K. S. Chen

Faculty Publications

A mathematical model for the electroless deposition of copper on a planar electrode is presented and used to make time-dependent predictions on the various quantities in the system. The model takes into account mass transport by diffusion and migration, Butler-Volmer kinetics at the electrode surface, and mixed potential theory. A finite difference approach is used to solve the equations, and the resultant model is used to predict the concentration profiles, potential response, and plating rate as a function of time and concentration of various reactive components.

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Mathematical Modeling Of The Lithium Deposition Overcharge Reaction In Lithium‐Ion Batteries Using Carbon‐Based Negative Electrodes, Pankaj Arora, Marc Doyle, Ralph E. White Jan 1999

Mathematical Modeling Of The Lithium Deposition Overcharge Reaction In Lithium‐Ion Batteries Using Carbon‐Based Negative Electrodes, Pankaj Arora, Marc Doyle, Ralph E. White

Faculty Publications

No abstract provided.

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Influence Of Some Design Variables On The Thermal Behavior Of A Lithium‐Ion Cell, Gerardine G. Botte, Bradley A. Johnson, Ralph E. White Jan 1999

Influence Of Some Design Variables On The Thermal Behavior Of A Lithium‐Ion Cell, Gerardine G. Botte, Bradley A. Johnson, Ralph E. White

Faculty Publications

No abstract provided.

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Mathematical Modeling Of Electrochemical Capacitors, Venkat Srinivasan, John W. Weidner Jan 1999

Mathematical Modeling Of Electrochemical Capacitors, Venkat Srinivasan, John W. Weidner

Faculty Publications

Analytic solutions to the mathematical model of an electrochemical capacitor (EC) are used to study cell performance under two types of operating conditions: (i) constant current and (ii) electrochemical impedance spectroscopy. The analytic solution under constant-current operation is used to investigate the relative importance of ionic resistance in the separator, and ionic and electronic resistances in the porous electrode in the design and operation of an EC. Model results are presented that show the trade-off between energy and power density, as the physical properties of the cell components are varied (e.g., electrode thickness). The analytic solution …

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When Y2k Causes "Economic Loss" To "Other Property", Peter A. Alces, Aaron S. Book Jan 1999

When Y2k Causes "Economic Loss" To "Other Property", Peter A. Alces, Aaron S. Book

Faculty Publications

No abstract provided.

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Revisiting The Stock Price Impact Of Quality Awards, Gregory L. Adams, Grant Mcqueen, Kristie Seawright Jan 1999

Revisiting The Stock Price Impact Of Quality Awards, Gregory L. Adams, Grant Mcqueen, Kristie Seawright

Faculty Publications

In an event study, Hendricks and Singhal [Hendricks KB, Singhal VR. Quality awards and the market value of the firm: an empirical investigation. Management Sci 1996;42:415±36.] find evidence that firms that win quality awards are further rewarded with a stock price increase on the day of the award announcement. We revisit Hendricks and Singhal (1996), extend their research and find four reasons why management, owners and analysts should be cautious about expecting an abnormal return when a firm wins a quality award. First, in our sample of Baldrige Award winners, the evidence of a stock price response on the announcement …

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Curricular Approaches To Developing Positive Interethnic Relations, Rosemary C. Henze Jan 1999

Curricular Approaches To Developing Positive Interethnic Relations, Rosemary C. Henze

Faculty Publications

This article examines whether and in what ways curricular approaches can be helpful in building positive interethnic relations in a large, ethnically diverse high school. Through this case study of curricular reform, the author documents four curricular approaches teacher leaders used to explicitly address issues of race and ethnicity and explores the impact of these approaches on student learning. By tracing the process of curricular change, the case illuminates how teacher leaders and administrators created the conditions for these curricular reforms to be sustainable.

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Measurement Of High-Q2 Neutral-Current E+P Deep Inelastic Scattering Cross-Sections At Hera, J. Breitweg, S. Chekanov, M. Derrick, D. Krakauer, S. Magill, B. Musgrave, A. Pellegrino, J. Repond, R. Stanek, R. Yoshida, Margarita C. K. Mattingly, G. Abbiendi, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, N. Coppola, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Laurenti Jan 1999

Measurement Of High-Q2 Neutral-Current E+P Deep Inelastic Scattering Cross-Sections At Hera, J. Breitweg, S. Chekanov, M. Derrick, D. Krakauer, S. Magill, B. Musgrave, A. Pellegrino, J. Repond, R. Stanek, R. Yoshida, Margarita C. K. Mattingly, G. Abbiendi, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, N. Coppola, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Laurenti

Faculty Publications

The e+p neutral-current deep inelastic scattering differential cross-sections dσ/dQ2, for Q2 > 400 GeV2, dσ/dx and dσ/dy, for Q2 > 400, 2500 and 10000 GeV2, have been measured with the ZEUS detector at HERA. The data sample of 47.7 pb-1 was collected at a center-of-mass energy of 300 GeV. The cross-section, dσ/dQ2, falls by six orders of magnitude between Q2 = 400 and 40000 GeV2. The predictions of the Standard Model are in very good agreement with the data. Complementing the observations of time-like Z° contributions to fermion-antifermion annihilation, the data provide direct evidence for the presence of Z° exchange in the …

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