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BLOW UP FOR A QUASILINEAR SCHROEDINGER EQUATION IN NONISOTROPIC SPACES

Journal of Partial Differential Equations 2007年第4期20卷 313-321页

作者： Chen Jianqing Institute of Applied Physics and Computational Mathematics PO Box 8009 Beijing 100088 School of Mathematics and Computer Science Fujian Normal University Fuzhou 350007 China

Consider the blow up results for local smooth solutions of a quasilinear Schrodinger equation iut＋Δu＋β｜u｜^P-2u＋θ（Δ＋｜u｜^2）u／0,u｜t=0=u0（x）,x∈R^Nin nonisotropic space.

Consider the blow up results for local smooth solutions of a quasilinear Schrodinger equation iut＋Δu＋β｜u｜^P-2u＋θ（Δ＋｜u｜^2）u／0,u｜t=0=u0（x）,x∈R^N in nonisotropic space.

关键词： Blow up quasilinear Schroedinger equation.

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Automated social hierarchy detection through email network analysis

Automated social hierarchy detection through email network a...

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Joint 9th WebKDD and 1st SNA-KDD Workshop 2007 on Web Mining and Social Network Analysis. Held in conjunction with 13th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, KDD 2007

作者： Rowe, Ryan Creamer, German Hershkop, Shlomo Stolfo, Salvatore J. Columbia University Department of Applied Mathematics New York NY 10027 Columbia University Center for Computational Learning Systems New York NY 10027 Columbia University Computer Science Department New York NY 10027

ISBN: (纸本)9781595938480

This paper provides a novel algorithm for automatically extracting social hierarchy data from electronic communication behavior. The algorithm is based on data mining user behaviors to automatically analyze and catalog patterns of communications between entities in a email collection to extract social standing. The advantage to such automatic methods is that they extract relevancy between hierarchy levels and are dynamic over time. We illustrate the algorithms over real world data using the Enron corporation's email archive. The results show great promise when compared to the corporations work chart and judicial proceeding analyzing the major players. Copyright 2007 ACM.

关键词： Hierarchical systems

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Interactive 3D Graphics Applications Embedded in Web Pages

Interactive 3D Graphics Applications Embedded in Web Pages

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International Conference on computer Graphics, Imaging and Visualization, CGIV

作者： Francisco Luengo Mariela Contreras Aurely Leal Andres Iglesias Department of Computer Science University of Zulia Venezuela Department of Applied Mathematics and Computational Sciences University of Cantabria Spain

As Internet and the World Wide Web (WWW) are becoming more and more popular, there is an increasing demand for new web services and developments. In particular, there is a need of new technologies (often referred to as Web3D) to create and manipulate interactive three-dimensional (3D) environments on the Web. A major problem in this subject is the lack of specialized 3D graphics libraries for Internet, with similar functionalities to those of OpenGL for standalone applications. Although several APIs (Java3D, GJ4JAVA, JOGL, LWJGL, jGL) have been proposed to tackle this issue, none of them has become an official part of core Java package so far. Consequently, it is still hard to build reliable Internet-oriented 3D graphics programs providing the web users with the same realism and interactivity usually found on standalone applications. This paper proposes a based-on-Java framework to develop interactive 3D graphics applications embedded in web pages. Our approach is not based on the development of new programming tools, the emphasis being placed upon the careful selection of already existing technologies (also described in this paper) that provide the best results for our goals along with the optimized design of the workflow. Some applications aimed at showing the potential of our approach are also briefly reported.

关键词： Graphics Web pages Java Web and internet services Web sites World Wide Web Web services Libraries Packaging Design optimization

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Dynamic Load-Balancing and High Performance Communication in Jcluster

Dynamic Load-Balancing and High Performance Communication in...

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International Symposium on Parallel and Distributed Processing (IPDPS)

作者： Bao-Yin Zhang Ze-Yao Mo Guang-Wen Yang Wei-Min Zheng Institute for Applied Physics and Computational Mathematics Beijing China Department of Computer Science and Technology Tsinghua University Beijing China

This paper describes the dynamic load-balancing and high performance communication provided in Jcluster, an efficient Java parallel environment. For the efficient load-balancing, we implement a task scheduler based on a transitive random stealing algorithm, which improves the random stealing, a well-known load-balancing algorithm. The experiment results show that the scheduler performs efficiently, especially for a large-scale cluster. With the method of asynchronously multithreaded transmission, a high performance PVM-like and MPI-like message passing interface is implemented in pure Java. The evaluation of the communication performance is conducted among Jcluster, LAM-MPI and mpiJava on LAM-MPI based on the Java Grande Forum's pingpong benchmark.

关键词： Java Large-scale systems Clustering algorithms Message passing Load management Processor scheduling High performance computing Scheduling algorithm Physics Concurrent computing

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Predicting secret keys via branch prediction

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Cryptographers Track at the RSA Conference, CT-RSA 2007

作者： Acıiçmez, Onur Koç, Çetin Kaya Seifert, Jean-Pierre School of Electrical Engineering and Computer Science Oregon State University CorvallisOR97331 United States Information Security Research Center Istanbul Commerce University Eminönü Istanbul34112 Turkey Applied Security Research Group The Center for Computational Mathematics and Scientific Computation Faculty of Science and Science Education University of Haifa Haifa31905 Israel Institute for Computer Science University of Innsbruck Innsbruck6020 Austria

ISBN: (纸本)9783540693277

This paper announces a new software side-channel attack — enabled by the branch prediction capability common to all modern high-performance CPUs. The penalty paid (extra clock cycles) for a mispredicted branch can be used for cryptanalysis of cryptographic primitives that employ a data-dependent program flow. Analogous to the recently described cache-based side-channel attacks our attacks also allow an unprivileged process to attack other processes running in parallel on the same processor, despite sophisticated partitioning methods such as memory protection, sandboxing or even virtualization. In this paper, we will discuss several such attacks for the example of RSA, and experimentally show their applicability to real systems, such as OpenSSL and Linux. Moreover, we will also demonstrate the strength of the branch prediction side-channel attack by rendering the obvious countermeasure in this context (Montgomery Multiplication with dummy-reduction) as useless. Although the deeper consequences of the latter result make the task of writing an efficient and secure modular exponentiation (or scalar multiplication on an elliptic curve) a challenging task, we will eventually suggest some countermeasures to mitigate branch prediction side-channel attacks. © Springer-Verlag Berlin Heidelberg 2007.

关键词： Side channel attack

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Log-correlation Distance And Fourier Transform With Kullback-Leibler Divergence Distance For Construction Of Vertebrate Phylogeny Using Complete Mitochondrial Genomes

Log-correlation Distance And Fourier Transform With Kullback...

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International Conference on Natural Computation (ICNC)

作者： L.Q. Zhou Z.G. Yu P.R. Nie F.F. Liao V.V. Anh Y.J. Chen School of Mathematics and Computational Science Xiangtan University Hunan China School of Mathematical Sciences Queensland University of Technology Brisbane Australia Department of Applied Computer Science University of Winnipeg Winnipeg MAN Canada

For vertebrate mitochondrial genomes, some phylogenies have been built by various methods with or without sequence alignment. These methods are important for the problem of classification and evolution. In this paper, we propose two approaches to analyze the phylogenetic relationship of 64 vertebrates using complete mitochondrial genomes without sequence alignment. The first approach combines discrete Fourier transform (DFT) with Kullback-Leibler divergence (KLD) distance. The second one directly uses a log-correlation distance. Both methods are based on compositional vectors of DNA sequences or protein sequences from the complete genome. The phylogenetic trees show that the mitochondrial genomes are separated into three major groups. One group corresponds to mammals; one group corresponds to fish; and the other one is Archosauria (including birds and reptiles). In particular, the structure of the tree based on log-correlation distance are roughly in agreement in topology with the current known phylogenies of vertebrates.

关键词： Fourier transforms Phylogeny Genomics Bioinformatics Sequences Discrete Fourier transforms DNA Proteins Marine animals Birds

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MADNESS applied to density functional theory in chemistry and nuclear physics

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Journal of Physics: Conference Series 2007年第1期78卷

作者： Fann, G.I. Harrison, R.J. Beylkin, G. Jia, J. Hartman-Baker, R. Shelton, W.A. Sugiki, S. Computational Mathematics Group Computer Science and Mathematics Division Oak Ridge National Laboratory Oak Ridge TN 37831 United States Computational Chemical Sciences Group Computer Science and Mathematics Division Oak Ridge National Laboratory Oak Ridge TN 37830 United States Department of Chemistry University of Tennessee Knoxville TN United States Department of Applied Mathematics University of Colorado at Boulder 526 UCB Boulder CO 80309-0526 United States

We describe some recent mathematical results in constructing computational methods that lead to the development of fast and accurate multiresolution numerical methods for solving quantum chemistry and nuclear physics problems based on Density Functional Theory (DFT). Using low separation rank representations of functions and operators in conjunction with representations in multiwavelet bases, we developed a multiscale solution method for integral and differential equations and integral transforms. The Poisson equation, the Schrodinger equation, and the projector on the divergence free functions provide important examples with a wide range of applications in computational chemistry, nuclear physics, computational electromagnetic and fluid dynamics. We have implemented this approach along with adaptive representations of operators and functions in the multiwavelet basis and low separation rank (LSR) approximation of operators and functions. These methods have been realized and implemented in a software package called Multiresolution Adaptive Numerical Evaluation for Scientific Simulation (MADNESS). © 2007 IOP Publishing Ltd.

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Oscillator models and collective motion

IEEE Control Systems Magazine

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IEEE Control Systems Magazine 2007年第4期27卷 89-105页

作者： Paley, Derek A. Leonard, Naomi Ehrich Sepulchre, Rodolphe Grünbaum, Daniel Parrish, Julia K. Princeton University Department of Mechanical and Aerospace Engineering Princeton NJ 08544 United States Department of Mechanical and Aerospace Engineering Program in Applied and Computational Mathematics Princeton University Princeton NJ 08544 United States Department Electrical Engineering and Computer Science University of Liège Liège Belgium School of Oceanography Department of Biology University of Washington Seattle WA United States Biology Department School of Aquatic and Fishery Sciences University of Washington Seattle WA United States

A description of the so called "particles with coupled oscillator dynamics" (PCOD) is presented which is used to model, analyze and synthesize collective motion. An oscillator model with spatial dynamics is presented to help describe how to design steering control laws while it is being used to study biological collectives. Lastly, both engineering and biological analysis were described.

关键词： Oscillators (mechanical)

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Study on Parallel Computing

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Journal of computer science & Technology 2006年第5期21卷 665-673页

作者：陈国良孙广中张云泉莫则尧 Anhui Province-MOST Key Co-Lab of High Performance Computing and Its Applications Department of Computer Science and Technology University of Science and Technology of China Hefei 230027 P.R. China Laboratory of Parallel Computing Institute of Software Chinese Academy of Sciences Beijing 100080 P.R. China Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics Beijing 100088 P.R. China

In this paper, we present a general survey on parallel computing. The main contents include parallel computer system which is the hardware platform of parallel computing, parallel algorithm which is the theoretical base of parallel computing, parallel programming which is the software support of parallel computing. After that, we also introduce some parallel applications and enabling technologies. We argue that parallel computing research should form an integrated methodology of ＂architecture algorithm programming application＂. Only in this way, parallel computing research becomes continuous development and more realistic.

关键词： parallel computing parallel architecture parallel programming parallel algorithm parallel application

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Instantaneous radar polarimetry with multiple dually-polarized antennas

Instantaneous radar polarimetry with multiple dually-polariz...

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40th Asilomar Conference on Signals, Systems, and computers, ACSSC '06

作者： Calderbank, A.R. Howard, S.D. Moran, W. Pezeshki, A. Zoltowski, M. Program in Applied and Computational Mathematics Princeton University Princeton NJ United States Defence Science and Technology Organization Edinburgh Australia Electrical Engineering and Computer Science University of Melbourne Melbourne Australia Electrical and Computer Engineering Purdue University West Lafayette IN United States

ISBN: (纸本)1424407850

Fully Polarimetric radar systems are capable of simultaneously transmitting and receiving in two orthogonal polarizations. Instantaneous radar polarimetry exploits both polarization modes of a dually-polarized radar transmitter and receiver on a pulse by pulse basis, and can improve the radar detection performance and suppress range sidelobes. In this paper, we extend the use of instantaneous radar polarimetry for radar systems with multiple dually-polarized transmit and receive antennas. Alamouti signal processing is used to coordinate transmission of Golay pairs of phase codes waveforms across polarizations and multiple antennas. The integration of multi-antenna signal processing with instantaneous radar polarimetry can further improve the detection performance, at a computational cost comparable to single channel matched filtering.

关键词： Polarimeters

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