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International Wireless Communications and Mobile computing Conference, IWCMC

作者： Boyu Li Hong Ju Park Ender Ayanoglu Center of Pervasive Communications and Computing Department of Electrical Engineering and Computer Science The Henry Samueli School of Engineering University of California Irvine Irvine CA USA Samsung Electronics Company Limited Suwon South Korea

Multiple beamforming is realized by singular value decomposition of the channel matrix which is assumed to be known to both the transmitter and the receiver. Bit-Interleaved Coded Multiple Beamforming (BICMB) can achieve full diversity as long as the code rate R c and the number of employed subchannels S satisfy the condition R c S ≤ 1. Bit-Interleaved Coded Multiple Beamforming with Constellation Precoding (BICMB-CP), on the other hand, can achieve full diversity without the condition R c S ≤ 1. However, the decoding complexity of BICMB-CP is much higher than BICMB. In this paper, a reduced complexity decoding technique, which is based on Sphere Decoding (SD), is proposed to reduce the complexity of Maximum Likelihood (ML) decoding for BICMB-CP. The decreased complexity decoding achieves several orders of magnitude reduction, in terms of the average number of real multiplications needed to acquire one precoded bit metric, not only with respect to conventional ML decoding, but also, with respect to conventional SD.

关键词： Complexity theory Measurement Array signal processing Signal to noise ratio Interleaved codes Maximum likelihood decoding

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Parallel Performance Measurement of Heterogeneous Parallel Systems with GPUs

Parallel Performance Measurement of Heterogeneous Parallel S...

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International Conference on Parallel Processing (ICPP)

作者： Allen D. Malony Scott Biersdorff Sameer Shende Heike Jagode Stanimire Tomov Guido Juckeland Robert Dietrich Duncan Poole Christopher Lamb Department of Computer and Information Science University of Oregon Eugene USA Innovative Computing Laboratory (ICL) University of Tennessee Knoxville USA Center of Information Services and High Performance Computing (ZIH) Technische Universität Dresden Germany NVIDIA Corporation Santa Clara CA USA

The power of GPUs is giving rise to heterogeneous parallel computing, with new demands on programming environments, runtime systems, and tools to deliver high-performing applications. This paper studies the problems associated with performance measurement of heterogeneous machines with GPUs. A heterogeneous computation model and alternative host-GPU measurement approaches are discussed to set the stage for reporting new capabilities for heterogeneous parallel performance measurement in three leading HPC tools: PAPI, Vampir, and the TAU Performance System. Our work leverages the new CUPTI tool support in NVIDIA's CUDA device library. Heterogeneous benchmarks from the SHOC suite are used to demonstrate the measurement methods and tool support.

关键词： Graphics processing unit Kernel Performance evaluation Libraries Hardware Radiation detectors

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Privacy preserving computation of trust-value in wireless sensor networks

Privacy preserving computation of trust-value in wireless se...

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International Conference on Communication Software and Networks, ICCSN

作者： Xing Yuan Liusheng Huang Wei Yangt Suzhou Institute of Advanced Study University of Science and Technology Suzhou China Suzhou Institute for Advanced Study University of Science and Technology of China Suzhou China National High Performance Computing Center at Hefei Department of Computer Science and Technology University of Science and Technology of China Hefei 230026 China

The traditional cryptographic mechanisms are not enough for wireless sensor networks (WSNs) when the control of sensor nodes are taken by an interior adversary. Trust management system can solve this problem efficiently, and enhance the security and reliability of WSNs. One of the key problems in trust management system is computing trust values of nodes. However, previous works pay little attention to preserving data privacy during computing trust values. This paper focus on the problem that how to protect the data privacy while computing trust values, and proposes a privacy preserving trust value computation (PPTC) protocol to solve this problem. We develop a new private distributed scalar product protocol based on semi-honest third party to achieve the PPTC protocol. A great advantage of PPTC protocol is that it does not need any encryption or decryption operations, and the computation and communication overheads is low to 0(n). What's more, we analyze the correctness and security of the PPTC protocol and prove that the protocol can resist to collusion of up to n -1 users.

关键词： Protocols Wireless sensor networks

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Critical events, entropy, and the grain boundary character distribution

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Physical Review B 2011年第13期83卷 134117-134117页

作者： K. Barmak E. Eggeling M. Emelianenko Y. Epshteyn D. Kinderlehrer R. Sharp S. Ta’asan Materials Research Science and Engineering Center Department of Materials Science and Engineering Carnegie Mellon University Pittsburgh PA 15213 United States Fraunhofer Austria Research GmbH Visual Computing A-8010 Graz Austria Department of Mathematics George Mason University Fairfax VA 22030 United States Department of Mathematics University of Utah Salt Lake City UT 84112 United States Center for Nonlinear Analysis Department of Mathematical Sciences Carnegie Mellon University Pittsburgh PA 15213 United States

Mesoscale experiment and simulation permit harvesting information about both geometric features and texture in polycrystals. The grain boundary character distribution (GBCD) is an empirical distribution of the relative length [in two dimensions (2D)] or area (in 3D) of an interface with a given lattice misorientation and normal. During the growth process, an initially random distribution of boundary types reaches a steady state that is strongly correlated to the interfacial energy density. In simulation, it is found that if the given energy density depends only on lattice misorientation, then the steady-state GBCD and the energy are related by a Boltzmann distribution. This is among the simplest nonrandom distributions, corresponding to independent trials with respect to the energy. In this paper, we derive an entropy-based theory that suggests that the evolution of the GBCD satisfies a Fokker-Planck equation, an equation whose stationary state is a Boltzmann distribution. Cellular structures coarsen according to a local evolution law, curvature-driven growth, and are limited by space-filling constraints. The interaction between the evolution law and the constraints is governed primarily by the force balance at triple junctions, the natural boundary condition associated with curvature-driven growth, and determines a dissipation relation. A simplified coarsening model is introduced that is driven by the boundary conditions and reflects the network level dissipation relation of the grain growth system. It resembles an ensemble of inertia-free spring-mass dashpots. Application is made of the recent characterization of Fokker-Planck kinetics as a gradient flow for a free energy in deriving the theory. The theory predicts the results of large-scale two-dimensional simulations and is consistent with experiment.

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Empirical comparison of correlation measures and pruning levels in complex networks representing the global climate system

Empirical comparison of correlation measures and pruning lev...

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IEEE Symposium on Computational Intelligence and Data Mining (CIDM)

作者： Alex Pelan Karsten Steinhaeuser Nitesh V. Chawla Dilkushi A. de Alwis Pitts Auroop R. Ganguly Department of Computer Science and Engineering Interdisc. Center of Network Science and Applications University of Notre Dame Notre Dame IN USA Center of Research Computing University of Notre Dame Notre Dame IN USA GIST Group CSED Oak Ridge National Laboratory Oak Ridge TN USA

Climate change is an issue of growing economic, social, and political concern. Continued rise in the average temperatures of the Earth could lead to drastic climate change or an increased frequency of extreme events, which would negatively affect agriculture, population, and global health. One way of studying the dynamics of the Earth's changing climate is by attempting to identify regions that exhibit similar climatic behavior in terms of long-term variability. Climate networks have emerged as a strong analytics framework for both descriptive analysis and predictive modeling of the emergent phenomena. Previously, the networks were constructed using only one measure of similarity, namely the (linear) Pearson cross correlation, and were then clustered using a community detection algorithm. However, nonlinear dependencies are known to exist in climate, which begs the question whether more complex correlation measures are able to capture any such relationships. In this paper, we present a systematic study of different univariate measures of similarity and compare how each affects both the network structure as well as the predictive power of the clusters.

关键词： Meteorology Correlation Sea measurements Mutual information Time series analysis Euclidean distance Context

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Biomedical and Bioinformatics Challenges to computer science: Bioinformatics, Modeling of Biomedical Systems and Clinical Applications

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Procedia computer science 2011年 4卷 1058-1061页

作者： Mario Cannataro Rodrigo Weber dos Santos Joakim Sundnes Department of Experimental Medicine and Clinic University “Magna Græcia” of Catanzaro Catanzaro Italy and ICAR-CNR Rende Italy Department of Computer Science Universidade Federal de Juiz de Fora Juiz de Fora Brazil Center for Biomedical Computing Simula Research Laboratory Lysaker Norway

This is the fourth edition of the workshop on Biomedical and Bioinformatics Challenges to computer science. The purpose of the workshop series is to bring together scientists from computer science and life sciences, to discuss current challenges in this inter-disciplinary field. A wide range of life science applications will be addressed, ranging from classical bioinformatics to mathematical models of systems physiology.

关键词： Bioinformatics modeling and simulation of biological systems biomedical data management and integration clinical applications

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Mapping between the OBO and OWL ontology languages

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Journal of Biomedical Semantics 2011年第1期2卷 1-16页

作者： Tirmizi, Syed Hamid Aitken, Stuart Moreira, Dilvan A. Mungall, Chris Sequeda, Juan Shah, Nigam H. Miranker, Daniel P. The University of Texas at Austin Department of Computer Science Austin 78701 TX United States The University of Edinburgh Artificial Intelligence Applications Institute Edinburgh EH8 9LE United Kingdom The University of Edinburgh Informatics Life-Sciences Institute Edinburgh EH8 9LE United Kingdom Mathematics and Computing Institute University of São Paulo Department of Computer Science São Carlos São Paulo Brazil Lawrence Berkeley National Laboratory Berkeley 94720 CA United States School of Medicine Stanford University Center for Biomedical Informatics Research Stanford 94305 CA United States The University of Texas at Austin Institute for Cell and Molecular Biology Austin 78701 TX United States

Background: Ontologies are commonly used in biomedicine to organize concepts to describe domains such as anatomies, environments, experiment, taxonomies etc. NCBO BioPortal currently hosts about 180 different biomedical ontologies. These ontologies have been mainly expressed in either the Open Biomedical Ontology (OBO) format or the Web Ontology Language (OWL). OBO emerged from the Gene Ontology, and supports most of the biomedical ontology content. In comparison, OWL is a Semantic Web language, and is supported by the World Wide Web consortium together with integral query languages, rule languages and distributed infrastructure for information interchange. These features are highly desirable for the OBO content as well. A convenient method for leveraging these features for OBO ontologies is by transforming OBO ontologies to OWL. Results: We have developed a methodology for translating OBO ontologies to OWL using the organization of the Semantic Web itself to guide the work. The approach reveals that the constructs of OBO can be grouped together to form a similar layer cake. Thus we were able to decompose the problem into two parts. Most OBO constructs have easy and obvious equivalence to a construct in OWL. A small subset of OBO constructs requires deeper consideration. We have defined transformations for all constructs in an effort to foster a standard common mapping between OBO and OWL. Our mapping produces OWL-DL, a Description Logics based subset of OWL with desirable computational properties for efficiency and correctness. Our Java implementation of the mapping is part of the official Gene Ontology project source. Conclusions: Our transformation system provides a lossless roundtrip mapping for OBO ontologies, i.e. an OBO ontology may be translated to OWL and back without loss of knowledge. In addition, it provides a roadmap for bridging the gap between the two ontology languages in order to enable the use of ontology content in a language independent manner. ©

关键词： Resource Description Framework Layer Cake Ontology Language Open Biomedical Ontology Local Identifier

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The performance of GRAPE-DR for dense matrix operations

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Procedia computer science 2011年 4卷 888-897页

作者： Junichiro Makino Hiroshi Daisaka Toshiyuki Fukushige Yutaka Sugawara Mary Inaba Kei Hiraki Center for Computational Astrophysics National Astronomical Observatory of Japan Mitaka Tokyo 181-8588 Faculty of Commerce and Management Hitotsubashi University Kunitachi Tokyo 186-8601 K&F Computing Research Chofu Tokyo 182-0026 Department of Computer Science Graduate School of Information Science and Technology The University of Tokyo Tokyo 133-0033

We describe the implementation and performance of dense matrix multiplication and LU decomposition on the GRAPE-DR SIMD accelerator board. A GRAPE-DR card, with 4 GRAPE-DR chips, has the theoretical peak DP performance of 819 Gflops. Each GRAPE-DR chip has 512 processing elements and operates with 400 MHz clock cycle. each PE can perform one addition and one multiplication in every two clock cycles. The measured performance of matrix multiplication is 730 Gflops for the multiplication of matrices with size 51200 by 2048 and 2048 by 51200. The performance of LU decomposition is 480 Gflops for the problem size of 51200.

关键词： Numerical methods 02.60.-x

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DigiScope - Unobtrusive Collection and Annotating of Auscultations in Real Hospital Environments

DigiScope - Unobtrusive Collection and Annotating of Auscult...

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Annual International Conference of the IEEE Engineering in Medicine and Biology Society

作者： D. Pereira F. Hedayioglu R. Correia T. Silva I. Dutra F. Almeida S. S. Mattos M. Coimbra Center for Research in Health Technologies and Information Systems (CINTESIS) Faculty of Medicine University of Porto Instituto de Telecomunicacoes (IT) Department of Computer Science Faculty of Science University of Porto Health Information and Decision Sciences Department (CIDES) and the Center for Research in Health Technologies and Information Systems (CINTESIS) Faculty of Medicine University of Porto Instituto de Engenharia de Sistemas e Computadores - Porto (INESC-Porto) and the Center for Research in Advanced Computing Systems (CRACS) Department of Computer Science Faculty of Science University of Porto Unidade de Cardiologia e Medicina Fetal Real Hospital Portugues

ISBN: (纸本)9781424441211

Digital stethoscopes are medical devices that can collect, store and sometimes transmit acoustic auscultation signals in a digital format. These can then be replayed, sent to a colleague for a second opinion, studied in detail after an auscultation, used for training or, as we envision it, can be used as a cheap powerful tool for screening cardiac pathologies. In this work, we present the design, development and deployment of a prototype for collecting and annotating auscultation signals within real hospital environments. Our main objective is not only pave the way for future unobtrusive systems for cardiac pathology screening, but more immediately we aim to create a repository of annotated auscultation signals for biomedical signal processing and machine learning research. The presented prototype revolves around a digital stethoscope that can stream the collected audio signal to a nearby tablet PC. Interaction with this system is based on two models: a data collection model adequate for the uncontrolled hospital environments of both emergency room and primary care, and a data annotation model for offline metadata input. A specific data model was created for the repository. The prototype has been deployed and is currently being tested in two Hospitals, one in Portugal and one in Brazil.

关键词： Auscultation Hospital environment medical signal processing audio signals hospital WAREHOUSE Second Opinion Stethoscopes data models Medical device emergency room PROTOTYPE

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面向并行文件系统的性能评估及相对预测模型

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软件学报 2011年第9期22卷 2206-2221页

作者：赵铁柱董守斌 Verdi MARCH Simon SEE 华南理工大学广东省计算机网络重点实验室广东广州510641 五邑大学计算机学院广东江门529020 Technical and Cloud Computing Center Oracle Corporation Department of Computer Science National University of Singapore Department of Mechanical&Aerospace Engineering Nanyang Technological University

基于Lustre文件系统，对并行文件系统的性能评估和性能建模进行了研究．通过对性能因子的调研，进行了一系列性能评估实验，并提出性能相关性模~（PRModel）．在实验评估和PRModel分析中发现，在不同的性能因子之间存在着紧密的性能相... 详细信息

基于Lustre文件系统，对并行文件系统的性能评估和性能建模进行了研究．通过对性能因子的调研，进行了一系列性能评估实验，并提出性能相关性模~（PRModel）．在实验评估和PRModel分析中发现，在不同的性能因子之间存在着紧密的性能相关性，为了挖掘并利用这种相关性信息，提出了一种相对性能预测模（RPPModel）来预测不同性能因子条件下的性能．为了验证RPPModel的有效性，设计了大量实验用例．结果表明，预测结果的平均相对误差能够控制在170／o---28％的范围内，易于使用且具有较好的预测准确度．

关键词：并行文件系统性能评估性能模型 Lustre文件系统

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