检索结果-内蒙古大学图书馆

Algebraic two-level preconditioners for the Schur complement method

SIAM JOURNAL ON SCIENTIFIC computing 2001年第6期22卷 1987-2005页

作者： Carvalho, LM Giraud, L Le Tallec, P UERJ Inst Matemat & Estatist Rio De Janeiro Brazil CERFACS F-31057 Toulouse France Ecole Polytech F-91128 Palaiseau France

The solution of elliptic problems is challenging on parallel distributed memory computers since their Green's functions are global. To address this issue, we present a set of preconditioners for the Schur complement domain decomposition method. They implement a global coupling mechanism, through coarse-space components, similar to the one proposed in [Bramble, Pasciak, and Shatz, Math. Comp., 47 (1986), pp. 103-134]. The definition of the coarse-space components is algebraic;they are defined using the mesh partitioning information and simple interpolation operators. These preconditioners are implemented on distributed memory computers without introducing any new global synchronization in the preconditioned conjugate gradient iteration. The numerical and parallel scalability of those preconditioners are illustrated on two-dimensional model examples that have anisotropy and/or discontinuity phenomena.

关键词： domain decomposition two-level preconditioning Schur complement parallel distributed computing elliptic partial differential equations

来源：评论

学校读者我要写书评

暂无评论

Grid transfer operators for highly variable coefficient problems in two-level non-overlapping domain decomposition methods

引用

NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS 2003年第5-6期10卷 467-484页

作者： Giraud, L Vasquez, FG Tuminaro, RS CERFACS F-31057 Toulouse France Rice Univ CAAM Dept Houston TX 77005 USA Sandia Natl Labs Livermore CA USA

We propose a robust interpolation scheme for non-overlapping two-level domain decomposition methods applied to two-dimensional elliptic problems with discontinuous coefficients. This interpolation is used to design a preconditioner closely related to the BPS scheme proposed in [Bramble et al. (Math. Comput. 1986;47(175):103)]. Through numerical experiments, we show on structured and unstructured finite element problems that the new preconditioning scheme reduces to the BPS method on smooth problems but outperforms it on problems with discontinuous coefficients. In particular it maintains good scalable convergence behaviour even when the jumps in the coefficients are not aligned with subdomain interfaces. Copyright (C) 2003 John Wiley Sons, Ltd.

关键词： domain decomposition two-level preconditioning Schur complement parallel distributed computing elliptic partial differential equations discontinuous coefficients

来源：评论

学校读者我要写书评

暂无评论

Local preconditioners for two-level non-overlapping domain decomposition methods

引用

NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS 2001年第4期8卷 207-227页

作者： Carvalho, LM Giraud, L Meurant, G CERFACS F-31057 Toulouse France Univ Estado Rio De Janeiro IME Rio De Janeiro Brazil DCSA CEA DIF F-91680 Bruyeres Le Chatel France

We consider additive two-level preconditioners, with a local and a global component, for the Schur complement system arising in non-overlapping domain decomposition methods. We propose two new parallelizable local preconditioners. The first one is a computationally cheap but numerically relevant alternative to the classical block Jacobi preconditioner. The second one exploits all the information from the local Schur complement matrices and demonstrates an attractive numerical behaviour on heterogeneous and anisotropic problems. We also propose two implementations based on approximate Schur complement matrices that are cheaper alternatives to construct the given preconditioners but that preserve their good numerical behaviour. Through extensive computational experiments we study the numerical scalability and the robustness of the proposed preconditioners and compare their numerical performance with well-known robust preconditioners such as BPS and the balancing Neumann-Neumann method. Finally, we describe a parallel implementation on distributed memory computers of some of the proposed techniques and report parallel performances. Copyright (C) 2001 John Wiley & Sons, Ltd.

关键词： domain decomposition two-level preconditioning Schur complement parallel distributed computing elliptic partial differential equations parabolic partial differential equations

来源：评论

学校读者我要写书评

暂无评论

Iterative versus direct parallel substructuring methods in semiconductor device modelling

引用

NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS 2005年第1期12卷 33-53页

作者： Giraud, L Marrocco, A Rioual, JC CERFACS F-31057 Toulouse France INRIA Rocquencourt France

The numerical simulation of semiconductor devices is extremely demanding in term of computational time because it involves complex embedded numerical schemes. At the kernel of these schemes is the solution of very ill-conditioned large linear systems. In this paper, we present the various ingredients of some hybrid iterative schemes that play a central role in the robustness of these solvers when they are embedded in other numerical procedures. On a set of two-dimensional unstructured mixed finite element problems representative of semiconductor simulation, we perform a fair and detailed comparison between parallel iterative and direct linear solution techniques. We show that iterative solvers can be robust enough to solve the very challenging linear systems that arise in those simulations. Copyright (C) 2004 John Wiley Sons, Ltd.

关键词： non-overlapping domain decomposition multifrontal solvers Krylov solvers preconditioning drift diffusion equations quasi-Fermi level parallel distributed computing

来源：评论

学校读者我要写书评

暂无评论

Verification of Dependability on parallel Differential Evolution Based Voltage and Reactive Power Control

Verification of Dependability on Parallel Differential Evolu...

引用

IFAC Workshop on Control of Transmission and Distribution Smart Grids (CTDSG)

作者： Iwata, Sohei Fukuyama, Yoshikazu Meiji Univ Tokyo Japan

This paper evaluates dependability on parallel differential evolution (DE) based voltage and reactive power control (Volt/Var Control: VVC) Considering large penetration of renewable energies and deregulated environment of power systems VVC requires fast computation even for larger-scale problems One solutions to increase the computation speed is to use parallel and distributed computing. Since power system is one of the infrastructures of social community, not only fast computation, but also sustainable control (dependability) is strongly required for VVC. The simulation results with IEEE 14, 30, 57, and 118 bus systems indicate that parallel DE is superior to parallel Particle Swarm Optimization (PSO) especially for dependability on VVC. (C) 2016, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

关键词： Voltage and reactive power control parallel distributed computing Meta-heuristics parallel differential evolution Dependability

来源：评论

学校读者我要写书评

暂无评论

Genetic Algorithms applied to Fourier Descriptor based geometric models for anatomical object recognition in medical images

Genetic Algorithms applied to Fourier Descriptor based geome...

引用

Conference on Image Processing - Medical Imaging 1996

作者： Delibasis, K Undrill, PE Cameron, GG UNIV ABERDEEN DEPT BIOMED PHYS & BIOENGNABERDEEN AB9 2ZDSCOTLAND

ISBN: (纸本)0819420859

In this work we encode the shape complexity of a search object using 3D Fourier descriptors (FDs) and allow genetic algorithms (GAs) to optimize the object's shape and position. Using magnetic resonance image (MRI) data, we perform an approximate segmentation on one lateral ventricle in the brain and use the FDs from this as seeding values for the GAs to search for the left and right lateral ventricles in subsequent 3D data sets. We show that the method is capable of coping with normal biological variation. We compare a GA-guided segmentation with an interactive region growing method and find an agreement of not less than 80 plus or minus 6% in voxel classification with a corresponding average edge placement error of 2.2 plus or minus 0.4 mm. Finally we examine how the optimization can be speeded up by a distributed parallel implementation.

关键词： Fourier Descriptors Genetic Algorithms anatomical interpretation parallel distributed computing

来源：评论

学校读者我要写书评

暂无评论

Massively parallel Causal Inference of Whole Brain Dynamics at Single Neuron Resolution 26

Massively Parallel Causal Inference of Whole Brain Dynamics ...

引用

26th IEEE International Conference on parallel and distributed Systems (IEEE ICPADS)

作者： Watanakeesuntorn, Wassapon Takahashi, Keichi Ichikawa, Kohei Park, Joseph Sugihara, George Takano, Ryousei Haga, Jason Pao, Gerald M. Nara Inst Sci & Technol Nara Japan US Dept Interior Gainesville FL USA Univ Calif San Diego San Diego CA 92103 USA Natl Inst Adv Ind Sci & Technol Tsukuba Ibaraki Japan Salk Inst Biol Studies 10010 N Torrey Pines Rd La Jolla CA 92037 USA

ISBN: (纸本)9781728190747

Empirical Dynamic Modeling (EDM) is a nonlinear time series causal inference framework. The latest implementation of EDM, cppEDM, has only been used for small datasets due to computational cost. With the growth of data collection capabilities, there is a great need to identify causal relationships in large datasets. We present mpEDM, a parallel distributed implementation of EDM optimized for modern GPU-centric supercomputers. We improve the original algorithm to reduce redundant computation and optimize the implementation to fully utilize hardware resources such as GPUs and SIMD units. As a use case, we run mpEDM on AI Bridging Cloud Infrastructure (ABCI) using datasets of an entire animal brain sampled at single neuron resolution to identify dynamical causation patterns across the brain. mpEDM is 1,530x faster than cppEDM and a dataset containing 101,729 neuron was analyzed in 199 seconds on 512 nodes. This is the largest EDM causal inference achieved to date.

关键词： Empirical Dynamic Modeling Causal Inference parallel distributed computing GPU High-Performance computing Neuroscience

来源：评论

学校读者我要写书评

暂无评论

A Heterogeneity Based Greedy Algorithm for Scheduling Out-Tree Task Graphs

A Heterogeneity Based Greedy Algorithm for Scheduling Out-Tr...

引用

2nd International Conference on Sensors, Measurement and Intelligent Materials (ICSMIM 2013)

作者： Zhang, Jian Jun Qu, Yong Mei, Dan Naval Univ Engn Coll Sci Wuhan 430033 Peoples R China

ISBN: (纸本)9783037859711

The scheduling of Out-Tree task graphs is one of the critical factors in implementing the compilers of parallel languages and improving the performance of parallel computing. When applied to Out-Tree task graphs, many previous classical heterogeneity based algorithms always ignored the economization on processors and the minimization of the schedule length, which led to low efficiency in real applications. This paper proposes a heterogeneity based greedy algorithm for scheduling Out-Tree task graphs, which is based on list and task duplication, tries to find the best point between balancing loads and shortening the schedule length and improves the schedule performance without increasing the time complexity of the algorithm. The comparative experimental results demonstrate that the proposed algorithm could achieve shorter schedule length while using less number of processors.

关键词： parallel distributed computing heterogeneous computing system task scheduling Out-Tree task graph task duplication list scheduling

来源：评论

学校读者我要写书评

暂无评论

Implementing Molecular Dynamics Simulation on Sunway TaihuLight System

Implementing Molecular Dynamics Simulation on Sunway TaihuLi...

引用

18th IEEE International Conference on High Performance computing and Communications (HPCC) / 14th IEEE International Conference on Smart City (Smart City) / 2nd IEEE International Conference on Data Science and Systems (DSS)

作者： Dong, Wenqian Kang, Letian Quan, Zhe Li, Kenli Li, Keqin Hao, Ziyu Xie, Xiang-Hui Hunan Univ Coll Informat Sci & Engn Changsha 410082 Hunan Peoples R China SUNY Coll New Paltz Dept Comp Sci New Paltz NY 12561 USA Jiangnan Inst Comp Technol Wuxi 214000 Jiangsu Peoples R China

ISBN: (纸本)9781509042975

Molecular dynamics (MD) simulation is a common tool to study the physical movements of atoms and molecules in many research fields. However, it is an extremely time-consuming application which takes researchers weeks or months to run a single simulation when simulation size scales up and computing demands keep growing. In this paper, an improved MD implementation on Sunway TaihuLight supercomputer is developed to solve the above mentioned issues. The new implementation is extended from an existing implementation (i. e., LAMMPS) which widely uses the MD application. Sunway TaihuLight is a heterogeneous supercomputer with a fully customized integration approach and a brand new many-core processor SW26010. The Sunway TaihuLight takes the world's first place with peak performance over 100PFlops. We propose an optimization method of the MD simulation in three steps: paralleled extensions to SW26010, memory-access optimizations, and vectorization. After the optimization process, an 8x speedup is achieved on a single computing node. Superiorly, we also scale up to 95 thousands computing nodes (6 millions cores) with an almost leaner speedup. Besides, the proposed methods can also be applied to many other molecular dynamics codes, or similar applications.

关键词： Sunway TaihuLignt Molecular Dynamics Simulation High performance computing parallel distributed computing

来源：评论

学校读者我要写书评

暂无评论

Teaching on Demand: an HPC Experience

Teaching on Demand: an HPC Experience

引用

Workshop on Education for High Performance computing (EduHPC)

作者： Carratala-Saez, Rocio Iserte, Sergio Catalan, Sandra Univ Jaume 1 Dept Comp Sci & Engn Castellon de La Plana Spain Univ Jaume 1 Dept Mech & Engn Construct Castellon de La Plana Spain Univ Valencia Valencia Spain Barcelona Supercomp Ctr Dept Comp Sci Barcelona Spain

ISBN: (纸本)9781728159751

In this work we present the experience of the course "Build your own supercomputer with Raspberry Pi", offered as a non-mandatory workshop with the purpose of bringing High Performance computing (HPC) closer to bachelor students of Universitat Jaume I (UJI, Spain). The intention of the course is twofold;on the one hand, we target towards increasing the knowledge of Computer Science and Engineering students about the labor performed by the HPC community;on the other hand, we aim to create a personalized experience for each student by fulfilling their curiosity about the topics presented and discussed in the class. In order to evaluate the impact and learning, we analyze two surveys filled out by the students respectively before and after the course, where HPC interest and knowledge are exposed.

关键词： Computational Cluster Undergrad Teaching System Administration parallel distributed computing Raspberry Pi

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：