检索结果-内蒙古大学图书馆

Grey video compression methods using fractals

INTERNATIONAL JOURNAL OF COMPUTER MATHEMATICS 2007年第11期84卷 1567-1590页

作者： Wang, Meiqing Lai, Choi-Hong Fuzhou Univ Coll Math & Comp Sci Fujian 350002 Peoples R China Univ Greenwich Sch Comp & Math Sci Old Rayal Naval Coll London SE10 9LS England

The authors' experience in the treatment of grey video compression using fractals is summarized and compared with other research in the same field. Experience with parallel and distributed computing is also discus... 详细信息

关键词： fractals video compression adaptive partition parallel algorithm

来源：评论

学校读者我要写书评

暂无评论

Splitting extrapolation method for solving second-order parabolic equations with curved boundaries by using domain decomposition and d-quadratic isoparametric finite elements

引用

INTERNATIONAL JOURNAL OF COMPUTER MATHEMATICS 2007年第6期84卷 767-781页

作者： He, Xiaoming Lu, Tao Virginia Tech Dept Math Blacksburg VA 24061 USA Sichuan Univ Dept Math Chengdu 610064 Peoples R China

This article discusses a splitting extrapolation method for solving second-order parabolic equations with curved boundaries by using domain decomposition and d-quadratic isoparametric finite elements. This method possesses superconvergence, a high order of accuracy and a high degree of parallelism. First, we prove the multi-variable asymptotic expansion of fully discrete d-quadratic isoparametric finite element errors. Based on the expansion, we generate splitting extrapolation formulas. These formulas generate a numerical solution on a globally fine grid with higher accuracy by solving only a set of smaller discrete subproblems on different coarser grids. Therefore, a large-scale multidimensional problem with a curved boundary is turned into a set of smaller discrete subproblems on a polyhedron. Because these subproblems are independent of each other and have similar scales, our algorithm possesses a high degree of parallelism. In addition, this method is effective for solving discontinuous problems if we regard the interfaces of the problems as the interfaces of the initial domain decomposition. Our numerical results also show that the algorithm is effective for solving nonlinear parabolic equations.

关键词： splitting extrapolation domain decomposition d-quadratic iso-parametric mapping parallel algorithm

来源：评论

学校读者我要写书评

暂无评论

Schwarz type algorithms for parabolic problems

引用

APPLIED MATHEMATICS AND COMPUTATION 2007年第1期188卷 206-213页

作者： Yang, Jianhua Shandong Univ Sci & Technol Sch Informat Sci & Engn Qingdao 266510 Peoples R China

Based on overlapping domain decomposition, we give a parallel subspace correction algorithm for semi-linear parabolic problems. We consider the dependence of convergence rate of this algorithm on parameters of time-step and space-mesh. We give the error estimate, which tell us that the convergence of the approximate solution is independent of the iteration number at each time level. (C) 2006 Elsevier Inc. All rights reserved.

关键词： parabolic problems domain decomposition parallel algorithm error estimate

来源：评论

学校读者我要写书评

暂无评论

A versatile incompressible Navier-Stokes solver for blood flow application

引用

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS 2007年第5期54卷 473-496页

作者： Garbey, M. Pacull, F. Univ Houston Dept Comp Sci Houston TX 77204 USA Univ Houston Dept Math Houston TX 77204 USA

We present in this paper an integrated approach to compute quickly an incompressible Navier-Stokes (NS) flow in a section of a large blood vessel using medical imaging data. The goal is essentially to provide a first-order approximation of some main quantities of interest in cardiovascular disease: the shear stress and the pressure on the wall. The NS solver relies on the L-2 penalty approach pioneered by Caltagirone and co-workers and combines nicely with a level set method based on the Mumford-Shah energy model. Simulations on stenosis cases based on angiogram are run in parallel with MatlabMPI on a shared-memory machine. While MatlabMPI communications are based on the load and save functions of Matlab and have high latency indeed, we show that our Aitken-Schwarz domain decomposition algorithm provides a good parallel efficiency and scalability of the NS code. Copyright (C) 2006 John Wiley & Sons, Ltd.

关键词： incompressible flow blood flow image analysis parallel algorithm

来源：评论

学校读者我要写书评

暂无评论

Numerical errors resulting from finite-difference approximation in computations of a one-dimensional Schrodinger equation with the Trotter formula

引用

COMPUTER PHYSICS COMMUNICATIONS 2007年第10期177卷 781-786页

作者： Inui, Norio Univ Hyogo Grad Sch Engn Himeji Hyogo 6712280 Japan

The parallel algorithm for solving time-dependent Schrodinger equations devised by De Raedt and based on the Trotter formula is not only simple but also unconditionally stable, explicit, and local. We consider the numerical errors resulting from the finite-difference approximation of De Raedt's algorithm by comparing an exact solution of a free particle with the approximate solution calculated by using the Trotter formula, which depends on the size of the spatial-temporal lattice. (C) 2007 Elsevier B.V. All rights reserved.

关键词： Schrodinger equation Trotter formula numerical error parallel algorithm

来源：评论

学校读者我要写书评

暂无评论

A method for solving the system of linear equations and linear inequalities

引用

MATHEMATICAL AND COMPUTER MODELLING 2007年第5-6期46卷 823-836页

作者： Pang, Li-Ping Spedicato, Emilio Xia, Zun-Quan Wang, Wei Dalian Univ Technol Dept Appl Math CORA Dalian 116024 Peoples R China Dalian Univ Technol Dept Phys Dalian 116024 Peoples R China Univ Bergamo Dept Math Stat Informat & Applicat I-24128 Bergamo Italy Liaoning Normal Univ Dept Math Dalian 116029 Peoples R China

A method, called the (I.) ABS-MPVT algorithm, for solving a system comprising linear equations and linear inequalities is presented. This method is characterized by solving the system of linear equations first via the ABS algorithms and then solving an unconstrained minimization obtained by substituting the ABS general form of solutions into the system of linear inequalities. For the unconstrained minimization problem it can be solved by a (modified) parallel algorithm. The convergence of this method is also given. (C) 2007 Elsevier Ltd. All rights reserved.

关键词： ABS algorithms abaffian matrix system of linear equations system of linear inequalities parallel algorithm convex programming minimax nonlinear programming

来源：评论

学校读者我要写书评

暂无评论

Stochastic DT-MRI connectivity mapping on the GPU

引用

IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS 2007年第6期13卷 1504-1511页

作者： McGraw, Tim Nadar, Mariappan W Virginia Univ Morgantown WV 26506 USA Siemens Corp Res New York NY 10022 USA

We present a method for stochastic fiber tract mapping from diffusion tensor MRI (DT-MRI) implemented on graphics hardware. From the simulated fibers we compute a connectivity map that gives an indication of the probability that two points in the dataset are connected by a neuronal fiber path. A Bayesian formulation of the fiber model is given and it is shown that the inversion method can be used to construct plausible connectivity. An implementation of this fiber model on the graphics processing unit (GPU) is presented. Since the fiber paths can be stochastically generated independently of one another, the algorithm is highly parallelizable. This allows us to exploit the data-parallel nature of the GPU fragment processors. We also present a framework for the connectivity computation on the GPU. Our implementation allows the user to interactively select regions of interest and observe the evolving connectivity results during computation. Results are presented from the stochastic generation of over 250,000 fiber steps per iteration at interactive frame rates on consumer-grade graphics hardware.

关键词： Bayes Methods Biodiffusion Biomedical MRI Brain Computer Graphic Equipment Data Visualisation Medical Image Processing Neurophysiology Probability Stochastic Processes Tensors Brain Data Visualization Magnetic Resonance Imaging parallel algorithm Graphics Processing Unit Inversion Method Bayesian Formulation Neuronal Fiber Path Probability Graphics Hardware Diffusion Tensor Stochastic Fiber Tract Mapping GPU Stochastic DT MRI Connectivity Mapping Stochastic Processes Diffusion Tensor Imaging Tensile Stress Visualization Graphics Anisotropic Magnetoresistance Injuries Ellipsoids Magnetic Resonance Imaging Hardware Diffusion Tensor Magnetic Resonance Imaging Stochastic Tractography

来源：评论

学校读者我要写书评

暂无评论

Particle model to optimize resource allocation and task assignment

引用

INFORMATION SYSTEMS 2007年第7期32卷 987-995页

作者： Shuai, Dianxun Shuai, Qing Dong, Yumin E China Univ Sci & Technol Shanghai 200237 Peoples R China Huazhong Univ Sci & Technol Dept Sociol Wuhan 430074 Peoples R China Qingdao Technol Univ Comp Network Ctr Qingdao 266033 Peoples R China

This paper presents a novel generalized particle model for the parallel optimization of the resource allocation and task assignment in complex environment of enterprise computing. The generalized particle model (GPM) transforms the optimization process into the kinematics and dynamics of massive particles in a force-field. The GPM approach has many advantages in terms of the high-scale parallelism, multi-objective optimization, multi-type coordination, multi-degree personality, and the ability to handle complex factors. Simulations show the effectiveness and suitability of the proposed GPM approach to optimize the enterprise computing. (c) 2006 Elsevier B.V. All rights reserved.

关键词： optimization resource allocation task assignment enterprise computing generalized particle non-linear dynamics parallel algorithm

来源：评论

学校读者我要写书评

暂无评论

SIMD processor-based turbo decoder supporting multiple third-generation wireless standards

引用

IEEE TRANSACTIONS ON VERY LARGE SCALE INTEGRATION (VLSI) SYSTEMS 2007年第7期15卷 801-810页

作者： Shin, Myoung-Cheol Park, In-Cheol Korea Adv Inst Sci & Technol Dept Elect Engn Taejon 305701 South Korea

A programmable turbo decoder is designed to support multiple third-generation wireless communication standards. We propose a hybrid architecture of hardware and software, which has small size, low power, and high performance like. hardware implementations, as well as the flexibility and programmability of software. It mainly consists of a configurable hardware soft-input-soft-output (SISO) decoder and a 16-b single-instruction multiple-data processor, which is equipped with five processing elements and special instructions customized for interleaving in order to provide interleaved data at the speed of the hardware SISO. A fast and flexible software implementation of the block interleaving algorithm is also proposed. The interleaver generation is split into two parts, preprocessing and on-the-fly generation, to reduce the timing overhead of changing the interleaver structure. We present detailed descriptions of the interleaving implementation applied to the W-CDMA and cdma2000 standard turbo codes. The decoder occupies 8.90 mm(2) in a 0.25-mu m CMOS with five metal layers and exhibits the maximum decoding rate of 5.48 Mb/s.

关键词： cdma2000 parallel algorithm turbo code turbo interleaver W-CDMA

来源：评论

学校读者我要写书评

暂无评论

Simulation of the paraxial laser propagation coupled with hydrodynamics in 3D geometry

引用

JOURNAL OF SCIENTIFIC COMPUTING 2007年第1期33卷 1-24页

作者： Ballereau, Ph. Casanova, M. Duboc, F. Dureau, D. Jourdren, H. Loiseau, P. Metral, J. Morice, O. Sentis, R. CEA Bruyeres F-91680 Bruyeres Le Chatel France

We address here numerical simulation problems for modeling some phenomena arising in plasmas produced in experimental devices for Inertial Confinement Fusion. The model consists of a compressible fluid dynamics system coupled with a paraxial equation for modeling the laser propagation. For the fluid dynamics system, a numerical method of Lagrange-Euler type is used. For the paraxial equation, a time implicit discretization is settled which preserves the laser energy balance;the method is based on a splitting of the propagation term and the diffraction terms according to the propagation spatial variable. We give some features on the 3D implementation of the method in the parallel platform HERA. Results showing the accuracy of the numerical scheme are presented and we give also numerical results related to cases corresponding to realistic simulations, with a mesh containing up to 500 millions of cells.

关键词： hydrodynamics with ponderomotive force paraxial solver laser-plasma interaction parallel algorithm space marching technique

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：