面向科学与工程计算的网上实验室设计与开发

科学与工程计算问题是当代信息技术时代最富挑战性的科学领域之一。研究和开发了面向科学与工程计算的网上实验室系统,它由实验演示、实时指导、协同工作、讨论交流、资料室管理等子系统组成。该网上实验室不仅能促进专业人员对科学与工程计算的研究,而且能提高学生对学习数值计算课程的兴趣和效率。     

计算思维的系统观

本文引用系统科学的理论与方法分析计算系统的特征、人与计算系统的关系以及设计计算系统的思维过程,阐述了建模与构造在计算系统的设计与应用中所发挥的作用,以及系统科学的思想方法运用于计算思维经历从数学思想到工程实施的过程。     

加大对计算科学支持力度，应对艾级超算应用挑战

1引言以超级计算为工具的计算科学,已经渗透到科学研究与工程设计的各个层面,成为一个具有战略意义的新兴学科。计算科学已成为理论和实验之外,人类进行科学探索和工程研究的第三种手段。为此,美国总统信息技术顾问委员会PITAC在2005年6月向总统布     

第15届全国流体力学数值方法研讨会将于2011年8月召开

第15届全国流体力学数值方法研讨会将于2011年8月23日—25日在北京举行.本届会议由中国计算数学学会主办,中国科学院计算数学与科学工程计算研究所科学与工程计算国家重点实验室承办,北京应用物理与计算数学研究所、北京大学数学科学学院、中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室、中国科学院力学研究所非线性力学国家重点实验室和北京航空航天大学数学与系统科学学院协办．     

面向大数据的信息与计算科学专业实验课程体系研究

本文从大数据时代的背景出发,结合信息与计算科学专业的实际,从面向未来挑战、丰富实验课程内容、培养应用型人才等方面,阐述了专业实验课程建设的思路和对策。     

论计算思维——计算思维的科学定位、基本原理及创新路径

指出计算思维、实验思维与理论思维是人类三大科学思维方式,并初步梳理出可计算性原理、形理算一体原理与计算机设计原理等三大计算机基本原理.还指出,交叉创新是计算思维创新发展的根本途径.     

志愿者计算环境下的应用

介绍志愿者计算环境下应用的研究现状,根据该环境下科学计算应用的类型,分析应用的任务关系图,包括静态任务关系图和动态任务关系图.描述了电力系统潮流计算和生物信息学的序列比对.提出这两个应用在志愿者计算环境下的任务划分方式、分析并行粒度和应用特点.通过在计算平台P2HP上对两个应用进行实验和性能分析,总结了适合在志愿者计算平台上运行并取得高性能的科学应用的特点及对平台的要求.     

论计算思维工程化的层次结构

探讨Wing的计算思维并分析它的局限性,根据计算杌科学与技术中的理论、技术、工程、工具、服务和应用将Wing的计算思维推广到计算机思维,然后讨论计算思维(或计算机思维)的工程化并提出计算思维工程化的层次结构.这一研究将有益于对计算思维、computing思维和computing作为一个学科的理解和研究.     

数据密集型科学与工程:需求和挑战

科学研究在经历了实验科学、理论科学、计算科学阶段后,进入了数据密集型科学阶段,与之相伴的是大数据时代的到来.大数据泛指规模达到几百TB,甚至PB级的数据①,其典型的特征是分布、异构、低质量等.尽管传统数据库管理技术(特别是商业关系型数据库)在过去40年间取得了巨大成功,但是这些技术和系统无法有效管理支持数据密集型科学与工程(Data-Intensive Science and Engineering,DISE)的大数据.文中探讨数据密集型科学与工程的具体需求和现实挑战.它涵盖的内容表现在4个层面,包括数据存储与组织、计算方法、数据分析以及用户接口技术等.同时,数据质量、数据安全、数据监护等内容也需要在各层面得到重视.文中尝试梳理了数据密集型科学与工程的整体架构,回顾了相关领域的新近发展,分析了面临的挑战,探讨了未来的研究方向.     

信息与计算科学专业数据库课程实验教学探索

分析信息与计算科学专业的培养目标和学生的知识体系及思维特点,提出该专业数据库课程实验教学教学目标和总体设计思路,然后从单元实验和综合实验两方面,探讨如何进行实验任务安排、实验环境构建、实验方法设计、实验选题优化等。     

软件测试中的新方法--区间代数方法

软件测试是提高软件可靠性、保证软件质量的重要手段,尤其在航天领域软件的研制过程中,软件测试更是起着至关重要的作用。但是,传统的软件测试方法在软件测试的某些方面还不尽人意,特别是对航天领域软件中涉及大量数值计算模块的测试更是力不从心。为此,提出软件测试的区间代数方法,能够很好地弥补传统测试方法在这方面的局限,发挥更好的作用。     

Coupling of finite element method with material point method by local multi-mesh contact method

As a Lagrangian particle method, the material point method (MPM) has the potential to model extreme deformation of materials, where the traditional finite element method (FEM) often encounters mesh distortion and element entanglement which lead to numerical difficulties. However, FEM is more accurate and efficient than MPM for problems with small deformation. It is therefore desirable to model the body with extreme deformation by MPM and the body with small deformation by FEM, respectively. In this paper, a method to handle the contact interaction between the MPM body and the FEM body is proposed, which is implemented on the background grid of MPM. By this method, FEM is coupled with MPM and a hexahedral element is incorporated into our 3D explicit MPM code MPM3D®. Several numerical examples, including plate impact, sphere rolling, perforation of thick plate, and fluid–structure interaction problems, are studied and the numerical results are in good agreement with analytical solution and results available in the literature. The coupling of FEM and MPM offers advantages of both FEM and MPM.     

Numerical method for shape optimization using meshfree method

A numerical method for continuum-based shape design sensitivity analysis and optimization using the meshfree method is proposed. The reproducing kernel particle method is used for domain discretization in conjunction with the Gauss integration method. Special features of the meshfree method from a sensitivity analysis viewpoint are discussed, including the treatment of essential boundary conditions, and the dependence of the shape function on the design variation. It is shown that the mesh distortion that exists in the finite element-based design approach is effectively resolved for large shape changing design problems through 2-D and 3-D numerical examples. The number of design iterations is reduced because of the accurate sensitivity information.     

Refined first-order reliability method using cross-entropy optimization method

Engineering with Computers - Generally, the first-order reliability method (FORM) is an efficient and accurate reliability method for problems with linear limit state functions (LSFs). It is showed...     

Empirical column selection method in the simplex method

Translated from Kibernetika i Sistemnyi Analiz, No. 4, pp. 182–186, July–August, 1995.     

传统相机标定方式的自动标定方法

摄像机标定技术是从二维平面图像中获得三维信息的关键步骤,摄像机的标定精度对保证系统测量精度有着至关重要的作用。提出了一种基于传统相机标定方式的自动标定方法。采用带有区域标记点的改进标定模板获取标定图像序列。利用边缘检测技术,确定特征点检测区域。根据摄像机透视投影模型,对摄相机进行线性标定,再进行非线性修正,得出摄像机各参数。实验结果表明,改进的标定方法具有更快的检测速度,稳定性好,鲁棒性高,使传统相机标定过程实现了自动化。     

Comparing parallel Newton''s method with parallel Laguerre''s method

Newton's and Laguerre's methods can be used to concurrently refine all separated zeros of a polynomial P(z). This paper analyses the rate convergence of both procedures, and its implication on the attainable number n of correct figures. In two special cases the number m of iterations required to reach an accuracy η = 10⁻ⁿ is shown to grow as log_λ n, where λ = 3 for Newton's and λ = 4 for Laguerre's. In the general case m is shown to grow linearly with n for both procedures. An assessment of the efficiency of the two methods is also given, by evaluating the computational complexity of operations in circular arithmetic, and the efficiency indices of the two iterative schemes.     

A method for static aeroelastic analysis based on the high-order panel method and modal method

A method for static aeroelastic analysis based on the high-order panel method and modal method is presented. The static aeroelastic characteristics of flexible wings are investigated using this method. Three-dimensional aerodynamic models of flexible wings are constructed based on the geometry of wing configuration, and the modal method is adopted to achieve the fluid-structure coupling. The static aeroelastic characteristics of the AGARD445.6 wing and a low-aspect-ratio wing are investigated in this study....     

Iterative methods improving newton's method by the decomposition method

In this paper, we present a sequence of iterative methods improving Newton's method for solving nonlinear equations. The Adomian decomposition method is applied to an equivalent coupled system to construct the sequence of the methods whose order of convergence increases as it progresses. The orders of convergence are derived analytically, and then rederived by applying symbolic computation of Maple. Some numerical illustrations are given.