基于框架技术的通用虚拟计算平台的实现

通过分析目前几种虚拟计算环境的现状、特点及适用范围,针对聚合异构分散计算资源的需求,提出了一种基于框架技术的虚拟计算环境的实现方法.研究了虚拟计算环境的关键实现技术,主要包括计算平台的总体框架和服务组件,以及各个组成部分之间的关系和通信方式;并基于服务分层设计方法来优化计算服务的架构,对各服务组件进行了详细的设计,实现了虚拟计算平台系统.以地震资料数据处理为例进行了实验测试,测试结果表明,该虚拟计算框架具有一定的可行性和有效性,能够整合零散、异构的计算资源,尤其适用于性能差异明显的计算组织,为用户提供了透明的资源访问模式,提高了计算资源的利用率.     

GPU通用计算及其在计算智能领域的应用

在日趋复杂的图形处理任务的推动下,GPU已经演化成为具有众多计算核心、计算能力强大的通用计算设备,并被越来越多地应用于图形处理之外的计算领域。GPU具有高并行、低能耗和低成本的特点,在数据并行度高的计算任务中,相比与传统的CPU平台有着显著的优势。随着GPU体系结构的不断演进以及开发平台的逐步完善,GPU已经进入到高性能计算的主流行列。GPU通用计算的普及,使个人和小型机构能有机会获得以往昂贵的大型、超级计算机才能提供的计算能力,并一定程度上改变了科学计算领域的格局和编程开发模式。GPU提供的强大计算能力极大地推动了计算智能的发展,并且已经在深度学习和群体智能优化方法等子领域获得了巨大的成功,更是在图像、语音等领域取得了突破性的进展。随着人工智能技术和方法的不断进步,GPU将在更多的领域获得更加广泛的应用。     

A general formulation of structural topology optimization for maximizing structural stiffness

This paper presents a general formulation of structural topology optimization for maximizing structure stiffness with mixed boundary conditions, i.e. with both external forces and prescribed non-zero displacement. In such formulation, the objective function is equal to work done by the given external forces minus work done by the reaction forces on prescribed non-zero displacement. When only one type of boundary condition is specified, it degenerates to the formulation of minimum structural compliance design (with external force) and maximum structural strain energy design (with prescribed non-zero displacement). However, regardless of boundary condition types, the sensitivity of such objective function with respect to artificial element density is always proportional to the negative of average strain energy density. We show that this formulation provides optimum design for both discrete and continuum structures.     

基于Web的无纸化通用考试平台的设计与实现

由于无纸化考试具有试题维护简便、考试实施简单、试卷评判公正和有利于实施能力考核等特点,逐渐代替了传统的纸质考核方式。本文从无纸化考试系统的通用性着手,对无纸化考试系统中试题存储、组卷算法、在线阅卷、考试过程监控等关键问题进行了研究,设计了一种通用的无纸化考试系统。该系统具有较高的存储效率、良好的扩展性和应用性。     

基于云计算的军事物流平台设计

通过研究云计算的理论技术,结合军事物流的发展现状,设计了基于云计算的军事物流平台的总体架构,提出了平台的技术架构和功能架构,并对平台提供的具体服务分别进行了阐述。最后对云计算技术在军事物流体系中的实际应用提出了展望。     

A general purpose Monte-Carlo program

Title of program: ERRCAL Catalogue number: AAUP Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland (see application form in this issue) Computer: Installation: CDC 6600 Data Center CDC, Rijswijk, The Netherlands Burroughs B 6700 Mons University Computing Center Operating system: SCOPE for CDC. MCP for Burroughs Programming language: FORTRAN IV High speed store required: 15000 words (CDC 6600) No. of bits in a word: 60 (CDC 6600) Overlay structure: None No. of magnetic tapes required: None Other peripherals used: Card reader, line printer No. of cards in combined program and test deck: 699 Card punching code: BCD     

A hyper-heuristic approach to aircraft structural design optimization

The conceptual design of an aircraft is a challenging problem in which optimization can be of great importance to the quality of design generated. Mass optimization of the structural design of an aircraft aims to produce an airframe of minimal mass whilst maintaining satisfactory strength under various loading conditions due to flight and ground manoeuvres. Hyper-heuristic optimization is an evolving field of research wherein the optimization process is continuously adapted in order to provide greater improvements in the quality of the solution generated. The relative infancy of hyper-heuristic optimization has resulted in limited application within the field of aerospace design. This paper describes a framework for the mass optimization of the structural layout of an aircraft at the conceptual level of design employing a novel hyper-heuristic approach. This hyper-heuristic approach encourages solution space exploration, thus reducing the likelihood of premature convergence, and improves the feasibility of and convergence upon the best solution found. A case study is presented to illustrate the effects of hyper-heuristics on the problem for a large commercial aircraft. Resulting solutions were generated of considerably lighter mass than the baseline aircraft. A further improvement in solution quality was found with the use of the hyper-heuristics compared to that obtained without, albeit with a penalty on computation time.     

A dependable Peer-to-Peer computing platform

This paper discusses a dependable and widely applicable Peer-to-Peer (P2P) computing platform. As the existing P2P computing platforms are limited due to the lack of support for various computational models, this paper proposes a workflow management mechanism to support task dependency in parallel programs while increasing computing efficiency. In general, task dependency leads to a serious performance degradation for failed task re-execution because of volatile peers. Therefore, it results in low dependability. Here, dependability is defined as a comparison of the actual performance with task failures to the theoretical one without failure on a P2P computing platform. Redundant task dispatch and a runtime optimization method are proposed to guarantee high dependability even with highly volatile peers. Large-scale simulation results indicate that the computing platform efficiently solves the problem of P2P computing due to volatile peers.     

Distributed computing for multidisciplinary design optimization using Java

The programming language Java (recently referred to as the computer language of the Web) offers substantial possibilities for the type of complex engineering problems typically encountered in multidisciplinary design optimization (MDO) problems. In order to demonstrate the potential uses of Java for MDO problems, this paper presents the development of the Web Interface for complex engineering design (WICkED) software, which simulates the convergence of a decomposed complex system in a distributed computing environment and computes the sensitivity derivatives of the system with respect to the independent input variables using the GSE method or the finite difference method. In this application, one computer is designated as the server and sends out required inputs to a number of client subsystems over the Internet. A number of client computers can connect to the server and then receive the inputs necessary to calculate the solution to their model. As the code necessary to solve the model already exists at the client, only the inputs have to be sent over the network. When the client has solved the calculation, it returns the results to the server which processes the result to produce new inputs.WICkED is written entirely in the Java programming language which allows server and clients to exist on completely different computer types and in heterogeneous, distributed networks. A number of parametric studies on the behaviour of complex systems in a distributed environment are performed and the results are reported in this paper. This research serves to identify potential problems as well as advantages in using Java for MDO applications.     

Comparison of evolutionary-based optimization algorithms for structural design optimization

In this paper, a comparison of evolutionary-based optimization techniques for structural design optimization problems is presented. Furthermore, a hybrid optimization technique based on differential evolution algorithm is introduced for structural design optimization problems. In order to evaluate the proposed optimization approach a welded beam design problem taken from the literature is solved. The proposed approach is applied to a welded beam design problem and the optimal design of a vehicle component to illustrate how the present approach can be applied for solving structural design optimization problems. A comparative study of six population-based optimization algorithms for optimal design of the structures is presented. The volume reduction of the vehicle component is 28.4% using the proposed hybrid approach. The results show that the proposed approach gives better solutions compared to genetic algorithm, particle swarm, immune algorithm, artificial bee colony algorithm and differential evolution algorithm that are representative of the state-of-the-art in the evolutionary optimization literature.     

A unified approach to optimization of structural members under general constraints

A unified numerical approach, based on a control parameterization technique, for solving structural crosssectional optimization problems is presented. The key factor to the unified formulation lies in the framing of the objective functional and the constraints into the same unified canonical form. Consequently, the different types of objective functionals, geometrical and performance constraints can be treated in the same way, thus paving the path for the problems to be solved under a single approach using a general purpose software. To demonstrate this versatile approach, several illustrative examples of cross-sectional shape optimization of structural members under a variety of constraints were examined.     

基于太空级 Virtex FPGA的灵活高性能计算平台

采用太空级Virtex FPGA与可重构的系统架构,可满足天基系统对尺寸、重量及功耗的苛刻要求,并缩短设计周期。SEAKR工程公司采用可重构的赛灵思VirtexFPGA创建了灵活的高性能计算平台,用作各种天基系统的核心。该全新计算平台已成功应用于4个太空任务。     

Particle swarm approach for structural design optimization

This paper presents in detail the background and implementation of a particle swarm optimization algorithm suitable for constraint structural optimization tasks. Improvements, effect of the different setting parameters, and functionality of the algorithm are shown in the scope of classical structural optimization problems. The effectiveness of the approach is illustrated by three benchmark structural optimization tasks. Results show the ability of the proposed methodology to find better optimal solutions for structural optimization tasks than other optimization algorithms.     

A general and flexible method of problem definition in structural optimization systems

This paper describes the implementation of a general and flexible method of formulating problems of mathematical programming in structural optimization systems. The method enables the formulation and solution of problems involving scalar, integral, min/max, max/min and possibly non-differentiable user defined functions in any conceivable mix. The mathematical formulation is based on the bound formulation, and the implementation specific details involve a parser capable of interpreting and performing symbolic differentiation of the user defined functions.