基于GPU并行计算及在模式识别中的研究

为了解决模式识别中的计算效率问题,文章研究GPU的体系架构,采用基于GPU的并行计算方法,针对人脸识别算法在GPU上做了相关实验,获得了较高的计算加速比,得到了采用基于GPU的并行计算方法可以较好解决在模式识别中的计算瓶颈问题的结论。     

改进的硅各向异性腐蚀GPU并行模拟

硅各向异性腐蚀过程复杂,采用元胞自动机模拟硅各向异性腐蚀非常耗时。为了加速腐蚀模拟过程,研究了基于图形处理器(GPU)进行硅的各向异性腐蚀模拟。针对串行算法直接并行化方法存在加速效率低等问题,提出了一个改进的并行模拟方法。该方法增加了并行部分的负载,减少了内存管理的开销,从而提高了加速性能。实验证明该方法能够获得较理想的加速比。     

基于CUDA的大规模流体实时模拟

流体模拟是计算机图形学中一个重要课题。使用基于粒子的光滑流体动力学SPH(smoothed particle hydrodynamics)方法模拟大规模流体的运动需要大量的粒子模拟流体,计算量巨大,传统的方法很难达到实时性要求。为了解决该问题,使用NVIDIA的并行计算架构CUDA(Compute Unified Device Architecture)将SPH方法的全部处理过程在GPU上实现,充分利用了GPU并行计算的性能优势。使用Z-order排列改进已有的并行邻域搜索算法,并通过优化数据结构及存储器分配,有效缓解了SPH方法在GPU架构上的性能瓶颈。实验结果表明,该方法能实时逼真地模拟大规模流体,与已有的GPU方法相比处理速度有显著的提升。     

元胞自动机可逆性研究

元胞自动机是对复杂适应系统建模的重要理论工具。可逆性是元胞自动机的一个重要属性,是模拟物理可逆空间的必要条件。本文介绍元胞自动机的基本概念、可逆性和可计算性,并介绍一维可逆元胞自动机可计算的证明思路。     

基于元胞自动机的交通流计算机模拟

元胞自动机是把复杂系统量化为简单的个体,在元胞自动机模型中.空间、时间都被离散化,每一个相互作用的单元仅为有限的状态.以元胞自动机理论为基础,把车辆在路段上交通流中运动的变化规律表述为元胞自动机的演化规则,建立了基于元胞自动机理论的交通流模拟模型,标定了元胞长度和最大速度等参数,分析了元胞变换的原则;详细探讨了元胞自动机在道路交通模拟中的应用,设计出了交通元胞自动机的结构,分析了交通元胞自动机所采取的状态变换原则,建立了一维(单车道)交通流模拟模型;并利用C语言编程实现模拟.模拟结果符合实际交通流的特点.     

GPU辅助的希尔伯特变换轮廓术

在希尔伯特变换轮廓术中,相位计算速度的快慢直接影响光学3维测量速度。由于相位计算是在每幅图像的每个像素上分别进行的,每个待处理的像素和已计算的像素之间不存在依赖性,因此具有极高的计算密度,可以通过多线程运行相同的程序进行并行计算。统一架构的图形处理器(GPU)具有强大的数值并行计算能力,可以在GPU上实现并行计算。在分析相位计算的特点后,在GPU上进行相位的并行计算,实现了CPU与GPU的协同工作,解决了在CPU上相位计算方法速度较慢的问题。实验结果表明,经GPU加速后,在相位计算的质量相同的情况下,计算速度有了较大的提高。     

基于CA的离散粒子系统仿真和显示研究

综合考虑计算的效率,根据真实存在的离散粒子系统的特点,进行元胞自动机模型的建立和规则设计,并以一个三维螺旋空间为例进行仿真和分析。实例表明,该方法在三维复杂空间中运行,元胞自动机模型能定性地体现粒子之间的碰撞和摩擦现象。该方法可以用于动态显示三维离散粒子系统的演化过程,计算效率优于传统的离散单元法.     

LBM算法在GPU组中的应用

为提高大规模并行计算的并行效率,充分发挥CPU与GPU的功能特点,特别是体现GPU强大的运算能力,提出了用消息传递接口(MPI)将一组GPU连接起来。使GPU通用计算与计算流体力学中的LBM(latticeBoltzmannmethod)算法相结合。根据GPU通用计算与LBM算法的原理,使MPI作为计算分配的机制,CUDA(compute unified device architecture)作为主要的计算执行引擎,建立支持CUDA的GPU集群,在集群上对LBM算法中的D2Q9模型进行二维方腔流数值模拟。实验结果表明,利用GPU组模拟与CPU模拟结果一致,更充分发挥了GPU的计算能力,提高了并行效率。     

CUDA架构下的三维弹性静力学边界元并行计算

针对传统边界元法计算量大、计算效率低的问题,以三维弹性静力学的边界元法为对象,将基于CUDA的GPU并行计算应用到其边界元计算中,提出了基于CUDA架构的GPU并行算法.该算法首先对不同类型的边界元系数积分进行并行性分析,描述了相关的GPU并行算法,然后阐述了边界元方程组的求解方法及其并行策略.实验结果表明,文中算法较传统算法具有显著的加速效果.     

基于元胞自动机扩展模型的图的最短路径算法

利用元胞自动机在元胞空间上的并行特性，采用元胞动态邻居，时间段自适应调整的方法，构造出一种新的基于元胞自动机扩展模型的最短路径搜索算法，即通过简单规则的元胞状态演化，得到带权图的最短路径；该方法经过优化，能够达到Dijkstra算法的时间效率；并且为基于元胞自动机扩展模型解决图的问题的提供了新的思路。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate