图形处理器用于通用计算的技术、现状及其挑战

多年来计算机图形处理器(GP以大大超过摩尔定律的速度高速发展.图形处理器的发展极大地提高了计算机图形处理的速度和图形质量,并促进了与计算机图形相关应用领域的快速发展与此同时,图形处理器绘制流水线的高速度和并行性以及近年来发展起来的可编程功能为图形处理以外的通用计算提供了良好的运行平台,这使得基于GPU的通用计算成为近两三年来人们关注的一个研究热点.从介绍GPU的发展历史及其现代GPU的基本结构开始,阐述GPU用于通用计算的技术原理,以及其用于通用计算的主要领域和最新发展情况,并详细地介绍了GPU在流体模拟和代数计算、数据库应用、频谱分析等领域的应用和技术,包括在流体模拟方面的研究工作.还对GPU应用的软件工具及其最新发展作了较详细的介绍.最后,展望了GPU应用于通用计算的发展前景,并从硬件和软件两方面分析了这一领域未来所面临的挑战.     

基于PC硬件的大规模数据场快速可视化方法

科学可视化技术在众多领域具有十分广泛的应用,然而直接体绘制技术却有着计算量大、计算时间长的缺点,在普通的PC机上很难实现对大规模数据的实时交互绘制。目前的三维可视化系统通常需要架构在高端的图形工作站或转用计算机上。随着计算机软硬件技术的发展,普通的PC机图形处理器GPU(Graphic Processing Unit)具有了可编程功能。正是借助GPU的可编程功能及其强大的并行处理能力,研究并实现了一种基于普通PC硬件的体会之方法。最后应用该方法对工业、医学等体数据进行可视化,结果证明该方法可以在普通PC上实现较大规模数据的快速可视化。     

基于GPU的加速网格求交算法分析与实现

随着近几年图形硬件的飞速发展,图形处理器(Graphics Processing Unit,简称GPU)的功能越来越强大.现代GPU具备了一定的可编程功能,此功能允许以用户自定义的功能替换原来固定图形流水线中某些模块原有的功能,这使得GPU在功能上更像一个通用处理(General Purpose GPU,GPGPU),针对地质建模软件中频繁使用的三角网格面求交算法进行了研究.通过对三角网格求交问题的具体分析及对图形硬件的分析,利用图形硬件的特殊设计和高浮点运算速度,高内存带宽,实现了高效的基于可视化查询方法计算网格求交的算法.     

基于GPU的真实感毛发快速绘制

提出一种基于图形处理器(GPU)加速的真实感毛发快速绘制方法.方法通过混合绘制多层次的半透明纹理层来表示物体表面的毛发效果,并在绘制过程充分运用了GPU的可编程功能.其中采用GPU的顶点绘制器来完成多层网格层顶点位置的计算;采用像素绘制器来实现毛发特殊光照效果的计算.实验表明,通过采用GPU可编程计算,毛发的绘制速度得到了明显提高.方法对中等规模的模型达到了实时的毛发绘制速度,并具有逼真的仿真效果.     

基于满二叉树分块策略的大规模数据场纹理映射体绘制算法

针对纹理映射体绘制物理内存空间的限制,本文提出一种可在通用图形硬件上完成大规模数据场实时体绘制的有效方法.该方法基于满二叉树纹理分块策略,利用GPU着色器可编程性,将纹理数据制作为一个一维传递函数查找表和一个规模等同于体数据场的动态纹理工作集,有效提高了大规模数据场体绘制的实时性.动态纹理工作集使用抽象分块与继承关系管...     

GPU在复杂场景的阴影绘制中的应用

通过有效利用图形硬件的图形处理单元（GPU）的运算能力和可编程性，将人量计算从CPU分离出来。在GPU上采用顶点和片元程序进行阴影计算，从而加速复杂场景阴影绘制。选择图像空间阴影算法进行GPU加速绘制。用Cg图形编程语言和OpenGL实现了算法的绘制过程，能够满足通用的复杂3D场景应用的需要，达到满意的实时绘制效果。     

基于GPU加速的光线与三角面片求交

近年来，随着图形处理器（GPU）能力以及可编程技术的发展，基于图形处理器的通用计算成为一个研究的热点。文章介绍了图形处理器的发展和结构，以及在使用通用计算时所面临的一些问题；具体介绍了利用GPU进行光线和空间三角形面片的求交测试。     

GPU在实时阴影绘制中的应用

实时阴影在增强三维场景真实感方面起着非常重要的作用。阴影体算法是实时阴影绘制中效果非常理想的一种方法。但是随着场景复杂度的增加,该算法计算量比较大,将导致绘制效率的降低。另一方面,随着可编程GPU技术的发展,GPU的渲染速度远远大于CPU,为提高三维场景的渲染效率提供了更大的空间。在此基础上,介绍了一种在GPU上生成阴影体的方法,加速实时阴影绘制。利用图形硬件的图形处理单元（GPU）的运算能力和可编程性,将生成阴影体的大量计算从CPU转移到GPU,从而有效地提高实时阴影的绘制效率。     

基于GPU的粒子系统的实现技术

为了提高大规模粒子系统绘制的实时性,在研究图形处理器(GPU)的编程架构和可编程接口基础上,实现了基于GPU的粒子系统.采用新的算法在GPU上完成了粒子系统与场景中其它物体的碰撞检测.与在CPU上实现的粒子系统相比,该系统在处理大规模粒子系统时,具有明显的速度优势.     

基于GPU的实时群体仿真算法实现

群体仿真在虚拟现实、影视动画、计算机游戏等领域有着广泛的应用。大规模的群体仿真中每个个体都要同其感知范围内的其他个体相互作用,当实时更新所有个体的状态时,就会导致O（ N2）计算量的问题。针对这一问题,实现了一种基于GPU（图形处理器）的BOIDS群体行为模拟算法,充分利用GPU并行计算的能力处理大规模群体运动的巨大计算量。该方法利用GPU的快速光栅化计算每个个体同其感知范围内的其他个体的相互作用力,通过像素颜色混合功能实现作用力的累加,利用GPU自动生成MipMap的能力计算所有个体的平均速度和平均位置。实验结果表明,该方法能够有效提高大规模群体运动的渲染速度。     

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