基于OpenGL与粒子系统实现三维喷泉模拟

喷泉、瀑布、火焰、水流、雨、雪等自然景物具有不规则性、动态性和随机性,模拟十分复杂。模拟自然景物的方法有两种:基于物理建模技术的方法与基于粒子系统建模的方法。运用粒子系统建模方法分析了喷泉水体模型,研究了喷泉水珠粒子产生、运动和消亡的机理,构建出三维喷泉粒子系统模型。采用了三维立体显示技术和纹理映射技术增强喷泉绘制过程中的渲染和真实感。基于OpenGL,采用Visual C++6.0编程实现了三维喷泉模拟。实验结果表明,该方法模拟效果真实,在普通的PC平台上即可满足一般动画的实时需求。     

基于物理模型的实时喷泉水流运动模拟

本文基于流体动力学和粒子系统给出了一个模拟实时喷泉水流运动的方法。     

基于OpenGL与粒子系统的喷泉模拟实现

喷泉效果能够极大地增强虚拟现实系统的沉浸感,在计算机动画、计算机游戏等领域有着广泛的应用,对喷泉的模拟也能够促进计算机仿真技术的发展.粒子系统是模拟喷泉的一种有效方法,文中基于OpenGL与粒子系统来实现喷泉模拟,基本思想是运用粒子系统建模方法分析喷泉水体模型,重点研究喷泉水珠粒子产生、运动和消失的机理,采用OpenGL显示列表方法和纹理映射技术增强喷泉绘制过程中的渲染和真实感.最后,在PC机上运用VC++6.0开发工具和OpenGL实现喷泉模拟,实验证明该方法具有很好的实时性和逼真性.     

基于大规模粒子系统的实时喷泉模拟

本文实现了一种新的喷泉模拟方法,与传统的在CPU上实现算法不同的是,本文算法完全基于计算机图形硬件(GPU)来实现,利用图形硬件的大规模并行计算能力,显著的增加了模拟喷泉的粒子数量,提高了渲染速度,同时减轻了CPU的负载,使整个三维场景的绘制更加高效。     

基于硬件加速和粒子系统的实时喷泉模拟

喷泉效果可以增强三维场景的真实感。论文用粒子系统作为喷泉建模的方法,通过动力学原理模拟水流的运动,对水流中粒子的运动采用循环式的重复使用,从而大大提高程序运行效率。利用Direct3D对粒子绘制的支持,通过Shader编程充分挖掘GPU的处理能力,并对水珠粒子进行多样化的高效绘制。通过CPU与GPU相互结合的方式,既保证了喷泉效果的真实感,又有较高的运行效率,也能满足系统实时性的速度需求。     

大规模三维云实时模拟方法

针对虚拟环境中大规模三维云渲染开销大的问题,提出一种大规模三维云实时模拟方法.在云建模方面,利用Navier-Stokes流体力学公式模拟云的动态生成,提出一种基于八叉树的模型化简策略,减少了云模型粒子数;在渲染阶段,提出一种基于Cell的绘制更新策略,结合Impostor技术自动混合绘制三维云与Impostor,实现了大规模三维云的实时模拟.实验结果表明,该方法基于物理的方法模拟云,同时在绘制阶段根据视点的移动实时更新,效果逼真;与同类方法相比,基于Cell的绘制策略更新时计算量更小,有效地避免了绘制更新时常见的抖动和跳变问题.     

GPU加速的并行粒子模拟在线可视化

粒子模拟是研究离散粒子和连续介质运动规律的常用方法.而大规模的粒子模拟通常借助高性能计算系统.近年来,得益于其众核架构,图形处理器(GPU)已成为高性能计算的重要设备,并被广泛用于大规模粒子模拟过程的加速.本文讨论了一种对GPU加速的分布式粒子模拟进行在线可视化的方法.在该方法中,GPU除了被用于加速粒子模拟过程外,也被用于数据到图像的快速转换.同时,并行绘制技术被用于分布式数据的可视化.通过本文所述的方法,用户可在并行计算运行过程中,通过显示于拼接显示墙的高分辨率图像,实时地观察到粒子模拟中发生的现象,并对计算过程进行跟踪和调整.     

风场作用下大规模真实感草地模拟

大规模草地场景的建模及实时绘制很难满足草体的逼真性以及实时性。针对以上问题,文中提出了在风场作用下基于GPU加速的大规模草地场景动态模拟方法。为真实地绘制大规模草地场景的动态效果,利用基于布告板的改进方法,建立了运算简单、草体茂盛效果真实的草体模型;同时,文中针对草体随风摆动的视觉效果设计出相应的数学模型,并利用可编程GPU对场景进行视觉效果优化。实验表明,该方法不仅能够绘制出大规模草体的逼真效果,同时对风场作用的实时变化有很好的支持。     

音乐喷泉系统的可视化设计及实时仿真

介绍音乐喷泉系统的结构设计思路。针对传统的音乐喷泉系统的缺点和实际存在的问题,提出了分级控制的思路和实现方法,详细论述了音乐喷泉的控制码（造型码）的可视化编程以及音乐喷泉造型的实时仿真,并用当前流行的当前流行的编程工具ＶＢ加以实现。系统集声音动画于一体,充分展现了多媒体体技术和音乐喷泉的魅力。     

TMS320C6713DSP在音乐喷泉控制系统中的应用

本文提出了一种音乐喷泉设计的方法,使喷泉水柱高低与音乐信号频谱的变化相一致。给出了喷泉系统总体设计框架,并且详细介绍了DSP在系统中的应用。DSP与立体声音频CODEC相连采集音频信号并对采集到的信号做实时的傅立叶变换。     

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