MSC.Nastran有限元计算效率和计算精度分析

本文通过一个简单的计算例子说明使用在有限元分析软件MSC.Nastran进行实际工程计算时，计算精度，计算机时与有限元规模之间的关系。通过比较中以看出，在工程实际工程计算中，应合理地对计算问题进行有限计算问题进行有限元网格的划分，以较高的计算效率较高的计算精度。     

有限元分析计算中的可视化技术及其实现

有限元分析计算中经常产生大量的数据，如何利用计算机设备对所产生的数据进行快速有效的分析。这成为有限元分析领域中得要的研究方向。本文主要在简要介绍可视化概念及其可视化软件基本能要求的基础上，讨论有限元分析计算中的可视化技术及其在ＩＮＦＥＧＡＳ系统中的实现。     

有限元分析计算结果的计算机图形可视化显示

科学计算结果的计算机图形可视化显示是提高计算效率，减少劳动强度，保证设计正确的有效方法，本文将计算机图形可视化技术应用于有限元分析中，开发了一个有限元分析结果的可视化显示系统，介绍了该系统所采用的、数据管理和实现的功能。重点介绍了有限元分析的网格、计算结果的位移和应力的可视化显示方法。     

有限元工程化的向项关键技术

本文是作者从事有限元应用开发工作的体会。从应用观点出发，作者认为：有限元数值分析及实验验证，有限元前后处理，一体化有限元软件接口，远程登录计算，是有限元方法在工程界得以普遍应用的四项关键技术；每项关键技术都在平行地发展并互相促进。     

有限元工程化的几项关键技术

本文是作者从事有限元应用开发工作的体会。从应用观点出发，作者认为：有限元数值分析及实验验证，有限元前后处理，一体化有限元软件接口，远程登录计算，是有限元方法在工程界得以普遍应用的四项关键技术；每项关键技术都在平行地发展并互相促进。     

面向快速产品开发的智能设计/FEA耦合系统初探

一、引言市场竞争的不断加剧使得产品开发速度日益成为最具挑战性的因素。设计制造体系结构相应随之逐步发展为快速反应制造与快速产品开发（RapidProductDevelopment，RPD）。这对于作为结构及多自由度体系分析有力工具的有限元分析技术（FiniteElementAnalysis，FEA）产生了深刻影响。传统制造体系下，将FEA看作一种孤立的分析手段，主要注重有限元技术解决问题的能力和精度；RPD则一方面注重有限元分析本身的速度，另一方面还要求从系统的角度来分析FEA在择计算方法和策略。有限元分析存在着众多的计算方法，对某一给定的问题，…     

齿轮接触应力有限元计算方法评价

本文以齿轮接触疲劳试验为依据,建立有限元模型并计算接触应力,将有限元计算结果与试验结果相比较,评价有限元计算结果的准确度,并以有限元模型简化及网格数量对计算结果的影响进行分析,最终给出合理的计算和评价准则。     

有限元法在板料二次成形中的应用

本文建立了板料成形动力显式有限元模拟，采用四节点退化壳单元对板料进行离散化，利用中心差分法离散时间域，建立显式计算格式，采用罚函数法和修正库仑定理计算接触力和摩擦力。对二次成形过程，建立了有限元分析计算模型。通过Dynaform对板料成形进行仿真得出最后结论。     

面向有限元分析的实体表面网格模型的优化

针对CAE软件开发的需要，将通用CAD软件输出的以表面三角形网格形式表示的实体模型输入CAE软件，作为有限元分析用几何模型。然后根据特定领域有限元分析的要求对表面网格进行优化处理，优化网格的数量和质量，以便进一步生成适合有限元计算需要的各种单元模型。     

400吨桥式起重机中的吊钩的有限元分析

本文应用ＥＵＣＬＩＤ和ＭＳＣ／ＮＡＳＴＲＡＮ软件对一台４００吨桥式起重机中的特殊形式的吊钩进行了有限元计算，介绍了有限元模型的建立，分析了计算结果并进行了该形状吊钩的设计改进建议。     

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