城域以太网技术及其应用

文章分析了城域以太网的核心技术——城域以太网的应用技术和安全技术，并以城域以太网论坛内容为基础，从城域以太网的架构、服务、网络保护和QoS、城域以太网的管理四个方面简要分析了城域以太网技术。最后，介绍了城域以太网技术的应用，即城域以太网提供业务的能力。     

论六种实时以太网的通信协议

在研究工业网络实时性要求的基础上，给出了工业以太网和实时以太网的定义，深入分析了6种主要实时以太网的通信协议。并概要论述了以太网运动控制、网络安全和以太网延伸至现场设备级等关键技术。同时，较全面地概述了我国ERA实时以太网技术及其标准。     

10G以太网在局域和城域网中的应用定位和发展趋势

以太网的发展已经经历了三个阶段,即以太网Ethernet阶段、快速以太网FE阶段和千兆以太网GE阶段。千兆以太网发展起来后,由于它具有成本低廉、互连性好、升级容易、组网简单、技术支撑厂家多、技术发展快的优势,千兆局域网已占据了整个局域网市场的大部分份额,成为设备的基本配置,甚至笔记本电脑的网卡也已经支持GE速率。最近10G以太网技术已日趋成熟,使得以太网的速度可以达到万兆。10G以太网技术简介10G以太网是以太网在速度和距离方面的自然演化,它的标准于2002年6月正式颁布。虽然以太网速度在不断提高,但是其基本帧格式仍保持不变,1…     

工业以太网与现场总线组网的研究

本文在简要介绍以太网、LON和CAN现场总线的基础上，并对工业以太网以及以太网与现场总线(LON、CAN)的集成进行了分析与论述，提出了工业以太网的组建和以太网与现场总线组网具体实施的一种方案。     

新服务开路以太网夺城

到2003年,以太网已经诞生整整30周年了。30年来,以太网不仅在企业网一统天下,而且向城域网和广域网进军。最近,以太网技术在城域网的应用方面又有重大突破。城域以太网论坛(MEF)宣布了它最有意义的一项成就,就是基于以太网技术统一了城域网的工业标准,未来的城域网将是新型的、规范化的城域以太网(MEN)。MEF总裁陈子南先生最近详细介绍了最新的城域以太网标准。     

城域以太网及其新标准

城域以太网作为城域网的主流技术已经取得了长足的发展。城域以太网论坛（MEF）推出了新的城域以太网的标准——Cartier Ethemet，推动了城域以太网的发展。在分析现有各种城域以太网的基础上，针对以太网升级到电信级城域网时在业务模型、端到端QoS、保护机制、操作、管理、维护等方面存在的不足，并对照MEF的Carrier Ethemet模型对这些不足进行了详细的分析，提出了解决这些问题的方法，并展望了Carder Ethemet的发展，为城域以太网新标准的实施提供参考。     

传统以太网升级和优化的相关技术

本文论述了传统以太网的基本特点及其存在的局限性，并分析研究了升级和优化传统以太网的一些主要技术手段，如高速以太网技术、以太网交换技术、路由器技术及虚拟局域网（ＶＬＡＮ）技术等，以期对以太网的设计、升级和优化工作有所借鉴和帮助。     

传统以太网升级和优化的相关技术

本文论述了传统以太网的基本特点及其存在的局限性,并分析研究了升级和优化传统 以太网的一些主要技术手段,如高速以太网技术、以太网交换技术、路由器技术及虚拟 局域网（ＶＬＡＮ）技术等,以期对以太网的设计、升级和优化工作有所借鉴和帮助。     

从EtherNet/IP工业以太网到工厂信息化技术

通过回顾以太网用于工业控制的历史，说明了工业以太网与传统以太网技术的根本区别，并简要介绍了开放式工业以太网技术EtherNet／IP的构成方式、发展和应用概况以及优势，并分析了工业以太网技术蓬勃发展的深刻动力及其与工厂信息化的关系。     

EPON在工业网络通讯中的应用

介绍了无源全光以太网EPON,描述了千兆以太网、交换式以太网和EPON构建工业网络的区别。     

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