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。     

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。     

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。     

工业以太网技术的新进展

介绍了工业以太网技术的新进展：工业以太环网冗余技术(单环冗余、双环冗余和变换式工业以太网)、实时以太网协议(Ethemet Powerlink和Beckhoff EtherCAT)、新型工业以太网连接器、以太网共缆供电规范、嵌入式Internet硬件芯片协议及其在现场仪表中的应用。     

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。     

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。     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

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.     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。     

基于AD9626的模拟信号采集存储卡设计

自然界的绝大部分信号都是以模拟的形式存在,因此模拟信号的采集转换存储在数字时代十分关键。文章讨论了在雷达信号处理领域基于AD9626的AD采集存储卡的设计原理、硬件结构和程序设计与芯片配置等问题,为今后相关领域的研究提供了可参考的方案。     

A human-computer interface for non-computer specialists

The COM teleconferencing system was designed to be easy to use for both beginners and people with much computer experience. A number of design choices in organizing the human-computer interface were considered very carefully. These design problems are not unique for teleconferencing applications, but will appear in many other developments of human-computer interfaces for non-computer specialists. This report discusses naming conventions, menu format, user commands, help facility and the treatment of ‘type ahead’ from the users.     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

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.     

Call for papers Special issue on Modeling and control technologies for civil,energy,and power systems

正The control of civil,energy,and power systems presents significant new challenges for modeling and control theory.The purpose of this special issue is to provide a forum for researchers and practical engineers to discuss the recent advances in modeling and control technology development for civil,energy,and power systems.Prospective authors are invited to submit their original contributions with the focus on theory or applications of modeling,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 and promote academic exchange between Chinese and foreign scientists everywhere.