基于CAN协议的混合网络的设计与实现

CAN是目前国际上应用广泛的实时控制网络。文章基于CAN协议,设计出有线和无线混合控制网络,提出了一种新型的混合网络实时通讯协议,并通过硬件实现验证了设计的正确。文章的混合控制网络的设计思想,特别是无线通讯协议的设计和实现,对于实现开放的工业网络与控制系统有重要意义。     

DASH7协议的Mesh网设计与实现

通过对DASH7协议栈的分析与设计,并利用嵌入式web服务器技术,实现了一个DASH7协议无线传感器网络的Mesh网络设计,同时基于网络分层思想设计了链路加权代价函数,优化了网络路由选择。该Mesh网的实现解决了DASH7协议网络无法多跳路由所带来的应用瓶颈。     

一体化标识网络下OSPF路由协议的实现

一体化标识网络与普适服务体系是一种全新的“标识分组网络”体系结构。为了完善一体化标识网络的路由功能,使得OSPF路由协议能够支持一体化标识协议栈,文中提出了一体化标识网中OSPF路由协议的设计与实现。通过对一体化网络协议栈的分析,给出了一体化网络中OSPFID接口以及分离机制的设计思路,然后修改路由协议的代码以及Linux内核代码实现了一体化标识网络中OSPFID的方案。最后,搭建拓扑对标识网络下OSPFID协议进行了测试,验证了OSPFID协议能够在一体化标识网络下很好地实现路由功能。     

基于Lonworks总线的网关工具的设计

文章简要阐述了Lonworks和Modbus协议的特点,设计了Lonworks/Modbus协议转换网关工具,介绍了如何利用协议转换网关工具实现Lonworks网络和Modbus网络间的通信。     

DHCP协议客户端的实现

DHCP协议是为TCP/IP网络分配网络参数而设计的应用层协议,它在嵌入式流媒体播放器中的实现,是IPTV系统的重要环节之一.重点介绍了DHCP协议在客户端的实现过程.     

NOC协议设计研究

片上网络芯片设计涵盖芯片设计的诸多方面,尤其是网络芯片的协议设计.论文主要研究网络芯片协议设计实现方式以及网络芯片的层次栈的划分,列出网络芯片所需要的协议层次.在网络芯片的协议层次中,分别对物理层、数据链路层、网络层、传输层的协议的设计重点与设计方实现进行阐述,而且介绍各个层次的设计关键技术和解决的方法.     

计算机网络的重要应用—远程视频会议系统

本文主要论述了视频会议系统的关键技术和视频会议系统的应用前景。通过对TCP协议和UDP协议的比较,选择不可靠传输协议UDP实现多媒体在网络上实时传输。采用了RTP和RTCP协议提出了基于UDP协议的RTP实时视、音频传输的设计思想,通过RTP/RTCP封包/解包的设计实现对网络的流量控制,并同时给出了RTP/RTCP组帧的流程。     

基于6LoWPAN的边缘路由器设计研究

提出了一种智能6LoWPAN传感网络边缘路由器设计实现方法。该方法基于嵌入式操作系统Linux系统平台和单CPU的方案实现,通过在系统Linux上移植6LoWPAN协议簇,使射频接口LAN承载6LoWPAN网络,本地6LoWPAN传感网络通过边缘路由器接入互联网。6LoWPAN传感网络边缘路由器采用多协议融合的方式实现IPv4/IPv6双栈协议、NAT64协议、6to4隧道协议的统一,实现6LoWPAN网络节点通过6LoWPAN边缘路由器与互联网在不同网络环境下的自适应接入。     

IP网络视频会议的MCU的设计和实现

本文在对H.323协议构成和软件实现分析和研究的基础上,讨论了基于H.323协议的IP网络视频会议系统的多点控制,并设计实现了基于多线程、集中式的网络视频会议系统.     

基于 Exata的网络通信协议仿真*

Exata是针对无线通信技术而设计的先进网络仿真系统,具有很高精确度和效率。文章详细研究了Exata仿真体系架构及其通信协议实现方法,在此基础上设计了一种移动Ad Hoc网络（MANET）MAC层协议,通过Exata平台对该协议进行了仿真,仿真结果表明该协议满足设计指标。     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

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.     

法律信息库系统

本文分析了法律数据库的结构和特点，介绍了采用面向对象设计方法和超文本数据库技术开发和实现法律信息库系统将作为重要网络资源之一为不同用户进行法律咨询服务。     

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.     

International Journal of Automation and Computing Table of Contents

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Information for authors

正SCIENCE CHINA Information Sciences(Sci China Inf Sci),cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press,is committed to publishing highquality,original results of both basic and applied research in all areas of information sciences,including computer science and technology;systems science,control science and engineering(published in Issues with odd numbers);information and communication engineering;electronic science and technology(published in Issues with even numbers).Sci China Inf Sci is published monthly in both print and electronic forms.It is indexed by Academic OneFile,Astrophysics Data System(ADS),CSA,Cabells,Current Contents/Engineering,Computing and Technology,DBLP,Digital Mathematics Registry,Earthquake Engineering Abstracts,Engineering Index,Engineered Materials Abstracts,Gale,Google,INSPEC,Journal Citation Reports/Science Edition,Mathematical Reviews,OCLC,ProQuest,SCOPUS,Science Citation Index Expanded,Summon by Serial Solutions,VINITI,Zentralblatt MATH.     

Erratum to: Fast global kernel fuzzy c-means clustering algorithm for consonant/vowel segmentation of speech signal

正Erratum to:J Zhejiang Univ-Sci C(ComputElectron)2014 15(7):551-563doi:10.1631/jzus.C1300320The original version of this article unfortunately contained mistakes.Algorithm 6 should be as follows:Algorithm 6 FGKFCM-F clustering Input:(1)X={x_1,x_2,…,x_N},,x_iR~d,i=1,2,…,N,the dataset;(2)C,1C≤N,the number of clusters;(3)ε0,the stopping criterion;     

Journal of Zhejiang University-SCIENCE C (Computers & Electronics) Total contents

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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.