业界

本刊记者 梁吴 近日,摩托罗拉与上海联通国脉通信股份有限公司在上海签定了对联通国脉现有iDEN(集成数字增强网络)系统进行大规模扩容的合同,双方将在上海建设中国规模最大、技术最先进的数字集群通信商业运营共网。扩容完成后,作为中国第一个商业运营共网,上海iDEN网不仅将为沪上众多企事业单位提供全新的、量身定制的移动通信和指挥调度服务,而且还将数字集群共网这一成功的商业模式带到中国,从而引发了中国共网运营市场的无限商机。摩托罗拉所开发的iDEN作为一种成熟的数字集群技术,充分考虑了商业共网建设和运营的需要,已在全球得到广泛的应用,并已被信息产业部批准为中国的数字集群移动通信推荐性标准之一。根据合同,扩容后的上海iDEN网将拥有40个基站,成为具有相当规模的区域性共网。其覆盖范围不仅遍及上海及周边城市,而且还可以实现与美国,加拿大以及其它拥有iDEN系统的美洲和亚洲国家的漫游通信。     

中国电科7所签约广州亚运数字集群通信系统

近日，中国电子科技集团公司（简称中国电科）7所成功签约广州800M数字集群通信系统共网项目。本项目将以全套的CETC品牌设备组网，于2010年4月建成投入运行，并作为核心通信系统向第十六届亚洲运动会和亚残会提供通信和指挥保障，同时将在广州市政府今后的日常政务通信、应急指挥通信、重大活动协调中发挥基础网络作用。该项目是广州800M数字集群共网项目的首期工程，覆盖广州市区及部分农村地区。     

4G无线通信系统在露天矿山中的应用

介绍了4G无线通信系统的概念及在某集团公司两个露天矿山的应用.通过现有TETRA数字集群网和GPS卡调MESH网络运行现状和用户需求,结合目前无线互联网公网和专网发展趋势,提出了符合集团公司实际的4G无线通信系统技术方案.该解决方案实现了专业语音集群通信、高可靠性和高实时性数据传输以及多媒体视频调度功能,并且和目前集团公司TETRA数字集群网实现2+4(TETRA+LTE)宽窄带通信融合,与GPS卡调MESH网无缝连接、有效融合,最大化地利用4G无线新技术的优势,提升矿区数字化建设水平.     

数字集群系统的安全机制与安全应用

数字集群系统在政府、公安、消防等应急移动通信领域应用广泛。同时,在这些应用领域中,对信息安全和通信安全的要求高于公众移动通信系统。该文分析了目前数字集群系统采用的密钥管理和安全机制,并对如何改进和实现未来安全的要求给出建议,展望了数字集群系统安全机制的发展。     

基于TETRA的可视化无线调度系统设计与开发

为了满足城市无线政务网用户的指挥调度需求,本文提出了一种基于TETRA数字集群共网的可视化无线调度系统的设计思路,详细介绍了系统的技术架构和实现方案,并对系统所涉及的关键技术进行了分析阐述。     

TETRA数字集群系统在消防行业发展趋势分析

近年来,随着我国经济社会的不断发展,对消防工作提出了更高的要求。准确把握消防行业通信规律特点,不断研究提高通信技术应用水平,对提升消防工作发展意义重大。因此,本文根据TETRA数字集群系统发展应用情况,在阐述TETRA数字集群通信系统的简介及介绍的基础上,对TETRA数字集群通信系统在消防行业的技术优势及适应性进行了深入的分析研究,对于优化提高消防工作通信系统的可靠性,提升消防工作水平具有一定的现实意义和理论依据。     

发展共用数字集群移动通信系统

本文回顾了时集群移动通信系统的认识过程,介绍了几种典型的数字集群移动通信系统,阐明了发展共用数字集群移动通信系统的必要性和可行性,最后强调集群系统的生产企业和使用部门必须密切关注国家数字集群通信的技术体制标准。     

Android在数字集群通信终端中的应用

为了使数字集群通信终端智能化并兼容Android平台丰富的应用,对如何将目前流行的智能操作系统Android应用到数字集群通信终端中进行了研究和实现.对于数字集群通信终端的重要组成部分——电话系统,详细地分析了Android自带的Telephony框架,然后根据TETRA数字集群系统的特点对Telephony框架进行了修改,最后对已修改的Android系统在TI的OMAP3530平台上进行了验证,实现了数字集群通信终端特有的功能.     

18基站盖全市——上海公安建立数字集群系统

借APEC会议之机,上海公安建立了800兆Tetra数字集群系统。2年过去了,上海公安Tetra数字集群系统已完成了二期工程的扩容建设,并初步完成了移动数据传输的二次应用开发,已全部投入使用。上海公安800兆数字集群系统由控制中心设备、基站设备、传输网络设备、     

TETRA在城市轨道交通无线通信系统中的应用

随着经济的发展,轨道交通是解决大城市交通拥挤的一种有效措施.在介绍了TETRA数字集群技术的特点及其强大功能后,分析了轨道交通无线通信系统的特点和功能,并结合重庆轻轨较新线一期工程项目,给出了其在城市轨道交通通信系统中的应用.从而更进一步地说明了TETRA数字集群技术是轨道交通无线通信系统的发展方向.     

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)

正~~     

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