无线网状网技术研究

无线网状网是一种新兴的无线局域网技术。通过分析无线局域网的现状,详细讨论了无线网状网的功能特点,同时对比几种厂商的无线网状网解决方案,对无线网状网的组网方式和实现方式进行了探讨。研究工作为无线网状网的设计提供了良好的技术依据。     

“无线网状网”在校园

无线网状网是对无线局域网技术的一种创新。它支持宽带和一定的移动性,目的不是为取代漫游的移动电话服务。无线网状网属于局域网,能以较高的性价比,覆盖较大的城市区域。     

IEEE 802系列无线网络网状组网与移动切换技术综述

传统的无线区域网络在进行大规模应用时受制于网络灵活扩展和对快速移动的支持。IEEE 802的相关标准组正在致力于推动网状组网和快速移动性支持方面的技术进步，制定相关的技术标准。以802.11s、802.15.5和802.16/20为例讨论了基于无线局域网、无线个域网和无线城域网的网状网技术与移动性支持技术。介绍了无线区域网络的发展趋势和技术路线，为更好地推动无线多跳网络的研究与应用奠定基础。     

无线网状网 网住校园

无线网状网是一种全新的、灵活的广域WLAN解决方案,能够在某一地区实现无线局域网的扩展与延伸,并提供室内外的安全无线接入覆盖。     

无线网状网与应用技术

无线网状网是一种新兴的无线组网技术并且具有良好的市场需求。该文首先简要介绍了无线网状网的产生和发展,然后针对无线网状网的定义特点关键技术以及应用前景等核心问题,进行了初步的探讨和总结。     

无线局域网技术在港口通信中的研究与应用

无线上网是无线数据传输应用最广泛、最基本的一种模式，其中作为有线网络延伸和扩展的无线局域网技术越来越得到重视。本课题基于秦皇岛港通信网的现状，结合港口生产的实际需要，以流动机械分公司为例，对无线局域网进行了研究与建立，包括无线局域网所采用的主要技术、协议标准、安全机制以及与有线网络的互联等。     

WMN的网络安全威胁及路由安全策略研究

无线网状网(WMN)是目前应用比较广泛的一种网络技术,但其面临的网络安全环境日趋复杂。文章着眼WMN面临的网络安全威胁,分析了当前无线网状网应用过程中面临的路由破坏攻击和资源消耗攻击两种类型共七中典型的网络安全威胁,同时,针对无线网状网应用过程中的威胁形式,从密码和检测两个方面介绍了     

无线Mesh网关键技术分析

无线网状网(Wireless Mesh Network,WMN)技术是一种具有良好市场应用前景的新型宽带无线网络技术。本文首先讨论了无线网状网的研究背景,并针对其结构特点、与其他通信网络的区别以及关键技术,进行了初步的探讨和总结。     

冲刺无线局域网

在目前的数据通信技术产业当中,无线局域网技术是少数的几个亮点之一,美国网件(Netgear)中国区CTO杨子江先生对此非常认同,他介绍说,随着基于802.11标准无线局域网技术产品的发展,美国网件从2003年的第一季开始,紧跟无线局域网技术的新发展及不同目标市场的需求,推出系列无线局域网新品。     

骨干无线网状网的排队延迟性能研究

对一种基于网状分布的骨干无线网状网的延迟性能进行研究.提出了一种基于均衡负载的最短路径路由协议.在此协议基础上,研究了无线网状网数据包的排队延迟,推导出无线网状网排队延迟与网络的规模、网关和网状路由器的服务能力、数据包到达率的相互关系.此外,还分析排队延迟和网络容量的相互制约关系,并给出了在延迟限制条件下的网络容量.     

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