基于贝叶斯博弈模型的无线多跳网络激励机制

节点智能性的提高使无线多跳网络的应用更为多样化,但也使网络的安全问题变得更为突出。为了有效控制自私节点和恶意节点给网络带来的不良影响,在博弈论的基础上结合跨层优化思想,构建了物理层与链路层部分信息共享的贝叶斯博弈模型。利用贝叶斯博弈理论对节点的交互信息构建策略空间并进行推导分析,形成有效激励节点合作的互监督机制。最后,分别通过典型案例与计算机仿真实验验证了该网络模型的可行性和公平性。     

基于无线多跳网络有限理性节点博弈分析

无线多跳网络的时空动态性,使得网络中的节点对服务质量的需求具有多样性,不同需求的变化促使节点扮演"有限理性"的参与者,去适时改变效用分析。本文基于博弈理论,结合"智猪博弈"典型模式,设计合理机制激励节点依据"杠杆原理"分析群体与个体之间的利益关系,使节点根据自身的实际需求寻求效用与通信代价之间的平衡点。     

基于改进的小世界网络的组搜索算法及其应用

针对合成氨工艺中,合成塔出口氨含量软测量神经网络模型的参数优化问题,提出了一种改进的小世界网络模型,并将其引入到组搜索优化算法中。改进后的小世界网络在计算节点之间相连接的概率时考虑节点间的距离因素,相距较近的节点间比相距较远的节点之间更容易连接。将改进后的小世界网络引入组搜索算法后,种群中的追随者在每次迭代中,根据当前迭代次数及与其它个体间的距离计算自身与其它个体的相连接概率,相连概率随着迭代增加而线性增大,随着个体间距离的增加而指数递减。追随者根据相连概率选择与自身相连接的个体,再用与其相连的个体构建自身的邻域并选取邻域中的最优个体作为局部最优解个体。追随者更新自身位置时不仅参考整个种群中的全局最优个体,还同时参考自身邻域中的局部最优个体。该算法能够提高种群中个体的多样性,具有更好的全局搜索能力和收敛速度。将该算法应用于氨合成塔出口氨含量软测量建模问题中,对神经网络模型的参数进行优化,并与其它3种方法比较。仿真结果表明,基于改进的小世界网络模型的组搜索算法能够获得更好的模型参数,提高软测量模型的精度。     

自组织P2P 网络分布式合作激励机制研究现状

自组织P2P网络本质上的节点自治及理性特征决定了网络系统目标与节点自身利益的不一致性,合作激励机制能够引导节点采用利他的行为策略,弥合系统与个体之间的利益冲突．以提高自组织网络可用性为目标,探讨了多种有效的、实用的分布式合作机制,总结了自组织P2P网络合作激励机制的设计中存在的问题和研究方向．     

基于群体智能的自组织重叠社团结构分析算法

社团结构分析是复杂网络研究的一项重要内容。基于群体智能思想提出了一种自组织的重叠社团结构分析算法SO^2CSA^2。基本思想是：把网络视为一个群体,网络节点是其中的一个个具有简单智能的个体,每个个体依据定义的社团连接分数自主决定要加入的社团（可同时加入多个社团）。首先在网络中寻找一组K-派系作为初始社团结构;在此基础上,所有个体迭代地选择其社团归属,最终整个网络的社团结构将逐渐生长出来;最后对获得的社团结构进行后处理,即调整少量节点的社团归属,以提高其质量。在一组合成网络和现实世界网络上的实验表明,SO^2CSA^2发现的社团结构的质量比两种对比算法（SLPA和OSLOM）更好,尤其是在网络中重叠节点较多或节点重叠度较大的情况下,社团结构质量的提升更为明显。     

基于合作贡献的移动社会网络自私路由协议

移动社会网络的路由工作中存在一个不合理的假设,即所有节点是无私合作的,愿意为其他节点转发数据。然而,MSN网络节点通常表现出自私性,因为在现实世界中,节点通常被人们所支配,而社会中的人们可能由于节点资源的匮乏不愿意节点参与转发。这种节点的自私行为无疑极大地降低了网络的性能。为了解决移动社会网络的自私路由问题,提出了一种基于用户合作和贡献的自私路由协议C2SR。C2SR根据候选中继节点与目标节点之间的合作度及该节点对网络的贡献度来决定下一跳节点。其中节点合作度由节点社会合作度和个体合作度决定,贡献度则包括节点之间的相互贡献以及对整个网络的社会贡献。与目标节点具有较高合作度并且贡献度较小的候选节点更适合作为下一跳中继节点。仿真结果表明,C2SR协议比SSAR和ANT等协议具有更好的性能。     

基于场势模型的网络节点重要性综合度量方法

针对网络节点的重要性受到多种因素影响的问题,提出一种基于场势模型的网络节点重要性综合度量方法。采用数据场模型对网络节点之间的相互作用关系进行形式化描述;根据节点的资产价值和互联节点之间的相互作用关系,综合量化节点的重要性;引入安全影响因素,通过可达性矩阵修正节点势场的可作用范围。理论分析与实验结果表明,该方法能够更客观准确地度量节点的重要性,有效区分边缘节点的差异性,使度量结果与节点的实际重要性相吻合。     

机会网络中考虑缓存的ProPhet路由算法

机会网络中的ProPhet等路由算法根据机会网络中节点的相遇频率进行节点之间消息的传递,不考虑节点每次相遇的持续时间以及节点中缓存剩余情况。在机会网络内部节点之间的移动速度很快的情况下,采用这些路由算法会使网络内数据的传输效率急剧下降。针对这一不足,结合ProPhet路由算法,计算节点之间的传输概率时充分考虑节点的相遇持续时间以及剩余缓存对节点之间传输概率的影响,使节点之间能更有效地传输数据。仿真结果表明,在给定的移动模型下,该算法能够有效提高消息传递成功率,降低网络中能量消耗等开销。     

一类多跳双环网络三节点故障情况下的通信能力分析

多跳双环网络是一种较为可靠的网络拓扑结构,但是网络节点出现故障会使网络的通信性能下降.分析这种网络在3个节点故障的情况下,正常节点之间互相通信的能力.指出它与网络节点数、跳跃距离有关,建立各种不同情况下的数学关系,还给出曲线,便于比较.     

能量均衡的无线传感器网络节点路由算法

为了提高无线传感器网络的生存时间,提出一种能量均衡的无线传感器网络节点路由算法。首先利用能量阈值和节点剩余能量将节点归类为2个区域,使得不同区域的节点当选为本轮簇头节点的概率不同,在数据稳定传输阶段,簇头与基站之间采用单跳与多跳相结合的通信方式,最后采用仿真实验测试算法的性能。结果表明,本算法有效提高了网络的能量利用率,能够实现节点之间的能耗均衡,使无线传感器的网络生存时间得到延长。     

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.     

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.     

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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