协作式云资源博弈分配

针对用户对云资源的异构性需求和竞争问题,提出了一种协作式资源分配博弈策略。建立了资源分配的协作式博弈模型,定义了协作博弈的用户效用函数和评估函数,证明了在该效用函数下协作博弈存在唯一Nash均衡,并讨论了用户组建联盟对协作特征函数和整体效用的影响。实验结果表明,在该协作博弈策略下,个体用户通过组建联盟集体出价的方式,能够为联盟用户带来更大效用,以收敛方式实现Pareto改进。     

基于博弈理论的经济网格资源配置研究

针对经济网格中,由于网格系统的复杂性和用户的私利性,使得网格用户在资源竞价过程中往往因相关信息的匮乏而导致资源竞价的盲目性问题,根据重复博弈分阶段执行的特点,将网格用户间对网格资源的竞争看作多阶段的重复博弈过程.用户依据前一阶段博弈的竞价值及竞价结果对当前阶段的竞价策略进行调整,通过有限次的阶段博弈达到均衡出价策略组合,实现用户最大效用下的资源分配.仿真表明,在不完全信息的网格环境中,该竞价模型可逐步改善网格用户的资源竞价策略,实现优化目标最大化下的网格资源分配.     

网格资源非对称进化博弈分配策略

针对经济模型的网格系统中资源分配的竞争问题,应用进化博弈论中多种群复制动态博弈模型对有限理性网格用户有差别的出价策略进行了研究,提出了一种非对称进化资源分配博弈模型,该模型将网格用户分为出价偏低的保守种群和出价偏高的激进种群,分析了两种网格种群采取合作与竞争策略的自发进化过程,求解了各自的复制动态方程,并通过实例化的非对称支付矩阵求解了复制动态系统的进化稳定策略。研究表明,只有博弈双方选择对等的行为策略才能促进网格资源的公平分配。     

一种基于序贯博弈的网格资源分配策略

网格环境中资源的负载预测是实现资源优化分配的关键任务之一,而网格资源的动态性和异构性使得准确判断资源的负载状态十分困难.针对已有的分配策略对资源负载评估的不足,提出了一种基于序贯博弈的优化用户时间的网格资源分配策略.该策略将正比例资源共享的网格环境中多用户竞争同一计算资源的问题形式化为一个多人序贯博弈,通过寻求该序贯博弈中各个阶段博弈的纳什均衡解来预测资源负载;然后利用此负载信息生成所有用户的最优出价组合和资源的优化价格;最后根据各用户出价,按比例分配资源的计算能力.通过对网格模拟器GridSim的实验研究,结果表明,该策略能够得到合理的用户出价,降低资源占用时间,从而弥补了Bredin提出的优化策略中未考虑资源未来负载变化的缺陷,实现了资源的优化分配.其结论说明运用序贯博弈方法预测资源负载是可行的,且能更好地适应网格环境下异构资源的动态性.     

基于微分博弈的群智频谱感知算法

计算机技术和通信技术的融合是一个必然的趋势,频谱感知作为计算机通信技术的一个组成部分,是解决现有无线系统频谱利用率低的关键技术之一。将群智感知与频谱感知相结合,提出了一种基于微分博弈的群智频谱感知算法。平台的效用定义为第三方支付的报酬减去付给次用户的报酬,次用户的效用定义为平台支付的报酬减去次用户参与频谱感知任务的成本,以各自效用最大为目标设计了一种非合作的微分博弈模型。该微分博弈模型包含一个微分方程、平台效用和次用户效用,通过公式推导求解其反馈纳什均衡,得到平台和用户的最优策略的表达式,即平台决定任务的最优价格,各个次用户确定频谱的最优检测概率(即感知时间)。仿真结果表明,平台和次用户采取最优策略时效用高于采取固定策略时的效用。     

云计算基于随机进化博弈动态的资源优化配置

云资源优化分配研究中,用户策略难免存在失误,以用户完全理性为前提的资源分配方法在实际环境下会出现失效。分析非完全理性的云用户种群下的资源分配过程及其策略演化过程,提出一种随机动态模型求解有限云种群中的资源分配进化博弈问题。模型克服用户完全理性的限制,利用带有频率依赖选择的Moran过程,在重复博弈过程中寻找云用户策略的入侵指数和固定指数策略选择偏好的条件。根据经济学云环境的特征,建立云用户的固定效用矩阵,量化策略选择动态。数值仿真结果证明,为了最大化自身效用,不同大小云种群中的个体策略会向着不同策略方向演化,资源在有限理性用户之间可以实现优化分配,且最优分配策略最终会处于稳定状态。     

基于多领导者Stackelberg博弈的分层联邦学习激励机制设计

分层联邦学习中隐私安全与资源消耗等问题的存在降低了参与者的积极性。为鼓励足够多的参与者积极参与学习任务，并针对多移动设备与多边缘服务器之间的决策问题，提出基于多领导者Stackelberg博弈的激励机制。首先，通过量化移动设备的成本效用与边缘服务器的支付报酬，构建效用函数并定义最优化问题；其次，将移动设备之间的交互建模为演化博弈，将边缘服务器之间的交互建模为非合作博弈。为求解最优边缘服务器选择和定价策略，提出多轮迭代边缘服务器选择算法（MIES）和梯度迭代定价算法（GIPA），前者用于求解移动设备之间的演化博弈均衡解，后者用于求解边缘服务器之间的定价竞争问题。实验结果表明，所提算法GIPA与最优定价预测策略（OPPS）、历史最优定价策略（HOPS）和随机定价策略（RPS）相比，可使边缘服务器的平均效用分别提高4.06%、10.08%和31.39%。     

移动通信系统中一种合作博弈CAC 策略

由于无线频谱是极为有限的资源,呼叫接纳控制(call admission control,简称CAC)成为移动通信系统中无线资源管理的一个重要部分.针对流媒体对接入资源的过度占用问题,提出了一种基于合作博弈理论的CAC策略,博弈方是处于服务状态的业务和申请接入的新业务,基站是保证协议强制执行的外在力量,基站选择效用和最大的策略组作为博弈过程的最终结果.仿真结果表明,所提策略有效缓解了流媒体业务对资源的捕获效应,保证了用户接入的公平性,对于实际系统性能的改善具有重要的意义.     

基于合作博弈的路由队列管理算法

针对网络用户的贪婪行为,引入合作博弈理论,在分布式流速控制算法(FCAG_SL)的基础上提出了更完善的博弈环境,建立合作博弈的模型.并基于此合作博弈的模型,设计了一种基于合作博弈的路由队列管理算法(MRQA_CG)动态响应网络的变化,对网络资源进行合理分配,从而达到了控制拥塞和提高整体用户效用的目的.最后通过仿真实验验证了MRQA_CG算法在平均延迟、用户效用,以及吞吐率方面比FCAG_SL算法更优越.     

基于CIS值的非合作-合作两型博弈的理论研究

针对Brandenburger和Stuart提出的非合作-合作两型博弈中的不足,提出一种基于转归集中心值(CIS值)的非合作-合作两型博弈理论框架.用CIS值作为合作博弈阶段的解,进而构造获得非合作博弈阶段的纯策略纳什均衡解,并证明该类两型博弈解存在的条件.所提出的非合作-合作两型博弈的求解方法降低了非合作-合作两型博弈的解和有效策略存在的要求,适合于联盟外局中人的策略对联盟具有外部影响时的非合作-合作两型博弈问题,使非合作-合作两型博弈模型的应用更具有一般化,为供应链管理等问题提供新的理论依据.最后,通过数值实例表明所提出模型和方法的有效性和实用性.     

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.     

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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