一种网格节点信誉评价算法及其在服务网格虚拟组织构建中的应用

 本文提出了一种新的服务网格节点信誉评价算法．通过构建由实体间的直接信任构成的有向加权图,并通过修改经典的Dijkstra算法来计算实体间的推荐信任,结合直接信任刻画实体间的信誉评价,同时,该算法参考虚拟组织发起者对虚拟组织愿景特征的理解,将组织间信任关系以及虚拟组织所需服务或资源的种类作为信誉评价的重要依据,细粒度刻画候选者实体的信誉,从而适合具有自治域的服务网格环境中虚拟组织的构建．仿真实验表明,该算法能够较为真实地反映网格实体间的信任关系,有效遏制不良节点对服务网格系统的危害,对虚假交易攻击以及诽谤攻击均具有较强的抵御能力．     

网格虚拟组织中基于标价的比例共享资源分配方法

0引言 网格中虚拟组织定义为个人或组织为共享资源进行复杂问题求解而形成的动态合作伙伴关系的集合。虚拟组织中的资源不同于传统的资源,它具有分布性、异构性、动态性的特点,因此传统的集中式资源分配方法不适合动态异构的网格环境,需要寻找一种高效的资源分配方法来实现网格中的资源共享。一种有效的解决办法是基于市场的资源分配。     

基于网格的数字图书馆资源组织模式构建

在网格环境下,对数字图书馆资源进行有效的组织为网格系统服务提供了工作准备,是用户获取信息的基础。针对网格资源异构性、分布性、动态性的特点,构建出一种全局/局域分层式数字图书馆资源组织模式,该模式避免了资源发现的盲目性,缩短了资源的查找时间,同时通过对局域资源服务器的实时监控,使检索结果按特定规则排列,大大提高了资源的利用率,有效地提高了网格系统的性能。     

集成网格服务的中国虚拟天文台工作流系统研究与设计

根据天文数据的广域分布、异构性以及共享性的特点,将网格技术应用于虚拟天文台项目中,并与工作流技术相结合,提出了集成网格技术的虚拟天文台的工作流体系结构。该结构利用网格技术有效解决了虚拟天文台建设中天文数据资源、计算资源、存储资源等各种资源的全面共享,工作流技术集成网格技术则使得服务调用应用的流程更加规范,实现了协同合作,达到更高的效率,以期望达到真正的无缝连接。     

基于动态信任的接入管控体系构建

近年来,伴随着企业的数字化转型快速落地,内部数据泄露和受高级可持续威胁攻击(Advanced Persistent Threat,APT)的风险不断升级,传统的接入管控模式暴露出一系列问题.针对广域网和云计算环境下接入访问的高度动态化特点,设计动态信任度量的接入管控体系,通过信任持续度量实现对接入访问的动态管控,在不断...     

网格计算环境下基于移动代理的动态资源发现模型的研究

以两种通用概念模型即资源提供者-目录-请求者和虚拟组织模型为基础。提出一种基于移动代理的资源发现模型。     

基于移动代理和信任机制的网格作业管理

介绍了网络计算环境下的作业管理,引入了移动代理技术和信任机制,并进行了深入分析,对所用到的关键技术进行了详细的解释,说明了基于移动代理和信任机制的网格作业管理运行步骤.     

基于网格技术的下一代电信网络架构与运作模式

首先详细介绍了基于网格技术的下一代电信网络架构及其应用．然后探讨了在此基础上的新运营模式．并讨论了引入网格技术对电信运营模式的影响。     

基于网格技术的下一代电信运作模式研究

随着网格理论技术的不断成熟,国内外对网格的商业应用研究成为网格技术研究的第二次浪潮。把对网格技术在拥有最大的网络覆盖面的电信业作为应用研究的切入点。首先对网格技术应用到电信业后的网络层次结构模型的影响作了详细介绍。随后重点介绍了网格技术的在电信领域的具体应用,以及电信行业引入网格技术后的运作模式的影响和改变。     

网格资源访问的一种主观信任机制

针对网格环境资源访问过程中的信任问题,为避免主观随意性,提出了基于贝叶斯函数的信任机制,通过判断并使用推荐能力最强的中间节点作为推荐者,搜索出对资源节点的信任链路,使用贝叶斯函数对由信任链路得到的资源节点的每种属性进行综合判断,最终确定是否访问该资源节点,模拟实验结果表明该信任模型的有效性.     

网格计算环境下资源管理优化策略研究

根据基于虚拟组织的网格计算资源管理方法自身的特点,对其自身存在的缺陷进行了研究,提出了利用移动代理优化资源管理的设想,建立了优化的基于虚拟组织的资源管理模式,并逐渐深入分析和提出了基于虚拟组织的资源管理优化算法和实现步骤。     

Communicating for advantage in the virtual organization

The paper looks at the virtual organization in an electronic market environment and the different models of communication and management that may be required. The authors begin by providing some clear definitions of virtual cultures and different models of virtuality that can exist within the electronic market. Degrees of virtuality can be seriously constrained by the extent to which organizations have predefined communication linkages in the marketplace and the extent to which these can be substituted by virtual ones, but also by the intensity of virtual linkages which support the virtual model. Six virtual organizational models are proposed within a dynamic framework of change. In order to realize strategic advantage, virtual organizations must align their management models and communication processes with their virtual culture     

DLRD：一种支持动态负载均衡的P2P网格资源发现机制

网格技术是分布式环境中资源共享和协同工作的有效手段,资源发现机制是网格技术中的关键问题.在深入分析目前网格中资源发现机制的基础上,提出了一种支持动态负载均衡的网格资源发现机制--DLRD,并给出了相应的实现算法.DLRD基于P2P实现完全分布式的动态资源发现,可以动态灵活地增加网格中的节点并在各个节点上实现资源的动态均衡注册和定位查找.     

在网格数据组织中使用概念

商业企业每天产生大量的网格数据,作为网页信息交换的实际标准,最重要的挑战之一是如何有效地进行数据搜索,数据搜索可以以链接的方式进行。一些研究人员已经研究出了演算法,以减少搜索过程中产生的无效信息。另一些研究人员引入了记录法,可以进行相关元素的定位,无需搜索原始网格文档,通过记录的方式完成搜索过程。文中介绍的方法是基于正在被搜索的数据的概念,以及对网格数据库的内容搜索及关键字搜索,使用概念搜索可以提高搜索效率。     

Support for resource-assured and dynamic virtual private networks

This paper describes VServ, a prototype architecture for a virtual private network (VPN) service, which builds and manages VPNs on demand. It allows each VPN to have guaranteed resources and customized control, and supports a highly dynamic VPN service where creation and modification operations can take place on fast timescales. These features are contingent on the automated establishment and maintenance of VPNs. A design process is described that attempts to satisfy the goals of both customer and VPN service provider (VSP). A pruned topology graph and tailored search algorithm are derived from the characteristics of the desired VPN. Although the searching procedure is theoretically intractable, it is shown that the complexity can be mitigated by a multitude of factors, VServ is built over the Tempest, a network control framework that partitions network resources into VPNs. An IP implementation of the Tempest is presented. Resource revocation is a mechanism that the VSP can use to react to violations of service level agreements-a protocol is described to enable graceful adaptation in the control plane to resource revocation events     

Overlay multicast for MANETs using dynamic virtual mesh

Overlay multicast protocol builds a virtual mesh spanning all member nodes of a multicast group. It employs standard unicast routing and forwarding to fulfill multicast functionality. The advantages of this approach are robustness and low overhead. However, efficiency is an issue since the generated multicast trees are normally not optimized in terms of total link cost and data delivery delay. In this paper, we propose an efficient overlay multicast protocol to tackle this problem in MANET environment. The virtual topology gradually adapts to the changes in underlying network topology in a fully distributed manner. To save control overhead, the participating nodes only keep a fisheye view of the dynamic mesh. The multicast tree is progressively adjusted according to the latest local topology information. Simulations are conducted to evaluate the tree quality. The results show that our approach solves the efficiency problem effectively. This research was supported in part by the National Science Foundation under the grants CCR-0296070 and ANI-0296034. The preliminary results of this work is presented in “Efficient Overlay Multicast in Mobile Ad Hoc Networks,” Proc. IEEE WCNC 2003. Chao Gui is a Technical Research Staff at Kiyon Inc (www.kiyon.com). His research interests include wireless networking and mobile computing. His current efforts are on industrial implementation of wireless mesh networks and embedded systems. Dr. Gui has received Ph.D. in Computer Science from University of California at Davis in 2005. Prasant Mohapatra is currently a Professor in the Department of Computer Science at the University of California, Davis. He has also held various positions at Iowa State University, Michigan State University, Intel Corporation, Panasonic Technologies, Institute of Infocomm Research, Singapore, and the National ICT, Australia. Dr. Mohapatra received his Ph.D. in Computer Engineering from the Pennsylvania State University in 1993. He was/is on the editorial boards of the IEEE Transactions on computers, ACM/Springer WINET, and Ad hoc Networks Journal. He has served on numerous technical program committees for international conferences, and served on several panels. He was the Program Vice-Chair of INFOCOM 2004, and the Program Co-Chair of the First IEEE International Conference on Sensor and Ad Hoc Communications and Networks, (SECON-2004). Dr. Mohapatra’s research interests are in the areas of wireless networks, sensor networks, Internet protocols and QoS.     

网格工作流生成中的一种流程执行机制

现有工作流生成研究大多只关注过程定义的自动创建,却很少讨论相应的流程执行机制,因而不仅缺乏对工作流动态生成的支持,也存在活动资源绑定过早、缺少人工活动支持等不足.针对该问题,结合基于流程模式的工作流生成规划,提出一个流程动态执行机制.它通过抽象活动即时规划实现工作流运行时细化;通过参与者服务化方法来实现活动资源的即时绑定执行.减少运行时异常的同时,也提供了对人工与自动活动的统一支持.     

Possible mechanism for observed dynamic resistance

A possible mechanism was proposed to explain the observance of motion induced short-term electrical discontinuities in degraded tin plated contacts (nanosecond). This mechanism requires unique conditions where cold-welded wear particles are stretched and sheared to the fracture limit during sliding. It is speculated that the release of elastic energy during fracture propagates through the surface structure at the speed of sound and causes rapid changes in contact resistance. An analysis of the microstructure was conducted and indicates this mechanism is theoretically possible. Moreover, data are provided that show incremental changes in normal force can cause counter intuitive changes in resistance. This data shows large changes occur during loading and unloading and it's believed these changes are the result of micro rocking that's induced by the step loading system. It is estimated the distances covered by rocking range from a few to tens of microns and the large changes in resistance are thought to result from making and breaking cold-welded asperities. In addition, this data suggests that a static contact resistance threshold for discontinuities exist around the 100 mΩ level. This is in agreement with other authors and lends credibility to the use of static contact resistance as a measure of contact stability     

Ad hoc网络中基于多径路由协议的信誉机制

基于多径路由协议,采用RS编码技术,设计了一种将数据信息编码后分片沿不同路径传输的方法,在目的节点对恶意篡改行为进行检测,确定恶意节点的具体位置或将恶意节点锁定在恶意节点组内.在此基础上提出了一个完整的抵制篡改数据攻击的信誉机制,充分利用了从数据传输和恶意节点检测过程中获得的信息,采用简单贝叶斯模型方法,对节点进行信誉评价,引入了恶意节点组的概念.数据在正常传输过程中无需重复加密和签名.实验表明,该信誉机制能够有机地与多径路由协议相结合,快速准确地孤立篡改数据的恶意节点.     

CNKI网格知识资源组织与开发

国家知识基础设施(nationai knowiedge infrastructure NKI)的概念，由世界银行提出于1998年。CNKI工程是以实现全社会知识资源传播共享与增值利用为目标的信息化建设项目，由清华大学、清华同方发起，始建于1999年6月。在党和国家领导以及教育部、中宣部、科技部、新闻出版总署、国家版权局、国家纪委大大力支持下，在全国学术界、教育界、出版界、图书情报界等社会各界的密切配合和清华大学的直接领导下，CNKI工程集团经过多年努力，采用自主开发并具有国际领先水平的数字图书馆技术，