一种基于Petri网的分布组件协调模型

协调是分布组件系统中的基本问题之一.但是,协调问题至今仍未得到很好的解决.根据实际应用的要求,提出了Concerto协调模型.它以Petri网为数学理论基础,扩充了Petri网的语义,引入了控制缓存和数据缓存,分别反映了分布组件的控制依赖和数据依赖关系,统一了现有的控制驱动和数据驱动两类协调模型.对于Concerto模型的运行,提出了驱动模式、动作规则和Concerto引擎.驱动模式有4种:依赖操作时间的驱动、依赖最小时间的驱动、依赖最大时间的驱动和依赖平均时间的驱动.这些驱动模式在实时系统、流量控制和任     

可视化分布组件协调环境

分布组件的协调是基于组件的分布系统开发中的一个基本问题。针对具体应用,提出了一种分布组件协调模型－－Ｃｏｎｃｅｒｔｏ。Ｃｏｎｃｅｒｔｏ模型以Ｐｅｔｒｉ网为理论基础,综合了现有的控制驱动和数据驱动两类协调模型。Ｐｅｔｒｉ网的变迁与分布组件系统中的事件、条件、操作和时间信息结合起来,提供了与计算机系统交互的方法。在Ｃｏｎｃｅｒｔｏ模型基础上,实现了可视化分布组件协调环境,对分布组件系统进行并发死锁验证     

对称协调博弈问题的多智能体强化学习

针对多机器人协调问题,利用协调博弈中智能体策略相似性,提出智能体的高阶信念修正模型和学习方法PEL,使智能体站在对手角度进行换位推理,进而根据信念修正将客观观察行为和主观信念推理结合起来。证明了信念修正模型的推理置信度只在0和1两个值上调整即可协调成功。以多机器人避碰为实验背景进行仿真,表明算法比现有方法能够取得更好的协调性能。     

Web服务组合事务处理研究与实现

通过重用已有的服务进行服务组合来实现应用集成;而保证服务组合的事务特性是实现服务组合的关键。文中提出一个Web服务组合事务处理模型,将BPEL (Business Process Execution Language,业务流程执行语言)的流程设计与WS-C/T (Web Services Coordination/Transaction,Web服务协调/事务)规范结合。该模型主要由客户端、BPEL执行引擎、事务协调器和参与者四个部分组成。客户端发起请求,BPEL执行引擎响应请求并开启事务,事务协调器和参与者根据事务协调算法完成事务协调。     

Web服务组合事务处理研究与实现

通过重用已有的服务进行服务组合来实现应用集成;而保证服务组合的事务特性是实现服务组合的关键。文中提出一个Web服务组合事务处理模型,将BPEL（Business Process Execution Language,业务流程执行语言）的流程设计与WS—C／T（Web Services Coordination/Transaction, Web服务协调／事务）规范结合。该模型主要由客户端、BPEL执行引擎、事务协调器和参与者四个部分组成。客户端发起请求,BPEL执行引擎响应请求并开启事务,事务协调器和参与者根据事务协调算法完成事务协调。     

基于二维协调空间的网格工作流调度算法研究

传统的网格工作流模型中分布式工作流管理器之间没有合作,因此可能发生源调度冲突问题,另外,在现有的工作流调度算法中,参与工作流调度的工作流管理器依托于集中或半集中的层次式的资源信息服务体系,导致系统的扩展性差.为了解决这些问题,在文中,提出了一个分布式的协同工作流调度算法.该算法基于二维协调空间来管理网格中的工作流管理器.二维协调空间负责资源发现和协调调度等功能.该算法不仅可以避免性能瓶颈,而且可以增强系统的可扩展性和自主性.     

基于BTP的Web服务事务协调研究与实现

Web服务技术为异构应用之间的集成和互操作提供了有效的解决手段。目前的Web服务还缺乏全局的事务环境,传统的事务模型不再适用于新的Web环境下的要求。针对Web服务中事务处理的协调问题,分析现有的事务处理模型和协议,设计实现了一个基于BTP协议的Web服务事务原型系统,把用于Web服务事务处理的BTP协议和用于传统事务的两阶段提交协议相结合来协调Web服务中的事务。通过运行应用实例,验证了原型系统的可行性,该系统具备协调短期事务与长事务的能力。     

MAS构建中的主观协调和客观协调研究

文章对MAS中协调的概念进行了分析,提出了MAS中同时存在主观协调和客观协调的观点。以两个agent堆积木块为例,阐释了主观协调和客观协调的本质区别。根据主观协调和客观协调对MAS构建的影响,结合对JAFMAS平台的分析,提出可以建立主观协调模型到本地模型、客观协调模型到社会模型的映射,从而提高基于JAFMAS平台开发MAS应用的效率。     

企业智能化Web商务数据挖掘引擎算法设计与实现

针对现有的数据挖掘引擎难以满足企业不断增长的需求的问题,在传统搜索引擎的基础上提出了一种企业专用的智能化Web商务数据挖掘引擎.从总体上给出了模型框架,得出企业智能化Web商务数据挖掘引擎是一个基于多模型的系统的结论.接着分别详细研究了该引擎的:Web内容挖掘、Web信息获取、客户行为挖掘3个核心模块.并给出了3个模块的详细算法设计和实现过程     

联合更换策略的机会性Lagrangian松弛方法

零部件的联合更换是通过协调不同零部件的更换决策使其尽可能共享资源以节约费用的优化问题. 这类随机组合策略优化问题在实际中大量存在,对生产生活的经济性起着重要影响. 由于随机因素和组合效应,其有限阶段的策略求解非常困难. 本文针对飞机引擎维护中的零部件联合更换问题,利用问题中随机耦合约束的特征, 给出了一个可分解的模型及相应的分解协调方法机会性Lagrangian松弛(Opportunistic Lagrangian relaxation, OLR). 与现有的两种利用先验最优策略规则的方法相比, OLR方法可在无先验知识的情况下直接得到更佳的协调效果.     

供应链协调的仿真建模方法研究综述*

分析了用仿真建模方法解决供应链管理中协调问题的研究现状及趋势。在介绍国内外供应链协调模型研究现状的基础上,从计算机仿真建模的技术特点、工具和方法等方面着手,归纳、分析和比较了集中式仿真、多代理仿真、分布式仿真和HLA仿真等方法在建立供应链协调模型的研究状况,最后指出了用仿真建模方法解决供应链协调问题的研究前景及发展趋势。     

Coordination policies to support decision making in distributed production planning

Distributed production networks are considered organizational structures able to match agility and efficiency necessary to compete in the global market. Performances of such organization structures heavily depend on the ability of the network actors of coordinating their activities. The research proposes to model and design coordination problems within production network by using the Multiple Agent Technology. In particular, the paper proposes new strategies for coordinating production-planning activities within production networks. Such models have been developed and tested by using a proper simulation environment developed by using open source code and architecture.

The results of the research can be located at two levels: (a) concerning the specific coordination problem addressed, the research provides some insights to make decisions about the choice of coordination approaches to be used in distributed production planning problems; (b) at more strategic level, the paper shows how Agent Technology and discrete event simulation can be used to build up efficient coordination structures for production networks.     

Coordination and control for energy distribution in distributed grid networks: Theory and application to power dispatch problem

This paper presents a new framework considering decentralized energy coordination and generation, and flow control for supply–demand balance in distributed grid networks. Consensus schemes using only local information are employed to produce energy coordination, generation, and flow control signals. For the supply–demand balance, it is required to determine the amount of energy needed at each distributed resource. Also, due to the different generation capacities of each energy resource, coordination of energy flows among distributed energy resources is essentially required. Thus, this paper proposes a new framework which gives decentralized energy coordination scheme, generation, and flow control method considering these constraints based on distributed consensus algorithms. The proposed framework in this paper can be nicely utilized in energy dispatch or energy flow scheduling. Furthermore, it can be applied to various engineering problems including water irrigation systems, traffic networks, and building automation systems since it deals with attributed distribution and resource allocation in large scale distributed systems. Through illustrative examples, the effectiveness of the proposed approaches is illustrated. A possible application to power dispatch problem in the IEEE-14bus is also addressed for more detailed and realistic evaluation.     

Web search engine based on DNS

Now no web search engine can cover more than 60% of all the pages on Internet. The update interval of most pages database is almost one month. This condition has not changed for many years. Coverage and update problems have become the bottleneck problem of current web search engine. To solve these problems, a new system, search engine based on DNS is proposed in this paper. This system adopts the layered distributed architecture like DNS, which is different from any current commercial search engine. In theory, this system can cover all the web pages on Internet. Its update interval could even be one day. The original idea, detailed content and implementation of this system all are introduced in this paper.     

元搜索引擎在油田领域信息分布式搜索的应用

当前大型集中式企业搜索引擎面临规模扩展、数据更新快速和用户需求专业化、多样化等一系列挑战。因此,在整个油田内建立一个高效、高质量的分布式搜索引擎体系架构,并保证不破坏各公司原有企业搜索引擎的基础之上,实现数据共享变得越来越重要。通过分析油田内部公司搜索引擎现状,结合元搜索引擎技术,提出构建一个合理的油田内部分布式搜索引擎体系架构的解决方案。主要从接口规范,查询调度,排序策略三个方面入手,解决分布式搜索引擎在油田应用查询中存在的问题。     

一种建立电子商务规则的协调模型

电子商务环境主要依托于Internet，涉及分布执行、多用户交互访问，中间件的使用等诸多问题，因此电子商务环境中的构件同CSCW、群件或工作流管理系统中的一样具有通信、合作、协调等特性，SIKA是作者开发的一种协调模型，介绍了其在建立电子商务规则中的应用，并且论述了这种方法的优点。     

基于工作流管理方式的应用协作模块分析与设计

ＣＩＭＳ应用集成平台是企业实施ＣＩＭＳ的有效支持工具。应用协作模块是ＣＩＭＳ集成平台的重要组成部分。它可以提高企业实施的ＣＩＭＳ的柔性和应变能力。文章主要研究了在工作流管理方法的支持下,利用面向对象的技术,进行应用协作模块总体设计的方法,定义了应用协作系统的体系结构、需求模型和分析模型,给出了应用协作的连接关系和工作流机组织方式。并讨论了应用协作模块在实现过程中的一些关键技术问题及其解决办法。     

Collaboration and knowledge sharing in network organizations

A network organization comprises a new type of environment around which people organize themselves so as to reach a common objective. A network organization enables the recommended interaction among people with different backgrounds, which happens when the problems they deal with are complex and multidisciplinary. Most network organizations require interactions in a geographically distributed fashion, fostering the serious challenge of displaying coherence of purpose necessary for global efficacy as from local activity: these features require an environment with special functionality. This paper describes and analyzes a collaborative environment for support to knowledge sharing and coordination of actions in geographically distributed network organizations. A case-study using the collaborative environment is presented, and the results obtained by using this environment are discussed.     

Checking sequences for distributed test architectures

Controllability and observability problems may manifest themselves during the application of a checking sequence in a test architecture where there are multiple remote testers. These problems often require the use of external coordination message exchanges among testers during testing. However, the use of coordination messages requires the existence of an external network that can increase the cost of testing and can be difficult to implement. In addition, the use of coordination messages introduces delays and this can cause problems where there are timing constraints. Thus, sometimes it is desired to construct a checking sequence from the specification of the system under test that will be free from controllability and observability problems without requiring the use of external coordination message exchanges. This paper gives conditions under which it is possible to produce such a checking sequence, using multiple distinguishing sequences, and an algorithm that achieves this.