Web服务动态协同组合研究
发布时间：2018-07-22 16:05
【摘要】：在互联网技术和计算机技术迅猛发展的时代,Web服务及其组合技术在学术界和工业界都得到了迅猛发展,作为开放式的业务提供方式得到广泛承认。Web服务有着极好的平台无关性、互通性和复用性,为了满足用户需求,服务推荐和服务组合的方法迅速出现。但是这些过程中服务都只能等待第三方调用后才能发挥作用,服务数量的增多,使得很多服务长期未被调用。软件Agent有着主动、自治和进化等特性,可以获取第三方的需求信息,向其推荐自身,在组成多Agent系统后利用协同技术可以实现更强的功能。但是它却没有web服务的那种平台无关性、互通性和灵活性。为了让服务本身具有智能性,得到智能的web服务和可以协同的服务组合算法,并验证服务的组合效率和组合成功率。将Agent与web服务结合,服务抓取网络中已有的用户需求信息,实时地、主动地向服务请求者推荐自身。抛弃处理静态请求的平台Jack和Jadex,选用Jade平台来处理动态组合。Agent封装后的服务采用基于偏好的离线部分可观测马尔科夫决策服务组合算法(PBOL_POMDP)和启发式的在线部分可观测马尔科夫决策服务组合算法(HO_POMDP)能高效、独立地完成服务组合的过程,并将结果返回服务调用者。将求解结果与经典AEMS2算法和引文中OPUMO1算法比较,验证了算法性能。基于此,本文做了如下工作： (1)引入Agent扩展web服务,将互联网中web服务组合模型扩展为多Agent动态协同服务组合系统,总结基于多Agent系统的动态协同的两层功能结构,给出执行服务组合的动态协同服务组合系统框架,对比了传统的两层框架和扩展后的多Agent动态协同组合的两层框架,组合过程完全由一些参与组合的服务Agent协同完成,保障服务组合的效率及准确率。 (2)首先,区分基础服务、结构化服务和非结构化服务。因为利用离线POMDP算法在全局范围搜索组合策略,虽然搜索全面但搜索耗时。本文采用PBOL_POMDP解决基础服务到结构化服务的组合过程,引入偏好信息的离线POMDP算法,既处理了全局的最优规划问题,也增大了搜索的目的性,大大减小了搜索耗费的时间,在长期偏好和中期偏好没有变化之前,搜索结果作为重要的数据信息保存下来。 (3)在传统在线POMDP算法之上,为了求解需求功能复杂的服务组合,将离线算法得到的解集合的上下界作为在线算法的启发式信息,进一步应用到在线算法中。采用HO_POMDP服务组合算法解决基础服务与前一步生成的所有服务之间的组合。 (4)搭建实验环境,将MADC_SCS框架和服务组合过程用JADE平台模拟出来,将自己部署的简单服务封装实验,将离线和在线POMDP算法扩展后应用到服务的动态协同组合过程中,有效地改善了服务组合的成功率和时耗特性。
[Abstract]:In the era of rapid development of Internet technology and computer technology, Web services and their composition technologies have developed rapidly in both academia and industry. As an open mode of business delivery, Web services have been widely recognized as having excellent platform independence. In order to meet the needs of users, the methods of service recommendation and service composition appear rapidly. But in these processes, the services can only wait for the third party to call, and the number of services increases, making many services have not been invoked for a long time. The software Agent has the characteristics of initiative, autonomy and evolution, it can obtain the third party's requirement information, recommend itself to it, and make use of the cooperative technology to realize stronger function after making up the multi-Agent system. But it doesn't have the platform independence, interoperability, and flexibility that web services do. In order to make the service itself intelligent, the intelligent web service and the cooperative service composition algorithm are obtained, and the composition efficiency and the composition success rate of the service are verified. By combining Agent with web services, the service grabs the information of the users' needs in the network, and recommends itself to the service requesters in real time and actively. The Jade platform is used to deal with the dynamic composition. Agent encapsulated services using the preference based offline observable Markov decision Service composition algorithm (PBOLSP) and the heuristic online part. Observe that the Markov decision Service composition algorithm (HOSP) is efficient, Independently completes the process of service composition and returns the result to the service caller. The results are compared with the classical AEMS2 algorithm and the OPUMO1 algorithm in the citation, and the performance of the algorithm is verified. Based on this, this paper has done the following work: (1) introduce Agent to extend web services, extend the web service composition model in the Internet to multi-Agent dynamic cooperative service composition system, summarize the two-tier function structure of dynamic collaboration based on multi-Agent system. The framework of dynamic cooperative service composition system for performing service composition is presented. The traditional two-tier framework and the extended two-tier framework of multi-Agent dynamic cooperative composition are compared. The composition process is completed entirely by some participating service Agent cooperation. Ensure the efficiency and accuracy of service composition. (2) first, distinguish between basic services, structured services and unstructured services. Because offline POMDP algorithm is used to search the combination strategy in the global scope, the search is comprehensive but time-consuming. In this paper, PBOLPOMDP is used to solve the composition process from basic services to structured services, and an off-line POMDP algorithm with preference information is introduced. It not only deals with the global optimal programming problem, but also increases the purpose of search, and greatly reduces the time spent in searching. Search results are preserved as important data information before long-term and medium-term preferences have not changed. (3) in order to solve the complex service composition with complex requirements, search results are saved on the basis of traditional online POMDP algorithm. The upper and lower bound of the solution set obtained by the offline algorithm is regarded as the heuristic information of the online algorithm, which is further applied to the online algorithm. The HOP-POMDP service composition algorithm is used to solve the composition between the basic services and all the services generated in the previous step. (4) the experimental environment is built, and the MADCSCS framework and service composition process are simulated by Jade platform. The self-deployed simple service encapsulation experiment is applied to the dynamic cooperative composition process of services by extending the offline and online POMDP algorithms. The success rate and time-consuming characteristics of service composition are improved effectively.
【学位授予单位】：陕西师范大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP393.09
本文编号：2138000
[Abstract]:In the era of rapid development of Internet technology and computer technology, Web services and their composition technologies have developed rapidly in both academia and industry. As an open mode of business delivery, Web services have been widely recognized as having excellent platform independence. In order to meet the needs of users, the methods of service recommendation and service composition appear rapidly. But in these processes, the services can only wait for the third party to call, and the number of services increases, making many services have not been invoked for a long time. The software Agent has the characteristics of initiative, autonomy and evolution, it can obtain the third party's requirement information, recommend itself to it, and make use of the cooperative technology to realize stronger function after making up the multi-Agent system. But it doesn't have the platform independence, interoperability, and flexibility that web services do. In order to make the service itself intelligent, the intelligent web service and the cooperative service composition algorithm are obtained, and the composition efficiency and the composition success rate of the service are verified. By combining Agent with web services, the service grabs the information of the users' needs in the network, and recommends itself to the service requesters in real time and actively. The Jade platform is used to deal with the dynamic composition. Agent encapsulated services using the preference based offline observable Markov decision Service composition algorithm (PBOLSP) and the heuristic online part. Observe that the Markov decision Service composition algorithm (HOSP) is efficient, Independently completes the process of service composition and returns the result to the service caller. The results are compared with the classical AEMS2 algorithm and the OPUMO1 algorithm in the citation, and the performance of the algorithm is verified. Based on this, this paper has done the following work: (1) introduce Agent to extend web services, extend the web service composition model in the Internet to multi-Agent dynamic cooperative service composition system, summarize the two-tier function structure of dynamic collaboration based on multi-Agent system. The framework of dynamic cooperative service composition system for performing service composition is presented. The traditional two-tier framework and the extended two-tier framework of multi-Agent dynamic cooperative composition are compared. The composition process is completed entirely by some participating service Agent cooperation. Ensure the efficiency and accuracy of service composition. (2) first, distinguish between basic services, structured services and unstructured services. Because offline POMDP algorithm is used to search the combination strategy in the global scope, the search is comprehensive but time-consuming. In this paper, PBOLPOMDP is used to solve the composition process from basic services to structured services, and an off-line POMDP algorithm with preference information is introduced. It not only deals with the global optimal programming problem, but also increases the purpose of search, and greatly reduces the time spent in searching. Search results are preserved as important data information before long-term and medium-term preferences have not changed. (3) in order to solve the complex service composition with complex requirements, search results are saved on the basis of traditional online POMDP algorithm. The upper and lower bound of the solution set obtained by the offline algorithm is regarded as the heuristic information of the online algorithm, which is further applied to the online algorithm. The HOP-POMDP service composition algorithm is used to solve the composition between the basic services and all the services generated in the previous step. (4) the experimental environment is built, and the MADCSCS framework and service composition process are simulated by Jade platform. The self-deployed simple service encapsulation experiment is applied to the dynamic cooperative composition process of services by extending the offline and online POMDP algorithms. The success rate and time-consuming characteristics of service composition are improved effectively.
【学位授予单位】：陕西师范大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP393.09
【参考文献】
相关期刊论文 前2条
1 章宗长;陈小平;;杂合启发式在线POMDP规划[J];软件学报;2013年07期
2 桂林;武小悦;;部分可观测马尔可夫决策过程算法综述[J];系统工程与电子技术;2008年06期
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