【作者】 程洁；

【导师】 饶若楠；

【作者基本信息】 上海交通大学 ， 计算机软件与理论， 2009， 硕士

【摘要】 随着计算机网络,传感器网络和移动设备的发展,普适计算得到了越来越多的关注和研究,基于普适计算的应用也越来越多。为了保证以服务为单位的应用程序执行的可靠性,需要考虑在服务组合和执行层面上的事务模型和上下文感知的事务管理。本文在总结服务组合技术和事务模型及现有规范基础上,结合普适环境自身的限制及其服务的特点,研究和设计一种普适环境下的服务层的事务模型,进而得出可靠服务组合中间件框架,用来保证服务的可靠性。主要研究分为以下几个方面:1.对服务组合的现有技术进行了分析和研究,参考相关的规范和协议,对事务模型和web service已有的事务规范进行了分析。在普适环境下的树状分层服务模型基础上,研究了适合于普适环境特性的事务模型。2.参考现有的上下文描述和推理技术,对上下文进行描述、建模和推理,向普适环境下的组合服务执行引擎传递上下文信息,以实现上下文感知的事务管理。3.在上述事务模型和实现上下文感知的基础上,设计了一种普适环境下的可靠服务组合中间件,完成了整体架构和各个功能模块设计。并实现了中间件原型系统。在普适计算环境下,事务模型大都是在数据流及其管理层面的。而随着研究的深入,SOA架构也被应用到普适计算环境中,设备可以被包装成服务和web服务组合起来共同完成任务。不论是原有的分布式事务还是web服务的事务模型都不能够完全满足普适环境下上下文感知和设备服务的动态加入或者退出计算的特性。本文针对这些特点,在分层设计服务层面上设计的事务模型在一定程度上解决了上述问题。通过系统原型实现的中间件系统在典型场景下能够达到预期目标。更多还原

【Abstract】 Along with the development of computer network, sensor network and mobile technology, pervasive computing gets more and more spotlights and people are more and more interested in applications in this area. In order to ensure the reliability of applications based on units of service, we need transaction model for service composition and executing as well as the context-aware transaction management. This paper concentrates the research and design of transaction model for service composition in pervasive computing taking the limitation and features of pervasive computing into consideration. We also design a middleware framework on the base of the model research.This paper mainly is divided into several parts:Referring to existing service composition technology, specification and protocols, the paper analysis the distribute transaction and web service transaction methods and design the transaction model suit for features of pervasive computing.This paper then describes the way to manipulate context message to realize context-aware feature by reasoning the context as well as describing and modeling.On the base of the above work, the middleware for reliable service composition in pervasive environment is designed. The paper has described the framework architecture and functional modules which is followed by the implementation.In pervasive computing environment, the existing work of transaction focuses on the data level. According to the development of research on pervasive computing using SOA architecture, devices can be encapsulated into services and can be combined together to accomplish tasks. But the original distributing transaction and the web service transaction both don’t meet the requirement of pervasive computing which means that devices and services can dynamically enter or exit the computing and they are context-aware. In this paper, the transaction model build upon the layered-architecture of service model can partly solve those problems. The implementation is also talked in detail.更多还原