文摘
Recently, the workflow systems such as uFlow and FollowMe adopt workflow models to support context-aware services in ubiquitous computing environments. A service in the ubiquitous computing environments must be executed according to a user’s situation information, which is generated dynamically from sensors. However, the existing workflow systems use such workflow languages as uWDL, BPEL and XLANG, which are not yet enough to support context-aware services in ubiquitous computing environments. In this paper, we propose a new workflow language and a workflow system for context-aware workflow services in ubiquitous computing environments. With the suggested workflow language and the workflow system, a user can describe contexts into workflow as service transition conditions and can apply changes of user’s service demand or situation information into an on-going workflow without interrupting or deleting workflow service. In order to verify the efficiency of the suggested language and system, we design a workflow scenario for context-aware services with the language and simulate a process that the proposed system changes dynamically contexts described in a workflow against changes of user’s situation information.