Task Processing Language for Semantic Web Servicing

Abstract

Local variables, the scope, and data flow from inputs of Web Services to outputs are introduced into the OWL-S 1.1 specification. However, these new features are not useful for agents to discover and compose Web Services. Agents must know the meanings of services through interpreting service parameters, i.e., inputs, outputs, preconditions, and effects (IOPEs). The subsumption of IOPEs helps agents to obtain the meanings, but understanding local variables and the scope is intricate for agents. The scope of variables and data flow is not what agents interpret but what agents generate as a result of web composing. Furthermore, it is very laborious for ones to describe tasks with the OWL-S expression. Therefore, based on Scheme and SWCLOS, a Semantic Web processor on top of CLOS, we design a task language that describes tasks and executed by agents. A task is captured as an ensemble of service, simple process, and complex process or atomic processes in OWL-S. Agents can obtain the meanings of services with subsumption of IOPEs of tasks, and composes them in order to accomplish given goals. Agents may perform those tasks directly, or may compile the task expressions into pieces of OWL-S code that includes descriptions of local variables and the scope.