Dynamic Description Logics Based Semantic Web Services Composition

摘要

The automatic Web services composition has been a research focus since an ever-increasing numbers of Web services are created and published. In this paper, we present a dynamic description logics (DDLs) based method for automatic Web services composition. DDLs are an extension of description logic with a dynamic dimension. It adds actions expressions into description logic and makes up a set of reasoning mechanism for action expressions. The DDLs reasoner has been built for DDLs formulas. As an Web service can be regarded as an action in Web, its accomplishment changes the state of Web, from original state to aim state, an Web service can be described as an action in DDLs, which this action can be described in terms of formulas in DDLs. Due to these relations between Web service and DDLs actions, our method describes both the goal service and atomic services in terms of DDLs formulas. We proved that if a goal formula can not be satisfied then the services composition can be found. The procedure of checking the satisfiability of the formula is also the procedure of discovering the services composition. Thus the problem of automatic services composition is reduced to the problem of checking the satisfiability of formulas in DDLs. An example of automatic services composition in travel area shows the effectiveness of our method.