The OWL
Semantic Web As proposed by Tim Berners-Lee in his original paper, the Semantic Web should be a new generation of World Wide Web in which information is given a computer understandable well-defined meaning (semantics), thus enabling a wide range of intelligent services such as search agents, information filters etc. As a consequence, using this semantics, or metadata, it will be possible, e.g., to perform search of Web resources by content rather than just by keywords. A significant step in this direction is the development of a new generation of Web markup languages such as Web Ontology Language (OWL) and its predecessor DAML+OIL.
Semantic Web Services Among the most important Web resources are those that provide services, i.e. not merely present static information but allow a human or a computer agent to effect some action (to process information, buy a product or control a physical device). The aim of researches into Semantic Web Services is to provide enabling infrastructure for e-Science, e-commerce and other Web applications by automating access to Web services. In particular, the objective is to automate the process of discovering and using services in order to perform a given task, and of composing multiple services in order to perform more complex tasks.
Dynamic Ontologies for Services Like the Description Logics on which they are based, languages such as DAML+OIL and OWL have limited expressive power. From the point of view of describing services, these restrictions are rather severe. In particular, they can only describe static aspects of the world, since they have no notion of time and change. One of approaches to overcome these limitations is the Web Services Ontology Language (OWL-S, formerly DAML-S) which is currently being developed as a part of the DAML program. This new Web markup language is expected to provide a computer-interpretable description for services and enable users and software agents to discover, invoke, compose, and monitor Web resources offering particular services.
A principled extension of Web ontology languages to represent and reason about dynamic situations first requires an extension of the underlying description logics on which they are based. The goal of this project is to develop a logical basis for a dynamic ontology language that is fully compatible with current, standard static ontology languages and provides the necessary expressive power for the structured representation of e-Science services. We propose to do this by extending existing description logics with the notions of time (both quantitative and qualitative), and change. Most importantly, we will specify and investigate inference problems that are well-suited to serve as a basis for reasoning systems to support the description and use of Web-services.