Seminář: Semantic Web Services: Research, Application and Standardization

Web services add a new level of functionality to the Web, stepping towards an open environment of distributed and heterogeneous applications. While current Web service technologies around SOAP, WSDL and UDDI have established the potential of a Web of services, they are hindered by dependence on XML-only descriptions. Without machine-understandable semantics, services must be located and bound to service requesters at design-time, limiting possibilities for automation. In order to address this drawback, initiatives around Web Service Modelling Ontology (WSMO)[1], OWL-S[2] and WSDL-S[3] aim to define a new layer on top of current Web service stack based on semantic mark-up for functional, non-functional and behavioural aspects of services descriptions. In particular, WSMO is the initiative driven by DERI which provides a conceptual model describing all relevant aspects of Web services. The description of WSMO elements is represented using the Web Service modelling Language (WSML) – a family of ontology languages – which consists of a number of variants based on different logical formalisms and different levels of logical expressiveness. WSMO and WSML thus provides grounds for semantic modelling of services as well as for Semantic Service Oriented Architectures with reference implementation called WSMX[9]. This technology is being evaluated and verified in a number of application-oriented research projects in both intra- and inter-enterprise integration settings including e-business[4, 5], e-government[10], e-health and telecommunications[6]. In order to bring the Semantic Web Service technology to its full-potential, efforts around W3C Semantic Annotation for WSDL (SAWSDL)[8] and OASIS Semantic Execution Environment Technical Committee (SEETC)[7] aim to standardize several aspects of WSMO and promote this way research prototypes to technology of industry-strength. [1] http://www.wsmo.org/TR/d2/v1.3/ [2] http://www.w3.org/Submission/OWL-S/ [3] http://www.w3.org/Submission/WSDL-S/ [4] http://www.vitvar.com/tomas/!publications/icsoc2006-WSMX.pdf [5] http://www.vitvar.com/tomas/!publications/ESWC2007-VitvarZM.pdf [6] http://www.vitvar.com/tomas/!publications/vitvar053.pdf [7] http://www.oasis-open.org/committees/semantic-ex [8] http://www.w3.org/2002/ws/sawsdl/ [9] http://www.wsmx.org [10] http://www.semantic-gov.org