As web services become more prevalent, tools will be needed to help users find, filter and integrate these services. Composing existing services to obtain new functionality will prove to be essential for both business-to-business and business-to-consumer applications. We have developed a prototype that guides a user in the dynamic composition of web services. Our semi-automatic process includes presenting matching services to the user at each step of a composition, filtering the possibilities by using semantic descriptions of the services. The generated composition is then directly executable through the WSDL grounding of the services. We tested our system by generating semantic descriptions for some of the common services available on the web such as translator, dictionary and map services. We also applied our approach to a prototype sensor network environment where each sensor provides its data as a network service.

Systems and infrastructures are currently being developed to support Web services. The main idea is to encapsulate an organization’s functionality within an appropriate interface and advertise it as Web services. While in some cases Web services may be utilized in an isolated form, it is normal to expect Web services to be integrated as part of workflow processes. The composition of workflow processes that model e-service applications differs from the design of traditional workflows, in terms of the number of tasks (Web services) available to the composition process, in their heterogeneity, and in their autonomy. Therefore, two problems need to be solved: how to efficiently discover Web services – based on functional and operational requirements – and how to facilitate the interoperability of heterogeneous Web services. In this paper, we present a solution within the context of the emerging Semantic Web, that includes use of ontologies to overcome some of the problems. We start by illustrating the steps involved in the composition of a workflow. Two of these steps are the discovery of Web services and their posterior integration into a workflow. To assist designers with those two steps, we have devised an algorithm to simultaneously discover Web services and resolve heterogeneity among their interfaces and the workflow host. Finally, we describe a prototype that has been implemented to illustrate how discovery and interoperability functions are achieved.

In this paper we present DAML-S, a DAML+OIL ontology for describing the properties and capabilities of Web Services. Web Services -- Web-accessible programs and devices -- are garnering a great deal of interest from industry, and standards are emerging for low-level descriptions of Web Services. DAML-S complements this effort by providing Web Service descriptions at the application layer, describing what a service can do, and not just how it does it. In this paper we describe three aspects of our ontology: the service profile, the process model, and the service grounding. The paper focuses on the grounding, which connects our ontology with low-level XML-based descriptions of Web Services.

Abstract. Service interface description languages such as WSDL, and related standards, are evolving rapidly to provide a foundation for interoperation between Web services. At the same time, Semantic Web service technologies, such as the Ontology Web Language for Services (OWL-S), are developing the means by which services can be given richer semantic specifications. Richer semantics can enable fuller, more flexible automation of service provision and use, and support the construction of more powerful tools and methodologies. Both sets of technologies can benefit from complementary uses and crossfertilization of ideas. This paper shows how to use OWL-S in conjunction with Web service standards, and explains and illustrates the value added by the semantics expressed in OWL-S. 1

More and more resources are becoming available on the Web, and there is a growing need for infrastructures that, based on advertised descriptions, are able to semantically match demands with supplies. We formalize general properties a matchmaker should have, then we present a matchmaking facilitator, compliant with desired properties. The system embeds a NeoClassic reasoner, whose structural subsumption algorithm has been modified to allow match categorization into potential and partial, and ranking of matches within categories. Experiments carried out show the good correspondence between users and system rankings.

The growing infrastructure for Web Services assumes a "programmer in the loop" that hardcodes the connections between Web Services and directly programs Web Service composition. Emerging technology based on DAML-S and the Semantic Web allows Web Services to connect and transact automatically with minimal or no intervention from programmers. In this paper we discuss the problems related with autonomous Web Services, and how DAMLS provides the information to solve them. Furthermore, we describe the implementation of two demonstration systems that use such technology: the first system is a B2B application in which a business that assembles computers automatically finds partners providing parts and automatically transacts with them; the second describes is an e-commerce application that helps a user to organize a trip to a meeting automatically interacting with different Web Services and the calendar of the user stored in MS Outlook. The results of these experiments show how Web Services can be deployed on the Web to interact and provide information dynamically; second, how the transaction can be carried on automatically with no programmer intervention.

semantic web, web services, architecture, agents This paper is an extended version of one presented at the International Semantic Web Conference, 2004. In it, we present an abstract conceptual architecture for semantic web services. We define requirements on the architecture by analyzing a set of case studies developed as part of the EU Semantic Web-enabled Web Services project. The architecture is developed as a refinement and extension of the W3C Web Services Architecture. We assess our architecture against the requirements, and provide an analysis of OWL-S.

Motivated by the matchmaking problem in electronic marketplaces, we study abduction in Description Logics. We devise suitable definitions of the problem, and show how they can model commonsense reasoning usually employed in analyzing classified announcements having a standardized terminology. We then describe a system partially implementing these ideas, and present a simple experiment, which shows the correspondence between the system behavior with human users judgement.

Abstract. The automatic location of services that fulfill a given need is seen as a key step towards dynamic and scalable integration. In this paper we present a model for the automatic location of services that considers the static and dynamic aspects of service descriptions and identifies what notions of match and techniques are useful for the matching of both. Our model presents three important features: ease of use for the requester, efficient pre-filtering of relevant services, and accurate contracting of services that fulfill a given requester goal. We further elaborate previous work and results on Web service discovery by analyzing what steps and what kind of descriptions are necessary for an efficient and usable automatic service location. Furthermore, we analyze the intuitive and formal notions of match that are of interest for locating services that fulfill a given goal. Although having a formal underpinning, the proposed model does not impose any restrictions on how to implement it for specific applications, but proposes some useful formalisms for providing such implementation. 1

Abstract. Web services are in the midst of making the transition from being a promising technology to being widely used in the industry. However, most efforts to use Web services have been manual, thus slowing down the ever changing and dynamic businesses of today. In this paper, we contend that more expressive descriptions of Web services will lead to greater automation and thus provide more agility to businesses. We present the METEOR-S frontend tools for source code annotation and semantic Web service description generation. We also present WSDL-S, a language created for incorporating semantic descriptions in the industry wide accepted WSDL, by extending WSDL 2.0. 1.