Abstract. Semantic annotations of web services can facilitate the discovery of services, as well as their composition into workflows. At present, however, the practical utility of such annotations is limited by the small number of service annotations available for general use. Resources for manual annotation are scarce, and therefore some means is required by which services can be automatically (or semi-automatically) annotated. In this paper, we show how information can be inferred about the semantics of operation parameters based on their connections to other (annotated) operation parameters within tried-and-tested workflows. In an open-world context, we can infer only constraints on the semantics of parameters, but these loose annotations are still of value in detecting errors within workflows, annotations and ontologies, as well as in simplifying the manual annotation task. 1

Abstract. Automatizing the Web Service Discovery is crucial for truly implementing a Service Oriented Architecture. Semantics has been shown to be useful. Several initiative, namely OWL-S, WSMO and WSDL-S, are successfully employing ontologies, but we believe that WSMO is right in highlighting mediation as the missing element. In this paper we provide a mediator centric re nement of the conceptual model for WSMO discovery and the related architecture as well as the prototypical implementation (named Glue) we are using in the projects COCOON and Nomadic Media. 1

With the expectable growth of the number of Web services available on the WWW and service repositories, the need for mechanisms that enable the automatic organization and discovery of services becomes increasingly important. Service classification using standard or proprietary taxonomies is a common and simple facility in this context, complementarily to more sophisticated service management retrieval techniques. In this paper we propose a heuristic approach for the semi-automatic classification of Web services, based on a three-level matching procedure between services and classification categories, assuming a corpus of previously classified services is available. An experimental test of the proposed techniques is reported, showing positive results.

In this work we propose a two-step, context-based semantic approach to the problem of matching and ranking web services for possible service composition. We present an analysis of different methods for classifying Web services for possible composition and supply a context-based semantic matching method for ranking these possibilities. Semantic understanding of Web services may provide added value by identifying new possibilities for compositions of services. The semantic matching ranking approach is unique since it provides the Web service designer with an explicit numeric estimation of the extent to which a possible composition “makes sense. ” First, we analyze two common methods for text processing, TF/IDF and context analysis, and two types of service description, free text and WSDL. Second, we present a method for evaluating the proximity of services for possible compositions. Each Web service WSDL context descriptor is evaluated according to its proximity to other services ’ free text context descriptors. The methods were tested on a large repository of real-world Web services. The experimental results indicate that context analysis is more useful than TF/IDF. Furthermore, the method evaluating the proximity of the WSDL description to the textual description of other services provides high recall and precision results.

The success of the Web service technology has brought topics such as software reuse and discovery once again on the agenda of software engineers. While there are several efforts towards automating Web service discovery and composition, many developers still search for services via online Web service repositories and then combine them manually. However, from our analysis of these repositories, it yields that, unlike traditional software libraries, they rely on little metadata to support service discovery. We believe that the major cause is the difficulty of automatically deriving metadata that would describe rapidly changing Web service collections. In this paper, we discuss the major shortcomings of current Web service repositories and, as a solution, we report on how to use techniques developed in the context of the Semantic Web (ontology learning, service annotation tools, automatic classifiers, metadata based presentation) Web service technology allows for uniform access via Web standards to software components residing on various platforms and written in different programming languages. At a technology level, we distinguish between WSDL 1 / SOAP 2 services, which rely

Abstract. With the envisioned proliferation of Web services available on the WWW and private repositories, new and better support techniques are needed for service discovery and organization to stay manageable. Service classification under hierarchic taxonomies is commonly a key feature for properly organizing service repositories in a rational way, as well as a good foundation for sophisticated retrieval techniques. In this paper, a heuristic approach for the semi-automatic classification of (semantic) Web services is proposed, based on matching new unclassified services to previously classified ones in a given corpus. This hypothesis is validated by an experimental test and the comparison with results achieved by other approaches. 1

Abstract not found

Abstract—A vast majority of web services exist without explicit associated semantic descriptions. As a result many services that are relevant to a specific user service request may not be considered during service discovery. In this paper, we address the issue of web service discovery given nonexplicit service description semantics that match a specific service request. Our approach to semanticbased web service discovery involves semantic-based service categorization and semantic enhancement of the service request. We propose a solution for achieving functional level service categorization based on an ontology framework. Additionally, we utilize clustering for accurately classifying the web services based on service functionality. The semantic-based categorization is performed offline at the universal description discovery and integration (UDDI). The semantic enhancement of the service request achieves a better matching with relevant services. The service request enhancement involves expansion of additional terms (retrieved from ontology) that are deemed relevant for the requested functionality. An efficient matching of the enhanced service request with the retrieved service descriptions is achieved utilizing Latent Semantic Indexing (LSI). Our experimental results validate the effectiveness and feasibility of the proposed approach. Index Terms—Web services publishing, web services discovery, services discovery process and methodology. Ç