In this paper, we introduce a vision for Semantic Web services which combines the growing Web services architecture and the Semantic Web and we will propose DAML-S as a prototypical example of an ontology for describing Semantic Web services. Furthermore, we show that DAML-S is not just an abstract description, but it can be efficiently implemented to support capability matching and to manage interaction between Web services. Specifically, we will describe the implementation of the DAML-S/UDDI Matchmaker that expands on UDDI by providing semantic capability matching, and we will present the DAML-S Virtual Machine that uses the DAML-S Process Model to manage the interaction with Web service. We will also show that the use of DAML-S does not produce a performance penalty during the normal operation of Web services. © 2003 Elsevier B.V. All rights reserved.

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

Abstract. The semantic web presents the vision of a distributed, dynamically growing knowledge base founded on formal logic. Common users, however, seem to have problems even with the simplest Boolean expressions. As queries from web search engines show, the great majority of users simply do not use Boolean expressions. So how can we help users to query a web of logic that they do not seem to understand? We address this problem by presenting a natural language interface to semantic web querying. The interface allows formulating queries in Attempto Controlled English (ACE), a subset of natural English. Each ACE query is translated into a discourse representation structure – a variant of the language of first-order logic – that is then translated into an N3-based semantic web querying language using an ontology-based rewriting framework. As the validation shows, our approach offers great potential for bridging the gap between the logic-based semantic web and its real-world users, since it allows users to query the semantic web without having to learn an unfamiliar formal language. Furthermore, we found that users liked our approach and designed good queries resulting in a very good retrieval performance (100 % precision and 90 % recall). 1

Pervasive computing environments are populated with networked services, i.e., autonomous software entities, providing a number of functionalities. One of the most challenging objectives to be achieved within these environments is to assist users in realizing tasks that integrate on the fly functionalities of the networked services opportunely according to the current pervasive environment. Towards this purpose, we present COCOA, a solution for COnversation-based service COmposition in pervAsive computing environments with QoS support. COCOA provides COCOA-L, an OWL-S based language for the semantic, QoSaware specification of services and tasks, which further allows the specification of services and tasks conversations. Moreover, COCOA provides two mechanisms: COCOA-SD for the QoS-aware semantic service discovery and COCOA-CI for the QoS-aware integration of service conversations towards the realization of the user task’s conversation. The distinctive feature of COCOA is the ability of integrating on the fly the conversations of networked services to realize the conversation of the user task, by further meeting the QoS requirements of user tasks. Thereby, COCOA allows the dynamic realization of user tasks according to the specifics of the pervasive computing environment in terms of available services and by enforcing valid service consumption. 1

Abstract: Finding a good similarity assessment algorithm for the use in ontologies is central to the functioning of techniques such as retrieval, matchmaking, clustering, data-mining, ontology translations, automatic database schema matching, and simple object comparisons. This paper assembles a catalogue of ontology based similarity measures, which are experimentally compared with a “similarity gold standard ” obtained by surveying 50 human subjects. Results show that human and algorithmic similarity predications varied substantially, but could be grouped into cohesive clusters. Addressing this variance we present a personalized similarity assessment procedure, which uses a machine learning component to predict a subject’s cluster membership, providing an excellent prediction of the gold standard. We conclude by hypothesizing ontology dependent similarity measures.

Abstract. Quality aspects become increasingly important when business process modeling is used in a large-scale enterprise setting. In order to facilitate a storage without redundancy and an efficient retrieval of relevant process models in model databases it is required to develop a theoretical understanding of how a degree of behavioral similarity can be defined. In this paper we address this challenge in a novel way. We use causal footprints as an abstract representation of the behavior captured by a process model, since they allow us to compare models defined in both formal modeling languages like Petri nets and informal ones like EPCs. Based on the causal footprint derived from two models we calculate their similarity based on the established vector space model from information retrieval. We validate this concept with an experiment using the SAP Reference Model and an implementation in the ProM framework.

We present and evaluate an approach to hybrid semantic Web service matching, called OWLS-MX, that utilizes both logic based reasoning and content based information retrieval techniques for services specified in OWL-S. Results of our comparative measurements of performance and scalability of OWLS-MX variants and selected token-based IR similarity metrics provide experimental evidence that building semantic Web service matchmakers purely on description logic reasoners artificially limits their potential. Experimental results show that logic based only approaches to semantic OWL-S service matching can be outperformed by both content-based and hybrid approaches to semantic service matching. 1

Abstract Good similarity measures are central for techniques such as retrieval, matchmaking, clustering, data-mining, ontology translations, automatic database schema matching, and simple object comparisons. Measures for the use with complex (or aggregated) objects in ontologies are, however, rare, even though they are central for semantic web applications. This paper first introduces SimPack, a library of similarity measures for the use in ontologies (of complex objects). The measures of the library are then experimentally compared with a similarity “gold standard ” established by surveying 94 human subjects in two ontologies. Results show that human and algorithm assessments vary (both between people and across ontologies), but can be grouped into cohesive clusters, each of which is well modeled by one of the measures in the library. Furthermore, we show two increasingly accurate methods to predict the cluster membership of the subjects providing the foundation for the construction of personalized similarity measures. Paper Type: Working Paper 1

Web services constitute a promising technology to support autonomic computing. Automatic discovery of new services, their composition and binding based on Quality of Service (QoS) are just some of the most promising features that can be provided using web services. In other words, a service oriented system is able to automatically discover, bind, and use, at run time, the services that, among those available, offer a given piece of functionality with a QoS compatible with the system non–functional requirements. This paper describes our work–in–progress related to the development of an electronic marketplace, named C 3 (Creation, Certification and Classification of Services) to enable the publication, semantic discovery, service buying, SLA negotiation and QoS-aware composition and replanning. The marketplace is mainly targeted to corporate intranets, although its technologies and approaches can be easily exported to a wider scenario. Keywords: Service-oriented systems, automatic service discovery, run–time binding, automatic service negotiation, service replanning 1.

The current state-of-the-art in electronic negotiations shows a focus on the trade of standardised mostly inexpensive products in fixed networks of suppliers and customers. To overcome these shortcomings, the goal must be to enable the trade of complex and valuable goods and to support many-to-many marketplace for that purpose. Once valuable goods are concerned, the trade process involves negotiations which consist of a number of communicative exchanges. The Language-Action Perspective has proved to be relevant for the analysis and modelling of communication acts. We will show that a LAP approach is indeed useful as the basis for complex negotiations but only if combined with other theoretical and conceptual foundations.