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.

Two important architectural choices underlie the success of the Web: numerous, independently operated servers speak a common protocol, and a single type of client---the Web browser---provides point-and-click access to the content and services on these decentralized servers. However, because HTML marries content and presentation into a single representation, end users are often stuck with inappropriate choices made by the Web site designer of how to work with and view the content. RDF metadata on the Semantic Web does not have this limitation: users can gain direct access to the underlying information and control how it is presented for themselves. This principle forms the basis for our Semantic Web browser---an end user application that automatically locates metadata and assembles point-and-click interfaces from a combination of relevant information, ontological specifications, and presentation knowledge, all described in RDF and retrieved dynamically from the Semantic Web. With such a tool, nave users can begin to discover, explore, and utilize Semantic Web data and services. Because data and services are accessed directly through a standalone client and not through a central point of access (e.g., a portal), new content and services can be consumed as soon as they become available. In this way we take advantage of an important sociological force that encourages the production of new Semantic Web content by remaining faithful to the decentralized nature of the Web.

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.

Web services have been recognized to have the potential to revolutionize ecommerce. The potential for businesses to be able to interact with each other on the fly is very appealing. To date, however, the activity of creating Web processes using Web services has been handled mostly at the syntactic level. Current composition standards focus on building the processes based on the interface description of the participating services. The limitation of such a rigid approach is that it does not allow businesses to dynamically change partners and services. We enhance the current Web process composition techniques by using Semantic Process Templates to capture the semantic requirements of the process. The semantic process templates can act as configurable modules for common industry processes maintaining the semantics of the participating activities, control flow, intermediate calculations, conditional branches and exposing it in an industry accepted interface. The templates are instantiated to form executable processes according to the semantics of the activities in the templates. The use of ontologies in template definition allows much richer description of activity requirements

Abstract. If agents are to negotiate automatically with one another they must share a negotiation mechanism, specifying what possible actions each party can take at any given time, when negotiation terminates, and what is the structure of the resulting agreements. Current standardization activities such as FIPA [2] and WS-Agreement [3] represent this as a negotiation protocol specifying the flow of messages. However, they omit other aspects of the rules of negotiation (such as obliging a participant to improve on a previous offer), requiring these to be represented implicitly in an agent’s design, potentially resulting incompatibility, maintenance and re-usability problems. In this chapter, we propose an alternative approach, allowing all of a mechanism to be formal and explicit. We present (i) a taxonomy of declarative rules which can be used to capture a wide variety of negotiation mechanisms in a principled and well-structured way; (ii) a simple interaction protocol, which is able to support any mechanism which can be captured using the declarative rules; (iii) a software framework for negotiation that allows agents to effectively participate in negotiations defined using our rule taxonomy and protocol and (iv) a language for expressing aspects of the negotiation based on OWL-Lite [4]. We provide examples of some of the mechanisms that the framework can support. 1

Abstract. The European Commission’s eEurope initiative aims to bring every citizen, home, school, business and administration online to create a digitally literate Europe. The value lies not in the objective itself, but in its ability to facilitate the advance of Europe into new ways of living and working. Just as in the first literacy revolution, our lives will change in ways never imagined. The vision of eEurope is underpinned by a technological infrastructure that is now taken for granted. Yet it provides us with the ability to pioneer radical new ways of doing business, of undertaking science, and, of managing our everyday activities. Key to this step change is the development of appropriate mechanisms to automate and improve existing tasks, to anticipate desired actions on our behalf (as human users) and to undertake them, while at the same time enabling us to stay involved and retain as much control as required. For many, these mechanisms are now being realised by agent technologies, which are already providing dramatic and sustained benefits in several business and industry domains, including B2B exchanges, supply chain management, car manufacturing, and so on. While there are many real successes of agent technologies to report, there is still much to be done in research and development for the full benefits to be achieved. This is especially true in the context of environments of pervasive computing devices that are envisaged in coming years. This paper describes the current state-of-the-art of agent technologies and

Abstract. Automating the process of B2B partner discovery and contract negotiation is expected to significantly optimise company processes. Numerous existing proposals for discovery follow the approach where service descriptions are expressed by concept expressions in description logics (DL), and description matching is performed by well-known DL inferences. However, these approaches do not always produce results one might intuitively expect, due to a gap between the formal semantics of service descriptions and human intuition. In this paper, we address this problem by analysing the connection between the modeler’s intuition and formal logic used to operationalise discovery. Furthermore, we show how to correctly map the intuition into description logic constructs. Finally, we investigate different inferences used to realise service discovery. 1

Abstract. We present and motivate a formal approach and algorithms for semantic matchmaking in an e-commerce framework. The proposed solution exploits nonmonotonic inferences to compute semantic-based ranking of offers and provides explanation services in the query-retrievalrefinement loop. 1

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