A conceptual architecture for semantic web services development and deployment

Several extensions of the Web Services Framework (WSF) have been proposed. The combination with Semantic Web technologies introduces a notion of semantics, which can enhance scalability through automation. Service composition to processes is an equally important issue. Ontology technology – the core of the Semantic Web – can be the central building block of an extension endeavour. We present a conceptual architecture for ontology-based Web service development and deployment. The development of service-based software systems within the WSF is gaining increasing importance. We show how ontologies can integrate models, languages, infrastructure, and activities within this architecture to support reuse and composition of semantic Web services

Forum Session at the First International Conference on Service Oriented Computing (ICSOC03)

The First International Conference on Service Oriented Computing (ICSOC) was held in Trento, December 15-18, 2003. The focus of the conference ---Service Oriented Computing (SOC)--- is the new emerging paradigm for distributed computing and e-business processing that has evolved from object-oriented and component computing to enable building agile networks of collaborating business applications distributed within and across organizational boundaries. Of the 181 papers submitted to the ICSOC conference, 10 were selected for the forum session which took place on December the 16th, 2003. The papers were chosen based on their technical quality, originality, relevance to SOC and for their nature of being best suited for a poster presentation or a demonstration. This technical report contains the 10 papers presented during the forum session at the ICSOC conference. In particular, the last two papers in the report ere submitted as industrial papers

Service discovery and negotiation with COWS

To provide formal foundations to current (web) services technologies, we put forward using COWS, a process calculus for specifying, combining and analysing services, as a uniform formalism for modelling all the relevant phases of the life cycle of service-oriented applications, such as publication, discovery, negotiation, deployment and execution. In this paper, we show that constraints and operations on them can be smoothly incorporated in COWS, and propose a disciplined way to model multisets of constraints and to manipulate them through appropriate interaction protocols. Therefore, we demonstrate that also QoS requirement specifications and SLA achievements, and the phases of dynamic service discovery and negotiation can be comfortably modelled in COWS. We illustrate our approach through a scenario for a service-based web hosting provider

Specification and Verification of Context-dependent Services

Current approaches for the discovery, specification, and provision of services ignore the relationship between the service contract and the conditions in which the service can guarantee its contract. Moreover, they do not use formal methods for specifying services, contracts, and compositions. Without a formal basis it is not possible to justify through formal verification the correctness conditions for service compositions and the satisfaction of contractual obligations in service provisions. We remedy this situation in this paper. We present a formal definition of services with context-dependent contracts. We define a composition theory of services with context-dependent contracts taking into consideration functional, nonfunctional, legal and contextual information. Finally, we present a formal verification approach that transforms the formal specification of service composition into extended timed automata that can be verified using the model checking tool UPPAAL.Comment: In Proceedings WWV 2011, arXiv:1108.208

Knowledge infrastructures for software service architectures

Software development has become a distributed, collaborative process based on the assembly of off-the-shelf and purpose-built components or services. The selection of software services from service repositories and their integration into software system architectures, but also the development of services for these repositories requires an accessible information infrastructure that allows the description and comparison of these services. General knowledge relating to software development is equally important in this context as knowledge concerning the application domain of the software. Both form two pillars on which the structural and behavioural properties of software services can be addressed. We investigate how this information space for software services can be organized. Focal point are ontologies that, in addition to the usual static view on knowledge, also intrinsically addresses the dynamics, i.e. the behaviour of software. We relate our discussion to the Web context, looking at the Web Services Framework and the Semantic Web as the knowledge representation framework

A semantical framework for the orchestration and choreography of web services

Web Services are software services that can be advertised by providers and invoked by customers using Web technologies. This concept is currently carried further to address the composition of individual services through orchestration and choreography to services processes that communicate and interact with each other. We propose an ontology framework for these Web service processes that provides techniques for their description, matching, and composition. A description logic-based knowledge representation and reasoning framework provides the foundations. We will base this ontological framework on an operational model of service process behaviour and composition

Issues about the Adoption of Formal Methods for Dependable Composition of Web Services

Web Services provide interoperable mechanisms for describing, locating and invoking services over the Internet; composition further enables to build complex services out of simpler ones for complex B2B applications. While current studies on these topics are mostly focused - from the technical viewpoint - on standards and protocols, this paper investigates the adoption of formal methods, especially for composition. We logically classify and analyze three different (but interconnected) kinds of important issues towards this goal, namely foundations, verification and extensions. The aim of this work is to individuate the proper questions on the adoption of formal methods for dependable composition of Web Services, not necessarily to find the optimal answers. Nevertheless, we still try to propose some tentative answers based on our proposal for a composition calculus, which we hope can animate a proper discussion

Organising the knowledge space for software components

Software development has become a distributed, collaborative process based on the assembly of off-the-shelf and purpose-built components. The selection of software components from component repositories and the development of components for these repositories requires an accessible information infrastructure that allows the description and comparison of these components. General knowledge relating to software development is equally important in this context as knowledge concerning the application domain of the software. Both form two pillars on which the structural and behavioural properties of software components can be addressed. Form, effect, and intention are the essential aspects of process-based knowledge representation with behaviour as a primary property. We investigate how this information space for software components can be organised in order to facilitate the required taxonomy, thesaurus, conceptual model, and logical framework functions. Focal point is an axiomatised ontology that, in addition to the usual static view on knowledge, also intrinsically addresses the dynamics, i.e. the behaviour of software. Modal logics are central here – providing a bridge between classical (static) knowledge representation approaches and behaviour and process description and classification. We relate our discussion to the Web context, looking at Web services as components and the Semantic Web as the knowledge representation framewor