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

Benefits and challenges of applying Semantic Web Services in the e-Government domain

Joining up services in e-Government usually implies governmental agencies acting in concert without a central control regime. This requires the sharing of scattered and heterogeneous data. Semantic Web Service (SWS) technology can help to integrate, mediate and reason between these datasets. However, since few real-world applications have been developed, it is still unclear which are the actual benefits and issues of adopting such a technology in the e-Government domain. In this paper, we contribute to raising awareness of the potential benefits in the e-Government community by analyzing motivations, requirements, and expected results, before proposing a reusable SWS-based framework. We demonstrate the application of this framework by a compelling use case: a GIS-based emergency planning system. We illustrate the obtained benefits and the key challenges which remain to be addressed

A Framework for Design and Composition of Semantic Web Services

Semantic Web Services (SWS) are Web Services (WS) whose description is semantically enhanced with markup languages (e.g., OWL-S). This semantic description will enable external agents and programs to discover, compose and invoke SWSs. However, as a previous step to the specification of SWSs in a language, it must be designed at a conceptual level to guarantee its correctness and avoid inconsistencies among its internal components. In this paper, we present a framework for design and (semi) automatic composition of SWSs at a language-independent and knowledge level. This framework is based on a stack of ontologies that (1) describe the different parts of a SWS; and (2) contain a set of axioms that are really design rules to be verified by the ontology instances. Based on these ontologies, design and composition of SWSs can be viewed as the correct instantiation of the ontologies themselves. Once these instances have been created they will be exported to SWS languages such as OWL-S

Digital Ecosystems: Ecosystem-Oriented Architectures

We view Digital Ecosystems to be the digital counterparts of biological ecosystems. Here, we are concerned with the creation of these Digital Ecosystems, exploiting the self-organising properties of biological ecosystems to evolve high-level software applications. Therefore, we created the Digital Ecosystem, a novel optimisation technique inspired by biological ecosystems, where the optimisation works at two levels: a first optimisation, migration of agents which are distributed in a decentralised peer-to-peer network, operating continuously in time; this process feeds a second optimisation based on evolutionary computing that operates locally on single peers and is aimed at finding solutions to satisfy locally relevant constraints. The Digital Ecosystem was then measured experimentally through simulations, with measures originating from theoretical ecology, evaluating its likeness to biological ecosystems. This included its responsiveness to requests for applications from the user base, as a measure of the ecological succession (ecosystem maturity). Overall, we have advanced the understanding of Digital Ecosystems, creating Ecosystem-Oriented Architectures where the word ecosystem is more than just a metaphor.Comment: 39 pages, 26 figures, journa

A METHOD FOR SEMANTIC WEB SERVICE COMPOSITION BASED ON PATTERN MATCHING

The composition of semantic web services is a very important and actual problem in the semantic web services research area. There are several semi-automatic approaches for this problem, but most of the results are related to automatic approaches. In this paper we present an automatic approach for the composition of semantic web services based on pattern matching. We consider a special type of semantic description, represented as a list of semantic descriptions corresponding to several semantic web services. The semantic description related to the semantic web service that we want to obtain is decomposed until all the parts of the semantic description correspond to semantic web services from a library. In the end, all the necessary semantic web services found in the library are composed in order to obtain the semantic web service that we wanted to construct.semantic web service composition, semantic description decomposition, pattern matching