Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Semantic Web Services: A Brokerage Architecture Proposal Gökay Burak AKKUŞ Computer Engineering, M.S. Thesis Proposal, 2004 Thesis Supervisor: Dr. Ayşe BENER It is obvious that the Internet could be more useful than it is today. One possible route forward is that of W3C’s Semantic Web initiative, which states that the future Web will be a new network that is interpretable by the machines. And the full power of the new network will be realized when agent programs are created that collect content from diverse sources, process the information and exchange the results with other programs. The effectiveness of such software agents will increase exponentially, as more machine-readable web content and automated services become available. Basic technologies will include XML, UDDI and SOAP together with Web Services, Ontologies, and OWL. XML, UDDI and SOAP are known industry standards. But the core elements –Semantic Web and Ontologies, in the thesis should be clarified. An ontology is a specification of a representational vocabulary for a shared domain of discourse and it includes a vocabulary of terms, and some specification of their meaning. The goal is to create an agreed-upon vocabulary and semantic structure for exchanging information about that domain. Each word used (for a relation or property) must explicitly declare its ontological commitment. In the case of the Semantic Web this means that we have to use URIs to achieve precision and to show its ontological commitment in the case of properties. The ontological commitment governs the use and meaning of the word, and as a consequence the applications' use of it. Further, an ontology is only a formal approximation of the world. Another important property is that the ontology is language-dependent while the conceptualization is language-independent. Two different ontologies might share the same conceptualization of a thing, e.g. the concept of price, but might map different words from their vocabulary to that concept. This means that it will become possible to achieve interoperability between different ontologies if the conceptualization is the same in some sense. But it also means that if two applications use the same words it does not mean that they map to the same conceptualization. Web services promise the dynamic creation of loosely coupled information systems that are built over reusable components. However, current approaches are logically centralized and lack key functionality, especially to locate, select and bind services meeting certain criteria of quality. So, there is a need of an architecture that allows clients of services to automatically select and bind with desired services, and with minimal intervention by the designers and implementers or the end users. Further, current approaches support no memory of service bindings and interactions, except whatever a specific application programmer may include in an ad hoc manner. The clients cannot learn from their past interactions to improve their future decisions, as there is no system that provides support from learning from the past interactions of others. Although much data handling and underlying protocols are automated through current standards, key aspects that support flexible decision-making with respect to the composition and selection of services are still treated in an ad hoc manner. The aim of this thesis is mainly to make these aspects systematic by constructing methodologies over sample service brokerage architecture and generating storable blueprints of workflows concerning web processes. Web Processes are next generation workflow technology to facilitate the interaction of organizations with markets, competitors, suppliers, customers etc. supporting enterprise-level and core business activities. Web processes describe how Web services are connected to create reliable and dependable business solutions and allow businesses to describe sophisticated processes that can both consume and provide Web services. The role of Web processes within the enterprise is to simplify the integration of business and application processes across technological and corporate domains. In this thesis, it is claimed that software development needs to progress from hand-made line-at-a-time techniques to methodologies that support reuse of existing software assets. In other words, software development needs to shift from paradigms that are purely creational to others that support compositional approaches. So, new software development paradigms are remarkable: Componentbased software engineering, Agent-based software engineering. These two disciplines are related and dependent upon each other. In the future, passive software components will be liberated by the proactive and social nature of agents. A framework for building up ontologies-based services and specialized brokering services to find Web services, which form up the main element to be processed by software agents, will be proposed and a guide for evolving in the path of next generation web services will be introduced from the Navigable Web, to the Semantic Web and then Trusted Web, and finally Dynamic and Transparent Web. The proposed framework will be compared with the existing specialized brokerage architectures such as MONET project (Mathematical Web services Brokerage). The criteria of comparison will be completeness of the architecture, flexibility, fault tolerance issues, applicability of the architecture using current technology, side-effects to the environment and business processes, the level of domain independence, and the level of human intervention. References: 1. Fensel D, 2000, Ontologies: Silver Bullet for Knowledge Management and Electronic Commerce, URL: http://www.cs.vu.nl/%7Edieter/ftp/paper/silverbullet.pdf 2. Paul A. Buhler, José M. Vidal, 2002, Semantic Web Services as Agent Behaviors 3. Danny Ayers, 2 July 2004, The Missing Webs, AIG SIGSEMIS Bulletin Vol. 1 No. 2 pp. 18-24. 4. E. Michael Maximillien, Munindar P. Singh, 2002, Conceptual Model of Web Service Reputation, ITR-0081742 5. Sheila A. McIlraith, Tran Coa Son, Honglei Zeng, 2001, Semantic Web Services, IEEE Intelligent Systems pp. 46-53. 6. W3C, 2000, Semantic Web, http://www.w3.org/sw/.