Dmitry O. Briukhov

Component-Based Information Systems Development Tool Supporting the SYNTHESIS Design Method

An approach intended to fill in the gap between the existing Object Analysis and Design (OAD) methods applying mostly top-down technique and the demand of the middleware architectures (OMG CORBA) for the information system development based on composition of pre-existing interoperating components is discussed. An overview of the SYNTHESIS method for component-based interoperable information systems design is presented. The heuristic procedure for the most common reduct construction for a pair of ontologically relevant type specifications is outlined. The refinement property of the common reduct leads to a justifiable identification of reusable component fragments. The process of design is based on such identification driven by ontologically relevant pairs of types. The common reducts discovered are composed further to construct specifications serving as concretizations of the required types. The structure and functions of the design tool supporting the SYNTHESIS method and a process of design under the tool are considered.

Information Sources Registration at a Subject Mediator as Compositional Development

Method for heterogeneous information source registration at subject mediators with local as view (LAV) organization is presented. LAV approach considers schemas exported by sources as materialized views over virtual classes of the mediator. This approach is intended to cope with a dynamic, possibly incomplete set of sources. To disseminate the information sources, their providers should register them at a respective subject mediator. Such registration can be done concurrently and at any time. The registration method proposed is new and contributes to the following. The method is applicable to wide class of source specification models representable in hybrid semistructured/object canonical mediator model. Ontological specifications are used for identification of mediator classes semantically relevant to a source class. Maximal subset of source information relevant to the mediator classes is identified. Concretizing types are defined so that federated classes instance types are refined by the source instance type. This direction naturally supports query planning refining a mediator query in terms of a specific source. Such refining direction is in contrast to conventional compositional development where specification of requirements is to be refined by specifications of components. Such inversion is natural for the registration process: a materialized view (requirements) is constructed over virtual specifications (components).

Extension of Compositional Information Systems Development for the Web Services Platform

The use of Web services on the World Wide Web is expanding rapidly to make applications interoperable in information systems (IS). Web services providing interfaces to information and software components are convenient entities for producing their compositions having Web service appearances. At the same time, most large scale enterprise solutions that are deployed today are composed of a combination of different technologies that go together to compose many diverse applications. An approach for compositional information systems development in a multi-technological framework including Web service components is discussed. This paper proposes to extend the SYNTHESIS method for compositional information systems development (CISD) to the world of Web services. The CISD method is intended for correct composition of existing components semantically interoperable in the context of a specific application. Originally, the CISD method has been developed for the object-oriented platforms (like CORBA, RMI, J2EE). In the CISD, an ontological model and canonical object model (the SYNTHESIS language) are used for the unified representation of the new application (specification of requirements) and of the pre-existing components. Discovery of components relevant to the application and producing their compositions is provided in frame of the domain ontology and the canonical object model. To apply the CISD method for Web services, the mapping of WSDL specifications into the canonical model is required. The basic steps of the approach for the information system compositional development applying Web services are demonstrated.

Designing personalized digital libraries over websites with semistructured data

Issues concerning the design of personalized digital libraries over collections of semistructured data available on the Web are considered. The approach suggested makes it possible to design libraries adjusted to the personal needs of information users that place various requirements upon the contents and representation of information. The digital library is designed as a composition of fragments of websites. In this paper, a method for the compositional design of information systems is applied to semistructured data on the Web. This method was developed at the Institute for Problems of Informatics of the Russian Academy of Sciences (IPI RAS) [2]. The design procedure is demonstrated by designing a library over two websites containing data about registered patents.

Value Reconciliation in Mediators of Heterogeneous Information Collections Applying Well-Structured Context Specifications

Method for value reconciliation in Local as Views (LAV) mediators of heterogeneous information collections applying well-structured specifications is presented. This approach extends a procedure for heterogeneous information sources registration at subject mediators with LAV organization. Conflicts in value semantics and representation in contexts of the mediator and a collection should be recognized and explicitly specified. According to the proposed method, value semantics contexts should be defined for the mediator and for a collection. In such context for each value kind a type is to be specified that includes a generic function converting values from a collection context into the mediator context (and/or back). Each type attribute having the respective value semantics is to be typed with such type definition. Such structuring of type attribute semantics definition gives significant economy in development of value conversion functions needed to reconcile values between the mediator and collection contexts.