1,721,046 research outputs found
A schema analysis and reconciliation tool environment for heterogeneous databases
No full textTo support the development of uniform query interfaces over distributed and heterogeneous databases, tools for the analysis and reconciliation of database conceptual schemas are required. The paper presents the ARTEMIS tool environment developed to support the analyst in the process of analyzing and reconciling sets of heterogeneous data schemas. Schema analysis in ARTEMIS is performed according to the concept of affinity, while schema reconciliation is performed interactively on clusters of elements with affinity, based on unification rules. Issues on expected tool interaction and on experimentation and applicability of ARTEMIS are discusse
Reuse of conceptual requirement specifications
No full textA methodological approach is presented to guide the definition of reusable components to be exploited for designing applications not from scratch, but by tailoring and adapting existing components. Reusability at the requirements specification level is considered, and tools to define reusable components are illustrated. Reusable components are defined as generic components with associated meta-components providing guidelines for reuse in a given applicatio
Enabling semantic search in P2P systems through a three-layer Distributed Service Registry
No full textEffective searching and access to data and functionalities in P2P environments require platform independency for integrating different sources over the Web and must take into account the presence of high dynamicity and the absence of a common resource conceptualization. Service Oriented Architecture enables to export shared data and functionalities through Web Services, thus enabling platform-independent resource discovery. In P2P networks, available services are published and retrieved on different registries, that are autonomous and heterogeneous. Semantic Web Service technology is suggested to face semantic heterogeneity. We propose a virtual Distributed Service Registry (DSR) and a reference architecture to support semantic search over P2P networks. The DSR is organized on three layers: a logical layer, in which single registries are connected as peers in a P2P network; a semantic layer, where peer registries are semantic-enriched and semantic links between peer registries holding similar services are established; a mapping layer, where mappings between similar services are defined to support service interoperability between heterogeneous peers. In the reference architecture, each peer is equipped with: a service knowledge evolution manager, to update peer local knowledge through interactions with other peers; a semantic search assistant, that exploits the three-layer organization of the DSR to satisfy requested user searches, also suggesting possible alternative services or related services suitable for composition, on the basis of semantic links
Semantic Dictionary Design for Database Interoperability
No full textCriteria and techniques to support the establishment of a semantic dictionary for database interoperability are described. The techniques allow the analysis of conceptual schemas of databases in a federation and the definition and maintenance of concept hierarchies. Similarity-based criteria are used to evaluate concept closeness and, consequently, to generate concept hierarchies. Experimentation of the techniques in the public administration domain is discusse
Proceedings of the seventeenth italian symposium on advanced database systems, SEBD 2009, Camogli, Italy, June 21-24, 2009
No full textReference Conceptual Architectures for Re-engineering Information Systems
No full textSystem evolution and re-engineering are becoming increasingly important as the size and complexity of Information Systems continue to grow. The paper addresses the problems related to the development of abstraction mechanisms for building reference conceptual architectures of Information Systems, i.e. standardized descriptions of their most significant concepts, to be used for matching and validating changes to the system
A Discovery-Based Approach to Database Ontology Design
No full textIn this paper, we introduce an approach to task-driven ontology design which is based on information discovery from database schemas. Techniques for semi-automatically discovering terms and relationships used in the information space, denoting concepts, their properties and links are proposed, which are applied in two stages. At the first stage, the focus is on the discovery of heterogeneity/ambiguity of data representations in different schemas. For this purpose, schema elements are compared according to defined comparison features and similarity coefficients are evaluated. This stage produces a set of candidates for unification into ontology concepts. At the second stage, decisions are made on which candidates to unify into concepts and on how to relate concepts by semantic links. Ontology concepts and links can be accessed according to different perspectives, so that the ontology can serve different purposes, such as, providing a search space for powerful mechanisms for concept location, setting a basis for query formulation and processing, and establishing a reference for recognizing terminological relationships between elements in different schemas
A Constructive Approach to Reuse of Conceptual Components
No full textA methodological approach to the design-for-reuse process is presented. Reusability at the conceptual design level is considered, and tools for preparing reusable components to be exploited for designing applications not from scratch, but tailoring and adapting existing components are presented. Reusable components are defined as generic components with associated metacomponents providing guidelines for reuse in a given applicatio
A Framework for Expressing Semantic Relationships between Multiple Information Systems for Cooperation
No full textAfter many years of information systems development, most private and public organizations are characterized by the presence of multiple information systems, possibly distributed and heterogeneous. Heterogeneity is generally related to representation languages, support technology, and evolution strategies. The result can be a deep disintegration of data and processes spread in several information systems. Methods and tools for the analysis and comparison of the existing information systems are required, to identify replication, overlapping, bad distribution of data and processes among the existing systems, to set the basis for reengineering activities. This paper proposes computer-based techniques for the analysis of multiple information systems. Following an inherently data-oriented approach, conceptual descriptions of processes are analyzed focusing on characteristics of data manipulated and exchanged and on operations performed by processes. The proposed techniques rely on similarity criteria and metrics and on a semantic dictionary, where the knowledge on process data and operations is properly organized. Process descriptions are analyzed for the aspects related to information and operation similarity, to evaluate semantic correspondences between processes and identify activity replication and overlapping, as well as for the aspects related to interaction/cooperation, to evaluate the degree of coupling between processes and identify the type and the nature of exchanged information flows. Experimental results of applying the analysis techniques to the information systems of the Italian Public Administration are discussed
A multi-perspective framework for the analysis of legacy information systems
No full textThis paper proposes a comprehensive framework for the analysis of sets of data, processes, and applications of legacy information systems in view of restructuring interventions, according to different perspectives. A "data asset structure perspective" supports the information system analysis in terms of semantic correspondences between data assets shared by different organization units and applications of the system. An "operational structure perspective" supports the information system analysis in terms of the semantic correspondences between processes, with respect to the similarity of the involved data and operations. Finally, an "organizational structure perspective" supports the information system analysis in terms of the organization unit cohesion and coupling properties with respect to the exchanged information flows. The perspectives are discussed with reference to the analysis of italian Public Administration information systems
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