Uma proposta de sistema de software para auxílio na geraçao de tranformaçoes de formalismo BAV para integraçao de bancos de dados

Orientador: André Luiz Pires GuedesDissertaçao (mestrado) - Universidade Federal do Paraná, Setor de Ciencias Exatas, Programa de Pós-Graduaçao em Informática. Defesa: Curitiba, 2004Inclui bibliografia e anexosRESUMO O objetivo da integra¸c˜ao de bancos de dados 'e fornecer uma interface integrada e uniforme para consultas em diversos bancos de dados que descrevam os mesmos objetos do mundo real. O formalismo "both as view"(BAV) foi desenvolvido de modo a ser aplicado em esquemas de bancos de dados para realizar a sua integraçao. Seu funcionamento se caracteriza por ver o processo de integra¸c˜ao como uma sequência de transforma¸c˜oes revers'?veis que modificam tanto o esquema como as instˆancia do banco de dados. Este trabalho apresenta uma proposta de sistema de software que automatiza parcialmente o processo de integra¸c˜ao, auxiliando o administrador de banco de dados na tarefa de integra¸c˜ao, guiando-o pelo processo de gerar transforma¸c˜oes e consultando-o em momentos em que seja imposs'?vel para o sistema tomar uma decis˜ao. Al'em disso s˜ao apresentados estudos realizados sobre o formalismo BAV e sua aplica¸c˜ao nos casos de conflito entre esquemas de bancos de dados.ABSTRACT The objective of the database integration is to supply an integrated uniform interface to consultations in diverse databases that describe same objects of the real world. The formalism "both view"(BAV) was developed in order to be applied in schemas during the process of databases integration. Its functionality characterizes for seeing the integration process as a sequence of reversible transformations that modify the schema and the instances of the data base. This work presents a proposal of system software that automatizes the integration process partially, assisting the user in the integration process, guiding him to generate transformations and consulting it at moments where the system can not take a decision. Moreover are presented studies about the BAV formalism and its applications in the cases of conflict between database schemas

A semantic and agent-based approach to support information retrieval, interoperability and multi-lateral viewpoints for heterogeneous environmental databases

PhDData stored in individual autonomous databases often needs to be combined and interrelated. For example, in the Inland Water (IW) environment monitoring domain, the spatial and temporal variation of measurements of different water quality indicators stored in different databases are of interest. Data from multiple data sources is more complex to combine when there is a lack of metadata in a computation forin and when the syntax and semantics of the stored data models are heterogeneous. The main types of information retrieval (IR) requirements are query transparency and data harmonisation for data interoperability and support for multiple user views. A combined Semantic Web based and Agent based distributed system framework has been developed to support the above IR requirements. It has been implemented using the Jena ontology and JADE agent toolkits. The semantic part supports the interoperability of autonomous data sources by merging their intensional data, using a Global-As-View or GAV approach, into a global semantic model, represented in DAML+OIL and in OWL. This is used to mediate between different local database views. The agent part provides the semantic services to import, align and parse semantic metadata instances, to support data mediation and to reason about data mappings during alignment. The framework has applied to support information retrieval, interoperability and multi-lateral viewpoints for four European environmental agency databases. An extended GAV approach has been developed and applied to handle queries that can be reformulated over multiple user views of the stored data. This allows users to retrieve data in a conceptualisation that is better suited to them rather than to have to understand the entire detailed global view conceptualisation. User viewpoints are derived from the global ontology or existing viewpoints of it. This has the advantage that it reduces the number of potential conceptualisations and their associated mappings to be more computationally manageable. Whereas an ad hoc framework based upon conventional distributed programming language and a rule framework could be used to support user views and adaptation to user views, a more formal framework has the benefit in that it can support reasoning about the consistency, equivalence, containment and conflict resolution when traversing data models. A preliminary formulation of the formal model has been undertaken and is based upon extending a Datalog type algebra with hierarchical, attribute and instance value operators. These operators can be applied to support compositional mapping and consistency checking of data views. The multiple viewpoint system was implemented as a Java-based application consisting of two sub-systems, one for viewpoint adaptation and management, the other for query processing and query result adjustment

Automated Deduction – CADE 28

This open access book constitutes the proceeding of the 28th International Conference on Automated Deduction, CADE 28, held virtually in July 2021. The 29 full papers and 7 system descriptions presented together with 2 invited papers were carefully reviewed and selected from 76 submissions. CADE is the major forum for the presentation of research in all aspects of automated deduction, including foundations, applications, implementations, and practical experience. The papers are organized in the following topics: Logical foundations; theory and principles; implementation and application; ATP and AI; and system descriptions