14 research outputs found

    Towards interoperability in heterogeneous database systems

    Get PDF
    Distributed heterogeneous databases consist of systems which differ physically and logically, containing different data models and data manipulation languages. Although these databases are independently created and administered they must cooperate and interoperate. Users need to access and manipulate data from several databases and applications may require data from a wide variety of independent databases. Therefore, a new system architecture is required to manipulate and manage distinct and multiple databases, in a transparent way, while preserving their autonomy. This report contains an extensive survey on heterogeneous databases, analysing and comparing the different aspects, concepts and approaches related to the topic. It introduces an architecture to support interoperability among heterogeneous database systems. The architecture avoids the use of a centralised structure to assist in the different phases of the interoperability process. It aims to support scalability, and to assure privacy and nfidentiality of the data. The proposed architecture allows the databases to decide when to participate in the system, what type of data to share and with which other databases, thereby preserving their autonomy. The report also describes an approach to information discovery in the proposed architecture, without using any centralised structure as repositories and dictionaries, and broadcasting to all databases. It attempts to reduce the number of databases searched and to preserve the privacy of the shared data. The main idea is to visit a database that either containsthe requested data or knows about another database that possible contains this data

    Mediators Metadata Management Services: An Implementation Using GOA++ System

    Get PDF
    The main contribution of this work is the development of a Metadata Manager to interconnect heterogeneous and autonomous information sources in a flexible, expandable and transparent way. The interoperability at the semantic level is reached using an integration layer, structured in a hierarchical way, based on the concept of Mediators. Services of a Mediator Metadata Manager (MMM) are specified and implemented using functions based on the Outlines of GOA++. The MMM services e are available in the form of a GOA++ API and they can be accessed remotely via CORBA or through local API calls.Sociedad Argentina de Informática e Investigación Operativ

    An Object-Oriented Heterogeneous Database Architecture

    Full text link
    Many data management environments face a critical need to integrate heterogeneous data-data that are stored in varying locations using various data management systems with diverse data formats and schemas. To address this problem, the database research community has developed the concept of a heterogeneous database system (HDB) that provides users with the illusion of a single unified database. However, HDBs rely on the implicit assumption that all data to be integrated into the HDB are stored in full-fledged database management systems (DBMS). This assumption leaves environments that need to integrate non-DBMS data unserved by HDB systems. Furthermore, HDBs are complex software solutions that are not easily lmplementable by database developers wrestling with heterogeneous data. This thesis presents a new, easily implemented HDB architecture that is suitable for integrating non-DBMS data. The key to our architecture is using an object-oriented database management system (OODBMS) as an implementation tool. Rather than developing an HDB from scratch, we leverage the power and facilities of the underlying OODBMS to provide a query language, application programmer interface, interactive query interface, concurrency control, etc. Using object-oriented technology gives us an additional benefit-our HDB becomes an object-oriented HDB (OOHDB) providing users with greater data model expressivity along with a powerful behavioral component. The OOHDB architecture we present is independent of a particular OODBMS and can be implemented using a number of commercial OODBMSs for a variety of data management environments. We describe one implementation of our architecture using the GemStone OODBMS for accessing heterogeneous materials science data. This implementation demonstrates how easily the architecture can be implemented. We use this implementation to analyze the performance of the architecture and examine the effectiveness of strategies for enhancing performance. We conclude that for many environments with heterogeneous non-DBMS data, our OOHDB architecture provides a good solution that is easy to implement using commercial OODBMS technology

    Resolving semantic conflicts through ontological layering

    Get PDF
    We examine the problem of semantic interoperability in modern software systems, which exhibit pervasiveness, a range of heterogeneities and in particular, semantic heterogeneity of data models which are built upon ubiquitous data repositories. We investigate whether we can build ontologies upon heterogeneous data repositories in order to resolve semantic conflicts in them, and achieve their semantic interoperability. We propose a layered software architecture, which accommodates in its core, ontological layering, resulting in a Generic ontology for Context aware, Interoperable and Data sharing (Go-CID) software applications. The software architecture supports retrievals from various data repositories and resolves semantic conflicts which arise from heterogeneities inherent in them. It allows extendibility of heterogeneous data repositories through ontological layering, whilst preserving the autonomy of their individual elements. Our specific ontological layering for interoperable data repositories is based on clearly defined reasoning mechanisms in order to perform ontology mappings. The reasoning mechanisms depend on the user‟s involvments in retrievals of and types of semantic conflicts, which we have to resolve after identifying semantically related data. Ontologies are described in terms of ontological concepts and their semantic roles that make the types of semantic conflicts explicit. We contextualise semantically related data through our own categorisation of semantic conflicts and their degrees of similarities. Our software architecture has been tested through a case study of retrievals of semantically related data across repositories in pervasive healthcare and deployed with Semantic Web technology. The extensions to the research results include the applicability of our ontological layering and reasoning mechanisms in various problem domains and in environments where we need to (i) establish if and when we have overlapping “semantics”, and (ii) infer/assert a correct set of “semantics” which can support any decision making in such domains

    Automated Reasoning

    Get PDF
    This volume, LNAI 13385, constitutes the refereed proceedings of the 11th International Joint Conference on Automated Reasoning, IJCAR 2022, held in Haifa, Israel, in August 2022. The 32 full research papers and 9 short papers presented together with two invited talks were carefully reviewed and selected from 85 submissions. The papers focus on the following topics: Satisfiability, SMT Solving,Arithmetic; Calculi and Orderings; Knowledge Representation and Jutsification; Choices, Invariance, Substitutions and Formalization; Modal Logics; Proofs System and Proofs Search; Evolution, Termination and Decision Prolems. This is an open access book

    Many spheres of music : hermeneutic interpretation of musical signification

    Get PDF
    Considerable interest has been shown in the field of music aesthetics in recent years, not only by aestheticians but also by writers from diverse fields such as musicology, psychology and linguistics. What we have witnessed in these discussions have been not only painstaking analyses of music in terms of its aesthetic value, but also explorations of music in relation to a varied range of research areas from examining the relations between music and mind using psychological methods, through evaluating music in terms of our post-modem notion of art, to exploring the relations between language and music in terms of their semantic and semiotic characteristics. Such accounts typically seek to show that music is more than mere sound, and, in particular, several accounts focus on its expressiveness and its possibility of conveying a certain significance

    Automatic Importation of Relational Schemas in Pegasus

    No full text
    This paper describes a technique for importing automatically an external relational schema into Pegasus, a heterogeneous, multidatabase system. The Pegasus data model is a functional object model which supports specialization, object-identity, and nested aggregation. The import algorithm generates the definition of a Pegasus schema which captures the semantics of a relational schema containing information about primary keys and referential integrity constraints. The algorithm described can be adapted easily for other semantic and objectoriented data models

    Many spheres of music : hermeneutic interpretation of musical signification

    Get PDF
    Considerable interest has been shown in the field of music aesthetics in recent years, not only by aestheticians but also by writers from diverse fields such as musicology, psychology and linguistics. What we have witnessed in these discussions have been not only painstaking analyses of music in terms of its aesthetic value, but also explorations of music in relation to a varied range of research areas from examining the relations between music and mind using psychological methods, through evaluating music in terms of our post-modem notion of art, to exploring the relations between language and music in terms of their semantic and semiotic characteristics. Such accounts typically seek to show that music is more than mere sound, and, in particular, several accounts focus on its expressiveness and its possibility of conveying a certain significance.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
    corecore