Browsing Institutt for informatikk by Author "Calvanese, Diego"

Now showing items 1-4 of 4

  • A systematic overview of data federation systems 
    Gu, Zhenzhen; Corcoglioniti, Francesco; Lanti, Davide; Mosca, Alessandro; Xiao, Guohui; Xiong, Jing; Calvanese, Diego (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    Data federation addresses the problem of uniformly accessing multiple, possibly heterogeneous data sources, by mapping them into a unified schema, such as an RDF(S)/OWL ontology or a relational schema, and by supporting ...
  • An Ontology-Based Framework for Geospatial Integration and Querying of Raster Data Cube Using Virtual Knowledge Graphs 
    Hamdani, Younes; Xiao, Guohui; Ding, Linfang; Calvanese, Diego (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    The integration of the raster data cube alongside another form of geospatial data (e.g., vector data) raises considerable challenges when it comes to managing and representing it using knowledge graphs. Such integration ...
  • Efficient Ontology-Based Data Integration with Canonical IRIs 
    Xiao, Guohui; Hovland, Dag; Bilidas, Dimitris; Rezk, Martin; Giese, Martin; Calvanese, Diego (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2018)
    In this paper, we study how to efficiently integrate multiple relational databases using an ontology-based approach. In ontology-based data integration (OBDI) an ontology provides a coherent view of multiple databases, and ...
  • Ontology-Based Integration of Cross-Linked Datasets 
    Calvanese, Diego; Giese, Martin; Hovland, Dag; Rezk, Martin (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2015)
    In this paper we tackle the problem of answering SPARQL queries over virtually integrated databases. We assume that the entity resolution problem has already been solved and explicit information is available about which ...