Now showing items 1-4 of 4

  • 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 ...
  • 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 ...
  • 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 ...
  • 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 ...