Now showing items 1-8 of 8

  • Jiménez-Ruiz, Ernesto; Kharlamov, Evgeny; Zheleznyakov, Dmitriy; Horrocks, Ian; Pinkel, Christoph; Skjæveland, Martin G; Thorstensen, Evgenij; Mora, Jose (Journal article / Tidsskriftartikkel / SubmittedVersion, 2015)
    Ontologies have recently became a popular mechanism to expose relational database (RDBs) due to their ability to describe the domain of data in terms of classes and properties that are clear to domain experts. Ontological ...
  • Thorstensen, Evgenij (Master thesis / Masteroppgave, 2009)
    We consider a fragment of first-order logic known as coherent logic or geometric logic. The essential difference to standard clausal form is that there may be existentially quantified variables in the positive literals of ...
  • Lembo, Domenico; Mora, Jose; Rosati, Riccardo; Savo, Domenico Fabio; Thorstensen, Evgenij (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2015)
    Ontology-based data access (OBDA) is a recent paradigm for accessing data sources through an ontology that acts as a conceptual, integrated view of the data, and declarative mappings that connect the ontology to the data ...
  • Lupp, Daniel Paul; Thorstensen, Evgenij (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    In ontology-based data access (OBDA), databases are connected to an ontology via mappings from queries over the database to queries over the ontology. In this paper, we define an ASP-based semantics for mappings from ...
  • Lembo, Domenico; Rosati, Riccardo; Santarelli, Valerio; Savo, Domenico Fabio; Thorstensen, Evgenij (Chapter / Bokkapittel / AcceptedVersion; Peer reviewed, 2017)
    In this paper we study the evolution of ontologybased data access (OBDA) specifications, and focus on the case in which the ontology and/or the data source schema change, which may require a modification to the mapping ...
  • Kharlamov, Evgeny; Jiménez-Ruiz, Ernesto; Lanti, Davide; Lie, Hallstein; Hovland, Dag; Pinkel, Christoph; Skjæveland, Martin G; Thorstensen, Evgenij; Rezk, Martin (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2015)
    Ontology Based Data Access (OBDA) is a prominent approach to query databases which uses an ontology to expose data in a conceptually clear manner by abstracting away from the technical schema-level details of the underlying ...
  • Forssell, Jon Henrik; Lupp, Daniel Paul; Skjæveland, Martin G; Thorstensen, Evgenij (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    Reasonable Ontology Templates, OTTRs for short, are OWL ontology macros capable of representing ontology design patterns (ODPs) and closely integrating their use into ontology engineering. An OTTR is itself an OWL ontology ...
  • Thorstensen, Evgenij (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2015)
    A wide range of problems can be modelled as constraint satisfaction problems (CSPs), that is, a set of constraints that must be satisfied simultaneously. Constraints can either be represented extensionally, by explicitly ...