Now showing items 1-12 of 12

    • Correcting Access Restrictions to a Consequence More Flexibly 

      Eldora; Knechtel M; Peñaloza R (CEUR, 2011)
      Recent research has shown that labeling ontologies can be useful for restricting the access to some of the axioms and their implicit consequences. However, the labeling of the axioms is an error-prone and highly sensible ...
    • DL-Lite with Attributes and Sub-Roles (Extended Abstract) 

      Artale A; Ibáñez-García A; Kontchakov R; Ryzhikov V (CEUR-WS.org, 2011)
    • Fuzzy Ontologies over Lattices with T-norms 

      Borgwardt S; Peñaloza R (CEUR, 2011)
    • Games for Query Inseparability of Description Logic Knowledge Bases 

      Botoeva E; Kontchakov R; Ryzhikov V; Wolter F; Zakharyaschev M (2016)
      We consider conjunctive query inseparability of description logic knowledge bases with respect to a given signature - a fundamental problem in knowledge base versioning, module extraction, forgetting and knowledge exchange.  ...
    • Logics of metric spaces 

      Kutz O; Wolter F; Sturm H; Suzuki N; Zakharyaschev M (2003)
      We investigate the expressive power and computational properties of two different types of languages intended for speaking about distances. First, we consider a first-order language FM the two-variable fragment of which ...
    • Metric Temporal Logic for Ontology-Based Data Access over Log Data 

      Calvanese D; Guzel Kalaycı E; Ryzhikov V; Xiao G; Zakharyaschev M (IJCAI Workshop 40, 2016)
      We present a new metric temporal logic HornMTL over dense time and its datalog extension datalogMTL. The use of datalogMTL is demonstrated in the context of ontology-based data access over meteorological data. We show ...
    • Ontology-Based Access To Temporal Data With Ontop: A Framework Proposal 

      Güzel Kalayci E; Brandt S; Calvanese D; Ryzhikov V; Xiao G; Zakharyaschev M (2019)
      Predictive analysis gradually gains importance in industry. For instance, service engineers at Siemens diagnostic centres unveil hidden knowledge in huge amounts of historical sensor data and use this knowledge to improve ...
    • Ontology-Based Data Access: A Survey 

      Xiao G; Calvanese D; Kontchakov R; Lembo D; Poggi A; Rosati R; Zakharyaschev M (IJCAI Organization, 2018)
      We present the framework of ontology-based data access, a semantic paradigm for providing a convenient and user-friendly access to data repositories, which has been actively developed and studied in the past decade.  ...
    • Ontology-Mediated Query Answering over Temporal Data: A Survey 

      Artale A; Kontchakov R; Kovtunova A; Ryzhikov R; Wolter F; Zakharyaschev M (Schloss Dagstuhl - Leibniz-Zentrum für Informatik GmbH, Dagstuhl Publishing, 2017)
      We discuss the use of various temporal knowledge representation formalisms for ontology-mediated query answering over temporal data. In particular, we analyse ontology and query languages based on the linear temporal logic ...
    • Query-Based Entailment and Inseparability for ALC Ontologies 

      Botoeva E; Lutz C; Ryzhikov V; Wolter F; Zakharyaschev M (AAAI Press, 2016)
      We investigate the problem whether two ALC knowledge bases are indistinguishable by queries over a given vocabulary. We give model-theoretic criteria and prove that this problem is undecidable for conjunctive queries (CQs) ...
    • Querying Log Data with Metric Temporal Logic 

      Brandt S; Güzel Kalaycı E; Ryzhikov V; Xiao G; Zakharyaschev M (2018)
      We propose a novel framework for ontology-based access to temporal log data using a datalog extension datalogMTL of the Horn fragment of the metric temporal logic MTL. We show that datalogMTL is EXPSPACE-complete even ...