no code implementations • 13 Jun 2023 • Jean Christoph Jung, Vladislav Ryzhikov, Frank Wolter, Michael Zakharyaschev
Recently, the study of the unique characterisability and learnability of database queries by means of examples has been extended to ontology-mediated queries.
no code implementations • 2 May 2023 • Marie Fortin, Boris Konev, Vladislav Ryzhikov, Yury Savateev, Frank Wolter, Michael Zakharyaschev
In reverse engineering of database queries, we aim to construct a query from a given set of answers and non-answers; it can then be used to explore the data further or as an explanation of the answers and non-answers.
no code implementations • 30 May 2019 • Vladislav Ryzhikov, Przemyslaw Andrzej Walega, Michael Zakharyaschev
We investigate the data complexity of answering queries mediated by metric temporal logic ontologies under the event-based semantics assuming that data instances are finite timed words timestamped with binary fractions.
no code implementations • 31 Jan 2019 • Elena Botoeva, Carsten Lutz, Vladislav Ryzhikov, Frank Wolter, Michael Zakharyaschev
We also consider the problem whether two ALC TBoxes give the same answers to any query over any ABox in a given signature and show that, for CQs, this problem is undecidable, too.
no code implementations • 20 Apr 2018 • Elena Botoeva, Boris Konev, Carsten Lutz, Vladislav Ryzhikov, Frank Wolter, Michael Zakharyaschev
The question whether an ontology can safely be replaced by another, possibly simpler, one is fundamental for many ontology engineering and maintenance tasks.
no code implementations • 14 Apr 2016 • Elena Botoeva, Carsten Lutz, Vladislav Ryzhikov, Frank Wolter, Michael Zakharyaschev
We also consider the problem whether two ALC TBoxes give the same answers to any query in a given vocabulary over all ABoxes, and show that for CQs this problem is undecidable, too, but becomes decidable and 2EXPTIME-complete in Horn-ALC, and even EXPTIME-complete in Horn-ALC when restricted to (unions of) rooted CQs.
Logic in Computer Science
no code implementations • 21 Apr 2013 • Marcelo Arenas, Elena Botoeva, Diego Calvanese, Vladislav Ryzhikov
Knowledge base exchange is an important problem in the area of data exchange and knowledge representation, where one is interested in exchanging information between a source and a target knowledge base connected through a mapping.
no code implementations • 25 Sep 2012 • Alessandro Artale, Roman Kontchakov, Vladislav Ryzhikov, Michael Zakharyaschev
We design temporal description logics suitable for reasoning about temporal conceptual data models and investigate their computational complexity.
