Denis K. Ponomaryov

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Recent years have seen the advent of large and complex ontologies, most notably in the medical domain. As a consequence, structuring mechanisms for ontolo-gies are nowadays viewed as an indispensible tool. A basic such mechanism is the automatic decomposition of the vocabulary of an ontology into independent parts. In this paper, we study decompositions(More)
We generalize the main notions of Formal Concept Analysis with the ideas of the semantic probabilistic inference. We demonstrate that under standard restrictions, our definitions completely correspond to the original notions of Formal Concept Analysis. From the point of view of applications, we propose a method of recovering concepts in formal contexts in(More)
The integration of the various specialized components of cognitive systems poses a challenge, in particular for those architectures that combine planning , inference, and human-computer interaction (HCI). An approach is presented that exploits a single source of common knowledge contained in an ontology. Based upon the knowledge contained in it, specialized(More)
We present an approach for integrating ontological reasoning and planning within cognitive systems. Patterns and mechanisms that suitably link planning domains and interrelated knowledge in an ontology are devised. In particular , this enables the use of (standard) ontology reasoning for extending a (hierarchical) planning domain. Furthermore, explanations(More)
In order to provide a qualitative support to the users during a web search, it is important to have access to a multitude of information sources simultaneously. Depending on the available domain expertise, the user can get an overview and insight to different information perspectives and compare the quality of resources. In this work, we present an(More)
Disjoint AND-decomposition of a boolean formula means its representation as a conjunction of two (or several) formulas having dis-joint sets of variables. We show that deciding AND-decomposability is intractable in general for boolean formulas given in CNF or DNF and prove tractability of computing AND-decompositions of boolean formulas given in positive(More)
It is known that in Description Logics explicit concept defin-ability is directly related to concept interpolation. The problem to decide whether a concept is definable under a TBox wrt a signature usually reduces to entailment in the underlying logic. If an explicit definition exists , then it can be found as a concept interpolant for a concept inclusion(More)