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)
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 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)
An inductive probabilistic approach to formal concept analysis (FCA) is proposed in which probability on formal contexts is considered; probabilistic formal concepts that have predictive force are defined: nonclassified objects can be assigned to earlier found probabilistic formal concepts; random attributes are eliminated from probabilistic formal(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)
AND-decomposition of a boolean formula means finding two (or several) formulas such that their conjunction is equivalent to the given one. Decomposition is called disjoint if the component formulas do not have variables in common. In the paper, we show that deciding AND-decomposability is intractable for boolean formulas given in CNF or DNF and prove(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)