Research of the fundamental properties of ontological knowledge bases

Abstract

The concept of ontology, its characteristic properties, causes of emergence and implementation mechanisms are analyzed. The connection between ontologies and knowledge bases is established. The concept of an ontological knowledge base is introduced and disclosed. The library of engineering ontologies, the OpenCyc knowledge base and its ancestor – Cyc – are briefly reviewed. On the example of OpenCyc, a number of fundamental properties of ontological knowledge bases are considered. In particular, there are structural equivalence of the composition of ontologies and fundamental elements of knowledge bases, a compromise between redundancy of knowledge and narrow specialization of ontologies, the necessity to implement an interaction language etc. The necessity for functions of various degrees, opportunities to optimize requests and commands to deepen the process of user interaction with the system was identified. The necessity for structures of a higher, abstract level and modularity of the knowledge base has been proved in order to increase the capabilities to support the software product, simplify its development and work with knowledge in it. Problems of consistency regulation in knowledge bases are considered: in particular, conflict cases between timeless truths and time-dependent truths; advantages of using ontological databases in such cases are given. The necessity of developing and maintaining high-quality interaction interfaces, in particular command and visual-interactive (graphical) interfaces, has been proven. The nuances of maintaining documentation of ontological knowledge bases are disclosed. The results of the accompanying study of the OpenCyc system are given. Prospective directions for further research, possible areas for implementation are identified