The subject ontology (in the context of the article) is understood as a combination of key concepts related to a certain field of science, with their semantic connections (thesaurus), supplemented by indices of various classification systems associated with this scientific field. Subject ontologies are a necessary component of each subspace that is part of the Common Digital Space of Scientific Knowledge (CDSSK). Compiling and supporting the subject ontology of any scientific field is a huge job. This work is complicated by the fact that new terms and relations between them are constantly emerging in many areas of not only the natural sciences, but also in the social sciences. These changes are being reflected in scientific publications. In this regard, the task of supporting subject ontologies requires constant monitoring of new scientific publications in order to identify new scientific terms. This article proposes a methodology for highlighting new keywords in a particular field of science, based on the use of existing classification systems in conjunction with citation databases(CSB) such as WEB of Science and Scopus (for English keywords) and Russian Citation Index (for Russian keywords). The methodology involves dividing the scientific field into a number of sections in accordance with the selected classification system, extracting from the CSB the core of articles related to each section, and from the articles - new author's keywords, which should constitute, in combination with the corresponding sections of classification systems, the basis of the subject ontologies of this scientific field.

scientific digital space, subject ontology, citation databases, keywords, thesaurus, classification systems

Kalenov Nikolay Evgenevich,  ,  orcid.org/0000-0001-5269-0988,  Joint Supercomputer Center of the Russian Academy of Sciences – JSCC