Semantic Encoding and Markup of Georeferenced Documents in Polythematic Digital Libraries of Scientific Literature

The paper considers the principles and basic stages of decomposing georeferenced documents oriented to the problems of markup and semantic search. The paper justifies the necessity to develop a multimodal semiotic system and discusses verbal-visual knowledge representation in digital libraries. To represent knowledge, verbal-visual thesaurus is proposed. The thesaurus includes verbal, verbal-visual and visual descriptors. Semiotic synonymy is included into the system of links between descriptors in the thesaurus. The concept of generalized semantic search of documents in an digital library is defined. It is proved that semiotic synonymy in the thesaurus provides for cognitive framework for solving the problems of generalized semantic search of documents.