Multi-stage recognition of named entities in natural language text based on morphological and semantic features

A system, comprising:

• a memory;
• a processor, coupled to the memory, the processor configured to:
• perform a lexico-morphological analysis of a natural language text comprising a plurality of tokens, each token comprising at least one natural language word;
• determine, based on the lexico-morphological analysis, one or more lexical meanings and grammatical meanings associated with each token of the plurality of tokens;
• for each token the plurality of tokens, evaluate one or more classifier functions using the lexical and grammatical meanings associated with the tokens, wherein a value of each classifier function is indicative of a degree of association of the token with a category of named entities;
• perform a syntactico-semantic analysis of at least part of the natural language text to produce a plurality of semantic structures representing the part of the natural language text;
• and
• interpret the semantic structures using a set of production rules to determine, for one or more tokens comprised by the part of the natural language text, a degree of association of the token with a category of named entities.

A computer-readable non-transitory storage medium comprising executable instructions that, when executed by a computer system, cause the computer system to:

• perform a lexico-morphological analysis of a natural language text comprising a plurality of tokens, each token comprising at least one natural language word;
• determine, based on the lexico-morphological analysis, one or more lexical meanings and grammatical meanings associated with each token of the plurality of tokens;
• for each token the plurality of tokens, evaluate one or more classifier functions using the lexical and grammatical meanings associated with the tokens, wherein a value of each classifier function is indicative of a degree of association of the token with a category of named entities;
• perform a syntactico-semantic analysis of at least part of the natural language text to produce a plurality of semantic structures representing the part of the natural language text;
• and
• interpret the semantic structures using a set of production rules to determine, for one or more tokens comprised by the part of the natural language text, a degree of association of the token with a category of named entities.