A Method of Pattern Recognition Using Rewriting Rules

This paper presents a method of apply­ ing rewriting rules to the recognition of patterns, structure of which are sequentially connected and can be expressed as symbol strings. Rewriting rules, which play the part of a recognizer, are formulated in a hierarchi­ cal structure. Rule 1 normalizes the length of string and extracts properties, rule 2 trans­ forms the deformed string in a context de­ pendent way and rule 3 determines the category. A procedure for producing rules from given sample patterns based on the similarity between the symbols and a procedure for modifying the rules when input patterns are added are de­ scribed. Experimental results of the recog­ nition of Japanese spoken digits to illustrate the method are exhibited.