A proposal of a knowledge based isolated word recognition

This paper describes a knowledge based isolated Japanese word recognition algorithm. The program is written with Prolog/KR [4] and has two basic inference processes, i.e., a Bottom-up search and a Top-down search. In the Bottom-up process, a segmentation and a vowel decision are performed and some target word patterns are generated. The Top-down process includes a consonant decision using a score of each candidate word calculated based on the Fuzzy Set Theory [1]. In the vowel inference, a template matching is applied mainly. In the segmentation, heuristic rules based on the spectrum transition and the wave form are used. But in the consonant inference, each rule has a hierarchy structure and it is defined automatically in the form of the multi-valued threshold function from learning data. This system can treat an obscure information about the consonant classification and to select the most effective decision rule in order to simplify the understanding process. The truth rate of consonant recognition is better than using statistical method.