Back transliteration from Japanese to English using target English context

Abstract

This paper proposes a method of automatic back transliteration of proper nouns, in which a Japanese transliterated-word is restored to the original English word. The English words are created from a sequence of letters; thus our method can create new English words that are not registered in dictionaries or English word lists. When a katakana character is converted into English letters, there are various candidates of alphabetic characters. To ensure adequate conversion, the proposed method uses a target English context to calculate the probability of an English character or string corresponding to a Japanese katakana character or string. We confirmed the effectiveness of using the target English context by an experiment of personal-name back transliteration.