Reordering Constraint Based on Document-Level Context
Takashi Onishi, Masao Utiyama, Eiichiro Sumita · 2011
One problem with phrase-based statistical ma-chine translation is the problem of long-distance reordering when translating between languages with different word orders, such as Japanese-English. In this paper, we propose a method of imposing reordering constraints us-ing document-level context. As the document-level context, we use noun phrases which sig-nificantly occur in context documents contain-ing source sentences. Given a source sen-tence, zones which cover the noun phrases are used as reordering constraints. Then, in de-coding, reorderings which violate the zones are restricted. Experiment results for patent translation tasks show a significant improve-ment of 1.20 % BLEU points in Japanese-English translation and 1.41 % BLEU points in English-Japanese translation. 1