@InProceedings{takeno-nagata-yamamoto:2016:WAT2016,
  author    = {Takeno, Shunsuke  and  Nagata, Masaaki  and  Yamamoto, Kazuhide},
  title     = {Integrating empty category detection into preordering Machine Translation},
  booktitle = {Proceedings of the 3rd Workshop on Asian Translation (WAT2016)},
  month     = {December},
  year      = {2016},
  address   = {Osaka, Japan},
  publisher = {The COLING 2016 Organizing Committee},
  pages     = {157--165},
  abstract  = {We propose a method for integrating Japanese empty category detection into the 
	preordering process of Japanese-to-English statistical machine translation.
	First, we apply machine-learning-based empty category detection to estimate 
	the position and the type of empty categories in the constituent tree of the 
	source sentence.
	Then, we apply discriminative preordering to the augmented constituent tree in 
	which empty categories are treated as if they are normal lexical symbols.
	We find that it is effective to filter empty categories based on the 
	confidence of estimation.
	Our experiments show that, for the IWSLT dataset consisting of short travel 
	conversations, the insertion of empty categories alone improves the BLEU score 
	from 33.2 to 34.3 and the RIBES score from 76.3 to 78.7, which imply that 
	reordering has improved
	For the KFTT dataset consisting of Wikipedia sentences, the proposed 
	preordering method considering empty categories improves the BLEU score from 
	19.9 to 20.2 and the RIBES score from 66.2 to 66.3, which shows both 
	translation and reordering have improved slightly.},
  url       = {http://aclweb.org/anthology/W16-4615}
}