Conventional dependency structure based models (Lin, 2004;Quirk et al., 2005;Ding and Palmer, 2005;Xiong et al., 2007) typically employ both substitution and insertion operation to complete translations, which make it difficult to specify ordering information directly in the translation rules.
they have to resort to either heuristics (Lin, 2004;Xiong et al., 2007) or separate ordering models (Quirk et al., 2005;Ding and Palmer, 2005) to control the word order of translations.