Their model is identical to our S-Distortion model that captures the relative jump distance knowledge on source words.
in recent years, end-to-end NMT (Kalchbrenner and Blunsom, 2013;Bahdanau et al., 2015) has made tremendous progress (Jean et al., 2015;Luong et al., 2015b;Shen et al., 2016;Sennrich et al., 2016;Tu et al., 2016;Johnson et al., 2016).