Zollmann and Vogel ( 2011 ) further labeled the SCFG rules with POS tags and unsupervised word classes .
a wordclass approach to labeling pscfg rules for machine translation
Andreas Zollmann Stephan Vogel
Zollmann and Venugopal ( 2006 ) substituted the non-terminal X in hierarchical phrase-based model by extended syntactic categories . Zollmann and Vogel ( 2011 ) further labeled the SCFG rules with POS tags and unsupervised word classes . Our work differs from theirs in that we present a Bayesian model to learn effective STSG translation rules and U-tree structures for tree-based translation models , rather than designing a labeling strategy for translation rules .
@@CITATION further labeled the SCFG rules with POS tags and unsupervised word classes .