Hierarchical Back-off Modeling of Hiero Grammar based on Non-parametric Bayesian Model Hidetaka Kamigaito author Taro Watanabe author Hiroya Takamura author Manabu Okumura author Eiichiro Sumita author 2015-09 text Proceedings of the 2015 Conference on Empirical Methods in Natural Language Processing Lluís Màrquez editor Chris Callison-Burch editor Jian Su editor Association for Computational Linguistics Lisbon, Portugal conference publication kamigaito-etal-2015-hierarchical 10.18653/v1/D15-1143 https://aclanthology.org/D15-1143/ 2015-09 1217 1227