Unsupervised Negation Focus Identification with Word-Topic Graph Model Bowei Zou author Guodong Zhou author Qiaoming Zhu 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 zou-etal-2015-unsupervised 10.18653/v1/D15-1187 https://aclanthology.org/D15-1187/ 2015-09 1632 1636