Sentiment Lexicon Expansion Based on Neural PU Learning, Double Dictionary Lookup, and Polarity Association Yasheng Wang author Yang Zhang author Bing Liu author 2017-09 text Proceedings of the 2017 Conference on Empirical Methods in Natural Language Processing Martha Palmer editor Rebecca Hwa editor Sebastian Riedel editor Association for Computational Linguistics Copenhagen, Denmark conference publication wang-etal-2017-sentiment 10.18653/v1/D17-1059 https://aclanthology.org/D17-1059/ 2017-09 553 563