Pyramid: A Layered Model for Nested Named Entity Recognition Jue Wang author Lidan Shou author Ke Chen author Gang Chen author 2020-07 text Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics Dan Jurafsky editor Joyce Chai editor Natalie Schluter editor Joel Tetreault editor Association for Computational Linguistics Online conference publication wang-etal-2020-pyramid 10.18653/v1/2020.acl-main.525 https://aclanthology.org/2020.acl-main.525/ 2020-07 5918 5928