Multi-granularity Textual Adversarial Attack with Behavior Cloning Yangyi Chen author Jin Su author Wei Wei author 2021-11 text Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing Marie-Francine Moens editor Xuanjing Huang editor Lucia Specia editor Scott Wen-tau Yih editor Association for Computational Linguistics Online and Punta Cana, Dominican Republic conference publication chen-etal-2021-multi 10.18653/v1/2021.emnlp-main.371 https://aclanthology.org/2021.emnlp-main.371/ 2021-11 4511 4526