Unsupervised Domain Adaptation for Sparse Retrieval by Filling Vocabulary and Word Frequency Gaps Hiroki Iida author Naoaki Okazaki author 2022-11 text Proceedings of the 2nd Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics and the 12th International Joint Conference on Natural Language Processing (Volume 1: Long Papers) Yulan He editor Heng Ji editor Sujian Li editor Yang Liu editor Chua-Hui Chang editor Association for Computational Linguistics Online only conference publication iida-okazaki-2022-unsupervised 10.18653/v1/2022.aacl-main.57 https://aclanthology.org/2022.aacl-main.57/ 2022-11 752 765