Learning Neural Sequence-to-Sequence Models from Weak Feedback with Bipolar Ramp Loss Laura Jehl author Carolin Lawrence author Stefan Riezler author 2019 text journal article Transactions of the Association for Computational Linguistics continuing MIT Press Cambridge, MA periodical academic journal jehl-etal-2019-learning 10.1162/tacl_a_00265 https://aclanthology.org/Q19-1015/ 2019 7 233 248