Improving translation models by applying asymmetric learning Setsuo Yamada author Masaaki Nagata author Kenji Yamada author 2003-sep 23-27 text Proceedings of Machine Translation Summit IX: Papers New Orleans, USA conference publication yamada-etal-2003-improving https://aclanthology.org/2003.mtsummit-papers.56/ 2003-sep 23-27