The University of Washington machine translation system for the IWSLT 2007 competition Katrin Kirchhoff author Mei Yang author 2007-oct 15-16 text Proceedings of the Fourth International Workshop on Spoken Language Translation Trento, Italy conference publication kirchhoff-yang-2007-university https://aclanthology.org/2007.iwslt-1.13/ 2007-oct 15-16