Character Mapping And Ad-Hoc Adaptation: Edinburgh'S Iwslt 2020 Open Domain Translation System

This paper describes the University of Edinburgh's neural machine translation systems submitted to the IWSLT 2020 open domain Japanese <-> Chinese translation task. On top of commonplace techniques like tokenisation and corpus cleaning, we explore character mapping and unsupervised decoding-time adaptation. Our techniques focus on leveraging the provided data, and we show the positive impact of each technique through the gradual improvement of BLEU.