Overcoming the Rare Word Problem for Low-Resource Language Pairs in Neural Machine Translation
Table 2: The number of Japanese OOV words replaced by their synonyms.
['[EMPTY]', 'Train', 'dev2010', 'tst2010']
Due to the fact that Vietnamese WordNet is not available, we only exploit WordNet to tackle unknown words of Japanese texts in our Japanese→Vietnamese translation system. After using Kytea, Japanese texts are applied LSW algorithm to replace OOV words by their synonyms. We choose 1-best synonym for each OOV word. The replaced texts are then BPEd and trained on the proposed architecture. The largest improvement is +0.92 between (1) and (3). We observed an improvement of +0.7 BLEU points between (3) and (5) without using data augmentation described in Ngo2018.