Numerous recent work on unsupervised machine translation (UMT) implies that competent unsupervised translations of low-resource and unrelated languages, such as Nepali or Sinhala, are only possible if the model is trained in a massive multilingual environment, where theses low-resource languages are mixed with high-resource counterparts. Nonetheless, while the high-resource languages greatly help kick-start the target low-resource translation tasks, the language discrepancy between them may hinder their further improvement. In this work, we propose a simple refinement procedure to disentangle languages from a pre-trained multilingual UMT model for it to focus on only the target low-resource task. Our method achieves the state of the art in the fully unsupervised translation tasks of English to Nepali, Sinhala, Gujarati, Latvian, Estonian and Kazakh, with BLEU score gains of 3.5, 3.5, 3.3, 4.1, 4.2, and 3.3, respectively. Our codebase is available at https://github.com/nxphi47/refine_unsup_multilingual_mt

该论文提出一种简单的细化流程，将语言从预训练的多语言UMT模型中分离出来，使其专注于目标低资源任务，并实现了英语到尼泊尔语、僧伽罗语、古吉拉特语、拉脱维亚语、爱沙尼亚语和哈萨克语的全无监督翻译任务的最先进，其BLEU得分分别为3.5，3.5，3.3，4.1，4.2和3.3。

通过语言分离多语言模型提高低资源无监督翻译的精度