Before revision:  We experimentally show that our model-based adversarial samples effectively encourage NMT models to be less sensitive to segmentation errors and improve the robustness of NMT models in low-resource  datasets.
After revision:  We experimentally show that our model-based adversarial samples effectively encourage NMT models to be less sensitive to segmentation errors and improve the robustness of NMT models in low-resource and out-domain datasets.