Table 4 demonstrates that the proposed RNNbased model outperforms IBM 4 trained from the unlabeled 40 K data by employing either the 1 K labeled data or the 9 K unlabeled data, which is less than 25% of the training data for IBM 4.
the SMT system using RN N u+c trained from a small part of training data can achieve comparable performance to that using IBM 4 trained from all training data, which is shown in Table 3.