First, unsupervised WA is performed on the SMT training corpus where the Chinese sentences are treated as sequences of characters; then, the Chinese sentences are segmented by CTB segmenter and a dictionary of segmented words are built; finally, for each word in the dictionary, the relative frequency of being split at a certain position is cal-  Table 4: Extended features used in the CRF model for word splitting.
the word segmentation (WS) schemes of these annotated corpora are handcrafted for general usage, and may not be suitable for SMT.