9. The apparatus as set forth in claim 8 , wherein the model parameters optimization engine is configured to iteratively optimize values of the parameters of the conditional translation probability, the model parameters optimization engine in each iteration adding candidate aligned translations to the translation pool by sampling available candidate aligned translations in accordance with the conditional translation probability with parameter values of the current iteration.
10. The method as set forth in claim 9 , wherein the iterative optimization process employs the bilingual evaluation understudy (BLEU) method.