| W02-1032 | only models using unigram for | category probability estimation | are used for further experiments |
| W02-1032 | and the models using unigram for | category probability estimation | of Equation ( 7 ) as U-PHTM . |
| W02-1032 | denote the models using trigram for | category probability estimation | of Equation ( 6 ) as T-PHTM , |
