Motoi Iwashita Ken Nishimatsu Shinsuke Shimogawa Semantic Analysis Method for Unstructured Data in Telecom Services. 789-795 2008 ICDM Workshops http://dx.doi.org/10.1109/ICDMW.2008.79 conf/icdm/2008w db/conf/icdm/icdmw2008.html#IwashitaNS08