... Association for Computational Linguistics, pages 420–429,Avignon, France, April 23 - 27 2012.c2012 Association for Computational LinguisticsCombining Tree Structures, Flat Features and Patterns for ... PW Fstands for the new featurebased kernel (henceforth, TPWF kernel) com-puted using flat features collected by exploiting patterns, trigger words, negative cues and walk features. KSL and KP ... kernel on 5 benchmark PPI corpora before and after adding features collected using dependency patterns, regex patterns, trigger words and negative cues to the walk features. The TPWF kernel is a component...