Rough Sets and Knowledge Technology : 7th International Conference, RSKT 2012, Chengdu, China, August 17-20, 2012, Proceedings - Tianrui Li, Hung Son Nguyen, Guoyin Wang, Jerzy Grzymala-Busse, Ryszard Janicki, Aboul Ella Hassanien, Hong Yu ((Lecture Notes in Computer Science))