Qingdong Wang Huaping Dai Youxian Sun Develop Multi-hierarchy Classification Model: Rough Set Based Feature Decomposition Method. 164-171 2005 conf/icapr/2005-1 ICAPR (1) http://dx.doi.org/10.1007/11551188_18 db/conf/icapr/icapr2005-1.html#WangDS05