TY - JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE) A1 - ZHANG Xiao, YANG Yan-yan T1 - Algorithms of rule acquisition and confidence-preserved attribute reduction in covering decision systems Y1 - 2018-12-20 JF - JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE) JO - JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE) SP - 120 EP - 126 VL - 53 IS - 12 UR - http://lxbwk.njournal.sdu.edu.cn N1 - 10.6040/j.issn.1671-9352.0.2017.400 ER -