[Liu, Yong-Min;Kuang, Zhu-Fang] Cent South Univ Forestry & Technol, Coll Comp & Informat Engn, Changsha 410004, Hunan, Peoples R China.^[Wang, Ran] South China Normal Univ, Sch Geog, Guangzhou 510631, Guangdong, Peoples R China.^[Long, Hai-Quan] Zhuzhou CSR Times Elect Co Ltd, Safety Equipment Div, Zhuzhou 412000, Peoples R China.