1. Inst Risk Assessment and Control, Guangdong Technol Ctr Work Safety Co., Ltd., Guangzhou 510050, PR China
2. State Key Laboratory of High-Efficient Mining and Safety of Metal Mines (University of Science and Technology Beijing), Ministry of Education, Beijing 100083, PR China
3. Work Safety Key Lab on Prevention and Control of Gas and Roof Disasters for Southern Coal Mines, Hunan University of Science & Technology, Xiangtan 411201, PR China