1. China University of Mining and Technology (Beijing), State Key Laboratory of Coal Resources and Safety Mining, Beijing, China and China University of Mining and Technology (Beijing), College of Geoscience and Surveying Engineering, Beijing, China.
2. California State University, Electrical Engineering Department, Long Beach, California, USA. .
3. China University of Mining and Technology (Beijing), State Key Laboratory of Coal Resources and Safety Mining, Beijing, China and China University of Mining and Technology (Beijing), College of Geoscience and Surveying Engineering, Beijing, China. (corresponding author)
4. China University of Mining and Technology (Beijing), State Key Laboratory of Coal Resources and Safety Mining, Beijing, China.
5. China University of Mining and Technology (Beijing), College of Geoscience and Surveying Engineering, Beijing, China.