1. School of Network & Communication Engineering, Chengdu Technological University, Chengdu 611730, China
2. Engineering College of Tibet University, Lhasa 850011, China
3. Sichuan Industial Metrology and Testing Institute, Chengdu 610100, China
4. Erzhong (Deyang) Heavy Equipment Co., Ltd., Detecting &Testing Center, Deyang 618000, China