1. College of Electrical and Information Engineering, Hunan University, Changsha, Hunan, China
2. Engineering Training Center, Anyang Institute of Technology of China, Anyang, Henan, China
3. School of Physics and Electronics, Central South University, Changsha, China
4. School of Automation Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
5. Institute of Nondestructive Testing, National Research Tomsk Polytechnic University, Tomsk, Russia