1. School of Marine Science and Technology, Northwestern Polytechnical University, Xi’an 710072, P. R. China
2. School of Economics and Management, Fuzhou University, Fuzhou 350108, P. R. China
3. ICBC Wealth Manager Co., LTD, Beijing 100032 P. R. China
4. School of Computer Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, P. R. China
5. School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, P. R. China