1. School of Information Science and Engineering, Shandong Normal University, Jinan, China
2. College of Industry and Commerce, Shandong Management University, Jinan, China
3. Department of Electrical Engineering and Information Technology, Shandong University of Science and Technology, Jinan, China
4. Key Laboratory of Facility Agriculture Measurement and Control Technology and Equipment of Machinery Industry, Jiangsu University, Zhenjiang, China