1. College of Computer and Information Technology, China Three Gorges University, Yichang, China
2. State Key Laboratory of Integrated Service Networks, Xidian University, Xi’an, China
3. Hubei Key Laboratory of Intelligent Geo-Information Processing, School of Computer Science, China University of Geosciences, Wuhan, China
4. Information Coding & Transmission Key Laboratory of Sichuan Province, CSNMT International Cooperation Research Centre (MoST), Southwest Jiaotong University, Chengdu, China