1. Hubei Key Laboratory of Intelligent Vision Based Monitoring for Hydroelectric Engineering, College of Computer and Information Technology, China Three Gorges University, Yichang, Hubei, China
2. Department of Computer Science, Rowan University, Glassboro, NJ, USA
3. Department of Computer Science, University of Exeter, Exeter, U.K.
4. Center for Networked Computing, Temple University, Philadelphia, PA, USA