1. Department of Electrical Engineering, University of Houston, Houston, TX, USA
2. Ecological Livable College, Hunan Polytechnic of Environment and Biology, Hengyang, Hunan, China
3. School of Information, Renmin University of China, Beijing, China
4. Software Engineering Institute, East China Normal University, Shanghai, China
5. School of Computer Science, The University of Sydney, Sydney, NSW, Australia
6. Department of Electrical and Computer Engineering, University of Houston, Houston, TX, USA