1. College of Electronic and Information Engineering, Southwest University, Chongqing, China
2. Department of Electrical and Computer Engineering, University of Alabama in Huntsville, Huntsville, AL, USA
3. Department of Information Systems, University of Maryland, Baltimore County, Baltimore, MD, USA
4. Department of Computer and Information Sciences, University of Delaware, Newark, DE, USA
5. Department of Computer Science and Engineering, University at Buffalo, The State University of New York, Buffalo, NY, USA