1. School of Science, Guangdong University of Petrochemical Technology, Maoming, China
2. InterNetWorks Research Laboratory, School of Computing, Universiti Utara Malaysia, Sintok, Kedah, Malaysia
3. College of Electronic and Information Engineering, Guangdong University of Petrochemical Technology, Maoming, China
4. School of Computer Science, Guangdong University of Technology, Guangzhou, China