Hong-Ya Wang1, Guo-Qin Ning2, Guo-Hui Li3 and Kam-Yiu Lam4
1School of Computer Science and Technology
Donghua University
Shanghai 200016, P.R.C.
2Department of Information Technology
Central China Normal University
Hubei 430079, P.R.C.
3College of Computer Science and Technology
Huazhong University of Science and Technology
Hubei 430074, P.R.C .
4Department of Computer Science
City University of Hong Kong
Kowloon, Hong Kong