XINJUN MAO1,2, MENGGAO DONG2, LU LIU3 AND HUAIMING WANG2
1State Key Laboratory of Software Development Environment
Beihang University
Beijing, 100191 P.R. China
2Department of Computer Science and Technology
National University of Defense Technology
Changsha, 410073 P.R. China
3School of Computing and Mathematics
University of Derby
Derby, DE22 1GB UK