GUAN-FENG LI1 AND ZONG-MIN MA2,3,+,*
1College of Computer Science and Engineering
Northeastern University
Shenyang, 110819 P.R. China
2College of Computer Science and Technology
Nanjing University of Aeronautics and Astronautics
Nanjing, 211106 P.R. China
3Collaborative Innovation Center of Novel Software Technology and Industrialization
Nanjing, 210023 P.R. China