LUO Xiao-jun1,3,LI Bing1,LIU Quan-sheng1,2,XU Jia-wei1
1.School of Math. and Computing Science,Changsha Univ. of Science and Technology,Changsha 410076,China 2.Universite de Bretagne-Sud,Campus de Tohannic,56017,Vannes,France 3.Department of Computer,Shangqiu Vocational and Technical College,Shangqiu,Henan 476000,China