1. School of Computer Engineering, Jiangsu Ocean University,Lianyungang,P. R. China,222000
2. School of Electronic Engineering, Jiangsu Ocean University,Lianyungang,P. R. China,222000
3. School of Computer Engineering, and School of Marine Technology and Geomatics, Jiangsu Ocean University,Lianyungang,P. R. China,222000
4. School of Science, Jiangsu Ocean University,Lianyungang,P. R. China,222000