National Science Foundation of China(NSFC)under Grant No.11271097;Natural Science Foundation of China under Grant No.61472092;Guangdong Provincial Science and Technology Plan Project under Grant No.2013B010401037;Guang Zhou Municipal High School Science Research Fund under grant No.120142131
Our research has been supported by the National Science Foundation of China(NSFC)under GrantNo.11271097;the research project of Guangzhou Education Bureau under Grant No.2012A074;the project IIPL-2011-001 from Shanghai Key Laboratory of Intelligent Information Processing;the project KFKT2012B01 from State Key Laboratory for Novel Software Technology,Nanjing University