作者机构:School of Information Technology, Beijing Union University, Beijing 100101, P. R. China
相关基金:Supported by the National Natural Science Foundation of China (No. 61301103 ), the Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions ( No. CIT&TCD201504039 ) , and Funding Project for Academic Human Resources Development in Beiiinz Union University (No. BPHR2014A03, Rk100201510).