Authors:
Fengjing Shao, Corresponding author., College of Information Engineering, Qingdao University, Ningxia Road 308, Qingdao, 266071/Shandong, P. R. China
Yi Sui, College of Information Engineering, Qingdao University, Ningxia Road 308, Qingdao, 266071/Shandong, P. R. China