Information Engineering College, Shanghai Maritime University, Haigang Ave., Shanghai, 201306, P R China. weikong@shmtu.edu.cn|Information Engineering College, Shanghai Maritime University, Haigang Ave., Shanghai, 201306, P R China. weikong@shmtu.edu.cn|Information Engineering College, Shanghai Maritime University, Haigang Ave., Shanghai, 201306, P R China. weikong@shmtu.edu.cn