1. Key Laboratory of Intelligent Computing and Signal Processing, Ministry of Education, School of Computer Science and Technology, Anhui University, Hefei 230601, China, and also with the Anhui Provincial Key Laboratory of Multimodal Cognitive Computation, School of Computer Science and Technology, Anhui University, Hefei 230601, China.
2. Key Laboratory of Intelligent Computing and Signal Processing, Ministry of Education, School of Computer Science and Technology, Anhui University, Hefei 230601, China, and also with the Anhui Provincial Key Laboratory of Multimodal Cognitive Computation, School of Computer Science and Technology, Anhui University, Hefei 230601, China (e-mail: wft@ahu.edu.cn)