1. School of Information Science & Engineering; Lanzhou University; Lanzhou China
2. School of Software and Electrical Engineering; Swinburne University of Technology; Victoria Australia
3. Faculty of Engineering and Information Sciences; University of Wollongong; Wollongong Australia
4. Hubei Education Cloud Service Engineering Technology Research Center; Hubei University of Education; Hubei China
5. Department of Computer Science and Information Engineering; Providence University; Taichung Taiwan