1. School of Software, Yunnan University, Kunming, Yunnan, China
2. Engineering Research Center of Cyberspace, Yunnan University, Kunming, China
3. School of Physics and Electronic Science, Normal University, Zunyi, China
4. School of Mathematics and Statistics, Yunnan University, Kunming, Yunnan, China
5. Institute of Technology Management, National Chiao Tung University, Hsinchu, Taiwan