1. Xiamen University, Fujian Key Laboratory of Sensing and Computing for Smart Cities, School of Informatics, Xiamen University, Xiamen, China
2. Peking University, Key Laboratory of High Confidence Software Technologies (Peking University), Ministry of Education, Department of Computer Science and Technology, Peking University, Beijing, China
3. Peking University, Key Laboratory of High Confidence Software Technologies (Peking University), Ministry of Education, Department of Computer Science and Technology, Peking University, Beijing, China and Telecom SudParis, Institut Mines, Telecom SudParis, Evry, France