1. Jiangsu Key Laboratory of Urban ITS, Southeast University, Nanjing, China
2. Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong, China
3. Department of Geography, Ghent University, Ghent, Belgium
4. School of Electro-Mechanical Engineering, Guangdong University of Technology, Guangzhou, China
5. Department of Geography, University of Tartu, Tartu, Estoni
6. College of Civil Aviation, Nanjing University of Aeronautics and Astronautics, Nanjing, China