1. School of Geography and Information Engineering, China University of Geosciences, Wuhan, Hubei province, P. R. China
2. Center for Spatial Information Science, The University of Tokyo, Chiba, Japan
3. School of Urban Planning & Design, Peking University Shenzhen Graduate School, Shenzhen, Guangdong province, P. R. China
4. Cartography and Visual Analytics, Technical University of Munich, Munich, Germany