1. School of Mathematics and Statistics, Hebei University of Economics and Business, Shijiazhuang 050061, P. R. China
2. GIS Big Data Platform for Socio-Economy in Hebei, Shijiazhuang 050061, Hebei, P. R. China
3. School of Management Science and Engineering, Hebei University of Economics and Business, Shijiazhuang 050061, Hebei, P. R. China