Agglomeration China 2 Regional planning Sustainable development 2 Urban agglomerations 2 agglomeration 2 Beijing [China] 1 Beijing(Jing)-Tianjin(Jin)-Hebei(Ji) (JJJ) urban agglomeration 1 Beijing(jing)-tianjin(jin)-hebei(ji) (JJJ) urban agglomeration 1 CG-GSO model 1 Competition 1 Comprehensive gravity-gram schmidt orthogonalization coupling model model 1 Coupling models 1 Economic and social effects 1 Economics 1 Entropy TOPSIS model 1 Environmental pressures 1 Forecasting 1 Gram-Schmidt orthogonalizations 1 Gray forecast 1 Gray forecasts 1 Green manufacturing 1 Hebei 1 Hierarchical clustering 1 Hierarchical clustering analysis 1 Industrial green competitiveness 1 Industrial green development 1 Obstacle factor 1 Obstacle factors 1 Pearl River delta 1