To prediction of city spatial expansion, this part brings forward predicting method of point sources radiation diffusion based on the thought of regional diffusion and takes Jinan as an example.

Our proof of the convergence is based on an asymptotic diffusion expansion and requires error estimates on a matched boundary layer approximation to the solution of the discrete-ordinate method.

Bass Bass diffusion model (Bass, the diffusion model) and its expansion theory, is often used as a market analysis tools, new products, new technology demand forecast.