Research On Evaluation Model Of City Cyclic Economical System Based On Fuzzy Reasoning

In the course of implementing the sustainable development strategy of city, it is an inevitable choice of advancing sustainable development to establish and develop cyclic economic system in the city. The purpose of the city cyclic economy lies in making the economic development, social progress and protecting ecological environment of the city, so the city cyclic economy system is made up of economy subsystem , society subsystem and ecology subsystem, which must reach a kind of ideal optimization grouping state.The paper regards city cyclic economic system as the research object, constructing the evaluation index system of city cyclic economic system, establishing the evaluation model of the city cyclic economical system based on fuzzy reasoning. The evaluation model is applied to the appraisal of the cyclic economy system of Nanjing concretely. The main content includes three aspects as follow:Firstly, introduce some concepts: cyclic economy,city cyclic economy,ecocity and city sustainable development systemically. Sum up their main content and characteristic, explain the interrelation of city cyclic economical,ecocity and city sustainable development about city.Secondly, introduce the conceptual model of city cyclic economical system, found the model of regulation and control of this system. On this basis, the evaluation index system of the city cyclic economy system is established and the standardized method of the index is introduced. Then on the basis of fuzzy reasoning, the evaluation model based on city cyclic economy of fuzzy logic reasoning is set up. Study the solution method of evaluation model with emphasis. Finally, based on the evaluation model, the concept method of index sensitivity is found. According to the segmentation linear characteristic of membership function, the computing method similarly is obtained. Through above method, we analyze the effect on city cyclic economy system of result of calculation of the sensitivity.Thirdly, the development degree of Nanjing city cyclic economical system is evaluated through above evaluation model. As a result, it is in good state to obtain the cyclic economic development of Nanjing. According to the result of calculation of sensitivity of the index, every index plays some role to the cyclic economical system. It is concluded that energy consumption and waste water withdrawal every unit GDP play bigger negative role to city cyclic economical, the green expended the social cognition rate and the environmental protection investment occupied GDP the...