Evaluation Method Of Urban Sustainable Development Based On Bipolar Fuzzy Set

Since the reform and opening up,China's urbanization process has accelerated and its urban development shows a rapid trend.However,in the process of development in many cities,the rapid economic growth has been realized at the cost of over-exploiting resources and polluting the environment.Nowadays,many cities are facing the environmental and social problems,such as resource depletion and severe environmental pollution.The root cause is that they have insufficient concept about sustainable development.The sustainable development of a city is the coordinated development of economy,society and environment.There are inevitable contradictions existing between these three aspects,so how to coordinate the contradictions between them and how to promote sustainable urban development have been the focus of research as well as attention of scientific workers and city managers in the past ten years or so.During the process of research,it was found that when dealing with the conflicts among the three aspects in the course of urban development,there may be bipolar conflicts at each level itself.Taking the economy as an example,a resource-based city which takes the economy as its main development goal may obtain great economic benefits in the short term and its short-term economic evaluation has a high positive value.However,if the economic factors are taken into account for the long run,over-exploitation will result in environmental degradation as well as population loss.After the decline in resource output,economic development has often been into stagnation.Besides,the environmental restoration needs greater economic input and its longterm economic evaluation shows relatively high negative values.In the existing urban sustainable evaluation system,people often ignore the polarities of the evaluation factors.Even if they have noticed about that,they might not regard it as the polarities of one factor,Instead,they regard it separately as diverse factor to evaluate separately,which is obviously not reasonable.It is noted that compared with the common fuzzy sets,the unique incompatible bipolarity of bipolar valued fuzzy sets can well describe this kind of bipolarity conflict.Therefore,based on the bipolar fuzzy theory,this paper studies the evaluation of urban sustainable development from the perspective of bipolar conflict.The main work of this paper is as follows:1.In theory,in accordance with the demands of sustainable development evaluation of cities,some definitions of ordinary fuzzy sets are extended to the bipolar fuzzy environment: bipolar fuzzy similarity measures,algorithms,and distance measures are given respectively.Besides,that paper also combines with Hammy's mean,therefore,diverse forms of bipolar fuzzy set resolvers are also given.2.Whether the evaluation index system is completely and scientifically associated with the final result of the evaluation.This paper combines the interval value with the original singlevalued statistical method,puts forward a method for selecting interval statistical indicators,and applies it to the selection of indicators so as to carry out a more scientific and reasonable urban sustainable development evaluation index system.3.In terms of evaluation method,and in allusion to the evaluation of the sustainable development of static cities,this paper makes use of the DEMATEL method to determine the weight of indicators,which improves the defect that the traditional ELECTRE method ignores the interaction between indicators.This paper also extends ELECTRE to a bipolar fuzzy environment,and an urban sustainable development evaluation method combining the ELETRE and DEMATEL methods is contructed.In terms of the sustainable dynamic evaluation of the city,this paper takes into account the impact of time factors on the decision results and contructs an introduction of time-weighted dynamic decision-making methods for sustainable urban development.The information entropy of the bipolar evaluation values at diverse times is used to determine the time weights to form an integrated decision matrix,and the bipolar PROMETHEE method is used to sort the cities.Through case analysis as well as comparative analysis,this paper verifies the effectiveness and feasibility of the new method.This paper studies the sustainable development of cities from the perspective of bipolar conflict,which is relatively new.From the perspective of theory,this paper expands the relevant definitions and algorithms of bipolar fuzzy sets.In terms of methods,this paper integrates various existing methods in index selection and evaluation methods,expands them,and improves the research methods.Through examples,it can be proved that,compared with the existing methods,This paper constructs three evaluation methods from the perspective of bipolar conflict,which are more suitable for the needs of urban sustainable development.