Research On Urban Distribution Centers Layout From The Perspective Of Social Welfare

As an important part of logistics facilities,urban distribution centers play a pivotal role in the whole logistics system,whose layout has a great impact on the economy and efficiency of the whole logistics system.In recent years,with the large-scale expansion of megacities,logistics facilities have been moving from urban areas to suburbs,a phenomenon known as "logistics sprawl".The relocation of logistics facilities greatly increases the mileage of distribution vehicles,resulting in more negative externalities,such as the emission of air pollutants,traffic congestion,traffic noise and etc.,thus affecting the residents' living environment and harming the social welfare.In order to reduce the negative externalities of logistics activities and maintain the social welfare,it is necessary to make an in-depth exploration on the optimization of urban distribution centers' layout.From the perspective of social welfare,this paper is based on externality theory,fuzzy decision theory,system optimization theory and game theory,synthetically applies multi-attribute group decision making method,integer programming method and evolutionary game method,employs qualitative analysis and quantitative calculation,and finally studies the layout optimization of urban distribution centers under different information conditions and the design of governmental intervention mechanism.The specific work has been done in the following aspects:(1)This paper studies the layout optimization of urban distribution centers under uncertain information.A new multi-attribute group decision making technique based on Rough Analytic Hierarchy Process(RAHP)and 2-tuple hybrid ordered weighted averaging operator(THOWA)is proposed.The evaluation index system is constructed from four dimensions of economy,policy,society and ecology.The criteria weights are calculated by RAHP combing the evaluation of logistics experts,and the evaluation information of the scheme are aggregated with the improved THOWA.Through the case study,the validity of the method is verified,and the layout mode of distribution centers in megacities is studied with the evaluation method.The sensitivity analysis of the criterion weights is conducted to verify the stability and reliability of the method.(2)This paper studies the layout optimization of urban distribution centers under deterministic information.Considering the negative externalities of logistics activities,a new mixed integer linear programming model is proposed to optimize the layout of urban distribution centers.The objective of the model is to minimize the total cost,which contains the economic cost,environmental cost and socio-economic cost of logistics activities.Particularly the model is characterized with measuring and monetizing the negative externalities of logistics activities.To verify the validity of the model,a case study is conducted,and CPLEX is employed for the optimization purpose,which study the layout mode of distribution centers in megacities with the modeling method.In addition,the sensitivity analysis of negative externality cost is carried out to investigate the influence of various parameters coefficients on the optimal layout results.(3)This paper studies the design of governmental intervention mechanism in the layout of urban distribution centers.Under the condition that the urban distribution centers' layout optimization scheme is explicit,this paper designs a reasonable mechanism for the government to intervene in the layout optimization of urban distribution centers,establishes a static evolutionary game model and three dynamic evolutionary game models for the government and distribution enterprises with considering consumers' green preferences.Through theoretical derivation and case simulation,the interaction mechanism between government and distribution enterprises in the layout optimization is analyzed,the evolution direction of game system under different tax and subsidy mechanisms is studied,in addition the optimal combination intervention mechanism is obtained,which provides a theoretical basis for designing the governmental intervention mechanism scientifically.Furthermore,a sensitivity analysis of consumer's green preference coefficient is carried out to explore the influence of consumers' green preference on the evolutionary game system.