Methods For Emergency Facility Location,Route Planning And Risk Assessment In Fuzzy Environments

Due to the suddenness,uncertainty and high destructiveness of public emergencies,government departments are often required to formulate some reasonable measures to reduce the loss of people’s lives and property,and quickly recover normal production and life order after emergencies,which tests government departments’ emergency management capacity in the face of public emergencies.Compared with other decision-making problems,emergency decision-making problems confront more complex environment,resulting in a high degree of uncertain decision information during the emergency decision-making processes.In addition,some objective reasons,such as the complexity of emergency decision-making,the incompleteness of decision-making information,and the limited cognition of decision-makers,make it difficult for the crisp decision-making methods to deal with the complex emergency decision-making problems.Currently,fuzzy sets are acknowledged as an effective tool to deal with uncertain decision-making problems.Practices have proved that using fuzzy sets to handle uncertain decision information can effectively improve the flexibility of decision-making process and the credibility of decision results.Although some scholars have proposed some emergency decision-making methods under fuzzy environments,these methods are still difficult to effectively deal with the increasingly complex emergency decision-making problems.Based on the above analysis,combined with the theories of fuzzy sets,mathematical programming,multi-criteria decision-making and preference relations,this thesis puts forward some effective fuzzy decision-making theories and methods in different fuzzy environments to solve the decision-making problems involved in the emergency response and recovery stages,such as emergency facility location,rescue route planning and resumption risk assessment.The main contents of this thesis are detailed as follows:(1)In order to address the location problem of emergency distribution center(one special form of emergency distribution facilities)after earthquakes,a bi-objective program-based location method is proposed under trapezoidal fuzzy environment,in which the decision information is represented by trapezoidal fuzzy numbers(Tr FNs).This method requires to address three important and challenging issues:(i)How to build a 0-1 mixed integer linear program-based EDC location model;(ii)How to develop an effective method to convert the trapezoidal fuzzy EDC location model into a crisp one;(iii)How to demonstrate the validity,flexibility and superiorities of the constructed model and developed solution method.Considering the acceptance degree of trapezoidal fuzzy constraints to be violated,this thesis defines a novel flexible ranking relation for Tr FNs by using the a-cut set and analyzes its desirable properties.A bi-objective trapezoidal fuzzy EDC location model(BTFELM)is built for reflecting the urgency and uncertainty of large-scale emergencies.Some essential definitions and theorems are proposed for equivalently converting the fuzzy constraints of the BTFELM into crisp one.By employing the graded mean integration representation(GMIR)of Tr FN,the BTFELM is ultimately transformed into a single objective crisp EDC location linear programming model.Wenchuan earthquake case is studied to illustrate the practicality and validity of the proposed method.Furthermore,the sensitivity and comparative analyses are provided to justify the flexibility and superiorities of the proposed method.Finally,the accuracy analyses are conducted to illustrate the reliability of the proposed method.Based on the results of case analysis and comparative analysis,this thesis summarizes some management implications related to the EDC location decision-making.(2)Aiming at locating the Fang Cang hospital(one special form of emergency shelter facilities)during the COVID-19,this thesis develops an integrated trapezoidal interval type-2fuzzy(Tr IT2F)technique for democratic-autocratic multi-criteria group decision making based on BWM(best-worst method)and VIKOR(VIsekriterijumska optimizacija i KOm-promisno Resenje).In this technique,the decision information is represented by trapezoidal interval type-2 fuzzy sets(Tr IT2FSs)and decision-makers are composed of two different levels of experts,namely a senior decision-maker(SDM)and a group of junior decision makers(JDMs).This thesis improves the existing definition of Tr IT2 FS by adding two rational constraints.A weight-normalizing theorem is initiated to normalize the Tr IT2 F weights.To determine the Tr IT2 F weights of junior decision makers(JDMs)and criteria,the classical BWM is extended into Tr IT2 F environment,which is called Tr IT2F-BWM.In this Tr IT2F-BWM,the weight-normalizing theorem is applied to normalize the Tr IT2 F weights,a consistency ratio is designed to check the reliability of the obtained Tr IT2 F weights.Based on the determined weights of JDMs and criteria,a Tr IT2F-VIKOR is developed to rank alternatives.The validity of the proposed technique is demonstrated with a makeshift(Fang Cang)hospital selection example on COVID-19.Some sensitivity and comparison analyses are provided to show the robustness,flexibility,and superiorities of the proposed technique.Based on the results of case analysis and comparative analysis,this thesis extracts some management implications related to the Fang Cang hospital location decision-making.(3)For the emergency rescue routing problem after earthquakes,this thesis develops an interactive dynamic technique by combining data envelopment analysis(DEA),traveling salesman problem(TSP)and interval-valued hesitant fuzzy constraint cone(IVHFCC).This thesis gives the definition of additive consistent normal interval-valued hesitant fuzzy preference relation(NIVHFPR)and analyses its desirable properties.Based on these properties,three linear programming models are proposed and used to repair incomplete NIVHFPR,judge the consistency of the repaired NIVHFPR and generate the additive consistent NIVHFPR,respectively.Traditional DEA potentially presumes that the weights of the input and output criteria are unrestricted,resulting in its inapplicability to some practical decision-making problems.To address this issue,an IVHFCC,which is constructed based on expert’s subjective preferences expressed by interval-valued hesitant fuzzy sets,is used to restrict the weights of input and output criteria.By incorporating TSP,DEA and the constructed IVHFCC,an interactive dynamic model is originally proposed to generate the optimal rescue routing.Some desirable properties of this interactive dynamic model are analyzed.The validity of this model is demonstrated with a real case study of Wenchuan earthquake.Some comparative analyses are provided to show the superiorities of the proposed technique.Based on the results of case analysis and comparative analysis,this thesis sums up some management implications related to emergency rescue path planning decision-making.(4)To assess college resumption risk amid regular prevention and control of COVID-19,this thesis proposes a comprehensive risk evaluation method by combining DEMATEL(Decision-making trial and evaluation laboratory),BWM and SPA(set pair analysis)under interval-valued intuitionistic fuzzy(IVIF)environment.Considering experts’ intrapersonal and group consensus level simultaneously,a bi-objective weight-determining model is proposed to derive two types of experts’ dynamic weights.IVIF-DEMATEL and IVIF-BWM are proposed to determine the weights of dimensions and the weights of criteria under each dimension,respectively.In this IVIF-BWM,two bi-objective weight-determining models are constructed by regarding expert’s pessimistic and optimistic attitudes,respectively.Based on the determined weights of experts and criteria,an IVIF-SPA is developed to assess the risk levels of all colleges and rank them according to their risk levels.The validity of the proposed technique is demonstrated with a real case of college resumption risk assessment amid regular prevention and control of COVID-19.Some sensitivity and comparison analyses are provided to show the merits of the proposed technique.Based on the results of case analysis and comparative analysis,this thesis generalizes some management implications related to risk assessment decision-making.