Risk Assessment Method Based On Type-2 Fuzzy Sets And Its Application In Medical Waste Treatment

In recent years,the amount of medical waste has been increasing.The sudden outbreak of the COVID-19 has further aggravated the pressure on medical waste treatment.How to choose an appropriate medical waste treatment technology has become a key issue.Due to the direct or indirect infectiousness of medical waste,it is necessary to consider not only the treatment effect,personnel operation,and environmental impact,but also the potential risks during the treatment process.Therefore,the selection of appropriate medical waste treatment technology can be regarded as a risk assessment problem based on multi-attribute decision-making,and a multi-criteria evaluation system including risk criterion needs to be established.At the same time,the evaluation of qualitative criteria is uncertain,which is subjective cognitive information based on the knowledge and experience of relevant decision makers.Therefore,the thesis introduces the interval type-2 fuzzy sets into the decision-making process to take into account the uncertainty of the evaluation of qualitative criteria.It conducts basic theoretical research from two aspects: the risk analysis based on the type-2 fuzzy sets and the evaluation of alternative solutions based on the type-2 fuzzy sets.Then the whole process of risk assessment model is constructed and the application research is developed.The specific research contents are introduced below.Firstly,for the analysis of risk criterion under uncertain environment,the Fine-Kinney framework is introduced to identify potential hazards.The risk evaluation information of decision makers is converted into trapezoidal interval type-2 fuzzy numbers.The best-worst method(BWM)is introduced to calculate the objective weights of risk parameters.Then,based on the behavioral decision-making method,the risk prioritization method based on the generalized TODIM(an acronym in Portuguese of Interactive and Multi-criteria Decision Making)method is proposed to obtain the ranking results of potential hazards.Finally,an example is used to verify the validity and rationality of the proposed risk analysis model.Secondly,to solve the problem of the evaluation of alternative solutions under uncertain environment,the traditional DEMATEL method is combined with the type-2 fuzzy sets to calculate the criteria weights considering the correlation between criteria.At the same time,the prioritized aggregation(PA)operator is combined with the type-2 fuzzy sets to integrate the uncertain information considering the priority of decision makers.Based on the integrated comprehensive evaluation information,a type-2 fuzzy preference ranking organization methods for enrichment evaluations(PROMETHEE-Ⅱ)is proposed to determine the ranking results of all alternatives.A calculation example is used to verify the effectiveness of the proposed model.Thirdly,the thesis systematically describes the risk assessment problem based on multi-attribute decision-making under uncertain environment,and defines the process and specific calculation steps.Fine-Kinney method is introduced to identify potential hazards in risk analysis stage;fuzzy DEMATEL and fuzzy PA operator are proposed to consider the correlation between risk parameters and the priority relationship between decision makers,retaining the uncertainty in assessment information.Furthermore,the relative weights of the hazards are obtained according to the risk values of potential hazards,and the risk assessment information of all alternatives is integrated.In the evaluation of alternative solutions stage,all evaluation criteria are determined,and the fuzzy DEMATEL and fuzzy PA operators are used to calculate the weights of all criteria.The risk assessment information obtained in risk analysis stage is substituted into the evaluation process.Finally,the ranking results of all alternatives are determined by using type-2 fuzzy PROMETHEE-Ⅱ method based on the integrated evaluation information.Finally,the risk assessment model based on type-2 fuzzy multi-attribute decision-making proposed in the thesis is applied to the selection problem of medical waste treatment technology.An evaluation system based on medical waste treatment technology is established,and the qualitative evaluation results of decision makers are collected for calculation.Corresponding recommendations of medical waste treatment technology selection are proposed based on the evaluation results.