Research On Multiple Attribute Decision Making Methods Based On Q-rung Orthopair Fuzzy Information

Aiming at multiple attribute decision-making(MADM)problem in complex fuzzy uncertain environment,various fuzzy sets are introduced into the field of decision analysis.The q-rung orthopair fuzzy number can reflect people's wishes more accurately and express evaluation information more comprehensively and objectively.In this thesis,several MADM methods based on q-rung orthopair fuzzy information are studied.A hesitant Pythagorean fuzzy MADM method based on DEMATEL and VIKOR is proposed.Firstly,attribute weights are determined by the DEMATEL method by using the evaluation values given by decision makers and alternatives are ranked by the VIKOR method for the decision problems with conflicting attributes.Then compare ranking results of the proposed method with TOPSIS and weighted arithmetic average method.If the ranking results are inconsistent,the combined fuzzy Borda method is used to rank alternatives after pre-consistency test based on Kendall-W coefficient and the Spearman coefficient is used for the post-consistency test.Finally,a numerical example is given to illustrate that when the ranking results of several methods are inconsistent,and more reasonable ranking result can be obtained by considering the consistency test.A q-rung orthopair fuzzy COPRAS method with unknown attribute weights is studied.Firstly,the CRITIC method is a multiple attribute decision making method based on the contrast strength and conflict between attributes,in which attribute data is used to determine attribute weights.Secondly,the COPRAS method is introduced into q-rung orthopair fuzzy environment by considering conflicting factors between attributes to get reasonable results.Finally,a q-rung orthopair fuzzy MADM method based on CRITIC-COPRAS is proposed,and the feasibility and effectiveness of this method are demonstrated through comparative analysis.Some new aggregation operator based on q-rung orthopair fuzzy sets are studied.Firstly,some operation laws of Frank operator in q-rung orthopair fuzzy environment are defined.Secondly,some new aggregation operators are proposed based on Frank operator and Bonferroni mean operator including q-ROFFWA operator,q-ROFFWG operator,q-ROFFWBM operator and q-ROFFWGBM operator.Some desirable properties and some special cases of these operators have been studied.Finally,a new MADM method based on the above operators is proposed.Since parameters of Frank operator can be selected flexibly according to actual needs and Bonferroni mean operator can consider the relationship between input parameters,new operators based on the two operators can get more comprehensive decision making results.