为提升不确定环境下信息描述的准确性, 提出了区间值勾股三角模糊语言集(interval-valued pythagorean triangular fuzzy linguistic set, IVPTrFLS), 并研究了区间值勾股三角模糊语言变量(IVPTrFL variable, IVPTrFLV)相关的基本理论. 同时, 针对区间值勾股三角模糊语言环境的多准则决策问题, 提出了一种改进的基于区间的组合评价(combinative distance-based assessment, CODAS)方法, 即 IVPTrFL-CODAS 法. 首先, 定义了 IVPTrFLV 的概念、运算法则、Score 函数、Accuracy 函数及距离公式, 提出了区间值勾股三角模糊语言优先加权(IVPTrFL prioritized weighted arithmetic averaging, IVPTrFLPWAA)算子, 并对计算规则及算子性质给予证明; 然后, 通过求解属性权重的相对重要性系数, 建立了基于 IVPTrFLV 的改进 CODAS 方法; 最后, 通过实例对所提出方法的有效性及稳定性进行了验证.

To improve the accuracy of information descriptions in uncertain environments, an interval-valued Pythagorean triangular fuzzy linguistic set is proposed, and basic theories of interval-valued Pythagorean triangular fuzzy linguistic variables (IVPTrFLVs) are critically examined. In addition, an improved combinative distance-based assessment (CODAS) method for solving multi-criteria decision-making problems is developed. First, this study defines the IVPTrFLVs, operational rules, score function, accuracy function, and the formulas for calculating Hamming, Euclidean, and Taxicab distances. An IVPTrFL weighted arithmetic averaging (IVPTrFLPWAA) operator is proposed. Then, by calculating the relative importance coefficient of criteria weight, the study establishes an improved CODAS method based on IVPTrFLVs. Finally, the validity and stability of the proposed method are verified through an example.