Abstract
Many operators have been developed for aggregating interval-valued intuitionistic fuzzy information. However, the existing interval-valued intuitionistic fuzzy aggregation operators can not reflect the concentration of the data in group decision making. In this paper, we present some new synthesized interval-valued intuitionistic fuzzy aggregation operators based on the existing interval-valued intuitionistic fuzzy aggregation operators and the clustering technique. The characteristic of these synthesized interval-valued intuitionistic fuzzy aggregation operators is that they can consider and reflect the density of the interval-valued intuitionistic fuzzy information distribution. Moreover, an approach to group decision making based on interval-valued intuitionistic preference relations by using these proposed operators is developed. Finally a numerical example is given to illustrate the solution process of our method.