complex-number dea models in two-stage network structures complex-numbers, two-stage network dea

Data envelopment analysis (dea) is a nonparametric approach for measuring the relative efficiency of a decision making units consists of multiple inputs and outputs. especially the literature on network –structured performance analysis assumes semi positive real valued data, whilst in some real occasions, the data may have a complex structures. the motivation of this study is developing a two-stage network structures in presence of complex-valued numbers. as far as we are aware, the number of paper relying on complex-numbers are rare. the formulation developed in this paper enable one to estimate the efficiency when the data are complex.