Concordance Measures of a Class of Two-Parameter with Cube Generalized FGM Copulas

We study four groups of generalized FGM Copulas whose Kendall´sτ and Spearman´sρ contain nearly two parameters, with 3τ = 2ρ, that make them describe the dependence structure of the data more flexible and accurate than FGM Copula. Taking the relief factors of drainage height difference and cutting degree for example, this paper gives four specific Copulas which can prepared exactly to the dependence structure of the data.