This paper shows how scale efficiency can be measured from an arbitrary parametric hyperbolic distance function with multiple outputs and multiple inputs. It extends the methods introduced by Ray (J ...

M. Papadimitrakis, On Convexity of Level Curves of Harmonic Functions in the Hyperbolic Plane, Proceedings of the American Mathematical Society, Vol. 114, No. 3 (Mar., 1992), pp. 695-698 ...