In this paper, we aim to overcome three major shortcomings of the FDH (Free Disposal Hull) directional distance function through developing two new, named Linear and Fractional CDFDH, complete FDH measures of efficiency. To accomplish this, we integrate the concepts of similarity and FDH directional distance function. We prove that the proposed measures are translation invariant and unit invari...

This paper deals with evaluating congestion in free disposal hull (FDH) models. There are several approaches in data envelopment analysis (DEA) literatures which discuss the theory and application of congestion. However, almost all of these approaches considered convex DEA technologies. So, in the case of nonconvex technologies, including FDH technology, this field is almost nil. This paper mak...

In this paper we test the hypothesis that the economic transition toward a market economy increases the efficiency of firms. We study 32 Polish electricity distribution companies between 1997-2002, by applying common benchmarking methods to the panel: the nonparametric data envelopment analysis (DEA), the free disposal hull (FDH), and, as a parametric approach, the stochastic frontier analysis ...

Container terminal production is both an important and complicated element in the contemporary global economy. Amongst other methods, the efficiency of container port or terminal production can potentially be analysed by Data Envelopment Analysis (DEA) or by the Free Disposal Hull (FDH) Model. This paper aims to evaluate the efficiency of the world’s most important container ports and terminals...

We investigate technological change with regard to CO2 emissions by passenger cars, using a Free Disposal Hull methodology to estimate technological frontiers. We have a sample of cars available in the UK market in the period 2000 – 2007. Our results show that the rates of technological change (frontier movement) and diffusion (distance to frontier at the car brand level) differ substantial bet...

in this paper, we aim to overcome three major shortcomings of the fdh (free disposal hull) directional distance function through developing two new, named linear and fractional cdfdh, complete fdh measures of efficiency. to accomplish this, we integrate the concepts of similarity and fdh directional distance function. we prove that the proposed measures are translation invariant and unit invari...

This article describes a 3D CFD (computational fluid dynamics) simulation implementation of the stepped planning hull in calm water. The turbulent free surface flow around the stepped planing hull is computed with a RANSE method, using the solver ANSYS-CFX. The turbulence model used is standard k–ε. In order to simulate the disturbed free surface, VOF model is implemented. The CFD model has bee...

We propose a hull operator, the reflex-free hull, that allows us to define a 3D analogue to bays in polygons. The reflex-free hull allows a rich set of topological types, yet for polyhedral input with n edges, it remains a polyhedral set with O(n) edges. This is in contrast to other possible hull definitions that give non-planar surfaces and higher combinatorial complexity. The reflex-free hull...