In this study a directional output distance function which incorporates both desirable and undesirable output is employed to investigate the impact of privatization experienced by the Taiwan Motor Transport Company (TMTC). For the first time, we measure efficiency changes before and after privatization while treating transport risk as a joint but undesirable output. The empirical results demons...

The relationships between the generalized directional derivative of the distance function and the existence of nearest points as well as some geometry properties in Banach spaces are studied. It is proved in the present paper that the condition that for each closed subset G of X and x ∈ X \ G, the Clarke, Michel-Penot, Dini or modified Dini directional derivative of the distance function is 1 o...

In this paper, we address a shortest path problem where an autonomous vehicle moves on a polyhedral surface according to a distance function that depends on the direction of the movement (directional) and on the friction of the space (frictional). This shortest path problem generalizes a hierarchy of problems and finds geometric structure to solve several proximity problems. We perform the char...

Bankruptcy in the same amount of time and history is very rampant and therefore the vision of the future can be prevented. Using data envelopment analysis (DEA) and malmquist index can precise evaluating of the performances of many different kinds of decision making units (DMU) such as hospitals, universities, business firms, etc. In this paper, we will modify directional distance formulation o...

The efficiency measurement is a subject of great interest. The majority of studies on DEA models have been carried out using radial or non-radial approaches regarding the application of DEA for the efficiency measurement. This paper, based on the directional distance function, proposes a new generalized hybrid measure of efficiency under generalized returns to scale with the existence of both r...

There are several distance function definitions in a general production framework, including Data Envelopment Analysis, which can be used to describe the production technology and to define corresponding measures of technical efficiency notably the Shephard and the directional distance functions . This paper introduces a generalisation of the distance function concept based on the idea of minim...

A modified generalised directional distance function data envelopment analysis model is introduced into the smoothed bootstrap context. The new handles asymmetrically desirable and undesirable outputs deals with positive negative values, while bias-corrected estimators are independent of length direction vector. reason for development this efficiency assessment estimation degree operating gains...

The modification of the Clarke generalized subdiNerentia1 due to Michel and Penot is a useful tool in determining differentiability properties for certain classes of real functions on a normed linear space. The Glteaux differentiability of any real function can be deduced from the GBteaux differentiability of the norm if the function has a directional derivative which attains a constant related...