Super-efficiency model in the presence of negative data is a relatively neglected issue in the DEA field. The existing super-efficiency models have some shortcomings in practice. In this paper, a novel VRS radial super-efficiency DEA model based on Directional Distance Function (DDF) is proposed to provide a complete ranking order of units (including efficient and inefficient ones). The propose...

We describe a framework for the design of directional derivative kernels for two-dimensional discrete signals in which we optimize a measure of rotation-equivariance in the Fourier domain. The formulation is applicable to rst-order and higher-order derivatives. We design a set of compact, separable, linear-phase derivative kernels of di erent orders and demonstrate their accuracy.

directional simulation, among techniques for reliability analysis of engineering structures, is well known. in this context, directional simulation in load space, because of the considerable advantages of lower dimension of working space, is of considerable interest. as is expected due to structural resistance variability, the location of the relevant limit state(s) is no longer constant and mu...

high temperatures are often encountered in almost all of the combustion systems, therefore, thermal radiation heat transfer can influence the droplets heat up rate and consequently their life time. in this paper, the effect of thermal radiation heat transfer is investigated for two cases of directional and spherically symmetric illuminations. the flow and temperature fields insdie and outside o...

This article has focused on evaluation and identification of effective parameters in positioning performance with an odometry approach of an omni-directional mobile robot. Although there has been research in this field, but in this paper, a new approach has been proposed for mobile robot in positioning performance. With respect to experimental investigations of different parameters in omni-dire...

Light interacts with an organism's integument on a variety of spatial scales. For example in an iridescent bird: nano-scale structures produce color; the milli-scale structure of barbs and barbules largely determines the directional pattern of reflected light; and through the macro-scale spatial structure of overlapping, curved feathers, these directional effects create the visual texture. Mill...

BACKGROUND Many gait variability and stability measures have been proposed in the literature, with the aim to quantify gait impairment, degree of neuro-motor control and balance disorders in healthy and pathological subjects. These measures are often obtained from lower trunk acceleration data, typically acquired during rectilinear gait, but relevant experimental protocols and data processing t...

Preserving source location privacy in wireless sensor networks can be critical for several practical applications. Existing solutions proposed specifically for sensor networks rely on a combination of dynamic routing and dummy traffic to hide real event messages. While some privacy protection guarantees can be given, these solutions also tend to be expensive due to fake transmissions and non-sh...