in this paper, presenting two simple methods for ranking of efficient dmus in dea models that included to add one virtual dmu as ideal dmu and is using the additive model. note that, we use an ideal point just for comparing efficient dmus with. although these methods are simple, they have ability for ranking all efficient dmus, extreme points and the others, also they are capable of ranking the...

We analyze the global structure of a family of Einstein-Maxwell solutions parametrized by mass, charge and cosmological constant. In a qualitative classification there are: (i) generic black-hole solutions, describing a Wheeler wormhole in a closed cosmos of spatial topology S × S; (ii) generic naked-singularity solutions, describing a pair of “point” charges in a closed cosmos; (iii) extreme b...

In this paper we determine the computational complexity of the dynamic convex hull problem in the planar case. We present a data structure that maintains a finite set of n points in the plane under insertion and deletion of points in amortized O(logn) time per operation. The space usage of the data structure is O(n). The data structure supports extreme point queries in a given direction, tangen...

Twenty-four algorithmic variants of the path-generation approach were investigated, based on the formulated LP model (MMP, MMD), the LP solution method (primal, dual), the pricing mechanism (single, multiple, partial), and the selection of dual variables (extreme-point, interior-point). Table I summarizes the codings used to specify these 24 algorithms. In option C, the master problem was solve...

Climate is the most important factor which control desertification .In order to detect climate changes in desert zones, time trend analysis is applied to extreme indices in Kashan station using extreme climate index software (ECIS). Results show significant trends in extreme indices during the past decade 1995-2004 and the pronounced warming is associated with a negative trend in cold extremes....

The point density is a preeminent parameter on airborne laser scanner surveys. It is not only related to accuracy but costs and savings. The lack of uniformity of the point density across the survey is wellknown in the scientific community. This paper analyzes the behaviour of the point density derived by an oscillating mirror laser scanner on different single strips on flat bare ground in orde...

Even though most work on change-point estimation focuses on changes in the mean, changes in the variance or in the tail distribution can lead to more extreme events. In this paper, we develop a new method of detecting and estimating the change-points in the tail of multiple time series data. In addition, we adapt existing tail change-point detection methods to our specific problem and conduct a...

We consider the Survivable Network Design Problem (SNDP) and the Symmetric Traveling Salesman Problem (STSP). We give simpler proofs of the existence of a 2 -edge and 1-edge in any extreme point of the natural LP relaxations for the SNDP and STSP, respectively. We formulate a common generalization of both problems and show our results by a new counting argument. We also obtain a simpler proof o...