In a visual cryptography scheme, a secret image is encoded into n shares, in the form of transparencies. The shares are then distributed to n participants. Qualified subsets of participants can recover the secret image by superimposing their transparencies, but non-qualified subsets of participants have no information about the secret image. Pixel expansion, which represents the number of subpi...

Ota and Tokuda [2] gave a minimum degree condition for a K1,n-free graph to have a 2factor. Though their condition is best-possible, their sharpness examples have edge-connectivity one. In this paper, we improve their minimum degree condition for K1,n-free graphs with large connectivity or large edge-connectivity. Our bound is sharp, and together with Ota and Tokuda’s theorem, we completely det...

The classical error analysis for the Nédélec edge interpolation requires the so-called regularity assumption on the elements. However, in [18], optimal error estimates were obtained for the lowest order case, under the weaker hypothesis of the maximum angle condition. This assumption allows for anisotropic meshes that become useful, for example, for the approximation of solutions with edge sing...

Image Quality of spacecraft sensors vary between ground pre-launch measure, after launch and over satellite lifetime due to launching vibration and space harsh environment. Due to the inaccessibility of the satellite on orbit, it is mandatory to use indirect method in order to estimate satellite performances. The aim of this work is to estimate the Image Quality of satellite by using the sharp ...

Steganography is widely used to embed a massive amount of secret information. Several methods focus on taking advantage of a sharp area in which to embed secret information due to its ability to contain more secret bits undetected than a smooth area. Consequently, we propose a scheme that presents a major distinction between sharp areas and smooth areas by utilizing hybrid edge detection. To re...

A variational ν = 2/3 state, which unifies the sharp edge picture of MacDonald with the soft edge picture of Chang and of Beenakker is presented and studied in detail. Using an exact relation between correlation functions of this state and those of the Laughlin ν = 1/3 wavefunction, the correlation functions of the ν = 2/3 state are determined via a classical Monte Carlo calculation, for system...

Using a new MBE growth technique, we fabricate a two-dimensional electron system which is bent around an atomically sharp 90 corner. In the quantum Hall regime under tilted magnetic fields, we can measure equilibration between both coand counter-propagating edge channels of arbitrary filling factor ratio. We present here 4-point magnetotransport characterization of the corner junction with fill...

In this paper we propose a multipartite version of the classical Turán problem of determining the minimum number of edges needed for an arbitrary graph to contain a given subgraph. As it turns out, here the non-trivial problem is the determination of the minimal edge density between two classes that implies the existence of a given subgraph. We determine the critical edge density for trees and ...

We propose a method for extracting lowdimensional features from omnidirectional images to be used for robot localization and navigation. Edge detection is combined with thresholding to locate sharp edge pixels, the coordinates of which are fed into a Parzeii density estimator to compute the edge spatial density. The use of the Fast Fourier Transform makes this density estimate feasible in real-...