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Formont P.,ONERA | Formont P.,Supelec | Pascal F.,Supelec | Vasile G.,CNRS GIPSA Laboratory | And 3 more authors.
IEEE Journal on Selected Topics in Signal Processing | Year: 2011

This paper presents a general approach for high- resolution polarimetric SAR data classification in heterogeneous clutter, based on a statistical test of equality of covariance matrices. The Spherically Invariant Random Vector (SIRV) model is used to describe the clutter. Several distance measures, including classical ones used in standard classification methods, can be derived from the general test. The new approach provide a threshold over which pixels are rejected from the image, meaning they are not sufficiently close from any existing class. A distance measure using this general approach is derived and tested on a high-resolution polarimetric data set acquired by the ONERA RAMSES system. It is compared to the results of the classical α decomposition and Wishart classifier under Gaussian and SIRV assumption. Results show that the new approach rejects all pixels from heterogeneous parts of the scene and classifies its Gaussian parts. © 2010 IEEE. Source

Grange F.,CEA Grenoble | Delaveaud C.,CEA Grenoble | Viala B.,CEA Grenoble | Mahdjoubi K.,IETR
Applied Physics A: Materials Science and Processing | Year: 2011

In the present paper we study the effect of high-permeability self-polarized thin films on the characteristics of high-impedance surfaces. Analytical and numerical models are compared by using the anisotropic effective medium theory method and a full-wave simulation tool, respectively. Experimental measurements are shown and lead to a good agreement with both numerical and analytical calculations. The main objective of this paper is to predict the impact of the permeability and conductivity of the material on artificial magnetic conductor structures. © 2011 Springer-Verlag. Source

Rey T.,CNRS Complex Medical Engineering Laboratory | Razan F.,Ecole Normale Superieure de Cachan | Robin E.,R.A.U.M. | Faure S.,Ecole Normale Superieure de Cachan | And 4 more authors.
International Journal of Adhesion and Adhesives | Year: 2014

This paper investigates the effects of different surface treatments on the mechanical resistance of interface between wires of NiTi shape memory alloy and silicone rubber. Three different treatments were used; primer, plasma and combination of both. The wires deoxidation effects have also been studied. In order to characterize the interface properties in such composite material, pull-out tests were carried out by means of a home-made device. This test allows us to evaluate the mechanical resistance of the interface in terms of the maximum force reached during the test. First, results show that the debonding force is not higher after the wires deoxidation. This preparation is therefore not necessary. Second, using a primer PM820 and plasma separately leads to a significant improvment of the mechanical resistance. Third, the combination of these treatments (primer followed by plasma) and a longer time of exposure to the plasma alone get the debonding force higher. Consequently, NiTi/silicone rubber interface improved only by means of plasma offers a new way to obtain biocompatible interfaces in such composite material. © 2013 Elsevier Ltd. Source

Belhabib M.,CEA Grenoble | D'Errico R.,CEA Grenoble | Uguen B.,IETR
2016 10th European Conference on Antennas and Propagation, EuCAP 2016 | Year: 2016

This paper presents a comparison of different three dimensional (3D) MIMO Over-The-Air (OTA) multi-probe configurations. Spatial correlation is used as metric to evaluate the setup accuracy, considering different antenna probes emplacements and Elevation Spread (ES). Simulation results are presented in uniform and single cluster channel models for spherical and cylindrical 3D OTA. © 2016 European Association of Antennas and Propagation. Source

Belhabib M.,CEA Grenoble | D'Errico R.,CEA Grenoble | Bernard U.,IETR
2016 10th European Conference on Antennas and Propagation, EuCAP 2016 | Year: 2016

This paper investigates the effect of the radius of a Over-The-Air (OTA) multi-probes ring employing half-wavelength dipoles, on the emulated spatial correlation. The Device Under Test (DUT) is considered randomly oriented in the test zone. Based on the correlation error metric, antenna effect on correlation is evaluated for a Clarke's and single cluster scenarios and OTA two-dimensional rings with up to 32 probes. © 2016 European Association of Antennas and Propagation. Source

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