Saint-Léonard-de-Noblat, France
Saint-Léonard-de-Noblat, France

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Zerdzicki K.,Technical University of Gdansk | Klosowski P.,Technical University of Gdansk | Woznica K.,INSA Val de Loire | Woznica K.,PRISME Laboratory
Shell Structures: Theory and Applications - Proceedings of the 10th SSTA 2013 Conference | Year: 2014

The study of inelastic properties of the technical fabric Valmex used for 20 years as the roof structure of the Forest Opera in Sopot (Poland) is presented. Uniaxial tensile laboratory tests with constant strain rate have been conducted and analysed. Parameters of the Bodner-Partom constitutive model have been identified and verified by numerical simulations.Two approaches to parameter identification have been proposed: one (simplified) for laboratory analysis and the other (extended) for numerical calculations of the shell structures covered with the technical fabrics. Both approaches have proved their correctness in the FEM analysis.

Thameri M.,Telecom ParisTech | Boyer R.,University Paris - Sud | Abed-Meraim K.,PRISME Laboratory
ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings | Year: 2013

Statistical Resolution Limit (SRL), defined as the minimal separation to resolve two closely spaced signals, is one of the important tools to evaluate a given system performance. Based on S.T. Smith's formulation of the SRL, this paper provides a methodology to compute an approximate analytical expression of the resolution limit in the Gaussian model case. As an application, we consider the particular case of two sources located in the near field and consider the resolution limit in terms of minimum angular separation. Discussion and numerical illustrations are then given to get more insights on the proposed derivation and to validate our theoretical results. © 2013 IEEE.

Belayachi N.,PRISME laboratory | Bouasker M.,CNRS Center for Research on Divided Matter | Hoxha D.,PRISME laboratory | Al-Mukhtar M.,CNRS Center for Research on Divided Matter
Applied Mechanics and Materials | Year: 2013

This paper presents an investigation on the use of new light-weight construction material, composed of lime, water and cereal straw fiber. Two types of fibers were used: wheat and barley straw. The influence of some parameters such as fiber types, binder types (lime and/ or limecement), fiber to binder ratio (F/B) and Water to Binder ratio (W/B) on the mechanical and thermal properties is studied. Compressive strength, thermal conductivity and density of the material were investigated. The results indicated that the thermal conductivity of the straw-lime composites decreased with increasing straw content. The result comparisons also revealed that the composite reinforced by wheat straw fibres has the highest compressive strength. © (2013) Trans Tech Publications, Switzerland.

Boudjellal A.,Prisme Laboratory | Abed-Meraim K.,Prisme Laboratory | Belouchrani A.,Polytechnic School of Algiers | Ravier P.,Prisme Laboratory
IEEE Workshop on Statistical Signal Processing Proceedings | Year: 2014

This paper deals with adaptive Constant Modulus Algorithm (CMA) for the blind separation of communication signals. Ikhlef et al. proposed in 2010 an efficient block implementation of the CMA using Givens rotations. We introduce herein a fast adaptive implementation of this method which exploits recent developments on whitening techniques together with appropriate updating of the used statistics and efficient selection of the Givens rotation parameters. The proposed algorithm shows significantly improved performance with respect to existing techniques as illustrated by the simulation results. © 2014 IEEE.

Shah S.A.W.,King Fahd University of Petroleum and Minerals | Abed-Meraim K.,PRISME Laboratory | Al-Naffouri T.Y.,King Fahd University of Petroleum and Minerals | Al-Naffouri T.Y.,King Abdullah University of Science and Technology
ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings | Year: 2015

The issue of blind Multiple-Input and Multiple-Output (MIMO) deconvolution of communication system is addressed. Two new iterative Blind Source Separation (BSS) algorithms are presented, based on the minimization of Multi-Modulus (MM) criterion. A pre-whitening filter is utilized to transform the problem into finding a unitary beamformer matrix. Then, applying iterative Givens and Hyperbolic rotations results in Givens Multi-modulus Algorithm (G-MMA) and Hyperbolic G-MMA (HG-MMA), respectively. Proposed algorithms are compared with several BSS algorithms in terms of Signal to Interference and Noise Ratio (SINR) and Symbol Error Rate (SER) and it was shown to outperform them. © 2015 IEEE.

Haritopoulos M.,PRISME Laboratory | Roussel J.,PRISME Laboratory | Capdessus C.,PRISME Laboratory | Nandi A.K.,Brunel University
IFMBE Proceedings | Year: 2014

In this work, a novel method based on the cyclostationary properties of electrocardiogram (ECG) signals is introduced in order to classify independent subspaces into components reflecting the electrical activity of the foetal heart and those corresponding to mother's heartbeats, while the remaining ones are mainly due to noise. This research is inspired from multidimensional independent component analysis (MICA), a method that aims at grouping together into independent multidimensional components blind source separated signals from a set of observations. Given an input set of observations, independent component analysis (ICA) algorithms estimate the latent source signals which are mixed together. In the case of ECG recordings from the maternal thoracic and abdominal areas, the foetal ECGs (FECGs) are contaminated with maternal ECGs (MECG), electronic noise, and various artifacts (respiration, for example). When ICA-based methods are applied to these measurements, many of the output estimated sources have the same physiological origin: the mother's or the foetus' heartbeats. Thereby, we show that a procedure for automatic classification in independent subspaces of the extracted FECG and MECG components is feasible when using a criterion based on the cyclic coherence (CC) of the signal of interest. © Springer International Publishing Switzerland 2014.

Soury H.,King Abdullah University of Science and Technology | Abed-Meraim K.,PRISME Laboratory | Alouini M.-S.,King Abdullah University of Science and Technology
Conference Record - Asilomar Conference on Signals, Systems and Computers | Year: 2015

An impulsive noise environment is considered in this paper. A new aspect of signal truncation is deployed to reduce the harmful effect of the impulsive noise to the signal. A full rank direct solution is derived followed by an iterative solution. The reduced rank adaptive filter is presented in this environment by using two methods for rank reduction, while the minimized objective function is defined using the Lp norm. The results are presented and the efficiency of each method is discussed. © 2014 IEEE.

Mangeot A.,PRISME Laboratory | Mangeot A.,French National Center for Space Studies | Gascoin N.,PRISME Laboratory | Gillard P.,PRISME Laboratory
20th AIAA Computational Fluid Dynamics Conference 2011 | Year: 2011

Hybrid rocket technology is known since the 30's and it is covered by a large number of experimental, fundamental and applied research works. It still suffers from a lack of chemical description and of detailed numerical simulation of core phenomena. Several numerical codes have emerged to simulate hybrid rocket combustion chamber but with limited consideration for detailed chemistry. They generally use global Arrhenius law or tabulated regression rate to simulate the solid fuel pyrolysis and equilibrium calculation for the combustion. A new 2-D transient reactive numerical code is proposed in this paper with the use of detailed chemical mechanisms for both pyrolysis and combustion reactions (over 1000 species and 10000 reactions). The features of the numerical code are presented in this paper, as well as the equations used to model the physical and chemical phenomena. The simplification assumptions are presented and the code validation is proposed through analytical and numerical comparisons with bibliographic data on reference test cases. The heat transfer in solid phase has been validated with a 99, 9% accuracy. The mass and heat transfer in the gas phase have shown a mass and energy conservation of around 99, 7%. The gas flow has been validated also on the boundary layer with more than 99, 5% accuracy. For chemistry phenomena, special treatment must be applied, leading to an error less than 2% on the ignition delay for combustion process. © 2011 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

Boutat D.,PRISME Laboratory | Barbot J.-P.,ENSEA Cergy | Barbot J.-P.,French Institute for Research in Computer Science and Automation | Darouach M.,Nancy Research Center for Automatic Control
Proceedings of the IEEE Conference on Decision and Control | Year: 2013

This paper supplies a new algorithms to compute the internal dynamics (or inversion dynamics) of affine MIMO control nonlinear systems. This algorithm consider both cases regular or singular characteristic matrix. Furthermore, it provides an extension to a class of nonlinear descriptor systems. © 2013 IEEE.

Boudjelaba K.,Prisme Laboratory | Ros F.,Prisme Laboratory | Chikouche D.,University of mSila | Chikouche D.,Ferhat Abbas University Setif
Expert Systems with Applications | Year: 2014

Although genetic algorithms (GAs) have proved their ability to provide answers to the limitations of more conventional methods, they are comparatively inefficient in terms of the time needed to reach a repeatable solution of desired quality. An inappropriate selection of driving parameters is frequently blamed by practitioners. The use of hybrid schemes is interesting but often limited as they are computationally expensive and versatile. This paper presents a novel hybrid genetic algorithm (HGA) for the design of digital filters. HGA combines a pure genetic process and a dedicated local approach in an innovative and efficient way. The pure genetic process embeds several mechanisms that interact to make the GA self-adaptive in the management of the balance between diversity and elitism during the genetic life. The local approach concerns convergence of the algorithm and is highly optimized so as to be tractable. Only some promising reference chromosomes are submitted to the local procedure through a specific selection process. They are more likely to converge towards different local optima. This selective procedure is fully automatic and avoids excessive computational time costs as only a few chromosomes are concerned. The hybridization and the mechanisms involved afford the GA great flexibility. It therefore avoids laborious manual tuning and improves the usability of GAs for the specific area of FIR filter design. Experiments performed with various types of filters highlight the recurrent contribution of hybridization in improving performance. The experiments also reveal the advantages of our proposal compared to more conventional filter design approaches and some reference GAs in this field of application. © 2014 Elsevier Ltd. All rights reserved.

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