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441 results on '"University Politehnica of Bucharest [Romania] (UPB)"'

201. Improved Actuator-Fault Detection and Isolation Strategy Using Interval Observers and Invariant Sets

Author: Xu, Feng, Puig, Vicenç, Ocampo-Martinez, Carlos, Stoican, Florin, Olaru, Sorin, Universitat Politècnica de Catalunya [Barcelona] (UPC), University Politehnica of Bucharest [Romania] (UPB), Supélec Sciences des Systèmes (E3S), Ecole Supérieure d'Electricité - SUPELEC (FRANCE), European Commission, China Scholarship Council, Generalitat de Catalunya, and Lepeltier, Pascale
Subjects: [SPI]Engineering Sciences [physics], [SPI] Engineering Sciences [physics], ComputingMilieux_MISCELLANEOUS
Abstract: Trabajo presentado al 19th IFAC World Congress celebrado del 24 al 29 de agosto de 2014 en Cape Town (Sudafrica)., In this paper, an improved algorithm for an actuator fault detection and isolation (FDI) framework using a bank of interval observers previously proposed by the authors is presented, where each interval observer matches one possible system mode. Under a set of FDI conditions, this new algorithm can accurately detect and isolate the considered actuator faults. The advantage of this new algorithm consists in that it extends the effectiveness of this FDI framework. At the end, a circuit example is used to illustrate the effectiveness of this approach., The work was supported by the DGR of Generalitat de Catalunya (AGAUR Doctorat Industrial 2013-DI-041), European Commission through contract i-Sense (FP7-ICT-2009-6-270428), and China Scholarship Council (File No.2011629170).
Published: 2014

202. A multi-parameter optimization approach for complex continuous sparse modelling

Author: Emilie Chouzenoux, Jean-Christophe Pesquet, Anisia Florescu, Laboratoire d'Informatique Gaspard-Monge (LIGM), Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Bézout-ESIEE Paris-École des Ponts ParisTech (ENPC)-Université Paris-Est Marne-la-Vallée (UPEM), University Politehnica of Bucharest [Romania] (UPB), Université Paris-Est Marne-la-Vallée (UPEM)-École des Ponts ParisTech (ENPC)-ESIEE Paris-Fédération de Recherche Bézout-Centre National de la Recherche Scientifique (CNRS), and Chouzenoux, Emilie
Subjects: Mathematical optimization, [SPI] Engineering Sciences [physics], [INFO.INFO-TS] Computer Science [cs]/Signal and Image Processing, nonconvex optimization, hard thresholding, Forward–backward algorithm, Parameterized complexity, 010103 numerical & computational mathematics, 02 engineering and technology, 01 natural sciences, sparse modelling, [SPI]Engineering Sciences [physics], [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, Linearization, 2D spectrum estimation, 0202 electrical engineering, electronic engineering, information engineering, proximity operator, Differentiable function, 0101 mathematics, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing, Mathematics, forward-backward algorithm, 020206 networking & telecommunications, Sparse approximation, Function (mathematics), Lipschitz continuity, Noise, multivariate estimation, continuous compressive sensing, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract: International audience; The main focus of this work is the estimation of a complex valued signal assumed to have a sparse representation in an uncountable dictionary of signals. The dictionary elements are parameterized by a real-valued vector and the available observations are corrupted with an additive noise. By applying a linearization technique, the original model is recast as a constrained sparse perturbed model. The problem of the computation of the involved multiple parameters is addressed from a nonconvex optimization viewpoint. A cost function is defined including an arbitrary Lipschitz differentiable data fidelity term accounting for the noise statistics, and an l0-like penalty. A proximal algorithm is then employed to solve the resulting nonconvex and nonsmooth minimization problem. Experimental results illustrate the good practical performance of the proposed approach when applied to 2D spectrum analysis.
Published: 2014

203. Scattering centers monitoring in refocused SAR images on a high-resolution DEM

Author: Gabriel Vasile, Rémy Boudon, J.-P. Ovarlez, Irena Hajnsek, Silviu Ciochina, Remus Cacoveanu, Andrei Anghel, Cornel Ioana, Guy d'Urso, GIPSA - Signal Images Physique (GIPSA-SIGMAPHY), Département Images et Signal (GIPSA-DIS), Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), University Politehnica of Bucharest [Romania] (UPB), Sondra, CentraleSupélec, Université Paris-Saclay (COmUE) (SONDRA), ONERA-CentraleSupélec-Université Paris Saclay (COmUE), ONERA - The French Aerospace Lab [Palaiseau], ONERA-Université Paris Saclay (COmUE), EDF R&D (EDF R&D), EDF (EDF), DLR Microwaves and Radar Institute, and German Aerospace Center (DLR)
Subjects: Synthetic aperture radar, Layover, Early-warning radar, Spectral power distribution, Computer science, Scattering, Side looking airborne radar, Slant range, Geodesy, Space-based radar, Continuous-wave radar, Inverse synthetic aperture radar, [SPI]Engineering Sciences [physics], Bistatic radar, Radar imaging, Interferometric synthetic aperture radar, 3D radar, Tomography, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, SAR, Remote sensing
Abstract: International audience; Infrastructure monitoring applications can require the tracking of slowly moving points of a certain structure. Given a certain point from a structure to be monitored, in the context of available SAR products where the image is already focused in a slant range - azimuth grid, it is not obvious if this point is the scattering center, if it is in layover or if it is visible from the respective orbit. This paper proposes a scattering center monitoring procedure based on refocusing a set of SAR images on a provided high-resolution DEM of the structure. The scattering centers of the refocused image are detected in the 4-D tomography framework by testing if the main response is at zero elevation in the local elevation-velocity spectral distribution obtained using the Capon estimator. The algorithm is validated on real data acquired with the TerraSAR-X satellite over the Puylaurent water dam in France during March-June 2012. The relative displacements between scattering regions show very good agreement with the in situ measurements.
Published: 2014

204. Actuator-fault detection and isolation based on set-theoretic approaches

Author: Carlos Ocampo-Martinez, Sorin Olaru, Feng Xu, Vicenç Puig, Florin Stoican, Universitat Politècnica de Catalunya. Departament d'Enginyeria de Sistemes, Automàtica i Informàtica Industrial, Universitat Politècnica de Catalunya. SAC - Sistemes Avançats de Control, Universitat Politècnica de Catalunya [Barcelona] (UPC), University Politehnica of Bucharest [Romania] (UPB), Supélec Sciences des Systèmes (E3S), Ecole Supérieure d'Electricité - SUPELEC (FRANCE), China Scholarship Council, Universitat Politècnica de Catalunya, European Commission, and Generalitat de Catalunya
Subjects: Engineering, Informàtica::Automàtica i control [Àrees temàtiques de la UPC], Linear systems, Interval (mathematics), Fault (power engineering), Tolerància (Enginyeria), Invariant sets, Industrial and Manufacturing Engineering, Fault detection and isolation, Set (abstract data type), [SPI]Engineering Sciences [physics], Control theory, SYSTEMS, Zonotopes, Isolation (database systems), Invariant (mathematics), business.industry, Linear system, Tolerance (Engineering), Control engineering, Interval observers, Computer Science Applications, Control and Systems Engineering, Modeling and Simulation, Actuator, business
Abstract: Energy Efficient Buildings Special Issue., In this paper, an actuator-fault detection and isolation (FDI) approach is proposed. The FDI approach is based on a bank of interval observers, each of which is designed to match a healthy or faulty system mode. To ensure reliable FDI for all considered actuator faults, a collection of invariant set-based FDI conditions are established for the proposed technique. Under these guaranteed FDI conditions, all the considered faults can be detected and isolated during the transition induced by fault occurrences. Comparing with the existing set-based FDI approaches, the advantage of the proposed technique consists in that it combines the advantages of interval observers in the transient-state functioning and the advantages of invariant sets in the steady-state functioning. This paper is completed with the study of a continuous stirred-tank reactor (CSTR), which illustrates the effectiveness of the proposed method., The work has been supported by the DGR of Generalitat de Catalunya (SAC group Ref.2009/SGR/1491), the grant SHERECS DPI2011- 26243, European Commission through contract i-Sense (FP7-ICT-2009-6-270428) and China Scholarship Council (File No.2011629170).
Published: 2014

205. Electrical arc surveillance and localization system based on advanced signal processing techniques

Author: Mirel Paun, Daniela Deacu, Cornel Ioana, Teodor Petrut, Costin Vasile, Razvan D. Tamas, Angela Digulescu, GIPSA - Signal Images Physique (GIPSA-SIGMAPHY), Département Images et Signal (GIPSA-DIS), Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Constanta Maritime University [Roumania] (CMU), Applied Electronics and Information Engineering Department, University Politehnica of Bucharest [Romania] (UPB)-Faculty for Electronics, Telecommunications, and Information Technology, Université Maritime de Constanta, and UMC
Subjects: Signal processing, business.industry, Real-time computing, Context (language use), Multilateration, 7. Clean energy, Edge detection, Electric arc, [SPI]Engineering Sciences [physics], Wavelet, Partial discharge, Computer vision, Artificial intelligence, business, Recurrence plot, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, ComputingMilieux_MISCELLANEOUS, Mathematics
Abstract: This paper presents two methods applied in the context of surveilling and localizing electrical arcs which usually occur in photovoltaic power systems. The wavelet analysis has proved to be very powerful in transient signal detection, namely in multiscale edge detection, thereby we use this method to detect the electrical arcs and to localize them in time. Secondly, we applied the recurrence plot analysis (RPA) which presented succesful results in partial discharge time localization. In order to obtain the space localization of the electrical arc, we used the time-of-arrival of the arc at the acoustic sensor system. The system is composed of four sensors and the space localization is based on time difference of arrival, resulted from the time detection based on wavelet analysis and on RPA method.
Published: 2014

206. SAR images refocusing and scattering center detection for infrastructure monitoring

Author: Cornel Ioana, Gabriel Vasile, Remus Cacoveanu, Andrei Anghel, Jean-Philippe Ovarlez, Rémy Boudon, Guy d'Urso, Silviu Ciochina, GIPSA - Signal Images Physique (GIPSA-SIGMAPHY), Département Images et Signal (GIPSA-DIS), Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), University Politehnica of Bucharest [Romania] (UPB), Sondra, CentraleSupélec, Université Paris-Saclay (COmUE) (SONDRA), ONERA-CentraleSupélec-Université Paris Saclay (COmUE), ONERA - The French Aerospace Lab [Palaiseau], ONERA-Université Paris Saclay (COmUE), and EDF (EDF)
Subjects: Synthetic aperture radar, Layover, business.industry, Scattering, Computer science, Slant range, Inverse synthetic aperture radar, Optics, [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, Radar imaging, 3D radar, Tomography, business, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Remote sensing
Abstract: International audience; Infrastructure monitoring applications can require the tracking of slowly moving points of a certain structure. Given a certain point from a structure to be monitored, in the context of available SAR products where the image is already focused in a slant range - azimuth grid, it is not obvious if this point is the scattering center, if it is in layover or if it is visible from the respective orbit. This paper proposes a refocusing procedure of SAR images on a set of measured points among with a 4D tomography based scattering center detection. The refocusing procedure consists of an azimuth de-focusing followed by a modified back-projection on the given set of points. The presence of a scattering center at the given positions is detected by computing the local elevation-velocity plane for each point and testing if the main response is at zero elevation. The refocusing and scattering center detection algorithm is validated on real data acquired with the TerraSAR-X satellite during March-June 2012. The mean displacement velocities of the detected scatterers show good agreement with the in-situ measurements.
Published: 2014

207. On the vortex parameter estimation using wide band signals in active acoustic system

Author: Ion Candel, Cornel Ioana, Teodor Petrut, Georgiana Dunca, Angela Digulescu, Diana Maria Bucur, Alexandru Serbanescu, Florentina Bunea, GIPSA - Signal Images Physique (GIPSA-SIGMAPHY), Département Images et Signal (GIPSA-DIS), Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Department of Statistics, Florida State University [Tallahassee] (FSU), University Politehnica of Bucharest [Romania] (UPB), Académie Technique Militaire [Bucarest] (ATM), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), and Military Technical Academy [Romania] (MTA)
Subjects: Physics, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], Estimation theory, Acoustics, Process (computing), Signal, Vortex, Physics::Fluid Dynamics, [SPI]Engineering Sciences [physics], [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, Condensed Matter::Superconductivity, Cavitation, Fluid dynamics, Ultrasonic sensor, Recurrence plot, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, ComputingMilieux_MISCELLANEOUS
Abstract: International audience; This paper proposes a new method for detection of the vortex presence in ﬂuid ﬂow based on an active acoustic system. The experiment that validates the theory was done on a reduced scale facility using ultrasonic transceivers. The main objective was to highlight the effect of a cavitation vortex on an applied wide band signal. In order to accomplish that, the Recurrence Plot Analysis (RPA) was investigated which emhasizes similar states of a dynamic process. The Tests were done from no vortex cavitation ﬂow to vortex cavitation ﬂow and backward.
Published: 2014

208. Cramer-Rao Bound for a Sparse Complex Model

Author: Silviu Ciochina, Jean-Christophe Pesquet, Anisia Florescu, Emilie Chouzenoux, University Politehnica of Bucharest [Romania] (UPB), Laboratoire d'Informatique Gaspard-Monge (LIGM), Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Bézout-ESIEE Paris-École des Ponts ParisTech (ENPC)-Université Paris-Est Marne-la-Vallée (UPEM), Chouzenoux, Emilie, and Université Paris-Est Marne-la-Vallée (UPEM)-École des Ponts ParisTech (ENPC)-ESIEE Paris-Fédération de Recherche Bézout-Centre National de la Recherche Scientifique (CNRS)
Subjects: spectrum estimation, Mathematical optimization, estimation, Computer science, [SPI] Engineering Sciences [physics], [INFO.INFO-TS] Computer Science [cs]/Signal and Image Processing, nonconvex optimization, sparsity, Parameterized complexity, Image processing, Sparse approximation, Cramer-Rao bound, proximal methods, complex signals, [SPI]Engineering Sciences [physics], [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, Countable set, Algorithm, Cramér–Rao bound, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract: Complex-valued data play a prominent role in a number of signal and image processing applications. The aim of this paper is to establish some theoretical results concerning the Cramer-Rao bound for estimating a sparse complex-valued vector. Instead of considering a countable dictionary of vectors, we address the more challenging case of an uncountable set of vectors parameterized by a real variable. We also present a proximal forward-backward algorithm to minimize an l 0 penalized cost, which allows us to approach the derived bounds. These results are illustrated on a spectrum analysis problem in the case of irregularly sampled observations.
Published: 2014

209. Automated assessment of paraphrases in pupil's self-explanations

Author: Oprescu, B., Dascǎlu, M., Trǎuşan-Matu, Ş, Philippe Dessus, Bianco, M., Computer Science Department [Bucarest], University Politehnica of Bucharest [Romania] (UPB), Laboratoire des Sciences de l'Éducation (Grenoble) (LSE), Université Pierre Mendès France - Grenoble 2 (UPMF), 'Politehnica' Université de Bucarest, Roumanie, Romanian Academy of Sciences, and Dessus, Philippe
Subjects: Self-Explanation Reading Training (SERT), Entraînement à l'auto-explication en lecture, [SHS.EDU]Humanities and Social Sciences/Education, [SHS.EDU] Humanities and Social Sciences/Education, Self-explanations, Analyse Semantique Latente, Verbalisations, Latent Semantic Analysis (LSA), Automated assessment, Auto-explications, Evaluation automatique, Verbalizations
Abstract: National audience; Self-explanations are verbalizations that readers give to themselves while reading a text, in order to better understand it. Our implemented system is designed for automatically analyzing self-explanations in order to allow teachers to better grasp the comprehension of pupils of the previously read materials. Our method uses specific natural language processing techniques for French language and it is conceived for use with primary school pupils. Furthermore, we have integrated a word-based heuristic in order to measure similarity between the initial texts and the pupil's verbalizations.
Published: 2014

210. Well-defined second-order nonlinear optical polymers by controlled radical polymerization, via multifunctional macromolecular chain transfer agent: Design, synthesis, and characterizations

Author: André-Jean Attias, Anne-Lise Roy, Chong Bui, Ileana Rau, Bernadette Charleux, Francois Kajzar, Maud Save, David Kreher, Chimie des polymères (LCP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut Parisien de Chimie Moléculaire (IPCM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of General Chemistry, University Politehnica of Bucharest [Romania] (UPB), Laboratoire de Chimie, Catalyse, Polymères et Procédés, R 5265 (C2P2), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut pluridisciplinaire de recherche sur l'environnement et les matériaux (IPREM), Université de Pau et des Pays de l'Adour (UPPA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de synthèse organique (DCSO), École polytechnique (X)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC), and Institut Pluridisciplinaire de Recherche sur l'Environnement et les Matériaux (IPREM)
Subjects: chemistry.chemical_classification, Kinetic chain length, Materials science, Polymers and Plastics, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Organic Chemistry, Radical polymerization, Chain transfer, Polymer, chemistry, Polymerization, Polymer chemistry, Materials Chemistry, Copolymer, Living polymerization, Reversible addition−fragmentation chain-transfer polymerization
Abstract: International audience; To address the issue of the aggregation in second-order nonlinear optical (NLO) polymers we developed an approach based on the synthesis of a multifunctional macromolecular chain transfer agent. The controlled monomer insertion polymerization into the main chain by a 'reversible addition-fragmentation chain transfer' (RAFT) mechanism allows the spatial arrangement of the NLO chromophores along the polymeric chain in order to obtain sequence-ordered polymers. In a first step, a novel trithiocarbonate based macroinitiator containing the disperse red 19 (DR19) units in the main chain was synthesized by polycondensation; in a second step, this polymeric precursor was applied to the synthesis of a sequentially ordered polymer by controlled insertion radical polymerization of styrene. Size exclusion chromatography (SEC), nuclear magnetic resonance (NMR) data revealed that, (i) for the first time, polystyrenes (PS) bearing DR19 dyes covalently bounded were obtained, and (ii) both the insertion reaction and the length of the polystyrene segments were accurately controlled. Whatever the incorporated dye amount, all the copolymers were soluble in common solvents. Second-order optical nonlinearity in corona-poled thin films was evaluated, and second harmonic coefficients up to 80 pm/V were determined for loading ratio lower than 10 wt-% (DR19/PS). This approach opens up opportunities for the incorporation of more efficient chromophores even in apolar matrices.
Published: 2014

211. Investigation of UV optical fibers under synchrotron irradiation

Author: Adelina Sporea, Alin Lixandru, Elke Bräuer-Krisch, Dan Sporea, Laura Mihai, Natl Inst Laser Plasma & Radiat Phys, RO-077125 Magurele, Romania, University Politehnica of Bucharest [Romania] (UPB), and European Synchrotron Radiation Facility (ESRF)
Subjects: [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Materials science, Optical fiber, business.industry, Wiggler, Attenuation, Synchrotron radiation, Radiation, Atomic and Molecular Physics, and Optics, Synchrotron, law.invention, Optics, law, Dosimetry, Irradiation, business
Abstract: International audience; The focus of the present paper deals, for the first time, with commercial UV optical fibers, characterizing their behaviour as they are subjected to very high flux wiggler generated synchrotron radiation. Five distinct types of UV optical fibers, produced by three manufactures, were exposed to total doses between 5 Gy and 2000 Gy. The exposure to synchrotron radiation was performed in two campaigns. The tests were run off-line and considered the dependence of the radiation induced attenuation (RIA) as function of the total dose. The recovery of the radiation induced colour centres was studied at room temperature and after heating the samples up to 560 K. As a premiere, we also investigated through THz imaging and spectroscopy the irradiated optical fiber samples. Under these conditions, three of the optical fibers proved to be radiation resistant. The two optical fibers sensitive to synchrotron radiation exhibited a linear variation of the optical absorption at the wavelengths of lambda = 229 nm, lambda = 248 nm, and lambda = 265 nm, for total doses between 60 Gy and 2000 Gy. These two samples showed also an increase of the optical absorption in the UV spectral range when heated to 560 K. The optical fibers sensitive to synchrotron radiation can potentially be used for on-line radiation dosimetry. (C)2014 Optical Society of America
Published: 2014

212. Multiple equilibrium states during the quasi-steady formation of bubbles and drops at a circular orifice

Author: Sanda-Carmen Georgescu, Achard, Jean-Luc, University Politehnica of Bucharest [Romania] (UPB), Laboratoire des Écoulements Géophysiques et Industriels [Grenoble] (LEGI), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), and ACHARD, Jean-Luc
Subjects: [SPI.GPROC] Engineering Sciences [physics]/Chemical and Process Engineering, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, [SPI.FLUID] Engineering Sciences [physics]/Reactive fluid environment, ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2014

213. Underwater Object Tracking Using Time Frequency Signatures of Acoustic Signals

Author: Candel Ion, Bucur Diana, Digulescu Angela, Petrut Teodor, Ioana Cornel, Candel, Ion, GIPSA - Signal Images Physique (GIPSA-SIGMAPHY), Département Images et Signal (GIPSA-DIS), Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), and University Politehnica of Bucharest [Romania] (UPB)
Subjects: Physics, Turbulence, [INFO.INFO-TS] Computer Science [cs]/Signal and Image Processing, Acoustics, Interference (wave propagation), Instantaneous phase, Time–frequency analysis, Physics::Fluid Dynamics, [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, Video tracking, Waveform, 14. Life underwater, Underwater, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Underwater acoustic communication, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract: International audience; Detecting underwater objects is an important ap plication in marine applications. Most of the techniques are based on the amplitude related techniques, whereby the amplitude of the received echo is used to detect objects within specified bounds. Amplitude techniques however are prone to interference and attenuation, thus limiting the capabilities of such systems. Hence, the aim of this paper is to propose a new technique that detect and track underwater moving objects usingthe turbulence generated by the object. Wideband signals have proven to be a very efficient alternative for merging turbulent flow characteristics and waveform design in order to describe and explain the behavior of turbulence, both artificial and natural. Therefore, constructing adapted waveforms to the natural turbulence embedded in the flow, as well as to the artificial turbulence created by an unknown underwater moving object may hold the key for a new technique for underwater object tracking. When acoustic signals with a particular Instantaneous Frequency Law traveling into underwater environment will hit a moving object, their Instantaneous Frequency Law will capture the object's artificial turbulence, as well as the natural turbulence embedded in the flow. Experimental results carried out in our reduced scale facility provide the validation of the technique.
Published: 2014

214. A discussion on sensor recovery techniques for fault tolerant multisensor schemes

Author: Sorin Olaru, Florin Stoican, Maria M. Seron, José A. De Doná, University Politehnica of Bucharest [Romania] (UPB), Supélec Sciences des Systèmes (E3S), Ecole Supérieure d'Electricité - SUPELEC (FRANCE), Dynamical Interconnected Systems in COmplex Environments (DISCO), Laboratoire des signaux et systèmes (L2S), Université Paris-Sud - Paris 11 (UP11)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Department of Electrical Engineering and Computer Science (Institut Montefiore), Université de Liège, The ARC Centre for Complex Dynamic Systems and Control (ARC CENTRE FOR CDSC), and Newcastle University [Newcastle]
Subjects: Scheme (programming language), Engineering, business.industry, Acknowledgement, Fault tolerance, Computer Science Applications, Theoretical Computer Science, Moment (mathematics), [SPI]Engineering Sciences [physics], Control and Systems Engineering, Control theory, Recovery techniques, State (computer science), business, computer, Invariant (computer science), computer.programming_language
Abstract: International audience; The present paper deals with the interplay between healthy and faulty sensor functioning in a multisensor scheme based on a switching control strategy. Fault tolerance guarantees have been recently obtained in this framework based upon the characterisation of invariant sets for state estimations in healthy and faulty functioning. A source of conservativeness of this approach is related to the issue of sensor recovery. A common working hypothesis has been to assume that once a sensor switches to faulty functioning it can no longer be used by the control mechanism even if at an ulterior moment it switches back to healthy functioning. In the current paper, we present necessary and sufficient conditions for the acknowledgement of sensor recovery and we propose and compare different techniques for the reintegration of sensors in the closed-loop decision-making mechanism.
Published: 2014

215. Energy and exergy analyses of a solar-driven absorption cooling system

Author: Lavinia Grosu, Alexandru Dobrovicescu, Adrian Untea, Laboratoire Energétique Mécanique Electromagnétisme (LEME), Université Paris Nanterre (UPN), and University Politehnica of Bucharest [Romania] (UPB)
Subjects: Exergy, Chiller, Lithium bromide, business.industry, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Thermodynamics, Coefficient of performance, Solar energy, 7. Clean energy, law.invention, chemistry.chemical_compound, General Energy, chemistry, law, Absorption refrigerator, Exergy efficiency, Environmental science, Absorption (electromagnetic radiation), business, Exergie et Systèmes Energétiques
Abstract: In this paper, energy and exergy analyses of an absorption cooling system using H2O/LiBr and solar energy as heat source are conducted. A simple schematic of a chiller and an improved one, are compared using Thermoptim and EES software. An increase in the coefficient of performance (COP) from 0.69 to 0.8 was noticed. Numerical simulations are performed for six values of the condensing/absorption temperatures, which vary in the interval 31–36°C. The increase in these temperatures implies a decrease in the COP from 0.8 to 0.56. The exergy analysis of the overall system and of each component shows a decrease in the exergetic efficiency of the system from 0.27 to 0.18. A detailed exergy analysis of the absorber reveals the real causes of exergy destruction. A new exergy destruction indicator was introduced, which shows the importance of the irreversibility of each component, relative to the starting potential.
Published: 2014

216. Closed-loop actuator-fault detection and isolation using set tubes and invariant sets

Author: Xu, Feng, Puig, Vicenç, Ocampo-Martinez, Carlos, Stoican, Florin, Olaru, Sorin, China Scholarship Council, European Commission, Generalitat de Catalunya, Universitat Politècnica de Catalunya [Barcelona] (UPC), University Politehnica of Bucharest [Romania] (UPB), Supélec Sciences des Systèmes (E3S), and Ecole Supérieure d'Electricité - SUPELEC (FRANCE)
Subjects: [SPI]Engineering Sciences [physics]
Abstract: Trabajo presentado al 19th IFAC World Congress celebrado del 24 al 29 de agosto de 2014 en Cape Town (Sudafrica)., This paper proposes a new actuator-fault detection and isolation (FDI) strategy for closed-loop discrete time-invariant systems by using set tubes and invariant sets. In this approach, invariant sets are used for FDI and to establish FDI conditions, while set tubes are only generated for fault isolation (FI) during the transient state. Comparing to the existing relevant set-theoretic FDI techniques, the advantage of this approach consists in that it exhibits a balance between the conservativeness of FDI conditions and the rapidity of FI. The effectiveness of the proposed technique is illustrated by a numerical example., The work was supported by the DGR of Generalitat de Catalunya (AGAUR Doctorat Industrial 2013-DI-041), European Commission through contract i-Sense (FP7-ICT-2009-6-270428), and China Scholarship Council (File No.2011629170).
Published: 2014

217. On the Use of Time Frequency Analysis for Adaptive Target Detection in Highly Textured Monodimensional Radar Images

Author: Jean-Philippe Ovarlez, Gabriel Vasile, Andrei Anghel, Vasile, Gabriel, Sondra, CentraleSupélec, Université Paris-Saclay (COmUE) (SONDRA), ONERA-CentraleSupélec-Université Paris Saclay (COmUE), ONERA - The French Aerospace Lab [Palaiseau], ONERA-Université Paris Saclay (COmUE), GIPSA - Signal Images Physique (GIPSA-SIGMAPHY), Département Images et Signal (GIPSA-DIS), Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), University Politehnica of Bucharest [Romania] (UPB), and COMM 2014 International Conference
Subjects: [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, ComputingMilieux_MISCELLANEOUS, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract: International audience
Published: 2014

218. Space Charge in Thermally Aged Multilayer Joints

Author: Stancu, C., Notingher, P. V., Constantin, A., Cernat, A., NOTINGHER, Petru, Lungulescu, M., University Politehnica of Bucharest [Romania] (UPB), Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Groupe énergie et matériaux (GEM), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), and University Politehnica of Bucarest
Subjects: ComputingMilieux_MISCELLANEOUS, [SPI.TRON]Engineering Sciences [physics]/Electronics
Abstract: International audience
Published: 2014

219. Some Kinetic-Molecular considerations on gas-piston interaction and their implications at macroscopic scale

Author: Török, Arpad, Petrescu, Stoian, Popescu, Gheorghe, Feidt, Michel, University Politehnica of Bucharest [Romania] (UPB), Laboratoire Énergies et Mécanique Théorique et Appliquée (LEMTA ), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), and UL, Lemta
Subjects: [SPI]Engineering Sciences [physics], [SPI] Engineering Sciences [physics], Gas-piston interaction, Clausius model, Bent piston
Abstract: International audience; The present study aims to offer a microscopic description of the behavioral pattern of a gas system interacting with a mobile wall based on Clausius model and on its ensuing models. Starting from this analysis, the first part of this study comes to validate the equations published in the early works in Finite Speed Thermodynamics, while the second part deals with the interaction between the gas system and a mobile wall set off at a certain angle to its moving trajectory. The study conclusions are applies to the analysis of the interaction between gas or vapor systems and the mobile units of rotating devices.
Published: 2014

220. Short-range wideband FMCW radar for millimetric displacement measurements

Author: Remus Cacoveanu, Andrei Anghel, Gabriel Vasile, Silviu Ciochina, Cornel Ioana, GIPSA - Signal Images Physique (GIPSA-SIGMAPHY), Département Images et Signal (GIPSA-DIS), Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), and University Politehnica of Bucharest [Romania] (UPB)
Subjects: Heterodyne, Pulse repetition frequency, Synthetic aperture radar, Computer science, Acoustics, 0211 other engineering and technologies, 02 engineering and technology, law.invention, Radar engineering details, [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, law, Radar imaging, 0202 electrical engineering, electronic engineering, information engineering, Electrical and Electronic Engineering, Wideband, Radar, 021101 geological & geomatics engineering, Remote sensing, Low probability of intercept radar, Pulse-Doppler radar, 020206 networking & telecommunications, Side looking airborne radar, Radar lock-on, Continuous-wave radar, Inverse synthetic aperture radar, Bistatic radar, Direct-conversion receiver, General Earth and Planetary Sciences, Radar display, Radar configurations and types, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract: International audience; The frequency modulated continuous wave (FMCW) radar is an alternative to the pulse radar when the distance to the target is short. Typical FMCW radar implementations have a homodyne architecture transceiver which limits the performances for short-range applications: the beat frequency can be relatively small and placed in the frequency range affected by the specific homodyne issues (DC offset, self-mixing and 1/f noise). Additionally, one classical problem of a FMCW radar is that the voltage controlled oscillator adds a certain degree of nonlinearity which can cause a dramatic resolution degradation for wideband sweeps. This paper proposes a short-range X-band FMCW radar platform which solves these two problems by using a heterodyne transceiver and a wideband nonlinearity correction algorithm based on high-order ambiguity functions and time resampling. The platform's displacement measurement capability was tested on range profiles and synthetic aperture radar (SAR) images acquired for various targets. The displacements were computed from the interferometric phase and the measurement errors were situated below 0.1 mm for metal bar targets placed at a few meters from the radar.
Published: 2014

221. A Majorize-Minimize memory gradient method for complex-valued inverse problems

Author: Emilie Chouzenoux, Philippe Ciuciu, Jean-Christophe Pesquet, Anisia Florescu, Silviu Ciochina, University Politehnica of Bucharest [Romania] (UPB), Laboratoire d'Informatique Gaspard-Monge (LIGM), Université Paris-Est Marne-la-Vallée (UPEM)-École des Ponts ParisTech (ENPC)-ESIEE Paris-Fédération de Recherche Bézout-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Neuroimagerie Assistée par Ordinateur (LNAO), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Part of A. Florescu's work was supported by PhD Fellowship 'Investitii in cercetareinovare- dezvoltare pentru viitor (DocInvest)', EC project POSDRU/107/1.5/S/76813., and Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Bézout-ESIEE Paris-École des Ponts ParisTech (ENPC)-Université Paris-Est Marne-la-Vallée (UPEM)
Subjects: majorization-minimization, Mathematical optimization, sampling, Context (language use), Image processing, Iterative reconstruction, Operator (computer programming), [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, Convergence (routing), magnetic resonance imaging, Electrical and Electronic Engineering, Mathematics, inverse problems, Inverse problem, image reconstruction, proximal methods, Linear map, Control and Systems Engineering, Signal Processing, descent methods, Computer Vision and Pattern Recognition, complex-valued signals, subspace algorithms, Gradient method, optimization, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Software
Abstract: Complex-valued data are encountered in many application areas of signal and image processing. In the context of the optimization of functions of real variables, subspace algorithms have recently attracted much interest, owing to their efficiency for solving large-size problems while simultaneously offering theoretical convergence guarantees. The goal of this paper is to show how some of these methods can be successfully extended to the complex case. More precisely, we investigate the properties of the proposed complex-valued Majorize-Minimize Memory Gradient (3MG) algorithm. Important practical applications of these results arise in inverse problems. Here, we focus on image reconstruction in Parallel Magnetic Resonance Imaging (PMRI). The linear operator involved in the observation model then includes a subsampling operator over the k-space (2D Fourier domain) the choice of which is analyzed through our numerical results. In addition, sensitivity matrices associated with the multiple channel coils come into play. Comparisons with existing optimization methods confirm the better performance of the proposed algorithm. HighlightsAn extension of the Majorize-Minimize Memory Gradient algorithm for minimizing functions of complex variables is proposed.The convergence of the algorithm is proved under weak assumptions.A novel application of the algorithm to parallel Magnetic Resonance Imaging reconstruction is proposed.Through simulations on real data, the algorithm is shown to outperform recent optimization strategies in terms of convergence speed.The algorithm can handle various subsampling schemes, both convex and nonconvex penalization functions and different possibly redundant frame representations.
Published: 2014

222. The EOLES project Remote Labs across the Mediterranean

Author: Karim Bouchlaghem, Manuel Gericota, Andre Fidalgo, Paulo Ferreira, Denis Barataud, Guillaume Andrieu, Mohammed Ankrim, M. Cristea, Abdelhalim Benachenhou, Renaat De Craemer, C2S2 (XLIM-C2S2), XLIM (XLIM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), European Project, Repositório Científico do Instituto Politécnico do Porto, Instituto Superior de Engenharia do Porto [Porto] (ISEP), OSA (XLIM-OSA), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), University Politehnica of Bucharest [Romania] (UPB), University of Mostaganem, Mostaganem, Algeria, Université Cadi Ayyad [Marrakech] (UCA), and University of Kairouan, Kairouan, Tunisia
Subjects: Engineering, engineering, [SHS.EDU]Humanities and Social Sciences/Education, 020209 energy, TEMPUS, virtual classes, Remote laboratory, 02 engineering and technology, engineering e-learning course, e-learning course, Specialization (functional), 0202 electrical engineering, electronic engineering, information engineering, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, e-learning, Accreditation, Distributed learning, business.industry, electronics, 020208 electrical & electronic engineering, Engineering e-learning course, remote laboratory, optics, [SPI.TRON]Engineering Sciences [physics]/Electronics, Engineering management, Computer engineering, Electronic engineering education, Bachelor degree, Virtual learning environment, embedded systems, North african, distributed learning, Computer aided instruction, business, Virtual classes
Abstract: This paper describes the concept, methodology and first steps of an EU supported TEMPUS project EOLES (Electronics and Optics e-Learning for Embedded Systems). Its aim is the creation of a 3rd year Bachelor degree that relies exclusively on e-learning and remote laboratories. The project involves 15 institutions from four European countries and three North African countries. The proposed course will be run from several institutions simultaneously and should be accredited as a formal specialization year in all partner institutions, awarding 60 ECTU (European Transfer Credit Units). The course will integrate a Virtual Learning Environment and a Distributed Laboratory. ispartof: pages:943-946 ispartof: 2014 IEEE GLOBAL ENGINEERING EDUCATION CONFERENCE (EDUCON) pages:943-946 ispartof: IEEE Global Engineering Education Conference location:Istanbul: TURKEY date:3 Apr - 5 Apr 2014 status: published
Published: 2014

223. Vegetal bioproducts with antioxidant activity for prophylactic and therapeutic effect

Author: Nicoleta Badea, Carlos Vaca-Garcia, Cornelia Nichita, Aurelia Meghea, G. Caraene, Maria Giurginca, National Institute for Chemical-Pharmaceutical Research and Development (ICCF), University Politehnica of Bucharest [Romania] (UPB), Laboratoire de Chimie Agro-Industrielle (LCA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure de Chimie de Toulouse, Chimie Agro-Industrielle (CAI), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National de la Recherche Agronomique (INRA), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), National Institute for Chemical Pharmaceutical Research and Development (ROMANIA), University Politechnica of Bucharest (ROMANIA), Laboratoire de Chimie Agro-Industrielle - LCA (Toulouse, France), and Institut National Polytechnique de Toulouse - INPT (FRANCE)
Subjects: Antioxidant, Agronomie, medicine.medical_treatment, 030303 biophysics, [CHIM.THER]Chemical Sciences/Medicinal Chemistry, Antioxidants, Rosmarinus, 03 medical and health sciences, 0404 agricultural biotechnology, Bioproducts, medicine, General Materials Science, Food science, Rosmarinus officialis L, 0303 health sciences, biology, Pharmacological tests, Chemistry, Mechanical Engineering, Polyphenols, 04 agricultural and veterinary sciences, Condensed Matter Physics, biology.organism_classification, 040401 food science, Vegetal bioproducts, Biochemistry, Mechanics of Materials, Polyphenol, Officinalis, Chemiluminescence technique
Abstract: International audience; This paper presents the extractive technological process and processing of the selective vegetal extracts from the Rosmarinus officinalis L. species in order to obtain some vegetal bioproducts with proven antioxidant activity. By combining various active fractions, new vegetal bioproducts have been obtained and have been physically and chemically characterised (infrared, ultraviolet visible spectroscopy, chemiluminescence, determination of flavonoids, polyphenols, and polyphenolcarboxilic acids content) and finaly biologically tested. The antioxidant activity of Rosmarinus officinalis extracts have been evaluated by two techniques, in vitro chemiluminescence and ex vivo biological tests, both of them recommending the vegetal bioproducts for prophylactic and therapeutic purposes.
Published: 2009

224. Temperature behavior of the 6H-SiC pn diodes

Author: Jean-Pierre Chante, Marian Badila, Gh. Brezeanu, B. Tudor, A. A. Lebedev, José Millan, Marie-Laure Locatelli, Philippe Godignon, Ampère, Publications, University Politehnica of Bucharest [Romania] (UPB), Centre de génie électrique de Lyon (CEGELY), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and Centro Nacional de Microelectronica [Spain] (CNM)
Subjects: Materials science, chemistry.chemical_element, 02 engineering and technology, 01 natural sciences, 0103 physical sciences, Materials Chemistry, Breakdown voltage, Electrical and Electronic Engineering, Boron, Saturation (magnetic), Diode, parameter extraction, 010302 applied physics, business.industry, Mechanical Engineering, [SPI.NRJ]Engineering Sciences [physics]/Electric power, temperature behavior, General Chemistry, 021001 nanoscience & nanotechnology, Electronic, Optical and Magnetic Materials, chemistry, 6H-SiC pn junction, Boron doping, Optoelectronics, 0210 nano-technology, business, boron compensation, [SPI.NRJ] Engineering Sciences [physics]/Electric power
Abstract: International audience; The temperature behavior of 6H-SiC pn junctions and the effect of boron compensation are investigated. At room temperature, boron doping induces a quasi-intrinsic region, resulting in an important increase of the breakdown voltage. At higher temperatures the boron effect is reduced. Using optimal extraction the temperature dependence of the saturation currents is analyzed.
Published: 1999

225. Texture in ultra-strength Ti-25Ta-25Nb alloy strips

Author: D.M. Gordin, Doina Raducanu, Ion Cinca, Vasile Danut Cojocaru, University Politehnica of Bucharest [Romania] (UPB), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), This work was supported by the Project 'Functionalized superelastic alloys for load-bearing implants', Project code ISA MANUNET-2012-1003 from UEFISCDI-Romania., Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Alloy, 02 engineering and technology, STRIPS, engineering.material, 01 natural sciences, law.invention, law, 0103 physical sciences, Ultimate tensile strength, Materials Chemistry, Titanium alloys, 010302 applied physics, Condensed matter physics, Mechanical Engineering, Metallurgy, Metals and Alloys, Titanium alloy, Recrystallization (metallurgy), Ultra-fine grained materials, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Microstructure, Nanocrystalline material, Texture analysis, Mechanics of Materials, engineering, Elongation, 0210 nano-technology
Abstract: A Ti–25Ta–25Nb (wt%) alloy was subjected to a thermo-mechanical (TM) processing route consisting in following stages: plastic deformation by cold-rolling – recrystallization treatment – plastic deformation by cold-rolling. The aim was to promote formation of a nanocrystalline (NC) microstructure consisting of β-Ti and α″-Ti grains, with an average nanocrystalline domain size close to 26 nm in the case of β-Ti grains and respectively 33 nm in the case of α″-Ti grains. This NC microstructure exhibits a combination of high ultimate tensile strength (2423 MPa) and low elongation to fracture (1.46%). Obtained texture by TM processing shows a strong {0 0 1}〈1 1 0〉 texture component, main orientation component spreading from {0 0 1}〈 1 1 ¯ 0 〉 to {0 0 1}〈 1 ¯ 1 ¯ 0 〉. High intensity texture fibres (γ-fibre and α-fibre) were obtained also. In the case of γ-fibre the main orientation component spreads from {1 1 1}〈 1 1 ¯ 0 〉 to {1 1 1}〈 1 ¯ 1 ¯ 2 〉, while in the case of α-fibre the main orientation component spreads from {0 0 1}〈 1 1 ¯ 0 〉 to {1 1 2}〈 1 1 ¯ 0 〉.
Published: 2013

226. Semantic approach in image change detection

Author: Mallet, Clément, Blanc-Talon, Jacques, Kasinski, Andrzej, Philips, Wilfried, Popescu, Dan, Scheunders, Paul, Délégation générale de l'armement (DGA), Ministère de la Défense, Department of Telecommunications and Information Processing (TELIN/UGent), Universiteit Gent = Ghent University [Belgium] (UGENT), University Politehnica of Bucharest [Romania] (UPB), Vision Lab [Antwerp], and University of Antwerp (UA)
Subjects: [SDE]Environmental Sciences, [INFO.INFO-CV]Computer Science [cs]/Computer Vision and Pattern Recognition [cs.CV], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2013

227. Computation of the electric field in aged underground medium voltage cable insulation

Author: C. Stancu, P. Notingher, University Politehnica of Bucharest [Romania] (UPB), Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Groupe énergie et matériaux (GEM), and Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010302 applied physics, Permittivity, Materials science, business.industry, Electrical engineering, Charge density, 02 engineering and technology, Electrical treeing, Mechanics, 021001 nanoscience & nanotechnology, 01 natural sciences, Space charge, [SPI.TRON]Engineering Sciences [physics]/Electronics, Electric field, 0103 physical sciences, Power cable, Breakdown voltage, Electrical and Electronic Engineering, 0210 nano-technology, business, ComputingMilieux_MISCELLANEOUS, Voltage
Abstract: In this paper, the distribution of the electric field in the polyethylene insulation of a medium voltage power cable is computed in the absence and in the presence of water trees and space charge. The computations are made in variable regime, from the voltage switch-on up to one hour of application of the electrical stress. The water trees are considered of semi spherical shape and of known permittivity and conductivity. The conductivity and the characteristics of the water trees are determined experimentally. The influence of the dimensions of water trees and of the associated space charge layers (length and charge density) are analyzed in terms of local values of the electric field and of reduction of the cable breakdown voltage. It is shown that, for a water tree of given length, the probability of insulation breakdown reaches its maximum for a given ratio between space charge density and length of the space charge area.
Published: 2013

228. Nonlinearity Correction Algorithm for Wideband FMCW Radars

Author: Andrei Anghel, Gabriel Vasile, Remus Cacoveanu, Cornel Ioana, Silviu Ciochina, GIPSA - Signal Images Physique (GIPSA-SIGMAPHY), Département Images et Signal (GIPSA-DIS), Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), University Politehnica of Bucharest [Romania] (UPB), and Vasile, Gabriel
Subjects: [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, [INFO.INFO-TS] Computer Science [cs]/Signal and Image Processing, MathematicsofComputing_NUMERICALANALYSIS, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract: International audience; This paper presents a novel nonlinearity correction algorithm for wideband frequency modulated continuous wave (FMCW) radars based on high-order ambiguity functions (HAF) and time resampling. By emphasizing the polynomial phase nature of the FMCW signal, it is shown that the HAF is an excellent tool for estimating the sweep nonlinearity polynomial coefficients. The estimated coefficients are used to build a correction function which is applied to the beat signal by time resampling . The nonlinearity correction algorithm is tested by simulation and validated on real data sets acquired with an X-band FMCW radar.
Published: 2013

229. A complex-valued majorize-minimize memory gradient method with application to parallel MRI

Author: Chouzenoux, Emilie, Ciochina, Silviu, Ciuciu, Philippe, Florescu, Anisia, Pesquet, J.C., University Politehnica of Bucharest [Romania] (UPB), Laboratoire d'Informatique Gaspard-Monge (LIGM), Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Bézout-ESIEE Paris-École des Ponts ParisTech (ENPC)-Université Paris-Est Marne-la-Vallée (UPEM), Modelling brain structure, function and variability based on high-field MRI data (PARIETAL), Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Service NEUROSPIN (NEUROSPIN), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Part of this work was supported by PhD Fellowship 'Investitii in cercetare-inovare-dezvoltare pentru viitor (DocInvest)', EC project POSDRU/ 107/1.5/S/76813, Université Paris-Est Marne-la-Vallée (UPEM)-École des Ponts ParisTech (ENPC)-ESIEE Paris-Fédération de Recherche Bézout-Centre National de la Recherche Scientifique (CNRS), Service NEUROSPIN (NEUROSPIN), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), and Chouzenoux, Emilie
Subjects: majorization-minimization, sampling, [INFO.INFO-TS] Computer Science [cs]/Signal and Image Processing, inverse problems, 020206 networking & telecommunications, 02 engineering and technology, image reconstruction, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, 0202 electrical engineering, electronic engineering, information engineering, magnetic resonance imaging, descent methods, complex-valued signals, subspace algorithms, optimization, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract: International audience; Complex-valued data are encountered in many application areas of signal and image processing. In the context of optimization of functions of real variables, subspace algorithms have recently attracted much interest, due to their efficiency in solving large-size problems while simultaneously offering theoretical convergence guarantees. The goal of this paper is to show how some of these methods can be successfully extended to the complex case. More precisely, we investigate the properties of the proposed complex-valued Majorize- Minimize Memory Gradient (3MG) algorithm. An important practical application of these results arises for image reconstruction in Parallel Magnetic Resonance Imaging (PMRI). Comparisons with existing optimization methods confirm the good performance of our approach for PMRI reconstruction.
Published: 2013

230. Efficient Evaluation of Hyper-Rectangular Blocks of Update Operations Applied to General Data Structures

Author: Andreica, Mugurel Ionut, Grigorean, Andrei, Parvu, Andrei, Tapus, Nicolae, Parallel and Distributed Systems Laboratory [Bucarest], University Politehnica of Bucarest, Faculty of Mathematics-Informatics, University of Bucharest (UniBuc), Computer Science Department [Bucarest], University Politehnica of Bucharest [Romania] (UPB), and Andreica, Mugurel Ionut
Subjects: [INFO.INFO-DS]Computer Science [cs]/Data Structures and Algorithms [cs.DS], [INFO.INFO-DS] Computer Science [cs]/Data Structures and Algorithms [cs.DS]
Abstract: The paper is currently in press in "ACAM : Automation, Computers, Applied Mathematics" (ISSN: 1221-437X). The authors' participation in multiple algorithmic contests (both as contestants and as members of the scientific committee) influenced many of the results presented in this paper. The attached ZIP archive contains a few sample tasks and solutions (of the authors or of others) which are related to some of the algorithms and data structures presented in this paper.; International audience; In this paper we present novel solutions for the following problem: We have a general data structure $DS$ and a set of update operations organized into a $D$-dimensional cube of side $N$ (thus, there are $N^D$ update operations). We are interested in efficiently evaluating range queries of the following type: compute the result of applying all the update operations within a hyper-rectangular block $B$ of the $D$-dimensional cube to $DS$ (considering that $DS$ is initially empty). The result of applying the updates consists of computing some aggregate values over the data structure. We consider that the order of applying the updates is irrelevant (i.e. the update operations are commutative) and that the aggregate results corresponding to a block of updates cannot easily be computed by combining the results of a set of sub-blocks whose disjoint union is $B$. However, the results can be efficiently maintained after each update operation, if the operations are performed sequentially in any order.
Published: 2013

231. Voices' inter-animation detection with ReaderBench. Modelling and assessing polyphony in CSCL chats as voice synergy

Author: Stefan Trausan-Matu, Philippe Dessus, Mihai Dascalu, Computer Science Department [Bucarest], University Politehnica of Bucharest [Romania] (UPB), Laboratoire des Sciences de l'Éducation (Grenoble) (LSE), Université Pierre Mendès France - Grenoble 2 (UPMF), and Dessus, Philippe
Subjects: Computer science, media_common.quotation_subject, Discourse analysis, [SHS.EDU]Humanities and Social Sciences/Education, 05 social sciences, Perspective (graphical), [SHS.EDU] Humanities and Social Sciences/Education, Context (language use), 02 engineering and technology, Animation, 050105 experimental psychology, Human–computer interaction, Computer-supported collaborative learning, 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, 0501 psychology and cognitive sciences, Polyphony, Conversation, Computer animation, media_common
Abstract: International audience; Starting from dialogism in which every act is perceived as a dialogue, we shift the perspective towards multi-participant chat conversations from Computer Supported Collaborative Learning in which ideas, points of view or more generally put voices interact, inter-animate and generate the context of a conversation. Within this perspective of discourse analysis, we introduce an implemented framework, ReaderBench, for modeling and automatically evaluating polyphony that emerges as an overlap or synergy of voices. Moreover, multiple evaluation factors were analyzed for quantifying the importance of a voice and various functions were experimented to best reflect the synergic effect of co- occurring voices for modeling the underlying discourse structure.
Published: 2013

232. Short-Range FMCW Radar Platform for Millimetric Displacements Measurement

Author: Andrei Anghel, Gabriel Vasile, Remus Cacoveanu, Cornel Ioana, Silviu Ciochina, GIPSA - Signal Images Physique (GIPSA-SIGMAPHY), Département Images et Signal (GIPSA-DIS), Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), University Politehnica of Bucharest [Romania] (UPB), and Vasile, Gabriel
Subjects: [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, [INFO.INFO-TS] Computer Science [cs]/Signal and Image Processing, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract: International audience; A frequency modulated continuous wave (FMCW) radar platform for millimetric displacement measurements of short-range targets is presented in this paper. The platform's transceiver is based on a heterodyne architecture because the beat frequency is relatively small for short-range targets and it can be placed in the frequency range influenced by the specific homodyne architecture problems: DC offset, self-mixing and 1/f noise. The platform's displacement measurement capability was tested on range profiles and SAR images acquired for various targets. The displacements were computed from the interferometric phase. The displacements errors were situated below 0.1 mm for metallic bar targets placed at a few meters from the radar.
Published: 2013

233. ReaderBench, an Environment for Analyzing Text Complexity and Reading Strategies

Author: Dascalu, Mihai, Dessus, Philippe, Trausan-Matu, Stefan, Bianco, Maryse, Nardy, Aurélie, Dascălu, Mihai, Trăușan-Matu, Ștefan, Computer Science Department [Bucarest], University Politehnica of Bucharest [Romania] (UPB), Laboratoire des Sciences de l'Éducation (Grenoble) (LSE), Université Pierre Mendès France - Grenoble 2 (UPMF), MeTAH, Laboratoire d'Informatique de Grenoble (LIG), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Laboratoire des Sciences de l'Éducation (Grenoble) (LSE), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Pierre Mendès France - Grenoble 2 (UPMF), 'Politehnica' Université de Bucarest, Roumanie, Romanian Academy of Sciences, H. Chad Lane, Kalina Yacef, Jack Mostow, and Philip Pavlik
Subjects: Computer science, [SHS.EDU]Humanities and Social Sciences/Education, 02 engineering and technology, computer.software_genre, Latent Dirichlet allocation, symbols.namesake, Text Cohesion, Support Vector Machines, 0202 electrical engineering, electronic engineering, information engineering, Latent Dirichlet Allocation, Reading Strategies, business.industry, Latent semantic analysis, 4. Education, 05 social sciences, 050301 education, Comprehension, Cohesion (linguistics), Textual Complexity, Latent Semantic Analysis, symbols, 020201 artificial intelligence & image processing, [INFO.EIAH]Computer Science [cs]/Technology for Human Learning, Artificial intelligence, business, 0503 education, computer, Natural language processing
Abstract: Session: Educational Data Mining; International audience; ReaderBench is a multi-purpose, multi-lingual and flexible environment that enables the assessment of a wide range of learners' productions and their manipulation by the teacher. ReaderBench allows the assessment of three main textual features: cohesion-based assessment, reading strategies identification and textual complexity evaluation, which have been subject to empirical validations. ReaderBench covers a complete cycle, from the initial complexity assessment of reading materials, the assignment of texts to learners, the capture of metacognitions reflected in one's textual verbalizations and comprehension evaluation, therefore fostering learner's self-regulation process.
Published: 2013

234. Performance evaluation of a combined organic Rankine cycle and an absorption refrigeration system

Author: Marin, Andreea, Untea, Adrian, Grosu, Lavinia, Dobrovicescu, Alexandru, Queiros-Conde, Diogo, Laboratoire Energétique Mécanique Electromagnétisme (LEME), Université Paris Nanterre (UPN), University Politehnica of Bucharest [Romania] (UPB), and HAL Nanterre, Administrateur
Subjects: [SPI.NRJ]Engineering Sciences [physics]/Electric power, Exergie et Systèmes Energétiques, [SPI.NRJ] Engineering Sciences [physics]/Electric power
Published: 2013

235. Evaluation of the processability of boron-containing organosilazane polymers based on shear rheology

Author: Ting Ouyang, Samuel Bernard, Philippe Miele, Laura Gottardo, Rodica Chiriac, Corneliu Balan, University Politehnica of Bucharest [Romania] (UPB), Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Européen des membranes (IEM), and Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)
Subjects: Materials science, Polymers and Plastics, 02 engineering and technology, Borane, 010402 general chemistry, 01 natural sciences, Protein filament, chemistry.chemical_compound, Rheology, Materials Chemistry, Molecule, [CHIM]Chemical Sciences, Composite material, Spinning, ComputingMilieux_MISCELLANEOUS, chemistry.chemical_classification, Methylamine, General Chemistry, Polymer, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Surfaces, Coatings and Films, chemistry, Chemical engineering, Extensional viscosity, 0210 nano-technology
Abstract: The shear rheology of boron-containing organosilazane polymers has been investigated in detail with a double objective. The first objective was to evaluate their processability to form fibers by melt-spinning, and the second objective was to predict their molecular structure. We focused on a representative type of boron-containing organosilazane polymers called boron-modified poly- silazanes (BmPSs) with the ideal structure (B(C2H4SiCH3NCH3)3)n (C2H4 ¼ CHCH3 ,C H 2CH2). Characterization tools showed that their viscous and elastic properties are strongly affected by molecular parameters fixed during synthesis and in particular by the methylamine (MA) : tris(dichlorosilylethyl)borane (TDSB) molar ratio imposed during their synthesis. In the spinning domain, the frequency dependences of the storage and loss moduli showed that the prerequisite conditions for obtaining polymer fibers are ful- filled with samples having 9.0 � MA : TDSB molar ratios � 9.7. However, the presence of thickening in the computed extensional viscosity function and the loss of cohesion of filament derived from samples with MA : TDSB ratio > 9.2 during drawing put in evi- dence the best potential of polymers with 9 � MA : TDSB ratio � 9.2 to generate fine-diameter solid filaments in a stable process. Based on rheological tests, the molecular structure of BmPSs has been tentatively predicted in relation with the MA : TDSB ratio. The increase of the latter favored the disentanglement of the polymer framework, and we postulated that it lowered the molecular weight. V C 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 128: 248-257, 2013
Published: 2013

236. Influence of space charge related to water trees on the breakdown voltage of power cable insulation

Author: Petru V. Notingher, Cristina Stancu, Petru Notingher, University Politehnica of Bucharest [Romania] (UPB), Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Groupe énergie et matériaux (GEM), and Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Permittivity, Materials science, 02 engineering and technology, Conductivity, 01 natural sciences, Electric field, 0103 physical sciences, Breakdown voltage, Power cable, Electrical and Electronic Engineering, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, business.industry, Electrical engineering, Mechanics, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Space charge, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Exponential function, [SPI.TRON]Engineering Sciences [physics]/Electronics, 0210 nano-technology, business, Biotechnology, Voltage
Abstract: A three-dimensional computation of the electric field and breakdown voltage in power cable insulation containing water trees and space charges is presented. The breakdown voltage and the conductivity of cylindrical samples of cable insulation containing water trees were measured. The samples have been aged in wet environment under ac voltages of frequencies comprised between 1 and 5 kHz. Exponential and parabolic spatial variations of permittivity and space charge density and the electrostatic, electro-kinetic and quasi-stationary regimes of the electric field were considered. The best correlation between the experimental breakdown voltage and the calculated one has been obtained in quasi-stationary regime.
Published: 2013

237. Service Orientation in Holonic and Multi Agent Manufacturing and Robotics

Author: Borangiu, Theodor, Thomas, André, Trentesaux, Damien, Automatic laboratory, University of Bucharest (UniBuc), University Politehnica of Bucharest [Romania] (UPB), Centre de Recherche en Automatique de Nancy (CRAN), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Ecole Nationale Supérieure des Technologies et Industries du Bois (ENSTIB), Université de Lorraine (UL), Laboratoire de Thermique, Ecoulements Mécaniques matériaux mise en forme PrOduction (TEMPO), Université de Valenciennes et du Hainaut-Cambrésis (UVHC), Laboratoire d'Automatique, de Mécanique et d'Informatique industrielles et Humaines - UMR 8201 (LAMIH), Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Centre National de la Recherche Scientifique (CNRS)-INSA Institut National des Sciences Appliquées Hauts-de-France (INSA Hauts-De-France), Theodor Borangiu, André Thomas, Damien Trentesaux, and Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)
Subjects: 021103 operations research, 0211 other engineering and technologies, 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, 02 engineering and technology, [SPI.AUTO]Engineering Sciences [physics]/Automatic
Abstract: Contains selected papers presented at the 2nd International Workshop SOHOMA'12 held in Bucharest, Romania, May 23-24 2012; International audience; The book covers four research domains representing a trend for modern manufacturing control: Holonic and Multi-agent technologies for industrial systems; Intelligent Product and Product-driven Automation; Service Orientation of Enterprise's strategic and technical processes; and Distributed Intelligent Automation Systems. These evolution lines have in common concepts related to service orientation derived from the Service Oriented Architecture (SOA) paradigm. The service-oriented multi-agent systems approach discussed in the book is characterized by the use of a set of distributed autonomous and cooperative agents, embedded in smart components that use the SOA principles, being oriented by offer and request of services, in order to fulfil production systems and value chain goals. A new integrated vision combining emergent technologies is offered, to create control structures with distributed intelligence supporting the vertical and horizontal enterprise integration and running in truly distributed and global working environments. The service value creation model at enterprise level consists into using Service Component Architectures for business process applications, based on entities which handle services. In this componentization view, a service is a piece of software encapsulating the business/control logic or resource functionality of an entity that exhibits an individual competence and responds to a specific request to fulfil a local (product) or global (batch) objective.
Published: 2013

238. Mining the ESO WFI and INT WFC archives for known Near Earth Asteroids. Mega-Precovery software

Author: Vaduvescu, O., Popescu, M., Comsa, I., Paraschiv, A., Lacatus, D., Sonka, A., Tudorica, A., Birlan, M., Suciu, O., Char, F., Constantinescu, M., Badescu, T., Badea, M., Vidican, D., Opriseanu, C., Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Isaac Newton Group of Telescopes, Instituto de Astrofisica de Canarias (IAC), Faculty of Applied Sciences, Department of Physics, University Politehnica of Bucharest [Romania] (UPB), Bucharest Astroclub, Faculty of Mathematics and Informatics, Babes-Bolyai University [Cluj-Napoca] (UBB), Institute of Geodynamics 'Sabba S. Stefanescu', Institute of Geodynamics Sabba S. Stefanescu, Research Center for Atomic Physics and Astrophysics, Faculty of Physics, University of Bucharest (UniBuc), Astronomical Observatory 'Admiral Vasile Urseanu', Bucharest Municipal Museum, Bonn-Cologne Graduate School of Physics and Astronomy (BCGS), Rheinische Friedrich-Wilhelms-Universität Bonn, Argelander-Institut für Astronomie (AlfA), The Romanian Society for Meteors and Astronomy (SARM), Unidad de Astronomia, Universidad de Antofagasta, University of Bucharest, Faculty of Physics, Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Near Earth Asteroids, Orbital Amelioration, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Minor Planets, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Data Mining, Astrophysics - Instrumentation and Methods for Astrophysics, Image Archives, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics - Earth and Planetary Astrophysics
Abstract: The ESO/MPG WFI and the INT WFC wide field archives comprising 330,000 images were mined to search for serendipitous encounters of known Near Earth Asteroids (NEAs) and Potentially Hazardous Asteroids (PHAs). A total of 152 asteroids (44 PHAs and 108 other NEAs) were identified using the PRECOVERY software, their astrometry being measured on 761 images and sent to the Minor Planet Centre. Both recoveries and precoveries were reported, including prolonged orbital arcs for 18 precovered objects and 10 recoveries. We analyze all new opposition data by comparing the orbits fitted before and after including our contributions. We conclude the paper presenting Mega-Precovery, a new online service focused on data mining of many instrument archives simultaneously for one or a few given asteroids. A total of 28 instrument archives have been made available for mining using this tool, adding together about 2.5 million images forming the Mega-Archive., Accepted for publication in Astronomische Nachrichten (Sep 2012)
Published: 2013

239. A constrained optimization approach for complex sparse perturbed models

Author: Florescu, Anisia, Chouzenoux, Emilie, Pesquet, Jean-Christophe, Ciochina, Silviu, University Politehnica of Bucharest [Romania] (UPB), Laboratoire d'Informatique Gaspard-Monge (LIGM), Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Bézout-ESIEE Paris-École des Ponts ParisTech (ENPC)-Université Paris-Est Marne-la-Vallée (UPEM), EC project POSDRU/107/1.5/S/76813, and Chouzenoux, Emilie
Subjects: complex-valued data, nonsmooth analysis, [INFO.INFO-TS] Computer Science [cs]/Signal and Image Processing, nonconvex optimization, hard thresholding, 65K10, 90C26, 94A12, 62M15, 65F22, linear modelling, sparse approximation, proximal methods, perturbations, [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, signal processing, spectral estimation, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract: In this paper, we consider the problem of estimating a complex-valued signal having a sparse representation in an uncountable family of vectors. The available observations are corrupted with an additive noise and the elements of the dictionary are parameterized by a scalar real variable. By a linearization technique, the original model is recast as a constrained sparse perturbed model. An optimization approach is then proposed to estimate the parameters involved in this model. The cost function includes an arbitrary Lipschitz differentiable data fidelity term accounting for the noise statistics, and an l0 penalty. A forward-backward algorithm is employed to solve the resulting non-convex and non-smooth minimization problem. This algorithm can be viewed as a generalization of an iterative hard thresholding method and its local convergence can be established. Simulation results illustrate the good practical performance of the proposed approach when applied to spectrum estimation.
Published: 2013

240. Physico-chemical and antibacterial studies on silver doped nano-hydroxyapatite

Author: Ciobanu C., S., Andronescu, Ecaterina, Prodan A., M., Pall, Liv, Costescu, A., Le Coustumer, Philippe, Huneau, Frédéric, Marutescu, L., Ene, N. E., Trusca, R., Barna E., S., Iconaru, Simona Liliana, National Institute of Materials Physics, National Institute of materials Physics, Department of Science and Engineering of Oxide Materials and Nanomaterials, University Politehnica of Bucharest [Romania] (UPB), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB), Faculty of Physics, University of Bucharest (UniBuc), Géoressources & Environnement (ENSEGID), ENSEGID, Sciences pour l'environnement (SPE), Centre National de la Recherche Scientifique (CNRS)-Université Pascal Paoli (UPP), Faculty of Biology, and SC Metav-CD SA
Subjects: Silver, stomatognathic system, Antibacterial activity, [CHIM.MATE]Chemical Sciences/Material chemistry, Hydroxyapatite
Abstract: International audience; In this paper we show that preparation of Ag doped hydroxyapatite by an adapted co-precipitation method at 100°C has several advantages over other techniques. Specifically, it can generate highly crystalline nanopowder Ag:HAp which could be used for implantable medical devices. The XRD of HAp (xAg = 0) and Ag:HAp (xAg = 0.05, and xAg = 0.4) also demonstrates that powders obtained by co-precipitation at 1000C exhibit the apatite characteristics with good crystal structure and no new phase or impurity is found. The SEM results suggested that Ag+ doping had little influence on the morphology and dimension of the samples. It can be seen that all the samples consist of elipsoidal particles. The antibactericidal activity of Ag:HAp-NPs with xAg = 0, xAg = 0.05, and xAg = 0.4 on Bacilus and E.coli ESBL 1576 were presented. The Ag:HAp-NPs with xAg = 0.05, and xAg = 0.4 inhibited the biofilm development both by the gram-positive (Staphylococcus aureus 0364) and the gram-negative (Providencia stuartii 1116) strains. On the other hand, our studies have shown that Ag:HAp with xAg = 0 had no antibacterial activity against gram-positive and gram-negative bacteria.
Published: 2013

241. Texture evolution during ARB (Accumulative Roll Bonding) processing of Ti-10Zr-5Nb-5Ta alloy

Author: Ion Cinca, Vasile Danut Cojocaru, Doina Raducanu, D.M. Gordin, University Politehnica of Bucharest [Romania] (UPB), National Institute for Research and Development in Microtechnologies, Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Alloy, 02 engineering and technology, engineering.material, 01 natural sciences, Accumulative roll bonding, 0103 physical sciences, Deformation mechanisms, Materials Chemistry, Titanium alloys, Texture (crystalline), Composite material, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, Mechanical Engineering, Metallurgy, Metals and Alloys, Ultra-Fine Grained materials, Titanium alloy, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Orientation (vector space), Distribution function, Deformation mechanism, Texture analysis, Mechanics of Materials, engineering, Severe plastic deformation, 0210 nano-technology
Abstract: Titanium alloys are extensively used in a variety of applications due to their good mechanical properties, high biocompatibility and corrosion resistance. In the last decade, α-type Ti alloys containing Zr, Nb and Ta have received much attention, because they exhibit not only high strength but also bio-corrosion resistance and high biocompatibility. A α-type Ti–10Zr–5Nb–5Ta alloy was processed by Severe Plastic Deformation (SPD) – Accumulative Roll Bonding (ARB) procedure and investigated with the aim to observe the texture development during ARB processing. Texture data for the (0 0 0 2), ( 1 0 1 ¯ 0 ), ( 1 0 1 ¯ 1 ) and ( 1 0 1 ¯ 2 ) Pole figures (PFs) were obtained by X-ray experiments and Inverse Pole Figures (IPFs) and Orientation Distribution Functions (ODFs) were determined. The results showed presence of { 0 2 2 ¯ 3 } 〈 1 0 1 ¯ 0 〉 and { 0 1 1 ¯ 1 } 〈 1 0 1 ¯ 0 〉 texture components, {0 0 0 1} basal fibre and { 0 1 1 ¯ 0 }, { 1 1 2 ¯ 0 }, { 1 1 2 ¯ 3 }, { 1 1 2 ¯ 6 } fibres.
Published: 2013

242. Quasi-Izothermal Compressors And Expanders With Liquid Piston

Author: Török, Arpad, Petrescu, Stoian, Popescu, Gheorghe, Feidt, Michel, Arpad, Török, University Politehnica of Bucharest [Romania] (UPB), Laboratoire Énergies et Mécanique Théorique et Appliquée (LEMTA ), and Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)
Subjects: isothermal processes, liquid piston, [SPI.MECA.THER]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Thermics [physics.class-ph], [SPI.MECA.MEFL] Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], gas and vapor compression and expansion, ComputingMilieux_MISCELLANEOUS, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], quasi-isothermal processes, [SPI.MECA.THER] Engineering Sciences [physics]/Mechanics [physics.med-ph]/Thermics [physics.class-ph]
Abstract: International audience
Published: 2013

243. FMCW Transceiver Wideband Sweep Nonlinearity Software Correction

Author: Cornel Ioana, Silviu Ciochina, Gabriel Vasile, Remus Cacoveanu, Andrei Anghel, GIPSA - Signal Images Physique (GIPSA-SIGMAPHY), Département Images et Signal (GIPSA-DIS), Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Université Stendhal - Grenoble 3-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), University Politehnica of Bucharest [Romania] (UPB), and Vasile, Gabriel
Subjects: 020301 aerospace & aeronautics, Ambiguity function, business.industry, Computer science, [INFO.INFO-TS] Computer Science [cs]/Signal and Image Processing, 020206 networking & telecommunications, 02 engineering and technology, Software-defined radio, Nonlinear system, Software, 0203 mechanical engineering, [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, Resampling, 0202 electrical engineering, electronic engineering, information engineering, Electronic engineering, Continuous wave, Transceiver, Wideband, business, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract: International audience; This paper presents a novel sideband sweep nonlinearity software correction method for a frequency modulated continuous wave (FMCW) transceiver based on the high-order ambiguity function (HAF) and time resampling. By emphasizing the polynomial-phase nature of the FMCW signal, it is shown that the HAF processing algorithm is well suited for estimating the sweep nonlinearity coefficients. The estimated coefficients are used to build a correction function which is applied by resampling the beat signal on each sweep interval. The sweep nonlinearity correction procedure is validated on real data acquired with a low-cost X-band T/R module.
Published: 2013

244. Peut-on évaluer automatiquement les auto-explications lors de la lecture d'élèves de cycle 3 ?

Author: Bianco, Maryse, Dessus, Philippe, Nardy, Aurélie, Rémond, Martine, Lima, Laurent, Dascalu, Mihai, Oprescu, Bogdan, Trausan-Matu, Stefan, Laboratoire des Sciences de l'Éducation (Grenoble) (LSE), Université Pierre Mendès France - Grenoble 2 (UPMF), LInguistique et DIdactique des Langues Étrangères et Maternelles (LIDILEM), Université Stendhal - Grenoble 3, 'Politehnica' Université de Bucarest, Roumanie, Romanian Academy of Sciences, Computer Science Department [Bucarest], University Politehnica of Bucharest [Romania] (UPB), ANR-10-BLAN-1907,DEVCOMP,Le développement de la compréhension des textes: analyse des habiletés sous-jacentes et consruction d'un outil d'évaluation(2010), Dessus, Philippe, BLANC - Le développement de la compréhension des textes: analyse des habiletés sous-jacentes et consruction d'un outil d'évaluation - - DEVCOMP2010 - ANR-10-BLAN-1907 - BLANC - VALID, Axe 2 : Sociolinguistique et acquisition du langage, Université Stendhal - Grenoble 3-Université Stendhal - Grenoble 3-Laboratoire des Sciences de l'Éducation (Grenoble) (LSE), and Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Pierre Mendès France - Grenoble 2 (UPMF)
Subjects: Ecole élémentaire, Reading, Compréhension, [SHS.EDU]Humanities and Social Sciences/Education, [SHS.EDU] Humanities and Social Sciences/Education, Lecture, Stratégies, Elementary School, Computer System, Système informatisé
Abstract: Self-explanations elicited during reading capture the reading strategies used on-line by readers. In this paper, we first describe the results obtained with 79 children from grade 3 to 5 that self-explained during reading a narrative text. Afterwards, we present ReaderBench, a system that automatically assesses the reading strategies. Correlations between human coders and ReaderBench show the system behaves satisfactorily., La technique des auto-explications permet de saisir les stratégies de compréhension utilisées pendant la lecture. Nous détaillons ici les résultats obtenus avec cette technique auprès de 79 élèves de Cycle 3. Nous présentons ensuite ReaderBench, un système qui diagnostique le type de stratégies mises en œuvre. Une validation à partir des corrélations entre le codage des stratégies par des juges humains et ReaderBench montre que le système évalue les auto- explications de manière satisfaisante.
Published: 2013

245. Applying Semantic Web Technologies to Context Modeling in Ambient Intelligence

Author: Olivier Boissier, Gauthier Picard, Alexandru Sorici, Antoine Zimmermann, Computer Science Department [Bucarest], University Politehnica of Bucharest [Romania] (UPB), Département Informatique pour les Systèmes Coopératifs Ouverts et Décentralisés (ISCOD-ENSMSE), École des Mines de Saint-Étienne (Mines Saint-Étienne MSE), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Henri Fayol
Subjects: Context model, Ambient intelligence, Ambient Intelligence, Computer science, business.industry, [INFO.INFO-WB]Computer Science [cs]/Web, 02 engineering and technology, computer.file_format, Social Semantic Web, [INFO.INFO-AI]Computer Science [cs]/Artificial Intelligence [cs.AI], World Wide Web, 020204 information systems, Context Modeling, Ontologies, 0202 electrical engineering, electronic engineering, information engineering, Semantic analytics, SPARQL, 020201 artificial intelligence & image processing, Semantic Web Stack, Web intelligence, business, computer, Semantic Web
Abstract: http://www.emse.fr/~picard/publications/sorici13percam.pdf; International audience; Representation and reasoning about context information is a main area of research in Ambient Intelligence (AmI). Given the openness and decentralization of many AmI applications, we argue that usage of se- mantic web technologies for context modeling brings advantages in terms of standards, uniform representation and expressive reasoning. We present an approach for modeling of context information which builds and improves upon related lines of work (SOUPA, CML, annotated RDF). We provide a formalization of the model and an innovative realization using the latest proposals for semantic web standards like RDF and SPARQL. A commonly encountered ambient intelligence scenario showcases the approach.
Published: 2013

246. Parametric study and exergy analysis of solar water–lithium bromide absorption cooling system

Author: Michel Feidt, Elena Eugenia Vasilescu, Rabah Touaibi, Miloud Tahar Abbes, Université de Djilali Bounaama Khemis Miliana (univ-DBKM), Laboratoire Énergies et Mécanique Théorique et Appliquée (LEMTA ), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), University Politehnica of Bucharest [Romania] (UPB), and Université Hassiba Ben Bouali de Chlef (UHBC)
Subjects: Exergy, Work (thermodynamics), Lithium bromide, 020209 energy, Nuclear engineering, Thermodynamics, 02 engineering and technology, Cooling capacity, 7. Clean energy, Laws of thermodynamics, law.invention, chemistry.chemical_compound, [SPI]Engineering Sciences [physics], General Energy, 020401 chemical engineering, chemistry, 13. Climate action, law, Thermal, 0202 electrical engineering, electronic engineering, information engineering, Absorption refrigerator, Exergy efficiency, Environmental science, 0204 chemical engineering
Abstract: International audience; This paper presents the energy and exergy analysis of single–effect water–lithium bromide absorption cooling system driven by the heat supplied by a field of solar thermal collectors with a cooling capacity of 10 kW. The work is devoted to the study, the evaluation and distribution of the destroyed exergy for each component constituting this kind of system. The thermodynamic models have been derived using the first and second laws of thermodynamics. These models are employed in a computer program using the engineering equation solver (EES) software to perform the calculations and a sensitivity analysis to parameters is also presented. The results indicate that the contribution of some components to the overall exergy loss is very important. Exergy analysis also illustrates that the distribution of the destroyed exergy in the system between components depends strongly on the working temperatures.
Published: 2013

247. Estimation d'un signal complexe à partir d'un modèle parcimonieux perturbé

Author: Florescu, Anisia, Chouzenoux, Emilie, Pesquet, Jean-Christophe, Ciochina, Silviu, Chouzenoux, Emilie, University Politehnica of Bucharest [Romania] (UPB), Laboratoire d'Informatique Gaspard-Monge (LIGM), and Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Bézout-ESIEE Paris-École des Ponts ParisTech (ENPC)-Université Paris-Est Marne-la-Vallée (UPEM)
Subjects: [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, [INFO.INFO-TS] Computer Science [cs]/Signal and Image Processing, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing
Abstract: International audience; Dans ce travail nous abordons le problème de l'estimation, en présence de bruit, d'un signal à valeurs complexes admettant une représentation parcimonieuse dans une famille paramétrique de vecteurs dont les paramètres sont connus de manière imprécise. Nous formulons ce problème d'estimation comme celui de la minimisation d'une fonction de coût non convexe sous contraintes non convexes. Un algorithme de type explicite-implicite (forward-backward) permet d'apporter une solution numérique à ce problème d'optimisation. La mise en oeuvre de cet algorithme nécessite le calcul d'un opérateur proximal dont nous donnons la forme exacte. Nous montrons que la méthode proposée peut être vue comme une généralisation d'une technique de seuillage dur itératif. En utilisant des résultats récents d'analyse non lisse, nous étudions la convergence de l'algorithme d'optimisation employé. Par ailleurs, nous illustrons le bon comportement numérique de l'approche proposée sur des exemples d'analyse spectrale parcimonieuse.
Published: 2013

248. The available heat source influence on the operation of one stage absorption refrigeration systems

Author: Stanciu, Camelia, Stanciu, Dorin, Feidt, Michel, Costea, Monica, UL, Lemta, Société Française Thermique, University Politehnica of Bucharest [Romania] (UPB), Laboratoire Énergies et Mécanique Théorique et Appliquée (LEMTA ), and Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SPI]Engineering Sciences [physics], [SPI] Engineering Sciences [physics]
Abstract: National audience; On propose de présenter le fonctionnement d’une installation frigorifique à absorption alimentée par l’énergie thermique fournie par un captateur solaire plan. Le régime de fonctionnement optimum est visé, pour lequel on désire calculer la surface nécessaire du captateur solaire.
Published: 2013

249. Fault detection and isolation based on the combination of a bank of interval observers and invariant sets

Author: Sorin Olaru, Florin Stoican, Carlos Ocampo-Martinez, Feng Xu, Vicenç Puig, Universitat Politècnica de Catalunya [Barcelona] (UPC), University Politehnica of Bucharest [Romania] (UPB), Dynamical Interconnected Systems in COmplex Environments (DISCO), Laboratoire des signaux et systèmes (L2S), Université Paris-Sud - Paris 11 (UP11)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Supélec Sciences des Systèmes (E3S), Ecole Supérieure d'Electricité - SUPELEC (FRANCE), Universitat Politècnica de Catalunya. Departament d'Enginyeria de Sistemes, Automàtica i Informàtica Industrial, and Universitat Politècnica de Catalunya. SAC - Sistemes Avançats de Control
Subjects: Reliability theory, Automatic control, control system analysis, 0209 industrial biotechnology, bank of observers, Tolerància als errors (Informàtica), observability, Informàtica::Automàtica i control [Àrees temàtiques de la UPC], 02 engineering and technology, invariant sets, fault isolation, Invariant (physics), Fault-tolerant computing, Interval observers, Fault detection and isolation, control theory, fault detection, [SPI.AUTO]Engineering Sciences [physics]/Automatic, Control automàtic, 020901 industrial engineering & automation, Control theory, 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, Observability, Mathematics
Abstract: Presentado al 21st MED celebrado en Chania (Grecia) del 25 al 28 de junio de 2013., In this paper, a fault detection and isolation (FDI) approach using a bank of interval observers is developed. From the methodological point of view, a bank of interval observers is designed from different dynamical models of the system under healthy and faulty situations. Each dedicated interval observer matches one possible situation while all designed interval observers monitor the system simultaneously and independently. For the sake of guaranteed FDI, a set of FDI sufficient conditions are established based on invariant set notions. These conditions ensure that the faults can be accurately isolated after sufficiently long monitoring time. Finally, simulation results over a subsystem of a wind turbine are used to present the effectiveness of the proposed approach., The work of F. Xu, V. Puig and C. Ocampo-Martinez has been supported by the Spanish research project WATMAN (CICYT DPI2009-13744) of the Science and Technology Ministry and by the DGR of Generalitat de Catalunya (SAC group Ref. 2009/SGR/1491), and by European Comission through contract i-Sense (FP7-ICT-2009-6-270428). F. Xu is also supported by the China Scholarship Council (File No.2011629170).
Published: 2013

250. Influence of Al content on the pseudo-ternary compounds RENi4-xAlBx (RE = Gd, Y)

Author: Pall, Liv, Bobet, Jean-Louis, Andronescu, Ecaterina, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Department of Science and Engineering of Oxide Materials and Nanomaterials, University Politehnica of Bucharest [Romania] (UPB), Toulin, Stéphane, and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB)
Subjects: [CHIM.MATE] Chemical Sciences/Material chemistry, Intermetallics, Borides, [CHIM.MATE]Chemical Sciences/Material chemistry, Ternary compounds
Abstract: International audience; We have studied the influence of the substitution of Al for Ni in the ternary system RENi5-xBx (RE = Gd, Y). The compounds synthesized in the pseudo-ternary systems...
Published: 2013

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