[hal-01121383] Ab initio simulations of two-dimensional electronic spectra: The SOS//QM/MM approach

Two-dimensional electronic spectroscopy (2DES) is a cutting-edge technique for investigating with high temporal resolution energy transfer, structure, and dynamics in a wide range of systems in physical chemistry, energy sciences, biophysics, and biocatalysis. However, the interpretation of 2DES is challenging and requires computational modeling. This perspective provides a roadmap for the development of computational tools that could be routinely applied to simulate 2DES spectra of multichromophoric systems active in the UV region (2DUV) using state-of-the-art ab initio electronic structure methods within a quatum mechanics/molecular mechanics (QM/MM) scheme and the sum-over-states (SOS) approach (here called SOS//QM/MM). Multiconfigurational and multireference perturbative methods, such as the complete active space self-consistent field and second-order multireference perturbation theory (CASPT2) techniques, can be applied to reliably calculate the electronic properties of multichromophoric systems. Hybrid QM/MM method and molecular dynamics techniques can be used to assess environmental and conformational effects, respectively, that shape the 2D electronic spectra. DNA and proteins are important biological targets containing UV chromophores. We report ab initio simulation of 2DUV spectra of a cyclic tetrapeptide containing two interacting aromatic side chains, a model system for the study of protein structure and dynamics by means of 2DUV spectroscopy. © 2013 Wiley Periodicals, Inc.



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[hal-01121382] Facile Ecofriendly Synthesis of Monastrol and Its Structural Isomers via Biginelli Reaction

In this paper, a Q-tube equipment is proposed as a valid alternative to monomode MW technology to synthesize in a simple and economic way a library of dihydropyrimidine derivatives performing the Biginelli reaction in solvent-free conditions under pressure and with the catalysis of a very mild and environmentally benign Lewis acid consisting of erbium trichloride hexahydrate.



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[hal-01112834] Co-Localization of Audio Sources in Images Using Binaural Features and Locally-Linear Regression

This paper addresses the problem of localizing audio sources using binaural measurements. We propose a supervised formulation that simultaneously localizes multiple sources at different locations. The approach is intrinsically efficient because, contrary to prior work, it relies neither on source separation, nor on monaural segregation. The method starts with a training stage that establishes a locally-linear Gaussian regression model between the directional coordinates of all the sources and the auditory features extracted from binaural measurements. While fixed-length wide-spectrum sounds (white noise) are used for training to reliably estimate the model parameters, we show that the testing (localization) can be extended to variable-length sparse-spectrum sounds (such as speech), thus enabling a wide range of realistic applications. Indeed, we demonstrate that the method can be used for audio-visual fusion, namely to map speech signals onto images and hence to spatially align the audio and visual modalities, thus enabling to discriminate between speaking and non-speaking faces. We release a novel corpus of real-room recordings that allow quantitative evaluation of the co-localization method in the presence of one or two sound sources. Experiments demonstrate increased accuracy and speed relative to several state-of-the-art methods.



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[hal-01121379] Bidimensional electronic spectroscopy on indole in gas phase and in water from first principles

The electronic transitions of indole, the aromatic UV chromophore of the amino acid tryptophan, are characterized by using state-of-the-art multiconfigurational methods in gas-phase and aqueous solution, revealing the electronic spectrum up to 10 eV. Bidimensional near-ultraviolet (2D-NUV) electronic spectra of indole are simulated using the sum-over-states approach, based on ab initio calculations, accounting for different experimental set-ups, including rephasing (KI=-k1+k2+k3(KI=-k1+k2+k3), quasi-absorptive (PP) and double quantum coherence (KIII=k1+k2-k3(KIII=k1+k2-k3) signals, and both one-color (2D-NUV) and two-colors (2D-NUV/Vis) regimes. In order to obtain accurate energies of high lying excited states and reliable 2DES spectra, extravalence virtual orbitals have been included using the restricted active space technique. The 2D-NUV spectrum of indole shows off-diagonal signals due to the correlation of the GS → Lb and GS → La transitions, an indole “fingerprint” in the NUV region that differentiate it from other aromatic chromophores in proteins. Further indole-specific transitions are resolved in the whole Vis–NUV range. A background-free region bellow the ionization potential, which shows no absorption signals in the monomer, can be used to resolve charge transfer states in coupled chromophore aggregates with a two-color 2D-NUV/Vis experimental set-up. Fundamental information for design of the 2DES experiments of indole is provided, including possible experimental pulse configurations that improve spectral resolution, revealing anharmonicities and selecting transitions. The proposed 2DES experiments could provide unprecedented level of detail for tracking indole electronic transitions in proteins, laying the groundwork for the use of nonlinear ultrafast optical spectroscopy for the study of protein structure and dynamics in solution.



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[hal-01110031] Fusion of Range and Stereo Data for High-Resolution Scene-Modeling

This paper addresses the problem of range-stereo fusion, for the construction of high-resolution depth maps. In particular, we combine low-resolution depth data with high-resolution stereo data, in a maximum a posteriori (MAP) formulation. Unlike existing schemes that build on MRF optimizers, we infer the disparity map from a series of local energy minimization problems that are solved hierarchically, by growing sparse initial disparities obtained from the depth data. The accuracy of the method is not compromised, owing to three properties of the data-term in the energy function. Firstly, it incorporates a new correlation function that is capable of providing refined correlations and disparities, via subpixel correction. Secondly, the correlation scores rely on an adaptive cost aggregation step, based on the depth data. Thirdly, the stereo and depth likelihoods are adaptively fused, based on the scene texture and camera geometry. These properties lead to a more selective growing process which, unlike previous seed-growing methods, avoids the tendency to propagate incorrect disparities. The proposed method gives rise to an intrinsically efficient algorithm, which runs at 3FPS on 2.0MP images on a standard desktop computer. The strong performance of the new method is established both by quantitative comparisons with state-of-the-art methods, and by qualitative comparisons using real depth-stereo data-sets.



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[hal-01112834] Co-Localization of Audio Sources in Images Using Binaural Features and Locally-Linear Regression

This paper addresses the problem of localizing audio sources using binaural measurements. We propose a supervised formulation that simultaneously localizes multiple sources at different locations. The approach is intrinsically efficient because, contrary to prior work, it relies neither on source separation, nor on monaural segregation. The method starts with a training stage that establishes a locally-linear Gaussian regression model between the directional coordinates of all the sources and the auditory features extracted from binaural measurements. While fixed-length wide-spectrum sounds (white noise) are used for training to reliably estimate the model parameters, we show that the testing (localization) can be extended to variable-length sparse-spectrum sounds (such as speech), thus enabling a wide range of realistic applications. Indeed, we demonstrate that the method can be used for audio-visual fusion, namely to map speech signals onto images and hence to spatially align the audio and visual modalities, thus enabling to discriminate between speaking and non-speaking faces. We release a novel corpus of real-room recordings that allow quantitative evaluation of the co-localization method in the presence of one or two sound sources. Experiments demonstrate increased accuracy and speed relative to several state-of-the-art methods.



from HAL : Dernières publications http://ift.tt/16ECrVA

[hal-01110031] Fusion of Range and Stereo Data for High-Resolution Scene-Modeling

This paper addresses the problem of range-stereo fusion, for the construction of high-resolution depth maps. In particular, we combine low-resolution depth data with high-resolution stereo data, in a maximum a posteriori (MAP) formulation. Unlike existing schemes that build on MRF optimizers, we infer the disparity map from a series of local energy minimization problems that are solved hierarchically, by growing sparse initial disparities obtained from the depth data. The accuracy of the method is not compromised, owing to three properties of the data-term in the energy function. Firstly, it incorporates a new correlation function that is capable of providing refined correlations and disparities, via subpixel correction. Secondly, the correlation scores rely on an adaptive cost aggregation step, based on the depth data. Thirdly, the stereo and depth likelihoods are adaptively fused, based on the scene texture and camera geometry. These properties lead to a more selective growing process which, unlike previous seed-growing methods, avoids the tendency to propagate incorrect disparities. The proposed method gives rise to an intrinsically efficient algorithm, which runs at 3FPS on 2.0MP images on a standard desktop computer. The strong performance of the new method is established both by quantitative comparisons with state-of-the-art methods, and by qualitative comparisons using real depth-stereo data-sets.



from HAL : Dernières publications http://ift.tt/18p6xNl

[hal-01121379] Bidimensional electronic spectroscopy on indole in gas phase and in water from first principles

The electronic transitions of indole, the aromatic UV chromophore of the amino acid tryptophan, are characterized by using state-of-the-art multiconfigurational methods in gas-phase and aqueous solution, revealing the electronic spectrum up to 10 eV. Bidimensional near-ultraviolet (2D-NUV) electronic spectra of indole are simulated using the sum-over-states approach, based on ab initio calculations, accounting for different experimental set-ups, including rephasing (KI=-k1+k2+k3(KI=-k1+k2+k3), quasi-absorptive (PP) and double quantum coherence (KIII=k1+k2-k3(KIII=k1+k2-k3) signals, and both one-color (2D-NUV) and two-colors (2D-NUV/Vis) regimes. In order to obtain accurate energies of high lying excited states and reliable 2DES spectra, extravalence virtual orbitals have been included using the restricted active space technique. The 2D-NUV spectrum of indole shows off-diagonal signals due to the correlation of the GS → Lb and GS → La transitions, an indole “fingerprint” in the NUV region that differentiate it from other aromatic chromophores in proteins. Further indole-specific transitions are resolved in the whole Vis–NUV range. A background-free region bellow the ionization potential, which shows no absorption signals in the monomer, can be used to resolve charge transfer states in coupled chromophore aggregates with a two-color 2D-NUV/Vis experimental set-up. Fundamental information for design of the 2DES experiments of indole is provided, including possible experimental pulse configurations that improve spectral resolution, revealing anharmonicities and selecting transitions. The proposed 2DES experiments could provide unprecedented level of detail for tracking indole electronic transitions in proteins, laying the groundwork for the use of nonlinear ultrafast optical spectroscopy for the study of protein structure and dynamics in solution.



from HAL : Dernières publications http://ift.tt/1LXuLL5

[hal-01058732] Continuous Action Recognition Based on Sequence Alignment

Continuous action recognition is more challenging than isolated recognition because classification and segmentation must be simultaneously carried out. We build on the well known dynamic time warping (DTW) framework and devise a novel visual alignment technique, namely dynamic frame warping (DFW), which performs isolated recognition based on per-frame representation of videos, and on aligning a test sequence with a model sequence. Moreover, we propose two extensions which enable to perform recognition concomitant with segmentation, namely one-pass DFW and two-pass DFW. These two methods have their roots in the domain of continuous recognition of speech and, to the best of our knowledge, their extension to continuous visual action recognition has been overlooked. We test and illustrate the proposed techniques with a recently released dataset (RAVEL) and with two public-domain datasets widely used in action recognition (Hollywood-1 and Hollywood-2). We also compare the performances of the proposed isolated and continuous recognition algorithms with several recently published methods.



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[hal-01121378] Disentangling Peptide Configurations via Two-Dimensional Electronic Spectroscopy: Ab Initio Simulations Beyond the Frenkel Exciton Hamiltonian

Two-dimensional (2D) optical spectroscopy techniques based on ultrashort laser pulses have been recently extended to the optical domain in the ultraviolet (UV) spectral region. UV-active aromatic side chains can thus be used as local highly specific markers for tracking dynamics and structural rearrangements of proteins. Here we demonstrate that 2D electronic spectra of a model proteic system, a tetrapeptide with two aromatic side chains, contain enough structural information to distinguish between two different configurations with distant and vicinal side chains. For accurate simulations of the 2DUV spectra in solution, we combine a quantum mechanics/molecular mechanics approach based on wave function methods, accounting for interchromophores coupling and environmental effects, with nonlinear response theory. The proposed methodology reveals effects, such as charge transfer between vicinal aromatic residues that remain concealed in conventional exciton Hamiltonian approaches. Possible experimental setups are discussed, including multicolor experiments and signal manipulation techniques for limiting undesired background contributions and enhancing 2DUV signatures of specific electronic couplings.



from HAL : Dernières publications http://ift.tt/1C9TFqS

[hal-01053737] Robust Temporally Coherent Laplacian Protrusion Segmentation of 3D Articulated Bodies

In motion analysis and understanding it is important to be able to fit a suitable model or structure to the temporal series of observed data, in order to describe motion patterns in a compact way, and to discriminate between them. In an unsupervised context, i.e., no prior model of the moving object(s) is available, such a structure has to be learned from the data in a bottom-up fashion. In recent times, volumetric approaches in which the motion is captured from a number of cameras and a voxel-set representation of the body is built from the camera views, have gained ground due to attractive features such as inherent view-invariance and robustness to occlusions. Automatic, unsupervised segmentation of moving bodies along entire sequences, in a temporally-coherent and robust way, has the potential to provide a means of constructing a bottom-up model of the moving body, and track motion cues that may be later exploited for motion classification. Spectral methods such as locally linear embedding (LLE) can be useful in this context, as they preserve ''protrusions", i.e., high-curvature regions of the 3D volume, of articulated shapes, while improving their separation in a lower dimensional space, making them in this way easier to cluster. In this paper we therefore propose a spectral approach to unsupervised and temporally-coherent body-protrusion segmentation along time sequences. Volumetric shapes are clustered in an embedding space, clusters are propagated in time to ensure coherence, and merged or split to accommodate changes in the body's topology. Experiments on both synthetic and real sequences of dense voxel-set data are shown. This supports the ability of the proposed method to cluster body-parts consistently over time in a totally unsupervised fashion, its robustness to sampling density and shape quality, and its potential for bottom-up model construction.



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[hal-01121377] Tracking Conformational Dynamics of Polypeptides by Nonlinear Electronic Spectroscopy of Aromatic Residues: A First-Principles Simulation Study

The ability of nonlinear electronic spectroscopy to track folding/unfolding processes of proteins in solution by monitoring aromatic interactions is investigated by first-principles simulations of two-dimensional (2D) electronic spectra of a model peptide. A dominant reaction pathway approach is employed to determine the unfolding pathway of a tetrapeptide, which connects the initial folded configuration with stacked aromatic side chains and the final unfolded state with distant noninteracting aromatic residues. The π-stacking and excitonic coupling effects are included through ab initio simulations based on multiconfigurational methods within a hybrid quantum mechanics/molecular mechanics scheme. It is shown that linear absorption spectroscopy in the ultraviolet (UV) region is unable to resolve the unstacking dynamics characterized by the three-step process: T-shaped[RIGHTWARDS ARROW]twisted offset stacking[RIGHTWARDS ARROW]unstacking. Conversely, pump–probe spectroscopy can be used to resolve aromatic interactions by probing in the visible region, the excited-state absorptions (ESAs) that involve charge-transfer states. 2D UV spectroscopy offers the highest sensitivity to the unfolding process, by providing the disentanglement of ESA signals belonging to different aromatic chromophores and high correlation between the conformational dynamics and the quartic splitting.



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[hal-01058732] Continuous Action Recognition Based on Sequence Alignment

Continuous action recognition is more challenging than isolated recognition because classification and segmentation must be simultaneously carried out. We build on the well known dynamic time warping (DTW) framework and devise a novel visual alignment technique, namely dynamic frame warping (DFW), which performs isolated recognition based on per-frame representation of videos, and on aligning a test sequence with a model sequence. Moreover, we propose two extensions which enable to perform recognition concomitant with segmentation, namely one-pass DFW and two-pass DFW. These two methods have their roots in the domain of continuous recognition of speech and, to the best of our knowledge, their extension to continuous visual action recognition has been overlooked. We test and illustrate the proposed techniques with a recently released dataset (RAVEL) and with two public-domain datasets widely used in action recognition (Hollywood-1 and Hollywood-2). We also compare the performances of the proposed isolated and continuous recognition algorithms with several recently published methods.



from HAL : Dernières publications http://ift.tt/1DVR5Cg

[hal-01121378] Disentangling Peptide Configurations via Two-Dimensional Electronic Spectroscopy: Ab Initio Simulations Beyond the Frenkel Exciton Hamiltonian

Two-dimensional (2D) optical spectroscopy techniques based on ultrashort laser pulses have been recently extended to the optical domain in the ultraviolet (UV) spectral region. UV-active aromatic side chains can thus be used as local highly specific markers for tracking dynamics and structural rearrangements of proteins. Here we demonstrate that 2D electronic spectra of a model proteic system, a tetrapeptide with two aromatic side chains, contain enough structural information to distinguish between two different configurations with distant and vicinal side chains. For accurate simulations of the 2DUV spectra in solution, we combine a quantum mechanics/molecular mechanics approach based on wave function methods, accounting for interchromophores coupling and environmental effects, with nonlinear response theory. The proposed methodology reveals effects, such as charge transfer between vicinal aromatic residues that remain concealed in conventional exciton Hamiltonian approaches. Possible experimental setups are discussed, including multicolor experiments and signal manipulation techniques for limiting undesired background contributions and enhancing 2DUV signatures of specific electronic couplings.



from HAL : Dernières publications http://ift.tt/1C9TFqS

[hal-01053737] Robust Temporally Coherent Laplacian Protrusion Segmentation of 3D Articulated Bodies

In motion analysis and understanding it is important to be able to fit a suitable model or structure to the temporal series of observed data, in order to describe motion patterns in a compact way, and to discriminate between them. In an unsupervised context, i.e., no prior model of the moving object(s) is available, such a structure has to be learned from the data in a bottom-up fashion. In recent times, volumetric approaches in which the motion is captured from a number of cameras and a voxel-set representation of the body is built from the camera views, have gained ground due to attractive features such as inherent view-invariance and robustness to occlusions. Automatic, unsupervised segmentation of moving bodies along entire sequences, in a temporally-coherent and robust way, has the potential to provide a means of constructing a bottom-up model of the moving body, and track motion cues that may be later exploited for motion classification. Spectral methods such as locally linear embedding (LLE) can be useful in this context, as they preserve ''protrusions", i.e., high-curvature regions of the 3D volume, of articulated shapes, while improving their separation in a lower dimensional space, making them in this way easier to cluster. In this paper we therefore propose a spectral approach to unsupervised and temporally-coherent body-protrusion segmentation along time sequences. Volumetric shapes are clustered in an embedding space, clusters are propagated in time to ensure coherence, and merged or split to accommodate changes in the body's topology. Experiments on both synthetic and real sequences of dense voxel-set data are shown. This supports the ability of the proposed method to cluster body-parts consistently over time in a totally unsupervised fashion, its robustness to sampling density and shape quality, and its potential for bottom-up model construction.



from HAL : Dernières publications http://ift.tt/1Ao8yyZ

[hal-01121377] Tracking Conformational Dynamics of Polypeptides by Nonlinear Electronic Spectroscopy of Aromatic Residues: A First-Principles Simulation Study

The ability of nonlinear electronic spectroscopy to track folding/unfolding processes of proteins in solution by monitoring aromatic interactions is investigated by first-principles simulations of two-dimensional (2D) electronic spectra of a model peptide. A dominant reaction pathway approach is employed to determine the unfolding pathway of a tetrapeptide, which connects the initial folded configuration with stacked aromatic side chains and the final unfolded state with distant noninteracting aromatic residues. The π-stacking and excitonic coupling effects are included through ab initio simulations based on multiconfigurational methods within a hybrid quantum mechanics/molecular mechanics scheme. It is shown that linear absorption spectroscopy in the ultraviolet (UV) region is unable to resolve the unstacking dynamics characterized by the three-step process: T-shaped[RIGHTWARDS ARROW]twisted offset stacking[RIGHTWARDS ARROW]unstacking. Conversely, pump–probe spectroscopy can be used to resolve aromatic interactions by probing in the visible region, the excited-state absorptions (ESAs) that involve charge-transfer states. 2D UV spectroscopy offers the highest sensitivity to the unfolding process, by providing the disentanglement of ESA signals belonging to different aromatic chromophores and high correlation between the conformational dynamics and the quartic splitting.



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[hal-01121375] Atmosphère et climat de la Terre et des planètes.

[...]



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[hal-01121375] Atmosphère et climat de la Terre et des planètes.

[...]



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[halshs-00876404] L'amnistie décrétée en l'an 21 de Ptolémée Epiphane

[...]



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[halshs-00876120] Parthénios ?

[...]



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[hal-01121373] L'analyse de la pratique en formation infirmière

[...]



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[halshs-00876404] L'amnistie décrétée en l'an 21 de Ptolémée Epiphane

[...]



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[halshs-00876120] Parthénios ?

[...]



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[hal-01121373] L'analyse de la pratique en formation infirmière

[...]



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[hal-01121372] Une approche communicationnelle de la professionnalisation au sein des Instituts de formation en soins infirmiers en France

[...]



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[halshs-00840937] De Khaset-Dep à Khaset-Tep : étude toponimyque

[...]



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[hal-01121372] Une approche communicationnelle de la professionnalisation au sein des Instituts de formation en soins infirmiers en France

[...]



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[halshs-00840937] De Khaset-Dep à Khaset-Tep : étude toponimyque

[...]



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[hal-01121369] La gouvernance culturelle dans les eurorégions : enjeux et dynamiques

This article deals with the cultural policies that are developed in the context of euroregions and analyses the governance that results from such policies. The processes and modalities of euroregional cultural governance present a certain innovative dimension, as well as implementation limits, which raises broader questions about euroregional governance. The analysis is based on case studies from Western Europe: euroregion Pyrénées-Méditerranée and Grande Région. After a general presentation of euroregional cultural policies, and of the main criticism that these policies can be addressed, the hypothesis of a certain renewal of euroregional cultural governance is questioned following two lines: the policy discourse and means one the one hand, the appropriation of these policies by stakeholders and actors on the other hand.



from HAL : Dernières publications http://ift.tt/1vKrooM

[hal-01121369] La gouvernance culturelle dans les eurorégions : enjeux et dynamiques

This article deals with the cultural policies that are developed in the context of euroregions and analyses the governance that results from such policies. The processes and modalities of euroregional cultural governance present a certain innovative dimension, as well as implementation limits, which raises broader questions about euroregional governance. The analysis is based on case studies from Western Europe: euroregion Pyrénées-Méditerranée and Grande Région. After a general presentation of euroregional cultural policies, and of the main criticism that these policies can be addressed, the hypothesis of a certain renewal of euroregional cultural governance is questioned following two lines: the policy discourse and means one the one hand, the appropriation of these policies by stakeholders and actors on the other hand.



from HAL : Dernières publications http://ift.tt/1vKrooM

[hal-01078407] Self social data

Cet article présente le partage de données médico-sociales et sociales entre acteurs du soin comme un levier pour atténuer le cloisonnement entre professionnels des secteurs médical médico-social. Dans la perspective d'améliorer le parcours de soin de la personne fragile, notre contribution s'inscrit dans la pluridisciplinarité. Elle présente d’une part certains moyens qui, en terme de système d’information pourraient être mis en œuvre et propose d’autre part de poser un regard critique, sur les contraintes juridiques « supposées ou réelles ». Au-delà de ces constats, notre contribution permet de conclure de manière très provisoire que, les professionnels du soin ont avec la mise en place de nouveaux outils technologiques une carte maîtresse à jouer dans la silver économie.



from HAL : Dernières publications http://ift.tt/1DDOKMT

[hal-01078407] Self social data

Cet article présente le partage de données médico-sociales et sociales entre acteurs du soin comme un levier pour atténuer le cloisonnement entre professionnels des secteurs médical médico-social. Dans la perspective d'améliorer le parcours de soin de la personne fragile, notre contribution s'inscrit dans la pluridisciplinarité. Elle présente d’une part certains moyens qui, en terme de système d’information pourraient être mis en œuvre et propose d’autre part de poser un regard critique, sur les contraintes juridiques « supposées ou réelles ». Au-delà de ces constats, notre contribution permet de conclure de manière très provisoire que, les professionnels du soin ont avec la mise en place de nouveaux outils technologiques une carte maîtresse à jouer dans la silver économie.



from HAL : Dernières publications http://ift.tt/1DDOKMT

[hal-01121368] Creative Regions on a European Cross-Border Scale: Policy Issues and Development Perspectives

This article discusses the creative and cultural policies that are developed on a European cross-border scale. It provides a comparative case study of the Pyrenees-Mediterranean Euroregion, located on the French–Spanish eastern border and the Greater Region between Luxembourg, Germany, Belgium and France. The analysis is based on the concept of cultural development, which is related to Euroregions to emphasize the uses of culture, identity and creative resources in strategies of territorial attractiveness and institutional capacity-building. The analysis then shows how the dynamics of cultural development concretely impact Euroregional policies: implications, or even strengthening, of arts and creativity in cross-cutting policies—tourism and sustainable development, promotion of cultural diversity and the human dimension of development. Furthermore, these dynamics underline the contribution of cultural policy to the construction of territoriality, and subsequently the contribution of Euroregions to the territorial and cultural construction of Europe.



from HAL : Dernières publications http://ift.tt/1AUQnVo

[hal-00994171] Equivalent Damping Modeling In the Framework of SmEdA

City Lightweight Innovative Cab (project CLIC) aims at developing a new generation of lightweight trucks. Mass reduction of a structural body may necessitate extensive use of additive damping mechanisms. Statistical Modal Energy Distribution Analysis (SmEdA) can be used to analyze the energy transmission of a structure-cavity system in the mid-high frequency domain. In this paper, the methodology is extended to take into account the effect of dissipative materials applied to each subsystem. This includes a characterization of the damping material as an equivalent property of treated subsystems, which greatly reduces a size of a finite element system to be solved and leads to a more efficient numerical implementation.



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[hal-00994175] Mid Frequency Vibroacoustic Modeling of an Innovative Lightweight Cab - Floor/Cavity Interaction

The City Lightweight and Innovative Cab (CLIC) project is a scientific collaboration gathering different public and private organizations. The aim is to propose an innovative truck cab responding to new European legislations in security and CO2 emission. A very high strength steel will be used to lighten the structure. This could affects directly the acoustic environment of the cab. In order to control the noise requirements at the design stage, it is then necessary to be able to simulate the vibroacoustic behavior of a truck cab in the mid frequency range. In this context, a methodology is developed at INSA Lyon based on Statistical modal Energy distribution Analysis (SmEdA). This method is considered as substructuring approach for vibroacoustic problems and post-process for finite element methods (FEM). It is based on the knowledge of the uncoupled subsystem modes that can be computed using the FEM. In this paper, one focuses on the fluid-structure coupling of the cab floor with the interior cavity when they are represented by non-coincident meshes.



from HAL : Dernières publications http://ift.tt/1LWR03N

[hal-01121368] Creative Regions on a European Cross-Border Scale: Policy Issues and Development Perspectives

This article discusses the creative and cultural policies that are developed on a European cross-border scale. It provides a comparative case study of the Pyrenees-Mediterranean Euroregion, located on the French–Spanish eastern border and the Greater Region between Luxembourg, Germany, Belgium and France. The analysis is based on the concept of cultural development, which is related to Euroregions to emphasize the uses of culture, identity and creative resources in strategies of territorial attractiveness and institutional capacity-building. The analysis then shows how the dynamics of cultural development concretely impact Euroregional policies: implications, or even strengthening, of arts and creativity in cross-cutting policies—tourism and sustainable development, promotion of cultural diversity and the human dimension of development. Furthermore, these dynamics underline the contribution of cultural policy to the construction of territoriality, and subsequently the contribution of Euroregions to the territorial and cultural construction of Europe.



from HAL : Dernières publications http://ift.tt/1AUQnVo

[hal-00994171] Equivalent Damping Modeling In the Framework of SmEdA

City Lightweight Innovative Cab (project CLIC) aims at developing a new generation of lightweight trucks. Mass reduction of a structural body may necessitate extensive use of additive damping mechanisms. Statistical Modal Energy Distribution Analysis (SmEdA) can be used to analyze the energy transmission of a structure-cavity system in the mid-high frequency domain. In this paper, the methodology is extended to take into account the effect of dissipative materials applied to each subsystem. This includes a characterization of the damping material as an equivalent property of treated subsystems, which greatly reduces a size of a finite element system to be solved and leads to a more efficient numerical implementation.



from HAL : Dernières publications http://ift.tt/1LWR0kr

[hal-00994175] Mid Frequency Vibroacoustic Modeling of an Innovative Lightweight Cab - Floor/Cavity Interaction

The City Lightweight and Innovative Cab (CLIC) project is a scientific collaboration gathering different public and private organizations. The aim is to propose an innovative truck cab responding to new European legislations in security and CO2 emission. A very high strength steel will be used to lighten the structure. This could affects directly the acoustic environment of the cab. In order to control the noise requirements at the design stage, it is then necessary to be able to simulate the vibroacoustic behavior of a truck cab in the mid frequency range. In this context, a methodology is developed at INSA Lyon based on Statistical modal Energy distribution Analysis (SmEdA). This method is considered as substructuring approach for vibroacoustic problems and post-process for finite element methods (FEM). It is based on the knowledge of the uncoupled subsystem modes that can be computed using the FEM. In this paper, one focuses on the fluid-structure coupling of the cab floor with the interior cavity when they are represented by non-coincident meshes.



from HAL : Dernières publications http://ift.tt/1LWR03N

[hal-01121365] Tropospheric ozone and carbon monoxide measurement over China as seen by the thermal infrared IASI/MetOp sounder

[...]



from HAL : Dernières publications http://ift.tt/1LWImCo

[hal-01121365] Tropospheric ozone and carbon monoxide measurement over China as seen by the thermal infrared IASI/MetOp sounder

[...]



from HAL : Dernières publications http://ift.tt/1LWImCo

[hal-01121360] The Support to Aviation Control Service, an overview and recent developments

[...]



from HAL : Dernières publications http://ift.tt/1AFt7fj

[hal-01121359] Entropic Wasserstein Gradient Flows

This article details a novel numerical scheme to approximate gradient flows for optimal transport (i.e. Wasserstein) metrics. These flows have proved useful to tackle theoretically and numerically non-linear diffusion equations that model for instance porous media or crowd evolutions. These gradient flows define a suitable notion of weak solutions for these evolutions and they can be approximated in a stable way using discrete flows. These discrete flows are implicit Euler time stepping according to the Wasserstein metric. A bottleneck of these approaches is the high computational load induced by the resolution of each step. Indeed, this corresponds to the resolution of a convex optimization problem involving a Wasserstein distance to the previous iterate. Following several recent works on the approximation of Wasserstein distances, we consider a discrete flow induced by an entropic regularization of the transportation coupling. This entropic regularization allows one to trade the initial Wasserstein fidelity term for a Kulback-Leibler divergence, which is easier to deal with numerically. We show how KL proximal schemes, and in particular Dykstra's algorithm, can be used to compute each step of the regularized flow. The resulting algorithm is both fast, parallelizable and versatile, because it only requires multiplications by a Gibbs kernel. On Euclidean domains discretized on an uniform grid, this corresponds to a linear filtering (for instance a Gaussian filtering when $c$ is the squared Euclidean distance) which can be computed in nearly linear time. On more general domains, such as (possibly non-convex) shapes or on manifolds discretized by a triangular mesh, following a recently proposed numerical scheme for optimal transport, this Gibbs kernel multiplication is approximated by a short-time heat diffusion.



from HAL : Dernières publications http://ift.tt/1AFt7f9

[hal-01121360] The Support to Aviation Control Service, an overview and recent developments

[...]



from HAL : Dernières publications http://ift.tt/1AFt7fj

[hal-01121359] Entropic Wasserstein Gradient Flows

This article details a novel numerical scheme to approximate gradient flows for optimal transport (i.e. Wasserstein) metrics. These flows have proved useful to tackle theoretically and numerically non-linear diffusion equations that model for instance porous media or crowd evolutions. These gradient flows define a suitable notion of weak solutions for these evolutions and they can be approximated in a stable way using discrete flows. These discrete flows are implicit Euler time stepping according to the Wasserstein metric. A bottleneck of these approaches is the high computational load induced by the resolution of each step. Indeed, this corresponds to the resolution of a convex optimization problem involving a Wasserstein distance to the previous iterate. Following several recent works on the approximation of Wasserstein distances, we consider a discrete flow induced by an entropic regularization of the transportation coupling. This entropic regularization allows one to trade the initial Wasserstein fidelity term for a Kulback-Leibler divergence, which is easier to deal with numerically. We show how KL proximal schemes, and in particular Dykstra's algorithm, can be used to compute each step of the regularized flow. The resulting algorithm is both fast, parallelizable and versatile, because it only requires multiplications by a Gibbs kernel. On Euclidean domains discretized on an uniform grid, this corresponds to a linear filtering (for instance a Gaussian filtering when $c$ is the squared Euclidean distance) which can be computed in nearly linear time. On more general domains, such as (possibly non-convex) shapes or on manifolds discretized by a triangular mesh, following a recently proposed numerical scheme for optimal transport, this Gibbs kernel multiplication is approximated by a short-time heat diffusion.



from HAL : Dernières publications http://ift.tt/1AFt7f9

[hal-00271963] RIMES evaluation campaign for handwritten mail processing

[...]



from HAL : Dernières publications http://ift.tt/1wxMim4

[hal-00272079] La campagne d'évaluation RIMES pour la reconnaissance de courriers manuscrits

[...]



from HAL : Dernières publications http://ift.tt/1wxMi5s

[hal-00271963] RIMES evaluation campaign for handwritten mail processing

[...]



from HAL : Dernières publications http://ift.tt/1wxMim4

[hal-00272079] La campagne d'évaluation RIMES pour la reconnaissance de courriers manuscrits

[...]



from HAL : Dernières publications http://ift.tt/1wxMi5s

[hal-01074090] Combining Face Averageness and Symmetry for 3D-based Gender Classification

Although human face averageness and symmetry are valuable clues in social perception (such as attractiveness, masculinity/femininity, healthy/sick, etc.), in the literature of facial attribute recognition, little consideration has been given to them. In this work, we propose to study the morphological differences between male and female faces by analyzing the averageness and symmetry of their 3D shapes. In particular, we address the following questions: (i) is there any relationship between gender and face averageness/symmetry? and (ii) if this relationship exists, which specific areas on the face are involved? To this end, we propose first to capture densely both the face shape averageness (AVE) and symmetry (SYM) using our Dense Scalar Field (DSF), which denotes the shooting directions of geodesics between facial shapes. Then, we explore such representations by using classical machine learning techniques, the Feature Selection (FS) methods and Random Forest (RF) classification algorithm. Experiments conducted on the FRGCv2 dataset show a significant relationship exists between gender and facial averageness/symmetry when achieving a classification rate of 93.7% on the 466 earliest scans of subjects (mainly neutral) and 92.4% on the whole FRGCv2 dataset (including facial expressions)



from HAL : Dernières publications http://ift.tt/1yMj9s6

[hal-01074090] Combining Face Averageness and Symmetry for 3D-based Gender Classification

Although human face averageness and symmetry are valuable clues in social perception (such as attractiveness, masculinity/femininity, healthy/sick, etc.), in the literature of facial attribute recognition, little consideration has been given to them. In this work, we propose to study the morphological differences between male and female faces by analyzing the averageness and symmetry of their 3D shapes. In particular, we address the following questions: (i) is there any relationship between gender and face averageness/symmetry? and (ii) if this relationship exists, which specific areas on the face are involved? To this end, we propose first to capture densely both the face shape averageness (AVE) and symmetry (SYM) using our Dense Scalar Field (DSF), which denotes the shooting directions of geodesics between facial shapes. Then, we explore such representations by using classical machine learning techniques, the Feature Selection (FS) methods and Random Forest (RF) classification algorithm. Experiments conducted on the FRGCv2 dataset show a significant relationship exists between gender and facial averageness/symmetry when achieving a classification rate of 93.7% on the 466 earliest scans of subjects (mainly neutral) and 92.4% on the whole FRGCv2 dataset (including facial expressions)



from HAL : Dernières publications http://ift.tt/1yMj9s6

[hal-01121198] Characterization of Two-Dimensional Chiral Self-Assemblies L- and D-Methionine on Au(111).

[...]



from HAL : Dernières publications http://ift.tt/1G0IToa

[hal-01121196] Overestimation of the strength of size-assortative pairing in taxa with cryptic diversity: a case of Simpson's paradox.

Size-assortative pairing is one of the most common pairing patterns observed in nature and it probably occurs in many taxa with cryptic diversity. Observed patterns of size-assortative pairing in natural populations may thus be influenced by the co-occurrence of noninterbreeding cryptic groups of individuals living in sympatry. To quantify this potential bias, we sampled amphipods from the Gammarus pulex/Gammarus fossarum crustacean species complex in rivers containing two sympatric and morphologically cryptic groups, i.e. molecular operational taxonomic units (MOTUs). Within each river, MOTUs did not interbreed and differed in mean body size. We measured the strength of size-assortative pairing both within MOTUs and overall, combining both MOTUs for the analysis to test for potential effects of cryptic diversity on pairing patterns. Owing to body size differences between MOTUs, we expected size assortment to be stronger when combining MOTUs, which could represent a case of Simpson's paradox on measures of size-assortative pairing. In accordance with our predictions, in most rivers, combined-MOTU size-assortative pairing was stronger than within-MOTU size-assortative pairing. Combined-MOTU size-assortative pairing also increased with increasing body size difference between the two sympatric MOTUs. We discuss how such spurious correlations may lead to inferential fallacies when studying potential causes of pairing patterns and their consequences for sexual selection and phenotypic diversification. Previous results from studies measuring mating patterns in species in which cryptic diversity is likely to occur should be reappraised in the light of our findings.



from HAL : Dernières publications http://ift.tt/1G0IVfS

[hal-01121197] Complexité et algorithmique avancée (une introduction)

[...]



from HAL : Dernières publications http://ift.tt/185O5by

[hal-01121195] Some relational structures with polynomial growth and their associated algebras I: Quasi-polynomiality of the profile

The profile of a relational structure $R$ is the function $\varphi_R$ which counts for every integer $n$ the number $\varphi_R(n)$, possibly infinite, of substructures of $R$ induced on the $n$-element subsets, isomorphic substructures being identified. If $\varphi_R$ takes only finite values, this is the Hilbert function of a graded algebra associated with $R$, the age algebra introduced by P. J. Cameron. In this paper we give a closer look at this association, particularly when the relational structure $R$ admits a finite monomorphic decomposition. This setting still encompass well-studied graded commutative algebras like invariant rings of finite permutation groups, or the rings of quasi-symmetric polynomials. We prove that $\varphi_R$ is eventually a quasi-polynomial, this supporting the conjecture that, under mild assumptions on $R$, $\varphi_R$ is eventually a quasi-polynomial when it is bounded by some polynomial.



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[tel-01118877] Processing of titanium-based composite materials with nanosized TiC and TiB reinforcements using different powder metallurgy processes: hydrogenation/dehydrogenation sintering, and severe plastic deformation (Equal Channel Angular Pressing: ECAP)

Titanium based composites using nano-sized reinforcements are good candidates for the improvement in mechanical properties without affecting ductility. This study is dedicated to fabrication and characterisation of Ti-based composites using two different powder metallurgy processes: Densification using severe plastic deformation via Equal Channel Angular Pressing (ECAP) and Hydrogenation/Dehydrogenation (HDH) sintering processes (pressureless sintering and hot pressing).ECAP is a fast process based on a severe plastic deformation of material at relatively low temperature. HDH processes use the dehydrogenation of Ti as a leverage of the sintering. The different nanosized reinforcements used in this study are the TiC spherical particles and the whisker shaped TiB. This study shows the influence of either the reinforcement nature and type, and the powder metallurgy processes used, on the final microstructure and properties of the dense materials.



from HAL : Dernières publications http://ift.tt/1CSA4cp

[hal-01121200] ℋ−/ℋ∞ fault detection observer for switched systems

This paper addresses a method for fault detection (FD) by maximizing the fault to residual sensitivity. It uses the newly developed ℋ− index properties and minimizing the well known ℋ∞ norm for worst case disturbance attenuation. The fault detection problem is formulated as LMI feasibility problem in which a cost function is minimized subject to LMI constraints. This objective is coupled to a transient response specification expressed by eigenvalue assignment formulation. This approach is then studied for both proper and strictly proper systems. Sufficient conditions are also given to enhance the disturbance decoupling. The effectiveness of the proposed approach is shown by a numerical example



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[hal-01121070] Prétopologie et applications - Studia Informatica Universalis

[...]



from HAL : Dernières publications http://ift.tt/1MXUI0z

[hal-01121198] Characterization of Two-Dimensional Chiral Self-Assemblies L- and D-Methionine on Au(111).

[...]



from HAL : Dernières publications http://ift.tt/1G0IToa

[hal-01121196] Overestimation of the strength of size-assortative pairing in taxa with cryptic diversity: a case of Simpson's paradox.

Size-assortative pairing is one of the most common pairing patterns observed in nature and it probably occurs in many taxa with cryptic diversity. Observed patterns of size-assortative pairing in natural populations may thus be influenced by the co-occurrence of noninterbreeding cryptic groups of individuals living in sympatry. To quantify this potential bias, we sampled amphipods from the Gammarus pulex/Gammarus fossarum crustacean species complex in rivers containing two sympatric and morphologically cryptic groups, i.e. molecular operational taxonomic units (MOTUs). Within each river, MOTUs did not interbreed and differed in mean body size. We measured the strength of size-assortative pairing both within MOTUs and overall, combining both MOTUs for the analysis to test for potential effects of cryptic diversity on pairing patterns. Owing to body size differences between MOTUs, we expected size assortment to be stronger when combining MOTUs, which could represent a case of Simpson's paradox on measures of size-assortative pairing. In accordance with our predictions, in most rivers, combined-MOTU size-assortative pairing was stronger than within-MOTU size-assortative pairing. Combined-MOTU size-assortative pairing also increased with increasing body size difference between the two sympatric MOTUs. We discuss how such spurious correlations may lead to inferential fallacies when studying potential causes of pairing patterns and their consequences for sexual selection and phenotypic diversification. Previous results from studies measuring mating patterns in species in which cryptic diversity is likely to occur should be reappraised in the light of our findings.



from HAL : Dernières publications http://ift.tt/1G0IVfS

[hal-01121197] Complexité et algorithmique avancée (une introduction)

[...]



from HAL : Dernières publications http://ift.tt/185O5by

[hal-01121195] Some relational structures with polynomial growth and their associated algebras I: Quasi-polynomiality of the profile

The profile of a relational structure $R$ is the function $\varphi_R$ which counts for every integer $n$ the number $\varphi_R(n)$, possibly infinite, of substructures of $R$ induced on the $n$-element subsets, isomorphic substructures being identified. If $\varphi_R$ takes only finite values, this is the Hilbert function of a graded algebra associated with $R$, the age algebra introduced by P. J. Cameron. In this paper we give a closer look at this association, particularly when the relational structure $R$ admits a finite monomorphic decomposition. This setting still encompass well-studied graded commutative algebras like invariant rings of finite permutation groups, or the rings of quasi-symmetric polynomials. We prove that $\varphi_R$ is eventually a quasi-polynomial, this supporting the conjecture that, under mild assumptions on $R$, $\varphi_R$ is eventually a quasi-polynomial when it is bounded by some polynomial.



from HAL : Dernières publications http://ift.tt/185O2wp

[tel-01118877] Processing of titanium-based composite materials with nanosized TiC and TiB reinforcements using different powder metallurgy processes: hydrogenation/dehydrogenation sintering, and severe plastic deformation (Equal Channel Angular Pressing: ECAP)

Titanium based composites using nano-sized reinforcements are good candidates for the improvement in mechanical properties without affecting ductility. This study is dedicated to fabrication and characterisation of Ti-based composites using two different powder metallurgy processes: Densification using severe plastic deformation via Equal Channel Angular Pressing (ECAP) and Hydrogenation/Dehydrogenation (HDH) sintering processes (pressureless sintering and hot pressing).ECAP is a fast process based on a severe plastic deformation of material at relatively low temperature. HDH processes use the dehydrogenation of Ti as a leverage of the sintering. The different nanosized reinforcements used in this study are the TiC spherical particles and the whisker shaped TiB. This study shows the influence of either the reinforcement nature and type, and the powder metallurgy processes used, on the final microstructure and properties of the dense materials.



from HAL : Dernières publications http://ift.tt/1CSA4cp

[hal-00348369] EXPLORATION OF FINITE-DIMENSIONAL KAC ALGEBRAS AND LATTICES OF INTERMEDIATE SUBFACTORS OF IRREDUCIBLE INCLUSIONS

We study two infinite families of finite dimensional Hopf (in fact Kac) algebras constructed by L. Vainerman: automorphism groups, self-duality, lattices of coidalgebras, relations between the two families, etc. We derive many examples of lattices of intermediate subfactors of the inclusions of depth 2 associated to those Kac algebras, as well as the corresponding principal graphs, which is the original motivation. This research was driven by heavy computer exploration, whose tools and methodology we further describe.



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[hal-00348369] EXPLORATION OF FINITE-DIMENSIONAL KAC ALGEBRAS AND LATTICES OF INTERMEDIATE SUBFACTORS OF IRREDUCIBLE INCLUSIONS

We study two infinite families of finite dimensional Hopf (in fact Kac) algebras constructed by L. Vainerman: automorphism groups, self-duality, lattices of coidalgebras, relations between the two families, etc. We derive many examples of lattices of intermediate subfactors of the inclusions of depth 2 associated to those Kac algebras, as well as the corresponding principal graphs, which is the original motivation. This research was driven by heavy computer exploration, whose tools and methodology we further describe.



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[hal-01121193] Low-energy electron induced resonant loss of aromaticity: consequences on cross-linking in terphenylthiol SAMs

Aromatic self-assembled monolayers (SAMs) can be used as negative tone electron resists in functional surface lithographic fabrication. A dense and resistant molecular network is obtained under electron irradiation through the formation of a cross-linked network. The elementary processes and possible mechanisms involved were investigated through the response of a model aromatic SAM, p-terphenylthiol SAM, to low-energy electron (0-10 eV) irradiation. Energy loss spectra as well as vibrational excitation functions were measured using High Resolution Electron Energy Loss Spectroscopy (HREELS). A resonant electron attachment process was identified around 6 eV through associated enhanced excitation probability of the CH stretching modes ν(CH)(ph) at 378 meV. Electron irradiation at 6 eV was observed to induce a peak around 367 meV in the energy loss spectra, attributed to the formation of sp(3)-hybridized CHx groups within the SAM. This partial loss of aromaticity is interpreted to be the result of resonance formation, which relaxes by reorganization and/or CH bond dissociation mechanisms followed by radical chain reactions. These processes may also account for cross-linking induced by electron irradiation of aromatic SAMs in general.



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[hal-00632266] The biHecke monoid of a finite Coxeter group and its representations

For any finite Coxeter group W, we introduce two new objects: its cutting poset and its biHecke monoid. The cutting poset, constructed using a generalization of the notion of blocks in permutation matrices, almost forms a lattice on W. The construction of the biHecke monoid relies on the usual combinatorial model for the 0-Hecke algebra H_0(W), that is, for the symmetric group, the algebra (or monoid) generated by the elementary bubble sort operators. The authors previously introduced the Hecke group algebra, constructed as the algebra generated simultaneously by the bubble sort and antisort operators, and described its representation theory. In this paper, we consider instead the monoid generated by these operators. We prove that it admits |W| simple and projective modules. In order to construct the simple modules, we introduce for each w in W a combinatorial module T_w whose support is the interval [1,w]_R in right weak order. This module yields an algebra, whose representation theory generalizes that of the Hecke group algebra, with the combinatorics of descents replaced by that of blocks and of the cutting poset.



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[hal-00593838] Households under carbon constraints and the burden sharing issue

Well-known context : fossil fuels depletion, climate change & security of supply - French & European political context : 2020 & Factor 4: 50-75% reduction by 2050 -> Strong carbon constraint Issues - What are the least cost solutions of energy saving ? How to reach F4 constraint ? - How does this strong carbon constraint would be distributed over households ? -> Burden sharing issue : Efficiency and Equity are not necessarily linked



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[in2p3-01009961] Measurement of Multijet Production in ep Collisions at High Q^2 and Determination of the Strong Coupling alpha_s

Inclusive jet, dijet and trijet differential cross sections are measured in neutral current deep-inelastic scattering for exchanged boson virtualities 150 < Q^2 < 15000 GeV^2 using the H1 detector at HERA. The data were taken in the years 2003 to 2007 and correspond to an integrated luminosity of 351 pb^{-1}. Double differential Jet cross sections are obtained using a regularised unfolding procedure. They are presented as a function of Q^2 and the transverse momentum of the jet, P_T^jet, and as a function of Q^2 and the proton's longitudinal momentum fraction, Xi, carried by the parton participating in the hard interaction. In addition normalised double differential jet cross sections are measured as the ratio of the jet cross sections to the inclusive neutral current cross sections in the respective Q^2 bins of the jet measurements. Compared to earlier work, the measurements benefit from an improved reconstruction and calibration of the hadronic final state. The cross sections are compared to perturbative QCD calculations in next-to-leading order and are used to determine the running coupling and the value of the strong coupling constant as alpha_s(M_Z) = 0.1165 (8)_exp (38)_{pdf,theo}.



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[hal-00508569] Desperately seeking energy efficiency... using information and communication technologies?

This paper provides a reflection on the potential contribution of scientific computing with a view to improving energy system efficiency. First, we will consider energy efficiency globally in order to evaluate its potential. We will then focus on electricity, since electrical energy is interpreted as the universal vector of work. This will give us the understanding we need for envisaging a more efficient energy system. The use of ICTs (Information and Communication Technologies) as a final solution for improving system efficiency should be reconsidered. The drain on energy resources that they entail can, in fact, outweigh the expected gains. Better management of existing energy systems should therefore be privileged via scientific approaches designed to envisage the rational use of energy.



from HAL : Dernières publications http://ift.tt/1AAPUsw

[hal-00935540] CFAR Clustering of Polarimetric SAR Data

[...]



from HAL : Dernières publications http://ift.tt/1AhfTAt

[hal-00508562] Long-term planning and the sustainable power system: a focus on flexibility needs and network reliability

Long-term planning models are useful to describe future energy and technology options and to analyze environmental issues. They propose solutions for meeting future energy consumption. Focusing on the electricity sector, we argue that in order to provide a more relevant assessment of the power supply system ahead we need to tackle both flexibility needs and network reliability. On the one hand, flexibility is integrated in long-term planning models as an additional criterion for new investment decisions: it allows electricity generation capacity with short start-up periods to be part of the mix to satisfy peak demand, despite their higher marginal costs in comparison with the cost of base load technologies. On the other hand, and in order to assess network reliability, a suitable representation of dynamic dissipative processes over the electrical network is necessary. We introduce the notions of conveyance and reliability losses and their qualitative impacts on power transmission. We propose a methodology to exhibit the level of losses associated with a given level of reliability, whether generation capacities are centralized or decentralized. Our methodology is based on a thermodynamic description of the electric system and lumps it into a "one-loop grid". It provides a figure for the amount of reactive power and kinetic reserve needed to ensure network reliability and face admissible load fluctuations.



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[hal-01121188] Petromyzon marinus (Petromyzontidae), an unusual host for helminth parasites in Western Europe

[...]



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[halshs-01120661] Conceptualizing of Police

Overview Police as an institution cannot be said to have inspired in-depth conceptualization effortsfrom criminology and criminal justice so far. Scholars in this area show a clear preference for empirically exploring what individual police officers do or think, and the policing concept they most readily converge towards tends to hinge on the use of force, a notion developed by ethnomethodologist, Egon Bittner. This concept holds that what constitutes policing as such is " the distribution of non-negotiably coercive force ". In another tradition, stemming from European political philosophy, police are heir to a dual dimension, i.e. its relationship to both knowledge and dogma. However, numerous affinities between these two schools of thought – the Anglo-American sociological school, withits interactionistinclinations, and the European school of political philosophy – suggest that the concept of police should in fact be understood through a dualist epistemological approach. Both in legal and knowledge terms – two fundamental dimensions of policing –, police as an institution is highly idiosyncratic in that it concomitantly harbors both a) the rule of law and violence, and b) knowledge and ignorance. Main Text



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[hal-00593806] Chaire Modélisation prospective au service du Développement Durable

A la recherche de sentiers robustes à l'incertitude - Déficit de dialogue entre ingénieurs et économistes - Défis méthodologiques de l'hybridation - Enjeux scientifiques de la Chaire - L'expertise des laboratoires - Chaire Modélisation prospective - Programme de recherche - Les étapes de lancement de la Chaire - Scénarios France pour les engagements 2020 de la Chaire Modélisation prospective - Les 14 scénarios TIMES-de la Chaire ...



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[hal-00511593] Ressources agricoles, biocarburants et modéliation prospective TIMES

Le principe de l'approche TIMES: un accent mis sur la compétition entre chemins technologiques • Représentation des flux d'énergie et de matière, • Représentation des technologies mises en oeuvre, • Minimisation sous contrainte du surplus total.



from HAL : Dernières publications http://ift.tt/1AAPSAS

[hal-00593800] Enjeux mondiaux et impacts régionaux des contraintes carbone. Prospective long terme à l'aide du modèle TIAM-FR

L'objet de cette présentation est de reporter différents résultats issus de l'analyse prospective long terme des enjeux énergie-climat des contraintes carbone à l'aide de l'outil de modélisation ETSAPTIAM. TIAM est un modèle bottom up technico-économique de programmation linéaire décrivant le système énergétique mondial à travers une description détaillée des différentes formes d'énergie, de ressources, de technologies et d'usages finaux. Dans cette étude, il s'agit plus précisément de discuter les différents mécanismes de coordination des régions s'engageant dans des réductions d'émissions de CO2. Trois séries de scénarios régionaux de contraintes carbone couvrant la période 2000-2050 ont ainsi été spécifiés pour mettre en avant des futurs possibles pour l'après Kyoto. Cette analyse se focalise sur l'évolution de la consommation d'énergie primaire et le mix énergétique, les niveaux d'émission régionaux de CO2 et enfin les coûtsde la politique climatique. Il ressort clairement l'importance de mettre en balance l'effort global vers une réduction des émissions de CO2 avec le coût du carbone à supporter pour les régions contraintes dans la mise en place des politiques climatiques. Egalement, même si les énergies renouvelables se développent, le mix énergétique est encore fortement marqué en 2050 par les énergies fossiles, ceci en raison du développement des technologies de séquestration du carbone.



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[hal-00593792] Une approche désagrégée de la demande au niveau technique et comportemental dans le secteur résidentiel

1 - Segmentation de la demande d'énergie 2 - Modèle prospective TIMES/MARKAL 3 - Résultats



from HAL : Dernières publications http://ift.tt/1AAPSkl

[hal-01104124] Measuring the noise of imaging sensors in the presence of vibrations and illumination flickering: modeling, algorithm, and experiments

This report discusses camera noise estimation from a series of raw images of an arbitrary natural static scene, acquired with the same camera settings. Although it seems natural to characterize noise from the random time fluctuation of pixel intensity, it turns out that these fluctuations may also be caused by illumination flickering and mechanical micro-vibrations affecting the camera. In this context, the contributions are twofold. First, a theoretical model of image formation in the presence of illumination flickering and of vibrations is discussed. This parametric model is based on a Cox process. It is shown that illumination flickering changes the standard affine relation between noise variance and average intensity to a quadratic relation. Second, under these conditions an algorithm is proposed to estimate the main parameters governing sensor noise, namely the gain, the offset, and the read-out noise. The rolling shutter effect, which potentially affects the output of any focal-plane shutter camera, is also considered. Experiments show that this simple method gives results consistent with the photon transfer method which needs a special experimental setting and several data acquisitions, and with an algorithm based on a single image. The main practical result is to show that flickering, which is generally considered as an artifact, plays here a positive role since it finally enables us to estimate any of the sensor parameters. This report provides additional experiments to a published paper.



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[hal-01077745] The European Modern Pollen Database (EMPD) project

Modern pollen samples provide an invaluable research tool for helping to interpret the quaternary fossil pollen record, allowing investigation of the relationship between pollen as the proxy and the environmental parameters such as vegetation, land-use, and climate that the pollen proxy represents. The European Modern Pollen Database (EMPD) is a new initiative within the European Pollen Database (EPD) to establish a publicly accessible repository of modern (surface sample) pollen data. This new database will complement the EPD, which at present holds only fossil sedimentary pollen data. The EMPD is freely available online to the scientific community and currently has information on almost 5,000 pollen samples from throughout the Euro-Siberian and Mediterranean regions, contributed by over 40 individuals and research groups. Here we describe how the EMPD was constructed, the various tables and their fields, problems and errors, quality controls, and continuing efforts to improve the available data



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[hal-01059249] Historical fluvial palaeodynamics and multi-proxy palaeoenvironmental analyses of a palaeochannel, Allier River, France

[...]



from HAL : Dernières publications http://ift.tt/1tyEx2V

[hal-01087896] Prehistoric impact on landscape and vegetation at high altitudes: An integrated palaeoecological and archaeological approach in the eastern Pyrenees (Perafita valley, Andorra)

A multi-proxy palaeoenvironmental study (pollen, non-pollen palynomorphs-NPP, macrocharcoal particles) of a small fen located in the Perafita valley (2240 m a.s.l, eastern Pyrenees, Andorra) was undertaken to trace prehistoric human activities related to woodland clearance and past land-uses at high altitudes. The results of this study constrained by 9 AMS radiocarbon measurements are combined with archaeological data and compared with similar research carried out at the same altitude in the adjacent Madriu valley (Andorra). The overall objectives of this article are, first, to formulate different chronological patterns and spatial land-use distribution at a micro-regional scale during prehistory and, second, to discuss different drivers of prehistoric occupation models in the eastern Pyrenean highlands. The palaeoecological study of the Planells de Perafita fen was performed at high temporal resolution, allowing us to focus on detailed prehistoric (mainly Mesolithic and Neolithic) and Bronze Age human activity. It demonstrates that the shaping of this cultural landscape is the result of a long-term land-use history, which began at the late Mesolithic/early Neolithic transition onwards (ca 6400–6100 cal BC). The existence of three main phases of “inter-valley” land-use variability has also been highlighted, thus testifying a complex and heterogeneous upland land-use model during the Neolithic and Bronze Age. These land-use variabilities between the two adjacent Andorran valleys provide the basis for a discussion of the way in which environmental constraints influenced prehistoric land-use spatial organisation and of how the interaction between environmental (including climatic parameters), socio-economic and cultural conditions affected the temporal and spatial dynamics of landscape shaping in the eastern Pyrenean highlands



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[hal-01070655] Figement et configuration textuelle : les segments de discours répétés dans les rapports éducatifs

Cet article vise à montrer comment les segments de discours répétés (SDR) participent à la configuration textuelle d'écrits professionnels d'un type particulier : les rapports éducatifs. Portant sur un corpus de " brouillons " constitué des différentes versions de rapports, notre étude allie une approche textométrique permettant le répérage de séquences ou de " formats " récurrents (/Dét. poss. + N, discours + Modifieur/, SDR prépositionnels), et une approche génétique observant les réécritures affectant ces séquences, dans une perspective d'analyse de discours qui vise à rendre compte des contraintes diverses - visée pragmatique du genre, pratiques sociales, filiations interdiscursives - intervenant dans le processus d'écriture. Seront ainsi mis en évidence des routines discursives et des récurrences participant au profil sémantique des rapports éducatifs.



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[hal-01121193] Low-energy electron induced resonant loss of aromaticity: consequences on cross-linking in terphenylthiol SAMs

Aromatic self-assembled monolayers (SAMs) can be used as negative tone electron resists in functional surface lithographic fabrication. A dense and resistant molecular network is obtained under electron irradiation through the formation of a cross-linked network. The elementary processes and possible mechanisms involved were investigated through the response of a model aromatic SAM, p-terphenylthiol SAM, to low-energy electron (0-10 eV) irradiation. Energy loss spectra as well as vibrational excitation functions were measured using High Resolution Electron Energy Loss Spectroscopy (HREELS). A resonant electron attachment process was identified around 6 eV through associated enhanced excitation probability of the CH stretching modes ν(CH)(ph) at 378 meV. Electron irradiation at 6 eV was observed to induce a peak around 367 meV in the energy loss spectra, attributed to the formation of sp(3)-hybridized CHx groups within the SAM. This partial loss of aromaticity is interpreted to be the result of resonance formation, which relaxes by reorganization and/or CH bond dissociation mechanisms followed by radical chain reactions. These processes may also account for cross-linking induced by electron irradiation of aromatic SAMs in general.



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[hal-00632266] The biHecke monoid of a finite Coxeter group and its representations

For any finite Coxeter group W, we introduce two new objects: its cutting poset and its biHecke monoid. The cutting poset, constructed using a generalization of the notion of blocks in permutation matrices, almost forms a lattice on W. The construction of the biHecke monoid relies on the usual combinatorial model for the 0-Hecke algebra H_0(W), that is, for the symmetric group, the algebra (or monoid) generated by the elementary bubble sort operators. The authors previously introduced the Hecke group algebra, constructed as the algebra generated simultaneously by the bubble sort and antisort operators, and described its representation theory. In this paper, we consider instead the monoid generated by these operators. We prove that it admits |W| simple and projective modules. In order to construct the simple modules, we introduce for each w in W a combinatorial module T_w whose support is the interval [1,w]_R in right weak order. This module yields an algebra, whose representation theory generalizes that of the Hecke group algebra, with the combinatorics of descents replaced by that of blocks and of the cutting poset.



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[hal-00593838] Households under carbon constraints and the burden sharing issue

Well-known context : fossil fuels depletion, climate change & security of supply - French & European political context : 2020 & Factor 4: 50-75% reduction by 2050 -> Strong carbon constraint Issues - What are the least cost solutions of energy saving ? How to reach F4 constraint ? - How does this strong carbon constraint would be distributed over households ? -> Burden sharing issue : Efficiency and Equity are not necessarily linked



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[in2p3-01009961] Measurement of Multijet Production in ep Collisions at High Q^2 and Determination of the Strong Coupling alpha_s

Inclusive jet, dijet and trijet differential cross sections are measured in neutral current deep-inelastic scattering for exchanged boson virtualities 150 < Q^2 < 15000 GeV^2 using the H1 detector at HERA. The data were taken in the years 2003 to 2007 and correspond to an integrated luminosity of 351 pb^{-1}. Double differential Jet cross sections are obtained using a regularised unfolding procedure. They are presented as a function of Q^2 and the transverse momentum of the jet, P_T^jet, and as a function of Q^2 and the proton's longitudinal momentum fraction, Xi, carried by the parton participating in the hard interaction. In addition normalised double differential jet cross sections are measured as the ratio of the jet cross sections to the inclusive neutral current cross sections in the respective Q^2 bins of the jet measurements. Compared to earlier work, the measurements benefit from an improved reconstruction and calibration of the hadronic final state. The cross sections are compared to perturbative QCD calculations in next-to-leading order and are used to determine the running coupling and the value of the strong coupling constant as alpha_s(M_Z) = 0.1165 (8)_exp (38)_{pdf,theo}.



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[hal-00508569] Desperately seeking energy efficiency... using information and communication technologies?

This paper provides a reflection on the potential contribution of scientific computing with a view to improving energy system efficiency. First, we will consider energy efficiency globally in order to evaluate its potential. We will then focus on electricity, since electrical energy is interpreted as the universal vector of work. This will give us the understanding we need for envisaging a more efficient energy system. The use of ICTs (Information and Communication Technologies) as a final solution for improving system efficiency should be reconsidered. The drain on energy resources that they entail can, in fact, outweigh the expected gains. Better management of existing energy systems should therefore be privileged via scientific approaches designed to envisage the rational use of energy.



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[hal-00935540] CFAR Clustering of Polarimetric SAR Data

[...]



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[hal-00508562] Long-term planning and the sustainable power system: a focus on flexibility needs and network reliability

Long-term planning models are useful to describe future energy and technology options and to analyze environmental issues. They propose solutions for meeting future energy consumption. Focusing on the electricity sector, we argue that in order to provide a more relevant assessment of the power supply system ahead we need to tackle both flexibility needs and network reliability. On the one hand, flexibility is integrated in long-term planning models as an additional criterion for new investment decisions: it allows electricity generation capacity with short start-up periods to be part of the mix to satisfy peak demand, despite their higher marginal costs in comparison with the cost of base load technologies. On the other hand, and in order to assess network reliability, a suitable representation of dynamic dissipative processes over the electrical network is necessary. We introduce the notions of conveyance and reliability losses and their qualitative impacts on power transmission. We propose a methodology to exhibit the level of losses associated with a given level of reliability, whether generation capacities are centralized or decentralized. Our methodology is based on a thermodynamic description of the electric system and lumps it into a "one-loop grid". It provides a figure for the amount of reactive power and kinetic reserve needed to ensure network reliability and face admissible load fluctuations.



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[hal-01121188] Petromyzon marinus (Petromyzontidae), an unusual host for helminth parasites in Western Europe

[...]



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[halshs-01120661] Conceptualizing of Police

Overview Police as an institution cannot be said to have inspired in-depth conceptualization effortsfrom criminology and criminal justice so far. Scholars in this area show a clear preference for empirically exploring what individual police officers do or think, and the policing concept they most readily converge towards tends to hinge on the use of force, a notion developed by ethnomethodologist, Egon Bittner. This concept holds that what constitutes policing as such is " the distribution of non-negotiably coercive force ". In another tradition, stemming from European political philosophy, police are heir to a dual dimension, i.e. its relationship to both knowledge and dogma. However, numerous affinities between these two schools of thought – the Anglo-American sociological school, withits interactionistinclinations, and the European school of political philosophy – suggest that the concept of police should in fact be understood through a dualist epistemological approach. Both in legal and knowledge terms – two fundamental dimensions of policing –, police as an institution is highly idiosyncratic in that it concomitantly harbors both a) the rule of law and violence, and b) knowledge and ignorance. Main Text



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[hal-00593806] Chaire Modélisation prospective au service du Développement Durable

A la recherche de sentiers robustes à l'incertitude - Déficit de dialogue entre ingénieurs et économistes - Défis méthodologiques de l'hybridation - Enjeux scientifiques de la Chaire - L'expertise des laboratoires - Chaire Modélisation prospective - Programme de recherche - Les étapes de lancement de la Chaire - Scénarios France pour les engagements 2020 de la Chaire Modélisation prospective - Les 14 scénarios TIMES-de la Chaire ...



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[hal-00511593] Ressources agricoles, biocarburants et modéliation prospective TIMES

Le principe de l'approche TIMES: un accent mis sur la compétition entre chemins technologiques • Représentation des flux d'énergie et de matière, • Représentation des technologies mises en oeuvre, • Minimisation sous contrainte du surplus total.



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[hal-00593800] Enjeux mondiaux et impacts régionaux des contraintes carbone. Prospective long terme à l'aide du modèle TIAM-FR

L'objet de cette présentation est de reporter différents résultats issus de l'analyse prospective long terme des enjeux énergie-climat des contraintes carbone à l'aide de l'outil de modélisation ETSAPTIAM. TIAM est un modèle bottom up technico-économique de programmation linéaire décrivant le système énergétique mondial à travers une description détaillée des différentes formes d'énergie, de ressources, de technologies et d'usages finaux. Dans cette étude, il s'agit plus précisément de discuter les différents mécanismes de coordination des régions s'engageant dans des réductions d'émissions de CO2. Trois séries de scénarios régionaux de contraintes carbone couvrant la période 2000-2050 ont ainsi été spécifiés pour mettre en avant des futurs possibles pour l'après Kyoto. Cette analyse se focalise sur l'évolution de la consommation d'énergie primaire et le mix énergétique, les niveaux d'émission régionaux de CO2 et enfin les coûtsde la politique climatique. Il ressort clairement l'importance de mettre en balance l'effort global vers une réduction des émissions de CO2 avec le coût du carbone à supporter pour les régions contraintes dans la mise en place des politiques climatiques. Egalement, même si les énergies renouvelables se développent, le mix énergétique est encore fortement marqué en 2050 par les énergies fossiles, ceci en raison du développement des technologies de séquestration du carbone.



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[hal-00593792] Une approche désagrégée de la demande au niveau technique et comportemental dans le secteur résidentiel

1 - Segmentation de la demande d'énergie 2 - Modèle prospective TIMES/MARKAL 3 - Résultats



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[hal-01104124] Measuring the noise of imaging sensors in the presence of vibrations and illumination flickering: modeling, algorithm, and experiments

This report discusses camera noise estimation from a series of raw images of an arbitrary natural static scene, acquired with the same camera settings. Although it seems natural to characterize noise from the random time fluctuation of pixel intensity, it turns out that these fluctuations may also be caused by illumination flickering and mechanical micro-vibrations affecting the camera. In this context, the contributions are twofold. First, a theoretical model of image formation in the presence of illumination flickering and of vibrations is discussed. This parametric model is based on a Cox process. It is shown that illumination flickering changes the standard affine relation between noise variance and average intensity to a quadratic relation. Second, under these conditions an algorithm is proposed to estimate the main parameters governing sensor noise, namely the gain, the offset, and the read-out noise. The rolling shutter effect, which potentially affects the output of any focal-plane shutter camera, is also considered. Experiments show that this simple method gives results consistent with the photon transfer method which needs a special experimental setting and several data acquisitions, and with an algorithm based on a single image. The main practical result is to show that flickering, which is generally considered as an artifact, plays here a positive role since it finally enables us to estimate any of the sensor parameters. This report provides additional experiments to a published paper.



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[hal-01077745] The European Modern Pollen Database (EMPD) project

Modern pollen samples provide an invaluable research tool for helping to interpret the quaternary fossil pollen record, allowing investigation of the relationship between pollen as the proxy and the environmental parameters such as vegetation, land-use, and climate that the pollen proxy represents. The European Modern Pollen Database (EMPD) is a new initiative within the European Pollen Database (EPD) to establish a publicly accessible repository of modern (surface sample) pollen data. This new database will complement the EPD, which at present holds only fossil sedimentary pollen data. The EMPD is freely available online to the scientific community and currently has information on almost 5,000 pollen samples from throughout the Euro-Siberian and Mediterranean regions, contributed by over 40 individuals and research groups. Here we describe how the EMPD was constructed, the various tables and their fields, problems and errors, quality controls, and continuing efforts to improve the available data



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[hal-01059249] Historical fluvial palaeodynamics and multi-proxy palaeoenvironmental analyses of a palaeochannel, Allier River, France

[...]



from HAL : Dernières publications http://ift.tt/1tyEx2V

[hal-01087896] Prehistoric impact on landscape and vegetation at high altitudes: An integrated palaeoecological and archaeological approach in the eastern Pyrenees (Perafita valley, Andorra)

A multi-proxy palaeoenvironmental study (pollen, non-pollen palynomorphs-NPP, macrocharcoal particles) of a small fen located in the Perafita valley (2240 m a.s.l, eastern Pyrenees, Andorra) was undertaken to trace prehistoric human activities related to woodland clearance and past land-uses at high altitudes. The results of this study constrained by 9 AMS radiocarbon measurements are combined with archaeological data and compared with similar research carried out at the same altitude in the adjacent Madriu valley (Andorra). The overall objectives of this article are, first, to formulate different chronological patterns and spatial land-use distribution at a micro-regional scale during prehistory and, second, to discuss different drivers of prehistoric occupation models in the eastern Pyrenean highlands. The palaeoecological study of the Planells de Perafita fen was performed at high temporal resolution, allowing us to focus on detailed prehistoric (mainly Mesolithic and Neolithic) and Bronze Age human activity. It demonstrates that the shaping of this cultural landscape is the result of a long-term land-use history, which began at the late Mesolithic/early Neolithic transition onwards (ca 6400–6100 cal BC). The existence of three main phases of “inter-valley” land-use variability has also been highlighted, thus testifying a complex and heterogeneous upland land-use model during the Neolithic and Bronze Age. These land-use variabilities between the two adjacent Andorran valleys provide the basis for a discussion of the way in which environmental constraints influenced prehistoric land-use spatial organisation and of how the interaction between environmental (including climatic parameters), socio-economic and cultural conditions affected the temporal and spatial dynamics of landscape shaping in the eastern Pyrenean highlands



from HAL : Dernières publications http://ift.tt/1AAPToD

[hal-01070655] Figement et configuration textuelle : les segments de discours répétés dans les rapports éducatifs

Cet article vise à montrer comment les segments de discours répétés (SDR) participent à la configuration textuelle d'écrits professionnels d'un type particulier : les rapports éducatifs. Portant sur un corpus de " brouillons " constitué des différentes versions de rapports, notre étude allie une approche textométrique permettant le répérage de séquences ou de " formats " récurrents (/Dét. poss. + N, discours + Modifieur/, SDR prépositionnels), et une approche génétique observant les réécritures affectant ces séquences, dans une perspective d'analyse de discours qui vise à rendre compte des contraintes diverses - visée pragmatique du genre, pratiques sociales, filiations interdiscursives - intervenant dans le processus d'écriture. Seront ainsi mis en évidence des routines discursives et des récurrences participant au profil sémantique des rapports éducatifs.



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[hal-01120830] Rôle probable de la couche protéique de la coquille dans la tolérance au froid chez l’escargot natif du subantarctique, Notodiscus hookeri

[...]



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[in2p3-01120559] A search for high-mass resonances decaying to $\tau^{+}\tau^{-}$ in $pp$ collisions at $\sqrt{s}=8$ TeV with the ATLAS detector

A search for high-mass resonances decaying into $\tau^{+}\tau^{-}$ final states using proton-proton collisions at $\sqrt{s}= 8$ TeV produced by the Large Hadron Collider is presented. The data were recorded with the ATLAS detector and correspond to an integrated luminosity of 19.5-20.3 fb$^{-1}$. No statistically significant excess above the Standard Model expectation is observed; 95% credibility upper limits are set on the cross section times branching fraction of $Z^{\prime}$ resonances decaying into $\tau^+\tau^-$ pairs as a function of the resonance mass. As a result, $Z^{\prime}$ bosons of the Sequential Standard Model with masses less than 2.02 TeV are excluded at 95% credibility. The impact of the fermionic couplings on the $Z^{\prime}$ acceptance is investigated and limits are also placed on a $Z^{\prime}$ model that exhibits enhanced couplings to third-generation fermions.



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[hal-01111230] An incremental–iterative method for modeling damage evolution in voxel-based microstructure models

Numerical methods motivated by rapid advances in image processing techniques have been intensively developed during recent years and increasingly applied to simulate heterogeneous materials with complex microstructure. The present work aims at elaborating an incremental–iterative numerical method for voxel-based modeling of damage evolution in quasi-brittle microstructures. The iterative scheme based on the Lippmann–Schwinger equation in the real space domain (Yvonnet, in Int J Numer Methods Eng 92:178–205, 2012) is first cast into an incremental form so as to implement nonlinear material models efficiently. In the proposed scheme, local strain increments at material grid points are computed iteratively by a mapping operation through a transformation array, while local stresses are determined using a constitutive model that accounts for material degradation by damage. For validation, benchmark studies and numerical simulations using microtomographic data of concrete are performed. For each test, numerical predictions by the incremental–iterative scheme and the finite element method, respectively, are presented and compared for both global responses and local damage distributions. It is emphasized that the proposed incremental–iterative formulation can be straightforwardly applied in the framework of other Lippmann–Schwinger equation-based schemes, like the fast Fourier transform method.



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[hal-01111233] A numerical analysis of interface damage effect on mechanical properties of composite materials

Interfaces play an important role on macroscopic behaviors of composite materials. A number of studies have been devoted to analytical and numerical analyses of linear elastic interfaces. In this work, a new damage model is proposed to describe the progressive degradation of interfaces. The proposed model is implemented in the framework of extended finite element method. A series of numerical simulations performed. It is found that the interface damage induces a reduction of both macroscopic elastic stiffness and mechanical strength of composites. Further, related to the interface damage, we have also investigated the inclusion size effect on macroscopic behaviors of composites. It is found that the interface damage is enhanced by large size inclusions leading to a reduction of macroscopic damage threshold of materials.



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[hal-01120827] John of Jandun on Minima Sensibilia

[...]



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[hal-01120826] New insights into population structure and length-mass relationships in Notodiscus hookeri, the single land snail native from sub-Antarctic islands

[...]



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[hal-00812029] Recursive GF(2N) encoders using left-circulate function for optimum PSK-TCM schemes

[...]



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[hal-00796687] Multicast security protocol over satellite DVB based on chaotic sequences

[...]



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[hal-00696876] A combination scheme of CPWPM and BPSK for digital communication

[...]



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[hal-00999582] Steganalysis of a chaos-based steganographic method

Hiding information in a cover image can be regarded as introducing some stego-noise. These alterations may produce some form of degradation or some unusual characteristics and can then be exploited for the sake of detecting the hidden message. In this paper, we analyze the security of a chaos-based steganographic method, namely the Chaotic Edge adaptive Least Significant Bit Matching Revisited (Chaotic EALSBMR). We focus on the universal image steganalysis method which uses the higher-order statistics as features taken from the wavelet multiresolution approach. A Fisher Linear Discriminant classifier is used to classify cover and stego images.



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[hal-01094677] Efficient Multicore Implementation of An Advanced Generator of Discrete Chaotic Sequences

This paper details the design and implementation performances of an efficient generator of chaotic discrete integer valued sequences. The generator exhibits orbits having very large lengths compared to those given in the literature. It is implemented in C language and parallelized using the Parameterized and Interfaced Synchronous Dataflow Model of Computation (PiSDF MoC). The proposed structure is shown to be scalable, parallel and time efficient. The resulting implementation combines a very long minimal chaotic sequence omin > 7*2^128 32-bit samples and a very high throughput of 173Mbps on 4 cores of a General Purpose Processor.



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[hal-00870612] Enhancement of two spatial steganography algorithms by using a chaotic system : comparative analysis

In this paper we propose a chaos-based enhancement of two spatial steganographic algorithms the AE-LSB and the EA-LSBMR and we study their performances. The first algorithm is an adaptive LSB (Least Significant Bit) steganographic method using pixel value differencing that provides a large embedding capacity and imperceptible stegoimages. The second method is an edge adaptive scheme which can select the embedding region according to the size of secret message and the difference between two adjacent pixels in the cover image. The two methods suffer from low security against attacks to recover secret data. To overcome this weakness, we propose an enhancement of the message security of these methods. The enhancement consists by using an efficient chaotic system to choose in a pseudo-chaotic manner, the pixels in the cover image where the bits of the secret message will embed. In this way, the inserted message becomes secure against message recovery attacks and spread over the whole image in a uniform manner. Experiments show that the security of the algorithms is increased.



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[hal-00752294] Implementation of secure SPN chaos-based cryptosystem on FPGA

[...]



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[inserm-00713301] A transcriptional-switch model for Slr1738-controlled gene expression in the cyanobacterium Synechocystis.

BACKGROUND: Protein-DNA interactions play a crucial role in the life of biological organisms in controlling transcription, regulation, as well as DNA recombination and repair. The deep understanding of these processes, which requires the atomic description of the interactions occurring between the proteins and their DNA partners is often limited by the absence of a 3D structure of such complexes. RESULTS: In this study, using a method combining sequence homology, structural analogy modeling and biochemical data, we first build the 3D structure of the complex between the poorly-characterized PerR-like regulator Slr1738 and its target DNA, which controls the defences against metal and oxidative stresses in Synechocystis. In a second step, we propose an expanded version of the Slr1738-DNA structure, which accommodates the DNA binding of Slr1738 multimers, a feature likely operating in the complex Slr1738-mediated regulation of stress responses. Finally, in agreement with experimental data we present a 3D-structure of the Slr1738-DNA complex resulting from the binding of multimers of the FUR-like regulator onto its target DNA that possesses internal repeats. CONCLUSION: Using a combination of different types of data, we build and validate a relevant model of the tridimensional structure of a biologically important protein-DNA complex. Then, based on published observations, we propose more elaborated multimeric models that may be biologically important to understand molecular mechanisms.



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[hal-00837703] Recursive GF(2N) encoders using left-circulate function for optimum TCM schemes

[...]



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[hal-00684436] Enhanced adaptive data hiding in spatial LSB domain by using chaotic sequences

[...]



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[hal-00872265] Lightweight chaos-based cryptosystem for secure images

In the last two decades, several chaos-based cryptosystems have been proposed. Some of them have architecture comprising a layer of permutation and a layer of diffusion and these layers are simultaneously executed in a simple scan of plain-image pixels. In this kind of cryptosystems, due to the channel effect, a bit error(s) in the cipher-image produces, at the decryption side, a random bit error in the estimated plainimage. In this paper, we propose a cipher-block encryption algorithm in CBC (Cipher Block Chaining) mode. It consists of a permutation process on the bits achieved by a 2D-cat map, followed by a bitwise XOR operation. Here, each permuted bit (confusion phase) is immediately diffused in a simple manner in the same phase. Therefore, the confusion and diffusion effects are stronger and the cryptanalyses for permutation-only ciphers become ineffective.



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[hal-01023845] Comparing chemical fingerprints for ecotoxicology

We present a comparison between 14 chemical ngerprints using 1D/2D features and PMCSFG, a data mining method that induces features based on maximum common subgraphs. We provide an experimental evaluation and discuss the usefulness of the dierent methods on ecotoxicology data. The features generated by data mining yield a similar performance for predicting toxicity, while they are more interpretable by chemists



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