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1. Hollow Cobalt Phosphide with N-Doped Carbon Skeleton as Bifunctional Electrocatalyst for Overall Water Splitting

Author

Yanyu Xie, Mengke Cai, Huanfeng Huang, Jun Teng, Mihail Barboiu, Dawei Wang, Cheng-Yong Su, Ya-Nan Fan, Minqi Chen, Sun Yat-Sen University [Guangzhou] (SYSU), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Institute of Automation - Chinese Academy of Sciences-Institut National de Recherche en Informatique et en Automatique (Inria)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS), Institut Européen des membranes (IEM), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS), Xi'an Jiaotong University (Xjtu), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Sun Yat-Sen University (SYSU), and Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)

Subjects
Nanostructure, Hydrogen Evolution Reaction, Hydrogen, Dopamine, chemistry.chemical_element, 010402 general chemistry, Electrocatalyst, 01 natural sciences, 7. Clean energy, Metal-Organic Framework, Catalysis, Inorganic Chemistry, chemistry.chemical_compound, [CHIM]Chemical Sciences, Physical and Theoretical Chemistry, Bifunctional, 010405 organic chemistry, Oxygen evolution, Nanocrystals, 0104 chemical sciences, CO, chemistry, Chemical engineering, High-Performance, Nanoparticles, Water splitting, Highly Efficient, Metal-organic framework, Catalyst, Polyhedron
Abstract

International audience; The development of cost-effective, high-performance, and robust bifunctional electrocatalysts for overall water splitting remains highly desirable yet quite challenging. Here, by selecting appreciate precursors of dopamine and a Co-containing metal-organic framework of ZIF-67, we subtly couple their reaction processes to develop a facile approach for the synthesis of a hollow CoP nanostructure with N-doped carbon skeleton (H-CoP@NC). Benefiting from the highly porous nanostructure and conductive carbon skeleton, H-CoP@NC is capable of working as highly active and durable bifunctional electrocatalyst for both hydrogen and oxygen evolution reaction. When further used as the electrocatalyst for overall water splitting, H-CoP@NC delivers excellent activity (cell voltage of 1.72 V at a current density of 10 mA cm(-2)), close to that of the noble-metal-based benchmark catalyst couple of Pt/C parallel to RuO2. Our work thus provides new insights into the development of transitional metal phosphides based hollow hybrid nanostructures, particularly those with multiple functionalities in sustainable energy conversion technologies and systems.

Published
2019
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2. Numerical study of HCl and SO2 impact on sodium emissions in pulverized-coal flames

Author

Pascale Domingo, Zhihua Wang, Luc Vervisch, Yingzu Liu, Yong He, Yu Lv, Jun Xia, Kefa Cen, Kaidi Wan, Complexe de recherche interprofessionnel en aérothermochimie (CORIA), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Zhejiang University, Brunel University London [Uxbridge], Mississippi State University [Mississippi], Brain imaging (LIAMA), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS), This work was jointly supported by the National Natural Science Foundation of China(51706200), the China Postdoctoral Science Foundation (2018M632460), the Fundamental Research Funds for the Central Universities (2018FZA4012), the Engineering and Physical Sciences Research Council (EPSRC) and the Royal Society of the UK. Y.L. is funded by the Open Topic Exploration Program of the ZJU CEU laboratory. Special thanks are due to Prof. Peter Glarborg of DTU, who provided us the detailed mechanism of alkali metal species. Computing resources were provided by the National Supercomputer Center in Tianjin, China (http://www.nscc-tj.cn)., Sodium chemistry, National Natural Science Foundation of China (51706200), the China Postdoctoral Science Foundation (2018M632460), the Fundamental Research Funds for the Central Universities (2018FZA4012), the Engineering and Physical Sciences Research Council (EPSRC) and the Royal Society of the UK, Open Topic Exploration Program of the ZJU CEU laboratory, Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), and Institute of Automation - Chinese Academy of Sciences-Institut National de Recherche en Informatique et en Automatique (Inria)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Institute of Automation - Chinese Academy of Sciences-Institut National de Recherche en Informatique et en Automatique (Inria)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Sodium chemistry, 020209 energy, General Chemical Engineering, Diffusion, Sodium, Energy Engineering and Power Technology, chemistry.chemical_element, SO2, 02 engineering and technology, HCl, Combustion, complex mixtures, 7. Clean energy, Alkali metal, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], Corrosion, Emission, 020401 chemical engineering, 0202 electrical engineering, electronic engineering, information engineering, Coal, 0204 chemical engineering, HCI, Fouling, Pulverized coal-fired boiler, business.industry, Organic Chemistry, Fuel Technology, chemistry, Chemical engineering, 13. Climate action, Pulverized-coal combustion, business
Abstract

International audience; Sodium emissions during pulverized-coal combustion (PCC) are known to result in severeash-related operating issues of coal furnaces, e.g., fouling, slagging and corrosion. To relieve these issues and advance the clean utilization technologies of coal, a better understanding of thefundamental mechanisms driving the formation and transformation of the sodium species is required.In the present study, sodium emissions have been simulated in both one-dimensional (1D) premixed/diffusion flames of the coal volatile and an early-stage two-dimensional (2D)pulverized-coal flame. The properties of Loy Yang brown coal are used. The DRM22 skeletal mechanism is employed for volatile-gas combustion, and the reaction of sodium species is modeled by a detailed mechanism encompassing the elements Na, C, H, O, S and Cl. The compositions of the volatile fuels are obtained from the chemical percolation devolatilization (CPD) model, including CH4, C2H2, CO, H2, CO2 and H2O. The initial species of Na, Cl and S in the volatile gas is set to be NaOH, HCl and SO2, respectively. The transformation characteristics of 12 sodium species are investigated in both the 1D volatile flames and the 2D pulverized-coal flame. The response of the sodium chemistry to volatile-gas combustion is analyzed under fuel-lean, stoichiometric and fuel-rich conditions. Na, NaOH and NaCl are found to be the major sodium species during the combustion. Parametric studies with HCl, SO2 or both species removed from the volatile are then performed to investigate their effects on the sodium transformation characteristics in both the 1D and 2D flames. The results show that HCl has a much stronger ability to react with sodium species than SO2.

Published
2019
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3. Study of a harmonic mode lock stability under external continuous-wave injection

Author

Andrey Komarov, Georges Semaan, François Sanchez, Mohamed Salhi, Laboratoire de Photonique d'Angers (LPHIA), Université d'Angers (UA), Institute of Automation and Electrometry (IAE), and Institute of Automation and Electrometry

Subjects
Materials science, Physics::Optics, 02 engineering and technology, 01 natural sciences, Stability (probability), law.invention, 010309 optics, 020210 optoelectronics & photonics, Optics, law, Fiber laser, 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, Electrical and Electronic Engineering, Physical and Theoretical Chemistry, harmonic mode locking, [PHYS]Physics [physics], External optical injection, business.industry, Mode (statistics), Laser, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Power (physics), Wavelength, Mode-locked fiber laser, Harmonic, Continuous wave, business
Abstract

International audience; In this paper, we investigate experimentally the effect of an injected continuous external optical laser in a stable passive harmonic mode-locked fiber laser operating in the anomalous dispersion regime. Under specific conditions, the continuous-wave significantly increases the stability of the harmonic mode-locked regime. This occurs for a discrete set of wavelengths and below a critical injected power.

Published
2017
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4. Counting Co-Cyclic Lattices

Author

Phong Q. Nguyen, Igor E. Shparlinski, Institute for Advanced Study [Tsinghua], Tsinghua University [Beijing] (THU), Cryptanalyse (CRYPT), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Inria Paris-Rocquencourt, Institut National de Recherche en Informatique et en Automatique (Inria), University of New South Wales [Sydney] (UNSW), Tsinghua University [Beijing], Inria de Paris, Japanese French Laboratory for Informatics (JFLI), and National Institute of Informatics (NII)-Université Pierre et Marie Curie - Paris 6 (UPMC)-The University of Tokyo (UTokyo)-Centre National de la Recherche Scientifique (CNRS)

Subjects
FOS: Computer and information sciences, Discrete Mathematics (cs.DM), High Energy Physics::Lattice, General Mathematics, 0102 computer and information sciences, 01 natural sciences, Combinatorics, [INFO.INFO-CR]Computer Science [cs]/Cryptography and Security [cs.CR], Integer, FOS: Mathematics, Natural density, Asymptotic formula, Number Theory (math.NT), [MATH]Mathematics [math], Mathematics, Discrete mathematics, homogeneous congruences, Mathematics - Number Theory, cyclic lattices, Group (mathematics), Lattice problem, Order (ring theory), [MATH.MATH-NT]Mathematics [math]/Number Theory [math.NT], multiplicative functions, 010201 computation theory & mathematics, Computer Science - Discrete Mathematics
Abstract

International audience; There is a well-known asymptotic formula, due to W. M. Schmidt [Duke Math. J., 35 (1968), pp. 327--339], for the number of full-rank integer lattices of index at most $V$ in ${\mathbb{Z}}^n$. This set of lattices $L$ can naturally be partitioned with respect to the factor group ${\mathbb{Z}}^n/L$. Accordingly, we count the number of full-rank integer lattices $L \subseteq {\mathbb{Z}}^n$ such that ${\mathbb{Z}}^n/L$ is cyclic and of order at most $V$, and deduce that these co-cyclic lattices are dominant among all integer lattices: their natural density is $(\zeta(6) \prod_{k=4}^n \zeta(k))^{-1} \approx 85\%$. The problem is motivated by complexity theory, namely worst-case to average-case reductions for lattice problems.

Published
2016
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5. The effect of body–mind relaxation meditation induction on major depressive disorder: A resting-state fMRI study

Author

Xiaoling Wang, Jing Sui, Wei-dong Wang, Tianzi Jiang, Xueyu Lv, Tao Li, Jiliang Fang, Lingzhong Fan, Fangfang Chen, Shan Yu, Yang Hong, University of Science & Technology of China [Suzhou], China Academy of Chinese Medical Sciences, Columbia University [New York], Brain imaging (LIAMA), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), and Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)

Subjects
Adult, Male, Psychotherapist, Brain activity and meditation, Rest, media_common.quotation_subject, Prefrontal Cortex, Cognitive reappraisal, [SCCO]Cognitive science, medicine, Humans, Meditation, Depression (differential diagnoses), media_common, Brain Mapping, Depressive Disorder, Major, Relaxation (psychology), Resting state fMRI, Middle Aged, medicine.disease, Magnetic Resonance Imaging, Frontal Lobe, Psychiatry and Mental health, Clinical Psychology, Major depressive disorder, Female, Orbitofrontal cortex, Psychology, Neuroscience
Abstract

International audience; Background: Meditation has been increasingly evaluated as an important complementary therapeutic tool for the treatment of depression. The present study employed resting state functional magnetic resonance imaging (rs-fMRI) to examine the effect of body mind relaxation meditation induction (BMRMI) on the brain activity of depressed patients and to investigate possible mechanisms of action for this complex intervention.Method: 21 major depressive disorder patients (MDDs) and 24 age and gender-matched healthy controls (HCs) received rs-fMRI scans at baseline and after listening to a selection of audio designed to induce body-mind relaxation meditation. The rs-fMRI data were analyzed using Matlab toolbox to obtain the amplitude of low-frequency fluctuations (ALFF) of the BOLD signal for the whole brain. A mixed-design repeated measures analysis of variance (ANOVA) was performed On the whole brain to Find which brain regions were affected by the BMRMI An additional functional connectivity analysis was used to identify any atypical connection patterns after the BMRMI.Results: After the BMRMI experience, both the MDDs and HCs showed decreased ALFF values in the bilateral frontal pole (BA10). Additionally, increased functional connectivity from the right dorsal medial prefrontal cortex (dmPFC) to the left dorsal lateral prefrontal cortex (dlPFC) and the left lateral orbitofrontal cortex (OFC) was identified only in the MDDs after the BMRMI. Limitation: in order to exclude the impact of other events on the participants brain activity. the Hamilton Rating Scales for Depression (HDRS) was not measured after the body-mind relaxation induction.Conclusion: Our findings support the hypothesis that body-mind relaxation meditation induction may regulate the activities of the prefrontal cortex and thus may have the potential to help patients construct reappraisal strategies that can modulate the brain activity in multiple emotion-processing systems.

Published
2015
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6. From diagrammatic confluence to modularity

Author

Jiaxiang Liu, Jean-Pierre Jouannaud, Formal Methods for Embedded Systems (FORMES), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Inria Paris-Rocquencourt, and Institut National de Recherche en Informatique et en Automatique (Inria)

Subjects
General Computer Science, Modulo, Mathematics::General Topology, 0102 computer and information sciences, 02 engineering and technology, Characterization (mathematics), Modularity theorem, 01 natural sciences, Theoretical Computer Science, localcliffs, Computer Science::Logic in Computer Science, 0202 electrical engineering, electronic engineering, information engineering, modularity, Mathematics, Modularity (networks), decreasing diagrams, rewritingmodulo, [INFO.INFO-LO]Computer Science [cs]/Logic in Computer Science [cs.LO], localpeaks, cofinal derivations, ACM: F.: Theory of Computation/F.4: MATHEMATICAL LOGIC AND FORMAL LANGUAGES/F.4.2: Grammars and Other Rewriting Systems/F.4.2.0: Decision problems, Algebra, Diagrammatic reasoning, Mathematics::Logic, Cofinal, 010201 computation theory & mathematics, Confluence, confluence, Computer Science::Programming Languages, 020201 artificial intelligence & image processing, Rewriting, Computer Science(all)
Abstract

International audience; This paper builds on a fundamental notion of rewriting theory that characterizes confluence of a (binary) rewriting relation, Klop's cofinal derivations. Cofinal derivations were used by van Oostrom to obtain another characterization of confluence of a rewriting relation via the existence of decreasing diagrams for all local peaks. In this paper, we show that cofinal derivations can be used to give a new, concise proof of Toyama's celebrated modularity theorem and its recent extensions to rewriting modulo in the case of strongly-coherent systems, an assumption discussed in depth here. This is done by generalizing cofinal derivations to cofinal streams, allowing us in turn to generalize van Oostrom's result to the modulo case.

Published
2012
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7. blending multiple surfaces in polar coordinates

Author

Kan-Le Shi, Jiaguang Sun, Jean-Claude Paul, Jun-Hai Yong, School of Software (THSS), Tsinghua University [Beijing] (THU), Computer Aided Design (CAD ), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Inria Paris-Rocquencourt, Institut National de Recherche en Informatique et en Automatique (Inria), and Tsinghua University [Beijing]

Subjects
0209 industrial biotechnology, Curvilinear coordinates, Log-polar coordinates, 020207 software engineering, Basis function, Geometry, 02 engineering and technology, Computer Graphics and Computer-Aided Design, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Industrial and Manufacturing Engineering, Computer Science Applications, law.invention, 020901 industrial engineering & automation, Orthogonal coordinates, Parametric surface, law, 0202 electrical engineering, electronic engineering, information engineering, Cartesian coordinate system, Polar coordinate system, Parametric statistics, Mathematics
Abstract

International audience; This paper proposes a method of Gn blending multiple parametric surfaces in polar coordinates. It models the geometric continuity conditions of parametric surfaces in polar coordinates and presents a mechanism of converting a Cartesian parametric surface into its polar coordinate form. The basic idea is first to reparameterize the parametric blendees into the form of polar coordinates. Then they are blended simultaneously by a basis function in the complex domain. To extend its compatibility, we also propose a method of converting polar coordinate blending surface into N NURBS patches. One application of this technique is to fill N-sided holes. Examples are presented to show its feasibility and practicability.

Published
2010
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8. Computing the minimum distance between two Bézier curves

Author

Jean-Claude Paul, Yigang Wang, Xiao-Diao Chen, Linqiang Chen, Gang Xu, Jun-Hai Yong, School of Software (THSS), Tsinghua University [Beijing] (THU), Hangzhou Dianzi University (HDU), Computer Aided Design (CAD ), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Inria Paris-Rocquencourt, Institut National de Recherche en Informatique et en Automatique (Inria), and Tsinghua University [Beijing]

Subjects
Unit sphere, 0209 industrial biotechnology, Bézier curve, Sphere–cylinder intersection, Applied Mathematics, Osculating curve, Track transition curve, 020207 software engineering, Geometry, 02 engineering and technology, Singular point of a curve, [INFO.INFO-CG]Computer Science [cs]/Computational Geometry [cs.CG], Sweeping sphere clipping method, Inversion in a sphere, Computational Mathematics, 020901 industrial engineering & automation, 0202 electrical engineering, electronic engineering, information engineering, Minimum distance, Tripling-oriented Doche–Icart–Kohel curve, Mathematics
Abstract

International audience; A sweeping sphere clipping method is presented for computing the minimum distance between two Bézier curves. The sweeping sphere is constructed by rolling a sphere with its center point along a curve. The initial radius of the sweeping sphere can be set as the minimum distance between an end point and the other curve. The nearest point on a curve must be contained in the sweeping sphere along the other curve, and all of the parts outside the sweeping sphere can be eliminated. A simple sufficient condition when the nearest point is one of the two end points of a curve is provided, which turns the curve/curve case into a point/curve case and leads to higher efficiency. Examples are shown to illustrate efficiency and robustness of the new method.

Published
2009
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9. Computing the minimum distance between a point and a clamped B-spline surface

Author

Gang Xu, Jun-Hai Yong, Guozhao Wang, Jean-Claude Paul, Xiao-Diao Chen, Computer Aided Design (CAD ), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Inria Paris-Rocquencourt, Institut National de Recherche en Informatique et en Automatique (Inria), Hangzhou Dianzi University (HDU), Institute of Computer Graphics and Image Processing, Zhejiang University, School of Software (THSS), Tsinghua University [Beijing], and Tsinghua University [Beijing] (THU)

Subjects
Correctness, Computation, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, CAD, 02 engineering and technology, Computer graphics, symbols.namesake, 0202 electrical engineering, electronic engineering, information engineering, Newton's method, ComputingMethodologies_COMPUTERGRAPHICS, Mathematics, business.industry, B-spline, 020207 software engineering, Robotics, Computer Graphics and Computer-Aided Design, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Computer Science::Graphics, Modeling and Simulation, symbols, 020201 artificial intelligence & image processing, Geometry and Topology, Artificial intelligence, Clipping (computer graphics), business, Algorithm, Software
Abstract

International audience; The computation of the minimum distance between a point and a surface is important for the applications such as CAD/CAM, NC verification, robotics and computer graphics. This paper presents a spherical clipping method to compute the minimum distance between a point and a clamped B-spline surface. The surface patches outside the clipping sphere which do not contain the nearest point are eliminated. Another exclusion criterion whether the nearest point is on the boundary curves of the surface is employed, which is proved to be superior to previous comparable criteria. Examples are also shown to illustrate efficiency and correctness of the new method.

Published
2009
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10. Computing the minimum distance between a point and a NURBS curve

Author

Gang Xu, Xiao-Diao Chen, Jean-Claude Paul, Guozhao Wang, Jun-Hai Yong, Hangzhou Dianzi University (HDU), Computer Aided Design (CAD ), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Inria Paris-Rocquencourt, Institut National de Recherche en Informatique et en Automatique (Inria), School of Software (THSS), Tsinghua University [Beijing], Department of Mathematics [Hangzhou], Zhejiang University, Institute of Computer Graphics and Image Processing, and Tsinghua University [Beijing] (THU)

Subjects
Normalization property, business.industry, Minimum distance, Test point, 020207 software engineering, Geometry, 02 engineering and technology, Computer Science::Computational Geometry, [INFO.INFO-CG]Computer Science [cs]/Computational Geometry [cs.CG], Computer Graphics and Computer-Aided Design, Industrial and Manufacturing Engineering, Computer Science Applications, symbols.namesake, Robustness (computer science), 0202 electrical engineering, electronic engineering, information engineering, symbols, 020201 artificial intelligence & image processing, Clipping (computer graphics), business, Newton's method, Algorithm, ComputingMethodologies_COMPUTERGRAPHICS, Point projection, Mathematics, Subdivision
Abstract

International audience; A new method is presented for computing the minimum distance between a point and a NURBS curve. It utilizes a circular clipping technique to eliminate the curve parts outside a circle with the test point as its center point. The radius of the elimination circle becomes smaller and smaller during the subdivision process. A simple condition for terminating the subdivision process is provided, which leads to very few subdivision steps in the new method. Examples are shown to illustrate the efficiency and robustness of the new method.

Published
2008
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11. Adaptive geometry compression based on four-point interpolatory subdivision schemes with labels

Author

Jean-Claude Paul, Hui Zhang, Jun-Hai Yong, Computer Aided Design (CAD ), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Inria Paris-Rocquencourt, and Institut National de Recherche en Informatique et en Automatique (Inria)

Subjects
Mathematical optimization, Data_CODINGANDINFORMATIONTHEORY, 010103 numerical & computational mathematics, 02 engineering and technology, Computer Science::Computational Geometry, 01 natural sciences, Compression (functional analysis), 0202 electrical engineering, electronic engineering, information engineering, Point (geometry), 0101 mathematics, Time complexity, ComputingMethodologies_COMPUTERGRAPHICS, Mathematics, Subdivision, business.industry, Applied Mathematics, 020207 software engineering, [INFO.INFO-IA]Computer Science [cs]/Computer Aided Engineering, Computer Science Applications, Computer Science::Graphics, Computational Theory and Mathematics, Artificial intelligence, business, Algorithm, Data compression, Integer (computer science), Geometry compression
Abstract

International audience; We propose an adaptive geometry compression method with labels based on four-point interpolatory subdivision schemes. It can work on digital curves of arbitrary dimensions. With the geometry compression method, a digital curve is adaptively compressed into several segments with different compression levels. Each segment is a four-point subdivision curve with a subdivision step. Labels are recorded in data compression to facilitate merging the segments in data decompression. We provide high-speed four-point interpolatory subdivision curve generation methods for efficiently decompressing the compressed data. For an arbitrary positive integer k, formulae for the number of resultant control points of a four-point subdivision curve after k subdivision steps are provided. Some formulae for calculating points at the kth subdivision step are also presented. The time complexity of the new approaches is O(n), where n is the number of points in the given digital curve. Examples are provided to illustrate the efficiency of the proposed approaches.

Published
2007
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12. Altered functional connectivity in early Alzheimer's disease: A resting-state fMRI study

Author

Lixia Tian, Tianzi Jiang, Kun Wang, Kuncheng Li, Liang Wang, Meng Liang, Xinqing Zhang, Brain imaging (LIAMA), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS), Department of Radiology, Xuanwu Hospital of Capital-University of Medical Sciences / Beijing, and Department of Neurology

Subjects
Male, Neuropsychological Tests, Functional Laterality, Correlation, 0302 clinical medicine, Degenerative disease, Parietal Lobe, Neural Pathways, Image Processing, Computer-Assisted, low-frequency blood oxygenation level-dependent fluctuations, Research Articles, Radiological and Ultrasound Technology, medicine.diagnostic_test, fMRI, 05 social sciences, Parietal lobe, Brain, Alzheimer's disease, Middle Aged, Prognosis, Magnetic Resonance Imaging, Neurology, Disease Progression, Female, Occipital Lobe, Anatomy, Psychology, Prefrontal Cortex, 050105 experimental psychology, Central nervous system disease, 03 medical and health sciences, resting-state, Alzheimer Disease, Predictive Value of Tests, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, medicine, Humans, 0501 psychology and cognitive sciences, Radiology, Nuclear Medicine and imaging, Aged, Resting state fMRI, functional connectivity, medicine.disease, Early Diagnosis, Neurology (clinical), Nerve Net, Cognition Disorders, Occipital lobe, Functional magnetic resonance imaging, Neuroscience, 030217 neurology & neurosurgery
Abstract

Previous studies have led to the proposal that patients with Alzheimer's disease (AD) may have disturbed functional connectivity between different brain regions. Furthermore, recent resting‐state functional magnetic resonance imaging (fMRI) studies have also shown that low‐frequency (

Published
2007
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13. A rational extension of Piegl’s method for filling -sided holes

Author

Jun-Hai Yong, Jean-Claude Paul, Jiaguang Sun, Hui Zhang, Yi-Jun Yang, Computer Aided Design (CAD ), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Inria Paris-Rocquencourt, Institut National de Recherche en Informatique et en Automatique (Inria), School of Software (THSS), Tsinghua University [Beijing] (THU), and Department of Computer Science and Technology (CST)

Subjects
0209 industrial biotechnology, N-sided hole, 020207 software engineering, Geometry, Click to view the MathML source continuity, 02 engineering and technology, [INFO.INFO-IA]Computer Science [cs]/Computer Aided Engineering, [INFO.INFO-CG]Computer Science [cs]/Computational Geometry [cs.CG], Computer Graphics and Computer-Aided Design, Industrial and Manufacturing Engineering, Computer Science Applications, Vertex (geometry), NURBS, 020901 industrial engineering & automation, 0202 electrical engineering, electronic engineering, information engineering, Coons surfaces, Mathematics
Abstract

International audience; N-sided hole filling plays an important role in vertex blending. To deal with the case that the corner is surrounded by rational surfaces (i.e. NURBS surfaces), an algorithm to fill n-sided holes with ɛ-G1 continuous NURBS patches that interpolate the given boundary curves and approximate the given cross-boundary derivatives is presented based on Piegl's method. The NURBS surfaces joining along inner or boundary curves have normal vectors that do not deviate more than the user-specified angular tolerance ɛ. The boundaries as well as cross-boundary derivatives can all be NURBS curves. No restrictions are imposed on the number of boundary curves, and the cross-boundary derivatives can be specified independently.

Published
2006
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14. Changes in hippocampal connectivity in the early stages of Alzheimer's disease: Evidence from resting state fMRI

Author

Tao Wu, Liang Wang, Yong He, Xinqing Zhang, Meng Liang, Yu-Feng Zang, Kuncheng Li, Lixia Tian, Tianzi Jiang, Department of Radiology, Xuanwu Hospital of Capital-University of Medical Sciences / Beijing, Brain imaging (LIAMA), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS), National Laboratory of Pattern Recognition [Beijing] (NLPR), Institute of Automation - Chinese Academy of Sciences, Department of Neurology, Institute of Geriatrics, and Xuanwu Hospital of Capital

Subjects
Male, Cognitive Neuroscience, Precuneus, Hippocampus, Hippocampal formation, Functional Laterality, Functional connectivity, 03 medical and health sciences, 0302 clinical medicine, Alzheimer Disease, Reference Values, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, medicine, Humans, Resting state, Prefrontal cortex, Anterior cingulate cortex, Default mode network, Aged, Functional MRI, 030304 developmental biology, 0303 health sciences, Resting state fMRI, Middle Aged, Alzheimer's disease, Magnetic Resonance Imaging, medicine.anatomical_structure, nervous system, Neurology, Posterior cingulate, Female, Psychology, Neuroscience, 030217 neurology & neurosurgery
Abstract

A selective distribution of Alzheimer's disease (AD) pathological lesions in specific cortical layers isolates the hippocampus from the rest of the brain. However, functional connectivity between the hippocampus and other brain regions remains unclear in AD. Here, we employ a resting state functional MRI (fMRI) to examine changes in hippocampal connectivity comparing 13 patients with mild AD versus 13 healthy age-matched controls. Hippocampal connectivity was investigated by examination of the correlation between low frequency fMRI signal fluctuations in the hippocampus and those in all other brain regions. We found that functional connectivity between the right hippocampus and a set of regions was disrupted in AD; these regions are: medial prefrontal cortex (MPFC), ventral anterior cingulate cortex (vACC), right inferotemporal cortex, right cuneus extending into precuneus, left cuneus, right superior and middle temporal gyrus and posterior cingulate cortex (PCC). We also found increased functional connectivity between the left hippocampus and the right lateral prefrontal cortex in AD. In addition, rightward asymmetry of hippocampal connectivity observed in elderly controls was diminished in AD patients. The disrupted hippocampal connectivity to the MPFC, vACC and PCC provides further support for decreased activity in "default mode network" previously shown in AD. The decreased connectivity between the hippocampus and the visual cortices might indicate reduced integrity of hippocampus-related cortical networks in AD. Moreover, these findings suggest that resting-state fMRI might be an appropriate approach for studying pathophysiological changes in early AD.

Published
2006
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15. A Dynamic, Architectural Plant Model Simulating Resource-dependent Growth

Author

Michaël Dingkuhn, Philippe de Reffye, Hong-Ping Yan, Mengzhen Kang, Eco-informatics (LIAMA), Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Modélisation de la croissance et de l'architecture des plantes (DIGIPLANTE), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Mathématiques Appliquées aux Systèmes - EA 4037 (MAS), Ecole Centrale Paris-Ecole Centrale Paris, Département Amélioration des méthodes pour l'innovation scientifique (AMIS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS), Mathématiques Appliquées aux Systèmes - EA 4037 (MAS), Ecole Centrale Paris-Ecole Centrale Paris-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Ecole Centrale Paris, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), and Département Amélioration des méthodes pour l'innovation scientifique (Cirad- AMIS)

Subjects
0106 biological sciences, Organogénèse, Phénotype, F62 - Physiologie végétale - Croissance et développement, Application des ordinateurs, Plant Science, F50 - Anatomie et morphologie des plantes, phenotypic plasticity, 01 natural sciences, competition among sinks, Resource (project management), Plant production, Biomasse, Biomass, 2. Zero hunger, Port de la plante, demand functions, U10 - Informatique, mathématiques et statistiques, Ecology, Plant architecture, 04 agricultural and veterinary sciences, structural-functional models, source–sink relationships, Plant development, Imagerie, Anatomie végétale, Helianthus, Algorithms, Modèle mathématique, Développement biologique, Plant Development, Biology, Arbre, Models, Biological, Computer Simulation, Architecture, Croissance, Plant Transpiration, Modèle de simulation, Plant models, Original Articles, 15. Life on land, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, Modélisation, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, ComputingMethodologies_GENERAL, Biochemical engineering, Plant Structures, 010606 plant biology & botany
Abstract

Accès sur le site éditeur : http://aob.oxfordjournals.org/cgi/content/abstract/93/5/591; Background and Aims Physiological and architectural plant models have originally been developed for different purposes and therefore have little in common, thus making combined applications dif®cult. There is, however, an increasing demand for crop models that simulate the genetic and resource-dependent variability of plant geometry and architecture, because man is increasingly able to transform plant production systems through combined genetic and environmental engineering. d Model GREENLAB is presented, a mathematical plant model that simulates interactions between plant structure and function. Dual-scale automaton is used to simulate plant organogenesis from germination to maturity on the basis of organogenetic growth cycles that have constant thermal time. Plant fresh biomass production is computed from transpiration, assuming transpiration ef®ciency to be constant and atmospheric demand to be the driving force, under non-limiting water supply. The fresh biomass is then distributed among expanding organs according to their relative demand. Demand for organ growth is estimated from allometric relationships (e.g. leaf surface to weight ratios) and kinetics of potential growth rate for each organ type. These are obtained through parameter optimization against empirical, morphological data sets by running the model in inverted mode. Potential growth rates are then used as estimates of relative sink strength in the model. These and other `hidden' plant parameters are calibrated using the non-linear, least-square method. d Key Results and Conclusions The model reproduced accurately the dynamics of plant growth, architecture and geometry of various annual and woody plants, enabling 3D visualization. It was also able to simulate the variability of leaf size on the plant and compensatory growth following pruning, as a result of internal competition for resources. The potential of the model's underlying concepts to predict the plant's phenotypic plasticity is discussed.

Published
2004
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16. A systematic study of fuzzy PID controllers-function-based evaluation approach

Author

Bao-Gang Hu, Raymond G. Gosine, George K. I. Mann, Eco-informatics (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS), Mechanical Engineering Department, Queen's University [Kingston], Faculty of Engineering and Applied Science, Memorial University of Newfoundland [St. John's], Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Queen's University [Kingston, Canada], and Memorial University of Newfoundland = Université Memorial de Terre-Neuve [St. John's, Canada] (MUN)

Subjects
0209 industrial biotechnology, Mathematical optimization, control nonlinearities, [INFO.INFO-OH]Computer Science [cs]/Other [cs.OH], fuzzy control, Proportional control, Inference, PID controller, 02 engineering and technology, Fuzzy logic, three-term control, 020901 industrial engineering & automation, Artificial Intelligence, Control theory, 0202 electrical engineering, electronic engineering, information engineering, Inference engine, Mathematics, control system analysis, Applied Mathematics, Fuzzy control system, common-sense reasoning, Nonlinear system, Computational Theory and Mathematics, Control and Systems Engineering, fuzzy systems, Control system, 020201 artificial intelligence & image processing, fuzzy logic
Abstract

A function-based evaluation approach is proposed for a systematic study of fuzzy proportional-integral-derivative (PID)-like controllers. This approach is applied for deriving process-independent design guidelines from addressing two issues: simplicity and nonlinearity. To examine the simplicity of fuzzy PID controllers, we conclude that direct-action controllers exhibit simpler design properties than gain-scheduling controllers. Then, we evaluate the inference structures of direct-action controllers in five criteria: control-action composition, input coupling, gain dependency, gain-role change, and rule/parameter growth. Three types of fuzzy PID controllers, using one-, two- and three-input inference structures, are analyzed. The results, according to the criteria, demonstrate some shortcomings in Mamdani's two-input controllers. For keeping the simplicity feature like a linear PID controller, a one-input fuzzy PID controller with "one-to-three" mapping inference engine is recommended. We discuss three evaluation approaches in a nonlinear approximation study: function-estimation-based, generalization-capability-based and nonlinearity-variation-based approximations. The study focuses on the last approach. A nonlinearity evaluation is then performed for several one-input fuzzy PID controllers based on two measures: nonlinearity variation index and linearity approximation index. Using these quantitative indices, one can make a reasonable selection of fuzzy reasoning mechanisms and membership functions without requiring any process information. From the study we observed that the Zadeh-Mamdani's "max-min-gravity" scheme produces the highest score in terms of nonlinearity variations, which is superior to other schemes, such as Mizumoto's "product-sum-gravity" and "Takagi-Sugeno-Kang" schemes.

Published
2001
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17. New methodology for analytical and optimal design of fuzzy PID controllers

Author

Bao-Gang Hu, George K. I. Mann, Raymond G. Gosine, Eco-informatics (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS), Faculty of Engineering and Applied Science, Memorial University of Newfoundland [St. John's], Mechanical Engineering Department, Queen's University [Kingston], Memorial University of Newfoundland = Université Memorial de Terre-Neuve [St. John's, Canada] (MUN), Queen's University [Kingston, Canada], and Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)

Subjects
0209 industrial biotechnology, Adaptive neuro fuzzy inference system, Applied Mathematics, [INFO.INFO-OH]Computer Science [cs]/Other [cs.OH], PID controller, 02 engineering and technology, Fuzzy control system, Nonlinear control, Optimal control, Fuzzy logic, 020901 industrial engineering & automation, Computational Theory and Mathematics, Artificial Intelligence, Control and Systems Engineering, Control theory, Control system, 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, Mathematics
Abstract

This paper describes a new methodology for the systematic design of fuzzy PID controllers based on theoretical fuzzy analysis and genetic-based optimization. An important feature of the proposed controller is its simple structure. It uses a one-input fuzzy inference with three rules and at most six tuning parameters. A closed-form solution for the control action is defined in terms of the nonlinear tuning parameters. The nonlinear proportional gain is explicitly derived in the error domain. A conservative design strategy is proposed for realizing a guaranteed-PID-performance (GPP) fuzzy controller. This strategy suggests that a fuzzy PID controller should be able to produce a linear function from its nonlinearity tuning of the system. The proposed PID system is able to produce a close approximation of a linear function for approximating the GPP system. This GPP system, incorporating with a genetic solver for the optimization, will provide the performance no worse than the corresponding linear controller with respect to the specific performance criteria (i.e., response error, stability, or robustness). Two indexes, linearity approximation index (LAI) and nonlinearity variation index (NVI), are suggested for evaluating the nonlinear design of fuzzy controllers. The proposed control system has been applied to several first-order, secondorder, and fifth-order processes. Simulation results show that the proposed fuzzy PID controller produces superior control performance than the conventional PID controllers, particularly in handling nonlinearities due to time delay and saturation.

Published
1999
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18. Monitoring urban transformation in the old foreign concessions of Shanghai from 1987 to 2012

Author

Thomas Corpetti, Nicolas Courty, Antoine Lefebvre, Littoral, Environnement, Télédétection, Géomatique (LETG - Rennes), Littoral, Environnement, Télédétection, Géomatique UMR 6554 (LETG), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Université d'Angers (UA)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Brest (UBO)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut de Géographie et d'Aménagement Régional de l'Université de Nantes (IGARUN), Université de Nantes (UN)-Université de Nantes (UN)-Université de Caen Normandie (UNICAEN), Université de Nantes (UN)-Université de Nantes (UN), SEarch, Analyze, Synthesize and Interact with Data Ecosystems (SEASIDE), Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-Télécom Bretagne-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-Télécom Bretagne-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Université de Brest (UBO)-École pratique des hautes études (EPHE)-Université de Nantes (UN)-Université d'Angers (UA)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 2 (UR2), Normandie Université (NU)-Normandie Université (NU), Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Université de Bretagne Sud (UBS)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-Télécom Bretagne-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-CentraleSupélec-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Université de Rennes (UNIV-RENNES)-CentraleSupélec, Courty, Nicolas, Normandie Université (NU)-Normandie Université (NU)-Université d'Angers (UA)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Brest (UBO)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Géographie et d'Aménagement Régional de l'Université de Nantes (IGARUN), CentraleSupélec-Télécom Bretagne-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de Recherche en Informatique et en Automatique (Inria)-École normale supérieure - Rennes (ENS Rennes)-Université de Bretagne Sud (UBS)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Télécom Bretagne-Université de Rennes 1 (UR1), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), and Institute of Automation - Chinese Academy of Sciences-Institut National de Recherche en Informatique et en Automatique (Inria)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)

Subjects
05 social sciences, 0211 other engineering and technologies, 0507 social and economic geography, [INFO.INFO-CV]Computer Science [cs]/Computer Vision and Pattern Recognition [cs.CV], 021107 urban & regional planning, 02 engineering and technology, Change analysis, [INFO.INFO-CV] Computer Science [cs]/Computer Vision and Pattern Recognition [cs.CV], Transformation (function), Geography, Feature (computer vision), 11. Sustainability, 050703 geography, Cartography
Abstract

International audience; This paper is concerned with morphological change analysis in the old foreign concessions of Shanghai from 1969 to 2010. To that end, we use a series of 17 Landsat TM and Landsat ETM + images on which we estimate some feature parameters. The analysis of the resulting time series enables to isolate changes from traditional constructions to new buildings or gardens. Our results show that 70 % of the old urban pattern was converted in modern highrise buildings and green spaces.

Published
2014
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19. A Cloud-Based Decision Support System for Self-Healing in Distributed Automation Systems Using Fault Tree Analysis

Author

Xinping Guan, Wenbin Dai, Laurynas Riliskis, Peng Wang, Valeriy Vyatkin, Shanghai Jiao Tong University, Stanford University, CAS - Shenyang Institute of Automation, Department of Electrical Engineering and Automation, Aalto-yliopisto, and Aalto University

Subjects
Decision support system, Computer science, Distributed computing, Self-healing, Services, Cloud computing, 02 engineering and technology, Agent, Faster-than-real-time simulation, Architecture, 0202 electrical engineering, electronic engineering, information engineering, self-healing, Industrial automation, Electrical and Electronic Engineering, AGENT, Fault tree analysis, ARCHITECTURE, IOT, Downtime, Water heating, ta213, business.industry, 020208 electrical & electronic engineering, supervisory control, Cloud-based decision support systems, Process (computing), programmable logic controllers, distributed automation systems, faster-than-real-time simulation, 020207 software engineering, SERVICES, Technologies, Automation, Computer Science Applications, IEC 61499 function blocks (FBs), Distributed automation systems, Programmable logic controllers, Supervisory control, INDUSTRIAL AUTOMATION, Control and Systems Engineering, Software agent, Key (cryptography), TECHNOLOGIES, fault tree analysis (FTA), business, Information Systems
Abstract

Downtime is a key performance index for industrial automation systems. An industrial automation system achieves maximum productivity when its downtime is reduced to the minimum. One approach to minimize downtime is to predict system faults and recover from them automatically. A cloud-based decision support system is proposed for rapid problem identifications and to assist the self-management processes. By running multiple parallel simulations of control software with real-time inputs ahead of system time, faults could be detected and corrected automatically using autonomous industrial software agents. Fault trees, as well as control algorithms, are modeled using IEC 61499 function blocks that can be directly executed on both physical controllers and cloud services. A case study of water heating process is used to demonstrate the self-healing process supported by the cloud-based decision support system.

Published
2018
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20. Correlation between microstructures and mechanical properties in Ni-rich Ni–Mn–Ga high-temperature shape-memory alloys

Author

Hui Tong, Rene Moreau, Yves Fautrelle, Zhongming Ren, Xi Li, Long Hou, Yanchao Dai, State Key Laboratory of Advanced Special Steel, Shanghai University, Science et Ingénierie des Matériaux et Procédés (SIMaP ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Institute of Automation - Chinese Academy of Sciences

Subjects
010302 applied physics, Mechanical property, Materials science, Mechanical Engineering, 02 engineering and technology, Shape-memory alloy, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Microstructure, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Mechanics of Materials, Phase (matter), Martensite, 0103 physical sciences, General Materials Science, Crystallite, Composite material, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract

Microstructures and mechanical properties of polycrystalline and single-crystalline Ni55+xMn25Ga20−x (x = 1, 2, 3) alloys are investigated. The alloys exhibit a single martensite phase for x = 1, a...

Published
2017
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21. Tightness and duality of martingale transport on the Skorokhod space

Author

Nizar Touzi, Gaoyue Guo, Xiaolu Tan, The Institute of Automation of the Chinese Academy of Sciences (CASIA), Chinese Academy of Sciences [Beijing] (CAS), CEntre de REcherches en MAthématiques de la DEcision (CEREMADE), Centre National de la Recherche Scientifique (CNRS)-Université Paris Dauphine-PSL, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Centre de Mathématiques Appliquées - Ecole Polytechnique (CMAP), and École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Statistics and Probability, 01 natural sciences, FOS: Economics and business, 010104 statistics & probability, Mathematics::Probability, 0502 economics and business, FOS: Mathematics, Applied mathematics, 0101 mathematics, robust superhedging, Mathematics - Optimization and Control, Mathematics, Probability measure, 050208 finance, Applied Mathematics, Mathematical finance, Probability (math.PR), 05 social sciences, dynamic programming principle, [MATH.MATH-PR]Mathematics [math]/Probability [math.PR], Dynamic programming, Optimization and Control (math.OC), S−topology, Modeling and Simulation, Pricing of Securities (q-fin.PR), Martingale (probability theory), Quantitative Finance - Pricing of Securities, Mathematics - Probability
Abstract

International audience; The martingale optimal transport aims to optimally transfer a probability measure to another along the class of martingales. This problem is mainly motivated by the robust superhedging of exotic derivatives in financial mathematics, which turns out to be the corresponding Kantorovich dual. In this paper we consider the continuous-time martingale transport on the Skorokhod space of c`adì ag paths. Similar to the classical setting of optimal transport, we introduce different dual problems and establish the corresponding dualities by a crucial use of the S−topology and the dynamic programming principle 1 .

Published
2017
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22. Harmonic passive mode locking of bound-soliton structures in fiber lasers

Author

Konstantin Komarov, François Sanchez, Andrey Komarov, Laboratoire de Photonique d'Angers (LPHIA), Université d'Angers (UA), Institute of Automation and Electrometry, and Russian Academy of Sciences [Moscow] (RAS)

Subjects
media_common.quotation_subject, Physics::Optics, Solitons, Asymmetry, law.invention, Fiber lasers, nonlinear dynamics, Optics, law, Fiber laser, Electrical and Electronic Engineering, Physical and Theoretical Chemistry, Passive mode locking, Nonlinear Sciences::Pattern Formation and Solitons, media_common, [PHYS]Physics [physics], Physics, business.industry, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Nonlinear system, Nonlinear Sciences::Exactly Solvable and Integrable Systems, Mode-locking, Optical cavity, Harmonic, Soliton, business, Refractive index
Abstract

International audience; It has been shown by numerical simulation that additional inertial nonlinearity of the refractive index results in repulsion of solitons in multi-pulse passive mode-locked fiber lasers if the intersoliton distance is sufficiently large. At the same time, closely spaced solitons are attracted to each other. It has been found that the combination of these properties of soliton interaction can lead to harmonic passive mode locking of identical structures of bound solitons (generation with an equidistant arrangement of soliton structures in the laser cavity). These properties of soliton interaction are caused by the asymmetry of the wings of an individual soliton, which manifests itself as the asymmetry of Kelly's spectral peaks and is due to the inertial nonlinearity of the refractive index. Other possible mechanisms of this asymmetry are also discussed.

Published
2015
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23. Morphology control and fabrication of multi-shelled NiO spheres by tuning the pH value via a hydrothermal process

Author

Dandan Song, Zipei Wan, Meicheng Li, Lei Ding, Shangyi Dou, Lihua Chu, Jiewei Chen, Yu Wang, Changjiang Water Resources Commission (CWRC), Matériaux, Rayonnements, Structure (MRS), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Shenyang Institute of Automation, the Chinese Academy of Sciences (SIA), Chinese Academy of Sciences [Changchun Branch] (CAS), and Huazhong University of Science and Technology [Wuhan] (HUST)

Subjects
[PHYS]Physics [physics], Nanostructure, Materials science, Morphology (linguistics), Nickel oxide, Non-blocking I/O, Nanoparticle, Nanotechnology, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Hydrothermal circulation, 0104 chemical sciences, law.invention, law, General Materials Science, Calcination, 0210 nano-technology, Science, technology and society, ComputingMilieux_MISCELLANEOUS
Abstract

Controlling the morphology of nickel oxide (NiO) nanostructures is crucial to obtain excellent physical and chemical performance. Hence, the morphology of NiO was tuned by adjusting the pH value of the precursor solutions with NH3·H2O via a hydrothermal process and subsequent calcination. Different morphologies, including nanoparticles, porous structures and multi-shelled microspheres, were obtained with pH values varying from 8.30 to 10.90. The morphology evolution of as-synthesized NiO with the pH value indicates the important role of OH− in controlling the product morphology. Moreover, the formation mechanism of different NiO nanostructures at different pH values was discussed. Furthermore, the surface area and magnetic properties of NiO with different morphologies were also investigated, and indeed, these properties are very sensitive to the morphology. This work provides a facile way to control the morphology of NiO nanostructures, which also implies the potential application in modern science and technology with the modified magnetic properties.

Published
2014
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24. Crowd motion capture

Author

Courty, Nicolas, Corpetti, Thomas, Laboratoire de Recherche en Informatique et ses Applications de Vannes et Lorient (VALORIA), Université de Bretagne Sud (UBS), Laboratoire Franco-Chinois d'Informatique, d'Automatique et de Mathématiques Appliquées (LIAMA), and Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Chinese Academy of Sciences [Changchun Branch] (CAS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institute of Automation - Chinese Academy of Sciences-Centre National de la Recherche Scientifique (CNRS)

Subjects
0202 electrical engineering, electronic engineering, information engineering, 020207 software engineering, 020201 artificial intelligence & image processing, 02 engineering and technology, Computer Graphics and Computer-Aided Design, [INFO.INFO-GR]Computer Science [cs]/Graphics [cs.GR], Software, ComputingMethodologies_COMPUTERGRAPHICS
Abstract

International audience; In this paper a new and original technique to animate a crowd of human beings is presented. Following the success of data-driven animation models (such as motion capture) in the context of articulated figures control, we propose to derivate a similar type of approach for crowd motions. In our framework, the motion of the crowds are represented as a time series of velocity fields estimated from a video of a real crowd. This time series is used as an input of a simple animation model that ”advect” people along this timevarying flow. We demonstrate the power of our technique on both synthetic and real examples of crowd videos. We also introduce the notions of crowd motion editing and present possible extensions to our work.

Published
2007
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25. Multiple-Pulse Operation and Bound States of Solitons in Passive Mode-Locked Fiber Lasers

Author

Foued Amrani, A. K. Dmitriev, Andrey Komarov, Dmitry Meshcheriakov, François Sanchez, Konstantin Komarov, Institute of Automation and Electrometry, Russian Academy of Sciences [Moscow] (RAS), Laboratoire de Photonique d'Angers (LPHIA), and Université d'Angers (UA)

Subjects
Physics, [PHYS]Physics [physics], Annihilation, Computer simulation, Article Subject, Physics::Optics, 01 natural sciences, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, law.invention, 010309 optics, Nonlinear system, law, Fiber laser, Optical cavity, 0103 physical sciences, Bound state, lcsh:QC350-467, Soliton, Atomic physics, 010306 general physics, Nonlinear Sciences::Pattern Formation and Solitons, lcsh:Optics. Light, Excitation
Abstract

International audience; We present results of our research on a multiple-pulse operation of passive mode-locked fiber lasers. The research has been performed on basis of numerical simulation. Multihysteresis dependence of both an intracavity energy and peak intensities of intracavity ultrashort pulses on pump power is found. It is shown that the change of a number of ultrashort pulses in a laser cavity can be realized by hard as well as soft regimes of an excitation and an annihilation of new solitons. Bound steady states of interacting solitons are studied for various mechanisms of nonlinear losses shaping ultrashort pulses. Possibility of coding of information on basis of soliton trains with various bonds between neighboring pulses is discussed. The role of dispersive wave emitted by solitons because of lumped intracavity elements in a formation of powerful soliton wings is analyzed. It is found that such powerful wings result in large bounding energies of interacting solitons in steady states. Various problems of a soliton interaction in passive mode-locked fiber lasers are discussed.

Published
2012
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26. Relating Streamer Flows to Density and Magnetic Structures at the Parker Solar Probe

Author

Alexis P. Rouillard, A. K. Higginson, Davin Larson, Vincent Génot, Stuart D. Bale, A. Kouloumvakos, Nicholeen M. Viall, Peter Harvey, Phillip Hess, Robert J. MacDowall, Rui F. Pinto, Roberto Livi, Anthony W. Case, T. Dudok de Witt, Keith Goetz, Angelos Vourlidas, Justin C. Kasper, Phyllis Whittlesey, Yihong Wu, Kelly E. Korreck, N. E. Raouafi, Jasper Halekas, Philippe Louarn, Kévin Dalmasse, John W. Bonnell, Nicolas Poirier, Michael Lavarra, David M. Malaspina, Guillermo Stenborg, Marc Pulupa, Jackie A. Davies, Benoit Lavraud, Russell A. Howard, Emmanuel Penou, Michael L. Stevens, Léa Griton, Victor Réville, Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), University of Michigan [Ann Arbor], University of Michigan System, Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Naval Research Laboratory (NRL), Travaux et recherches archéologiques sur les cultures, les espaces et les sociétés (TRACES), École des hautes études en sciences sociales (EHESS)-Université Toulouse - Jean Jaurès (UT2J)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), Smithsonian Astrophysical Observatory, Smithsonian Institution, Département d'Astrophysique (ex SAP) (DAP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, National Laboratory of Pattern Recognition [Beijing] (NLPR), Institute of Automation - Chinese Academy of Sciences, University of California, Department of Physics and Astronomy [Iowa City], University of Iowa [Iowa City], The Crouch Oak Family Practice, NASA Goddard Space Flight Center (GSFC), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), ANR-18-ERC1-0006,SLOW_SOURCE,Trouver l'origine du vent solaire lent(2018), ANR-17-CE31-0006,COROSHOCK,EVALUER LE ROLE DU CHOC COMME ACCELERATEUR DE PARTICULES SOLAIRES(2017), European Project: 606692,EC:FP7:SPA,FP7-SPACE-2013-1,HELCATS(2014), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), École des hautes études en sciences sociales (EHESS)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université de Toulouse (UT)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), and University of California (UC)

Subjects
Physics, 010504 meteorology & atmospheric sciences, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], FOS: Physical sciences, Astronomy and Astrophysics, Solar coronal streamers (1486), 01 natural sciences, Solar coronal transients (312), Computational physics, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Physics::Plasma Physics, 0103 physical sciences, Physics::Space Physics, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Unified Astronomy Thesaurus concepts: Slow solar wind (1873), Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences
Abstract

The physical mechanisms that produce the slow solar wind are still highly debated. Parker Solar Probe's (PSP's) second solar encounter provided a new opportunity to relate in situ measurements of the nascent slow solar wind with white-light images of streamer flows. We exploit data taken by the Solar and Heliospheric Observatory (SOHO), the Solar TErrestrial RElations Observatory (STEREO) and the Wide Imager on Solar Probe to reveal for the first time a close link between imaged streamer flows and the high-density plasma measured by the Solar Wind Electrons Alphas and Protons (SWEAP) experiment. We identify different types of slow winds measured by PSP that we relate to the spacecraft's magnetic connectivity (or not) to streamer flows. SWEAP measured high-density and highly variable plasma when PSP was well connected to streamers but more tenuous wind with much weaker density variations when it exited streamer flows. STEREO imaging of the release and propagation of small transients from the Sun to PSP reveals that the spacecraft was continually impacted by the southern edge of streamer transients. The impact of specific density structures is marked by a higher occurrence of magnetic field reversals measured by the FIELDS magnetometers. Magnetic reversals originating from the streamers are associated with larger density variations compared with reversals originating outside streamers. We tentatively interpret these findings in terms of magnetic reconnection between open magnetic fields and coronal loops with different properties, providing support for the formation of a subset of the slow wind by magnetic reconnection., Comment: 15 pages, 8 figures, to appear in the Parker Solar Probe ApJ Special Issue

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