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7 results on '"Adina, Ciomaga"'

1. Hexagons to Ribbons: Flipping Cyanide on Au{111}

Author

David L. Allara, David D. Kes, Kristopher Barr, Kevin Bui, Leticia F. Torres, Jacob N. Fauman, Adina Ciomaga, Andrew I. Guttentag, Jérôme Gilles, Paul S. Weiss, Michael Zharnikov, Yang Yang, Nichole Sullivan, Tze-Bin Song, Laboratoire Jacques-Louis Lions (LJLL), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Department of Mathematics [UCLA], University of California [Los Angeles] (UCLA), University of California-University of California, Université Paris 1 Panthéon-Sorbonne - UFR d'Arts plastiques et sciences de l'art (UP1 UFR04), Université Paris 1 Panthéon-Sorbonne (UP1), and University of California (UC)-University of California (UC)

Subjects
Cyanide, Isocyanide, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Biochemistry, Catalysis, law.invention, chemistry.chemical_compound, Colloid and Surface Chemistry, law, Lattice (order), Monolayer, Ribbon, [CHIM]Chemical Sciences, Molecule, [INFO]Computer Science [cs], Crystallization, ComputingMilieux_MISCELLANEOUS, Chemistry, General Chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Blueshift, Crystallography, Chemical Sciences, 0210 nano-technology
Abstract

Cyanide monolayers on Au{111} restructure from a hexagonal close-packed lattice to a mixed-orientation "ribbon" structure through thermal annealing. The new surface structure loses most of the observed surface features characterizing the initial as-adsorbed system with "ribbon" domain boundaries isolating rotationally offset surface regions where the orientation is guided by the underlying gold lattice. A blue shift to higher frequencies of the CN vibration to 2235cm-1 with respect to the as-adsorbed CN/Au{111} vibration at 2146 cm-1 is observed. In addition, a new low-frequency mode is observed at 145 cm-1, suggesting a chemical environment change similar to gold-cyanide crystallization. We discuss this new structure with respect to a mixed cyanide/isocyanide monolayer and propose a bonding scheme consisting of Au-CN and Au-NC bound molecules that are oriented normal to the Au{111} surface.

Published
2016

2. Stochastic homogenization of interfaces moving with changing sign velocity

Author

Adina Ciomaga, Hung V. Tran, Panagiotis E. Souganidis, Department of Mathematics [Chicago], and University of Chicago

Subjects
viscosity solutions, random media, stochastic homogenization, 01 natural sciences, Homogenization (chemistry), front propagation, symbols.namesake, [MATH.MATH-GM]Mathematics [math]/General Mathematics [math.GM], non-coercive Hamiltonian, Ergodic theory, Initial value problem, 0101 mathematics, Linear combination, Normal velocity, Mathematics, Applied Mathematics, 010102 general mathematics, Mathematical analysis, Random media, Geodetic datum, level sets, 010101 applied mathematics, symbols, Hamiltonian (quantum mechanics), Hamilton-Jacobi equations, Analysis
Abstract

International audience; We are interested in the averaged behavior of interfaces moving in stationary ergodic environments, with oscillatory normal velocity which changes sign. This problem can be reformulated, using level sets, as the homogenization of a Hamilton-Jacobi equation with a positively homogeneous non-coercive Hamiltonian. The periodic setting was earlier studied by Cardaliaguet, Lions and Souganidis (2009). Here we concentrate in the random media and show that the solutions of the oscillatory Hamilton-Jacobi equation converge in $L^\infty$-weak $*$ to a linear combination of the initial datum and the solutions of several initial value problems with deterministic effective Hamiltonian(s), determined by the properties of the random media.

Published
2014

3. Large Time Behavior of Periodic Viscosity Solutions for Uniformly Parabolic Integro-Differential Equations

Author

Adina Ciomaga, Cyril Imbert, Emmanuel Chasseigne, Guy Barles, Laboratoire de Mathématiques et Physique Théorique (LMPT), Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS), Fédération de recherche Denis Poisson (FDP), Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Department of Mathematics, University of Chicago, Laboratoire d'Analyse et de Mathématiques Appliquées (LAMA), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Fédération de Recherche Bézout-Université Paris-Est Marne-la-Vallée (UPEM), Centre National de la Recherche Scientifique (CNRS)-Université de Tours, Université de Tours-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Université Paris-Est Marne-la-Vallée (UPEM)-Fédération de Recherche Bézout-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Université d'Orléans (UO)-Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS), Université d'Orléans (UO)-Université de Tours-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de Tours (UT)

Subjects
35B40, 35R09, 35D40, 35D10, Differential equation, media_common.quotation_subject, Ergodic problem, 01 natural sciences, Parabolic nonlinear integro-differential equations, Mathematics - Analysis of PDEs, FOS: Mathematics, Applied mathematics, Initial value problem, Ergodic theory, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], 0101 mathematics, Long time behavior, Lipschitz estimates, media_common, Mathematics, Variable (mathematics), Applied Mathematics, 010102 general mathematics, Order (ring theory), Infinity, Lipschitz continuity, 010101 applied mathematics, Nonlinear system, Analysis, Analysis of PDEs (math.AP), Strong maximum principle
Abstract

International audience; In this paper, we study the large time behavior of solutions of a class of parabolic fully nonlinear integro-differential equations in a periodic setting. In order to do so, we first solve the ergodic problem}(or cell problem), i.e. we construct solutions of the form $\lambda t + v(x)$. We then prove that solutions of the Cauchy problem look like those specific solutions as time goes to infinity. We face two key difficulties to carry out this classical program: (i) the fact that we handle the case of ''mixed operators'' for which the required ellipticity comes from a combination of the properties of the local and nonlocal terms and (ii) the treatment of the superlinear case (in the gradient variable). Lipschitz estimates previously proved by the authors (2012) and Strong Maximum principles proved by the third author (2012) play a crucial role in the analysis.

Published
2014

4. A proof of equivalence between level lines shortening and curvature motion in image processing

Author

Jean-Michel Morel, Adina Ciomaga, Centre de Mathématiques et de Leurs Applications (CMLA), and École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS)

Subjects
topographic map, Motion (geometry), Image processing, 02 engineering and technology, Curvature, 01 natural sciences, Mathematics - Analysis of PDEs, level lines, 0202 electrical engineering, electronic engineering, information engineering, FOS: Mathematics, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], 0101 mathematics, Mathematics, affine curvature motion, Mean curvature, affine shortening, Applied Mathematics, 010102 general mathematics, Mathematical analysis, Affine shape adaptation, Computational Mathematics, curve shortening, Line (geometry), mean curvature motion, 020201 artificial intelligence & image processing, Affine transformation, Viscosity solution, Analysis, Analysis of PDEs (math.AP)
Abstract

In this paper we define the continuous Level Lines Shortening evolution of a two-dimensional image as the Curve Shortening operator acting simultaneously and independently on all the level lines of the initial data, and show that it computes a viscosity solution for the mean curvature motion. This provides an exact analytical framework for its numerical implementation, which runs online on any image at http://www.ipol.im/. Analogous results hold for its affine variant version, the Level Lines Affine Shortening., 23 pages

Published
2013

5. Lipschitz Regularity of Solutions for Mixed Integro-Differential Equations

Author

Adina Ciomaga, Cyril Imbert, Guy Barles, Emmanuel Chasseigne, Laboratoire de Mathématiques et Physique Théorique (LMPT), Université de Tours-Centre National de la Recherche Scientifique (CNRS), Centre de Mathématiques et de Leurs Applications (CMLA), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), 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), Département de Mathématiques et Applications - ENS Paris (DMA), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS), Université Paris Dauphine-PSL, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), and École normale supérieure - Paris (ENS Paris)

Subjects
Integro-differential equations, viscosity solutions, Differential equation, Mathematics::Analysis of PDEs, Nonlinear elliptic equations, 01 natural sciences, Viscosity, Mathematics - Analysis of PDEs, Simultaneous equations, regularity of generalized solutions, FOS: Mathematics, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], 0101 mathematics, Diffusion (business), nonlinear elliptic equations integro partial-differential equations, Mathematics, Applied Mathematics, 35D10, 35D40, 35J60, 35R09, 010102 general mathematics, Mathematical analysis, Degenerate energy levels, Lipschitz continuity, Term (time), 010101 applied mathematics, Nonlinear system, Analysis, Analysis of PDEs (math.AP)
Abstract

We establish new Hölder and Lipschitz estimates for viscosity solutions of a large class of elliptic and parabolic nonlinear integro-differential equations, by the classical Ishii–Lionsʼs method. We thus extend the Hölder regularity results recently obtained by Barles, Chasseigne and Imbert (2011). In addition, we deal with a new class of nonlocal equations that we term mixed integro-differential equations. These equations are particularly interesting, as they are degenerate both in the local and nonlocal term, but their overall behavior is driven by the local–nonlocal interaction, e.g. the fractional diffusion may give the ellipticity in one direction and the classical diffusion in the complementary one.

Published
2012

6. Image Visualization and Restoration by Curvature Motions

Author

Jean-Michel Morel, Adina Ciomaga, Pascal Monasse, Centre de Mathématiques et de Leurs Applications (CMLA), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), imagine [Marne-la-Vallée], Laboratoire d'Informatique Gaspard-Monge (LIGM), Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Bézout-ESIEE Paris-École des Ponts ParisTech (ENPC)-Université Paris-Est Marne-la-Vallée (UPEM)-Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Bézout-ESIEE Paris-École des Ponts ParisTech (ENPC)-Université Paris-Est Marne-la-Vallée (UPEM)-Centre Scientifique et Technique du Bâtiment (CSTB), Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Bézout-ESIEE Paris-École des Ponts ParisTech (ENPC)-Université Paris-Est Marne-la-Vallée (UPEM), Centre Scientifique et Technique du Bâtiment (CSTB)-École des Ponts ParisTech (ENPC)-Laboratoire d'Informatique Gaspard-Monge (LIGM), Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Bézout-ESIEE Paris-École des Ponts ParisTech (ENPC)-Université Paris-Est Marne-la-Vallée (UPEM)-Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Bézout-ESIEE Paris-Université Paris-Est Marne-la-Vallée (UPEM), Université Paris-Est Marne-la-Vallée (UPEM)-École des Ponts ParisTech (ENPC)-ESIEE Paris-Fédération de Recherche Bézout-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Marne-la-Vallée (UPEM)-École des Ponts ParisTech (ENPC)-ESIEE Paris-Fédération de Recherche Bézout-Centre National de la Recherche Scientifique (CNRS)-Centre Scientifique et Technique du Bâtiment (CSTB), and Université Paris-Est Marne-la-Vallée (UPEM)-École des Ponts ParisTech (ENPC)-ESIEE Paris-Fédération de Recherche Bézout-Centre National de la Recherche Scientifique (CNRS)

Subjects
topographic map, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, General Physics and Astronomy, Image processing, 02 engineering and technology, Curvature, 01 natural sciences, Principal curvature, curvature scale space, level lines, 0202 electrical engineering, electronic engineering, information engineering, partial differential equations, Total curvature, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], Computer vision, curvature scale spaces, 0101 mathematics, scientific visualization, Mathematics, ComputingMethodologies_COMPUTERGRAPHICS, affine curvature motion, Mean curvature, business.industry, Ecological Modeling, General Chemistry, image reconstruction, 65D18, 65N99, 35K65, 53A04, 53C21, Computer Science Applications, 010101 applied mathematics, Willmore energy, Affine curvature, Modeling and Simulation, Computer Science::Computer Vision and Pattern Recognition, [INFO.INFO-TI]Computer Science [cs]/Image Processing [eess.IV], mean curvature motion, 020201 artificial intelligence & image processing, Artificial intelligence, Mathematics::Differential Geometry, image shape analysis, Theorema Egregium, business
Abstract

International audience; This paper presents a review, analysis, and comparison of numerical methods implementing the curvature motion and the affine curvature motion for two-dimensional (2D) images, shapes, and curves. These curvature scale spaces allow, in principle, one to compute an accurate multiscale curvature in digital images. The fastest and most invariant of them can be used in a complete image processing chain. This numerical chain simulates the accurate subpixel evolution of an image by mean curvature motion or by affine invariant curvature motion. To do so, it lets all the level lines of the image evolve by curvature shortening (of affine shortening), computes the image curvature directly on the smoothed level lines, and reconstructs the evolved image and its curvatures in an intrinsic, grid independent representation. The paper describes a careful implementation of this chain and analyzes its effects on many examples. The microscopic visualization of an image curvature map reveals after processing many image details. This image process improves graphic images and gets rid of compression and aliasing effects. It also gives an accurate tool to explore the validity of Attneave's and Julesz's theories on shape perception and texture discrimination. The "curvature microscope'' runs online for any image at http://www.ipol.im/pub/algo/cmmm_image_curvature_microscope/.

Published
2011

7. Level lines shortening yields an image curvature microscope

Author

Jean-Michel Morel, Pascal Monasse, Adina Ciomaga, Centre de Mathématiques et de Leurs Applications (CMLA), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), imagine [Marne-la-Vallée], Laboratoire d'Informatique Gaspard-Monge (LIGM), Université Paris-Est Marne-la-Vallée (UPEM)-École des Ponts ParisTech (ENPC)-ESIEE Paris-Fédération de Recherche Bézout-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Marne-la-Vallée (UPEM)-École des Ponts ParisTech (ENPC)-ESIEE Paris-Fédération de Recherche Bézout-Centre National de la Recherche Scientifique (CNRS)-Centre Scientifique et Technique du Bâtiment (CSTB), Université Paris-Est Marne-la-Vallée (UPEM)-École des Ponts ParisTech (ENPC)-ESIEE Paris-Fédération de Recherche Bézout-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Bézout-ESIEE Paris-École des Ponts ParisTech (ENPC)-Université Paris-Est Marne-la-Vallée (UPEM)-Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Bézout-ESIEE Paris-École des Ponts ParisTech (ENPC)-Université Paris-Est Marne-la-Vallée (UPEM)-Centre Scientifique et Technique du Bâtiment (CSTB), Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Bézout-ESIEE Paris-École des Ponts ParisTech (ENPC)-Université Paris-Est Marne-la-Vallée (UPEM), Centre Scientifique et Technique du Bâtiment (CSTB)-École des Ponts ParisTech (ENPC)-Laboratoire d'Informatique Gaspard-Monge (LIGM), and Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Bézout-ESIEE Paris-École des Ponts ParisTech (ENPC)-Université Paris-Est Marne-la-Vallée (UPEM)-Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Bézout-ESIEE Paris-Université Paris-Est Marne-la-Vallée (UPEM)

Subjects
Microscope, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Image processing, Geometry, 02 engineering and technology, Iterative reconstruction, Curvature, 01 natural sciences, law.invention, [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, law, 0202 electrical engineering, electronic engineering, information engineering, Computer vision, 0101 mathematics, Mathematics, ComputingMethodologies_COMPUTERGRAPHICS, Mean curvature, Pixel, business.industry, [INFO.INFO-CV]Computer Science [cs]/Computer Vision and Pattern Recognition [cs.CV], 010101 applied mathematics, Affine curvature, Computer Science::Computer Vision and Pattern Recognition, Line (geometry), 020201 artificial intelligence & image processing, Artificial intelligence, Mathematics::Differential Geometry, business, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract

International audience; This paper presents an image processing algorithm simulating a sub-pixel evolution of an image by mean curvature motion or by affine curvature motion. The sub-pixel algorithm computes the image curvature directly on the smoothed level lines, and yields a microscopic visualization of the curvature map revealing many image details, and getting rid of aliasing effects. This "curvature microscope" showing curvatures in false colors runs on line on any image proposed by users at http://www.ipol.im/pub/algo/cmmm_image_curvature_microscope/.

Published
2010

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