Nicolas Mercier

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The paper presents a motion estimation method based on data assimilation in a dynamic model, named Image Model, expressing the physical evolution of a quantity observed on the images. The application concerns the retrieval of apparent surface velocity from a sequence of satellite data, acquired over the ocean. The Image Model includes a shallow-water(More)
The poster describes an innovative method to simultaneously estimate motion and track a structure on an image sequence. To process noisy images, assumptions on dynamics should be involved. Consequently, the method relies on the dynamics equations of the studied physical system. The issue of tracking a structure has been largely studied in the image(More)
Synthesis Following the literature procedure 13 , trimethyloxonium tetrafluoroborate (2g mg, 1.35 10-2 mol) and 4,4'-dipyridyl (1g, 6.4 10-3 mol) were strirred in 10 mL of acetonitrile for 4 hours. The white precipitate was filtered, washed with acetonitrile and dried under vacuum. The product (1.83g, 79%) was obtained as a white crystalline powder. XRPD of(More)
Data Assimilation is a well-known mathematical technic used, in environmental sciences, to improve, thanks to observation data, the forecasts obtained by meteorological, oceanographic or air quality simulation models. It aims to solve the evolution equations, describing the dynamics of the state variables , and an observation equation, linking at each(More)
Image assimilation methods are nowadays widely used to retrieve motion from image sequences with heuris-tics on the underlying dynamics. A mathematical model on the temporal evolution of the motion field has to be chosen, according to these heuristics, that approximately describes the evolution of the velocity at a pixel over the sequence. In order to(More)
Data Assimilation is commonly used in environmental sciences to improve forecasts, obtained by meteorological, oceanographic or air quality simulation models, with observation data. It aims to solve an evolution equation, describing the dynamics, and an observation equation , measuring the mist between the state vector and the observations, to get a better(More)
This report concerns the validation of surface velocity estimated from satellite images. The estimation is obtained with a dynamic model based on shallow-water equations. We first compare the stationary assumption to the shallow-water heuristics to justify our choice. Second, we quantify the quality of the estimation by measuring the misfit between the(More)
The dehydration of a iodobismuthate hybrid built up from Bi(4)I(16) clusters and protonated L-cystine molecules involves an unprecedented reversible dynamic structural change in the solid state leading to 1D BiI(4) chains and 1D helical molecular chains, highlighting the templating effect of cations in the formation of iodobismuthate network.
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