Minimal time control of fed-batch processes with growth functions having several maxima

We address the issue of minimal time optimal control of fedbatch reactor in presence of complex non monotonic kinetics, that can be typically characterized by the combination of two Haldane models. The optimal synthesis may present several singular arcs. Global optimal trajectory results are provided on the basis of a numerical approach that considers an approximation method with smooth control inputs

Quantum optics with bosons and fermions

Atom optics, a field which takes much inspiration from traditional optics, has advanced to the point that some of the fundamental experiments of quantum optics, involving photon correlations, have found atomic analogs. We discuss some recent experiments on atom bunching and anti-bunching as well as some prospects for extending them to the field of many body physics.Comment: English version of "Optique atomique quantique : apr\`es les bosons, les fermions

Grid models versus TIN : geometric accuracy of multibeam data processing

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A robust asymptotic observer for systems that converge to unobservable states. A batch reactor case study

International audienceIn this paper we propose an observer for a dynam-ical system for which the states on the frontier of its domain are not observable, and all trajectories converge to the frontier. The proposed case study, a bioreactor in batch operating conditions with a single microbial reaction and gas production, is standard and largely encountered in practical situations. We show also how to extend this observer to obtain an observer in higher dimension that is robust with respect to unbiased noise

Structure and relaxation processes of an anisotropic molecular fluid confined into 1D nanochannels

Structural order parameters of a smectic liquid crystal confined into the columnar form of porous silicon are studied using neutron scattering and optical spectroscopic techniques. It is shown that both the translational and orientational anisotropic properties of the confined phase strongly couple to the one-dimensional character of the porous silicon matrix. The influence of this confinement induced anisotropic local structure on the molecular reorientations occuring in the picosecond timescale is discussed

Évaluation de quelques sources d’erreur dans un inventaire semi-automatisé de l’utilisation agricole du sol : étude de cas à Sainte-Foy

Un inventaire de l'occupation du sol pour chaque terrain agricole peut être produit par le croisement (automatisé) entre une image satellitaire classifiée et une image des terrains, provenant du cadastre numérisé. Trois sources d'erreur sont examinées. L'erreur planimétrique, créée par la « rasteurisation » des polygones-terrain, Terreur dans les proportions des classes d'occupation du sol due à la résolution spatiale, et l'erreur de la classification elle-même. Les résultats démontrent que chacune de ces erreurs varie en fonction des terrains, donnant des inventaires de qualité inégale. Il est difficile de le corréler avec les dimensions des terrains, et de fixer ainsi des dimensions minimales nécessaires au succès de l'inventaire agricole dans un milieu péri-urbain.An inventory of the land cover per individual agricultural plot can be produced by the cross-tabulation of a classified satellite image and an image of plots provided by the digitized land survey of the region. Three sources of error are examined. The planimetric error, created by the rasterization of the ground polygons, the proportional error in the land cover classes due to the spatial resolution and lastly, the classification error itself. The results show that each of these errors varies in relation to the land parcels which produces inventories of unequal quality. It is difficult to correlate them with the plot dimensions, and thus to set the minimal dimensions required to insure the success of the agricultural inventory in a suburban area