"Progresse-t-on en enseignement des langues étrangères?"

Scientific conference (2007, December)

"Questions de didactique des langues étrangères, du FLE" (cycle de conf.)

Scientific conference (2007, December)

A Hybrid Systems Approach to Trajectory Tracking Control for Juggling Systems

in Proceedings of the 46th IEEE Conference on Decision and Control (2007, December)

From a hybrid systems point of view, we provide a modeling framework and a trajectory tracking control design methodology for juggling systems. We present the main ideas and concepts in a one degree-of ... [more ▼]

From a hybrid systems point of view, we provide a modeling framework and a trajectory tracking control design methodology for juggling systems. We present the main ideas and concepts in a one degree-of-freedom juggler, which consists of a ball bouncing on an actuated robot. We design a hybrid control strategy that, with only information of the ball’s state at impacts, controls the ball to track a reference rhythmic pattern with arbitrary precision. We extend this hybrid control strategy to the case of juggling multiple balls with different rhythmic patterns. Simulation results for juggling of one and three balls with a single actuated robot are presented. [less ▲]

Stabilization of Collective Motion in Three Dimensions : A Consensus Approach

in Proceedings of 46th IEEE Conference on Decision and Control (2007, December)

This paper proposes a methodology to stabilize relative equilibria in a model of identical, steered particles moving in three- dimensional Euclidean space. Exploiting the Lie group structure of the ... [more ▼]

This paper proposes a methodology to stabilize relative equilibria in a model of identical, steered particles moving in three- dimensional Euclidean space. Exploiting the Lie group structure of the resulting dynamical system, the stabilization problem is reduced to a consensus problem on the Lie algebra. The resulting equilibria correspond to parallel, circular and helical formations. We rst derive the stabilizing control laws in the presence of all-to-all communication. Providing each agent with a consensus estimator, we then extend the results to a general setting that allows for unidirectional and time-varying communication topologies. [less ▲]

Atelier 1: la démarche expérimentale comme référent externe à l'autorité du professeur ... ou quand le bruit et l'action sont synonymes d'apprentissage et de compétences...

in Puzzle. CIFEN (Centre Interfacultaire de Formation des ENseignants) (2007), (23), 28-29

Comment mener une démarche expérimentale en classe de sciences. Mise en situation concrète du public pour dégager des pistes de réponses aux questions suivantes: que fait-on en classe lorsqu'on ... [more ▼]

Comment mener une démarche expérimentale en classe de sciences. Mise en situation concrète du public pour dégager des pistes de réponses aux questions suivantes: que fait-on en classe lorsqu'on expérimente? Quel est le rôle de l'élève? Celui du professeur? Quels sont les avantages de travailler de la sorte? Qui fait "Autorité" dans tout cela?... Réflexions étayées par des résultats de recherche-action au fondamental [less ▲]

An Arbitrary Lagrangian Eulerian Formulation for the Numerical Simulation of Forming Processes

in International Workshop 2007: Advancements in Design Optimization of Materials, Structures and Mechanical Systems (2007, December)

Fe-2(II)(PO4)(OH), a synthetic analogue of wolfeite

in Acta Crystallographica Section C-Crystal Structure Communications (2007), 63(Part 12), 119-121

This paper reports the hydrothermal synthesis and crystal structure refinement of diiron(II) phosphate hydroxide, Fe-2(II)(PO4)(OH), obtained at 1063 K and 2.5 GPa. This phosphate is the synthetic ... [more ▼]

This paper reports the hydrothermal synthesis and crystal structure refinement of diiron(II) phosphate hydroxide, Fe-2(II)(PO4)(OH), obtained at 1063 K and 2.5 GPa. This phosphate is the synthetic analogue of the mineral wolfeite, and has a crystal structure topologically identical to those of minerals of the triplite-triploidite group. The complex framework contains edge-and corner-sharing FeO4(OH) and FeO4(OH)(2) polyhedra, linked via corner-sharing to the PO4 tetrahedra (average P-O distances are between 1.537 and 1.544 angstrom). Four five-coordinated Fe sites are at the centers of distorted trigonal bipyramids (average Fe-O distances are between 2.070 and 2.105 angstrom), whereas the coordination environments of the remaining Fe sites are distorted octahedra (average Fe-O distances are between 2.146 and 2.180 angstrom). The Fe-O distances are similar to those observed in natural Mg-rich wolfeite, except for two Fe-O bond distances, which are significantly longer in synthetic Fe-2(2+) (PO4)(OH). [less ▲]

Consensus under general convexity

in Proceedings of the 46th IEEE Conference on Decision and Control (2007, December)

A method is proposed to characterize contraction of a set through orthogonal projections. For discrete-time multi-agent systems, quantitative estimates of convergence (to a consensus) rate are provided by ... [more ▼]

A method is proposed to characterize contraction of a set through orthogonal projections. For discrete-time multi-agent systems, quantitative estimates of convergence (to a consensus) rate are provided by means of contracting convex sets. Required convexity for the sets that should include the values that the transition maps of agents take is considered in a more general sense than that of Euclidean geometry. [less ▲]

Predatory boreholes in Tournaisian (Lower Carboniferous) spiriferid brachiopods

in Budd, G. E.; Streng, M.; Daley, A. C. (Eds.) et al Programme with abstracts of the 51st Palaeontological Association Annual Meeting (2007, December)

Intravenous iron therapy restores functional iron deficiency induced by infliximab

in Journal of Crohn’s and Colitis [=JCC] (2007), 1