Intersection cohomology of S^1-actions

55N33;57S15International audienceIn this work we shall consider smooth action of S^1 on a manifold M. We exhibit a Gysin sequence relating the cohomology of M with the intersection cohomology of the orbit space M/S^1. This generalizes the usual Gysin sequence associated with a free action of S^1. We also study the vanishiing of the assocaied Euler class

Lemme de moser feuilleté et classification des variétés de poisson réguliéres

Regular Poisson structures with fixed characteristic foliation F are described by means of foliated symplectic forms. Associated to each of these structures, there is a class in the second group of foliated cohomology H2 (F). Using a. foliated version of Moser's lemma, we study the isotopy classes of these structures in relation with their cohomology class. Explicit examples, with dim F = 2, are described

Sur l'intégration symplectique de la structure de poisson singuliére Λ = (x2 + y2) ∂/∂x Λ ∂/∂y de R2

The purpose of this note is to give an example of a singular Poisson structure on R2 which admits a symplectic realization by a Lie groupoid

Cohomologie d'intersection modéréee. Un Théorème de deRham

International audienceLe but de ce travail est d'établir un Théoème de deRham qui englobe le Théorème de deRham pour l'homologie d'intersection modérée dans la caégorie despseudovariétés stratifiées simpliciales

Perception of Presence in a Mixed-Reality Training Environment

Ground troop training within the Army typically involves three kinds of training: live mission rehearsal, virtual or simulated training exercises (e.g., within a Humvee simulator), and constructive training, in which warfighters battle artificially intelligent enemies in a video game format. Some leading edge training missions merge these formats to offer full LVC training (live, virtual, constructive) in a mixed-reality environment in which trainees rehearse in a physically immersive setting that is augmented with simulated constructive entities and integrated with virtual entities controlled by trainees at other locations. In this pilot study, a number of human factors that contribute to a sense of immersed presence were evaluated by 12 ROTC cadets engaged in a scenario within a mixed-reality training environment. Participants were evaluated via survey, interview, and After Action Review (AAR). Participants reported reasonably high levels of involvement on several measures, and the AAR offered meaningful objective measurements. The combined results provide a rich dataset that establishes a baseline for the participants’ sense of presence and provides useful insights into the environment’s human-system interactions, thus guiding future development