Stéphane Leroy

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This paper presents a geometric based approach for multiple mobile robot motion coordination. All the robot paths being computed independently, we address the problem of coordinating the motion of the robots along their own path in such a way they do not collide each other. The proposed algorithm is based on a bounding box representation of the obstacles in(More)
Owing to their agonist action on dopaminergic systems, cannabinoids may play a major role in substance dependency and schizophrenia. We examined the (AAT)n triplet repeat polymorphism nearby the CNR1 gene, which encodes human cannabinoid (CB1) receptor, in a male Afro-Caribbean population. The allelic and genotypic distributions were significantly different(More)
Previous studies testing the functional polymorphism in the promoter of the serotonin-transporter gene (5HTTLPR) in various psychiatric conditions have suggested that the association could be with an intermediate phenotype, impulsivity and/or violence rather than with a diagnosis. Schizophrenia is associated with a high risk of suicide, especially in(More)
This paper1 presents a geometry-based approach for multiple mobile robot motion coordination. The problem is to coordinate the motions of several robots moving along fixed independent paths to avoid mutual collisions. The proposed algorithm is based on a bounding box representation of the obstacles in the so-called coordination diagram. The algorithm is(More)
Autism is a complex neurodevelopmental disorder with severe cognitive and communication disabilities, that has a strong genetic predisposition. Reelin, a protein involved in neuronal migration during development, is encoded by a gene located on 7q22, within the candidate region on 7q showing increased allele sharing in previous genome scans. A case/control(More)
Abuse of cannabis is frequent among the young and is suspected to precipitate schizophrenia in vulnerable subjects. Cannabinoid receptor (CB1) is particularly concentrated in dopamine-modulated areas of the nervous system. An association between an AAT polymorphism of the CB1 gene and intravenous drug abuse has been previously reported, but not with(More)
Compared children (ages 8-18) with cancer (n = 24) and matched classroom control children (n = 24) using a modified version of the Revised Class Play (RCP). A wide variety of malignancies were represented, except brain tumors. Childrens' classroom teachers completed the RCP, an instrument modified to obtain teachers' impressions of three fundamental(More)
Evaluated the psychosocial adaptations of children with cancer (n = 24, ages 8-18) as compared with same classroom controls on indices of (a) peer- and self-perceptions of sociability, aggression, and social isolation; (b) overall popularity; (c) mutual friendships; (d) feelings of loneliness; and (e) self-concept in multiple domains. Although the peer(More)
Several schemes have been proposed in the path planning-literature to plan collision-free and feasible trajectories for non-holonomic mobile robots. A classical scheme is the two-step approach proposed in 4, 8, 5] which consists in rst computing a collision-free holonomic path, and then in transforming this path by a sequence of feasible ones. The quality(More)
This paper presents a geometric algorithm dealing with collision checking in the framework of multiple mobile robot coordination. We consider that several mobile robots have planned their own collision-free path by taking into account the obstacles, but ignoring the presence of other robots. We rst compute the domain swept by each robot when moving along(More)