La raquette à neige (Présence et fabrication au Canada français

Québec Université Laval, Bibliothèque 201

Réalisation d'un banc d'essai pour l'étude d'architectures de systèmes RF intelligents

Le concept des systèmes RF intelligents présenté dans ce mémoire de maîtrise cible la partie radiofréquence (RF) des circuits électroniques dans les appareils de télécommunication sans fil. Le mémoire est axé sur la réalisation d'un banc d'essai pour vérifier des circuits, des architectures ou des idées en relation aux systèmes RF intelligents. La première partie du document est consacrée à une revue de littérature sur les systèmes RF intelligents afin de faire le point sur ce sujet relativement nouveau et d'énoncer les besoins pour définir l'architecture du banc d'essai. La deuxième partie est dédiée à la réalisation du banc d'essai qui est composé d'un mélange de systèmes commerciaux et d'un circuit imprimé fait pendant la maîtrise. La dernière partie porte sur la vérification du fonctionnement du banc d'essai et sur deux applications réalisées avec ce dernier. Le mémoire constitue donc un document de référence contenant des informations sur les systèmes RF intelligents

Learning Obstacle Representations for Neural Motion Planning

Motion planning and obstacle avoidance is a key challenge in robotics applications. While previous work succeeds to provide excellent solutions for known environments, sensor-based motion planning in new and dynamic environments remains difficult. In this work we address sensor-based motion planning from a learning perspective. Motivated by recent advances in visual recognition, we argue the importance of learning appropriate representations for motion planning. We propose a new obstacle representation based on the PointNet architecture and train it jointly with policies for obstacle avoidance. We experimentally evaluate our approach for rigid body motion planning in challenging environments and demonstrate significant improvements of the state of the art in terms of accuracy and efficiency.Comment: CoRL 2020. See the project webpage at https://www.di.ens.fr/willow/research/nmp_repr

Viện Tim Institut du Coeur: Success of a Congenital Heart Disease Center in a Developing Country

ObjectiveThe goal of the Viện Tim Institute du Coeur is to provide high quality cardiac surgical care to the Vietnamese population with 25% of care allocated to the indigent. This article discusses the history; functional and financial implementation of creating a long-term fully sustainable adult and pediatric cardiac surgery center in Southeast Asia in a developing country.MethodsThe Institut du Coeur in Ho Chi Minh City, Vietnam is a fully functional and financially solvent cardiac surgery center that was formed 28 years ago. It was borne from the Alain Carpentier Foundation which oversees its activity and the Centre Médical International which is an outpatient clinic in Ho Chi Minh City and continues to financially support and oversee the development and future of the Institute. This article details many of the key components to the development of this sustainable program and its evolution.ResultsSince 1996, over 25,000 patients with complicated adult and congenital cardiac disease have been treated at the infirmary with support from the Alain Carpentier Foundation since it was established in 1992. The hospital has also performed surgery and treatment to poor patients across Vietnam with over 6,700 impoverished patients having had free operations with an estimated cost of VND230 billion (US$10.2 million). In addition, 96 surgeons and nearly 500 medical staff have carried out charitable health checks on 12,000 patients in many provinces and cities throughout Vietnam. Through profit sharing with the Centre Médical International and corporate and personal donations, proceeds are given to the Institute to help perform roughly 25% of all cardiac surgery free of charge to indigent patients in need of congenital heart surgery.ConclusionThe Viện Tim Institute du Coeur has stayed true to its goal of offering high quality cardiac surgical care including congenital heart surgery to a large patient population with one quarter directed to the medically indigent. It also continues to empower and train the health care professionals locally and throughout the country. Creation and growth through this model may help provide a fully functional and financially self-sustaining institution in a developing nation

Matching unrelated stimuli with same discriminative functions: training order effects

Previous research has shown that after training simple discriminations (A1+/A2-, B1+/B2-), bringing these tasks under conditional control (J1-A1, J2-A2) leads to transfer of discriminative control (J1+/J2-) and to generalized matching on the basis of same discriminative functions (e.g. J1-B1, J2-B2). The same occurs when conditional discriminations are trained (D1-E1, D2-E2; F1-G1, F2-G2). When the subjects are then trained to demonstrate correct relations (D1-E1, D2-E2) when given X1 and to demonstrate incorrect relations when given X2 (XD-E), transfer of discriminative control (X1+/X2-) and generalized matching on the basis of same discriminative functions emerges (e.g. X1F1-G1, X2F1-G2). The present study investigated if these performances are dependent on the training and/or testing order. In Experiment 1, the lower-order contingency tasks were trained before the higher-order contingency tasks (A1+/A2-, B1+/B2- before J-A, and D-E, F-G before XD-E). Half the subjects received the J-B test before the more complex XF-G test (Condition A), while for the other subjects, this testing order was reversed (Condition B). Finally, all subjects received additional tests in which they were given the opportunity to demonstrate the discriminative properties of the J and X stimuli (J1+/J2-, X1+/X2-), and to match the A, J, and X stimuli with newly introduced stimuli of same discriminative properties (e.g. J1-POLITE, J2-RUDE). Experiment 2 was the same except that the training order was reversed (J-A before A1+/A2-, B1+/B2-, and XD-E before D-E, F-G). The results were affected by the training order but not by the testing order. Transfer of discriminative functions and generalized matching on the basis of same functions only occurred reliably when the lower-order contingency tasks were trained first. A stimulus-control account of the data is offered

Equivalence-equivalence as a model of analogy: Further analyses

Equivalence-equivalence is assumed when training of A-B and A-C matching tasks not only leads to matching same-class B and C stimuli but also to matching BC compounds with same-class elements (e.g., B1 C1-B2C2) and with different-class elements (e.g., B1C2-B2C3). Like classical analogies (a : b :: c : d), equivalence-equivalence requires matching same functional relations. Experiments 1 to 4 examined equivalence-equivalence in 5-year-old children. In each experiment, subjects were tested for equivalence-equivalence before equivalence and, if they did not show equivalence-equivalence, also after the equivalence test. The experiments included various procedural arrangements designed to facilitate equivalence-equivalence, all of which failed. Only 8/18 children showed equivalence-equivalence, 2 before (11%) and 6 after equivalence (33%), irrespective of the facilitative procedures that were used. Adults served in Experiment 5. This experiment was the same as Experiments 1 through 4 but without facilitative arrangements. All adults showed equivalence-equivalence, most of them before equivalence. These and previously collected findings (Carpentier, Smeets, & Barnes-Holmes, 2002) suggest that equivalence-equivalence is an age-related performance similar to that which has been reported in earlier developmental studies on classical analogies. Yet, one should be cautious using equivalence-equivalence as a model for analogical reasoning. The testing procedures in both types of tasks are sufficiently different to permit the performances to be based on different behavioral processes

Learning Obstacle Representations for Neural Motion Planning

International audienceMotion planning and obstacle avoidance is a key challenge in robotics applications. While previous work succeeds to provide excellent solutions for known environments, sensor-based motion planning in new and dynamic environments remains difficult. In this work we address sensor-based motion planning from a learning perspective. Motivated by recent advances in visual recognition, we argue the importance of learning appropriate representations for motion planning. We propose a new obstacle representation based on the PointNet architecture [1] and train it jointly with policies for obstacle avoidance. We experimentally evaluate our approach for rigid body motion planning in challenging environments and demonstrate significant improvements of the state of the art in terms of accuracy and efficiency

Horizontal and vertical diversity jointly shape food web stability against small and large perturbations

The biodiversity of food webs is composed of horizontal (i.e. within trophic levels) and vertical diversity (i.e. the number of trophic levels). Understanding their joint effect on stability is a key challenge. Theory mostly considers their individual effects and focuses on small perturbations near equilibrium in hypothetical food webs. Here, we study the joint effects of horizontal and vertical diversity on the stability of hypothetical (modelled) and empirical food webs. In modelled food webs, horizontal and vertical diversity increased and decreased stability, respectively, with a stronger positive effect of producer diversity on stability at higher consumer diversity. Experiments with an empirical plankton food-web, where we manipulated horizontal and vertical diversity and measured stability from species interactions and from resilience against large perturbations, confirmed these predictions. Taken together, our findings highlight the need to conserve horizontal biodiversity at different trophic levels to ensure stability