3,083 research outputs found
The Domino Inequalities: Facets for the Symmetric Traveling Salesman Polytope
No full textAdam Letchford defines in [4] the Domino Parity inequalities for the Symmetric Traveling Salesman Polytope (STSP) and gives a polynomial algorithm for the separation of such constraints when the support graph is planar, generalizing a result of Fleischer and Tardos [2] for maximally violated comb inequalities. Naddef in [5] gives a set of necessary conditions for such inequalities to be facet defining for the STSP. These conditions lead to the Domino inequalities and it is shown in [5] that one does not lose any facet inducing inequality restricting the Domino Parity inequalities to Domino inequalities, except maybe for some very particular case. We prove here that all the domino inequalities are facet inducing for the STSP, settling the conjecture given in [5]. As a by product we will also have a complete proof that the comb inequalities are facet inducing
Contrasting activity profile of two distributed cortical networks as a function of attentional demands
No full textThe original publication is available at http://www.jneurosci.orgThis work was supported by R01 grant MH-073610 from the National Institutes of Health to Denis Paré
The Symmetric Traveling Salesman Polytope : New Facets from the Graphical Relaxation
No full textInternational audienceThe path, the wheelbarrow, and the bicycle inequalities have been shown by Cornuéjols, Fonlupt, and Naddef to be facetdefining for the graphical relaxation of STSP(n), the polytope of the symmetric traveling salesman problem on an n-node complete graph. We show that these inequalities, and some generalizations of them, define facets also for STSP(n). In conclusion, we characterize a large family of facet-defining inequalities for STSP(n) that include, as special cases, most of the inequalities currently known to have this property as the comb, the clique tree, and the chain inequalities. Most of the results given here come from a strong relationship of STSP(n) with its graphical relaxation that we have pointed out in another paper, where the basic proof techniques are also described
Is Tolerance Political? An Interview with Denis Lacorne
No full textcontribution à un site webDenis Lacorne is the author of "The Limits of Tolerance. Enlightenment Values and Religious Fanaticism" (Columbia University Press, 2019), the English translation of "Les limites de la tolérance" (Gallimard, awarded the Prix Montyon by the Académie Française). In his book, which is intellectually very inspiring because of the many questions it addresses and raises, Denis Lacorne traces the emergence of the notion of tolerance from its early thinkers to the Age of Enlightenment and finally questions the notion and its various understandings through more recent events in France and the United States. What is tolerance? Is tolerance political? Interview by Miriam Périer, CER
Contribution théorique et numérique à la résolution du problème du Voyageur de Commerce
No full textROSOThèse, INPG, Recherche Opérationnelle, Combinatoire et Optimisation, Laboratoire Informatique et Distribution (UMR 5132). Ecole Doctorale "Mathématiques, Sciences et Technologies de l'Information, Informatique". - Membre du Jury: Thomas Liebling ... et al
Timing of impulses from the central amygdala and bed nucleus of the stria terminalis to the brainstem
No full textThe amygdala and bed nucleus of the stria terminalis (BNST) are thought to subserve distinct functions with the former mediating rapid fear responses to discrete sensory cues and the latter longer “anxiety-like” states in response to diffuse environmental contingencies. Yet, these structures are reciprocally connected and their projection sites overlap extensively. To shed light on the significance of BNST-amygdala connections, we compared the antidromic response latencies of BNST and central amygdala (CE) neurons to brainstem stimulation. Whereas the frequency distribution of latencies was unimodal in BNST neurons (~10 ms mode), that of CE neurons was bimodal (~10 and ~30 ms modes). However, after stria terminalis (ST) lesions, only short-latency antidromic responses were observed, suggesting that CE axons with long conduction times course through the ST. Compared to the direct route, the ST greatly lengthens the path of CE axons to the brainstem, an apparently disadvantageous arrangement. Since BNST and CE share major excitatory basolateral amygdala (BL) inputs, lengthening the path of CE axons might allow synchronization of BNST and CE impulses to brainstem when activated by BL. To test this, we applied electrical BL stimuli and compared orthodromic response latencies in CE and BNST neurons. The latency difference between CE and BNST neurons to BL stimuli approximated that seen between the antidromic responses of BNST cells and CE neurons with long-conduction times. These results point to a hitherto unsuspected level of temporal coordination between the inputs and outputs of CE and BNST neurons, supporting the idea of shared functions.The original publication is available at: http://jn.physiology.org/cgi/content/full/100/6/342
Rehab Depot de la Plaine Saint-Denis
No full textRedesign for workshop Atelier Revision Intermediaire at the Depot de la Plaine Saint-Denis with a rehabilitation center as new functionRMITArchitecture and The Built Environmen
Severini e Denis
No full textL'A. prende in esame i controversi rapporti tra i due artisti, nel primo decennio del secolo e, più tardi, nella produzione di carattere religioso. Severini risulta influenzato da Denis più di quanto sostenga negli scritti teorici. The Author examines the controversial relationships between the two artists, in the first decade of the century and later on, in their religious production. Severini appears influenced by Denis more than he declares in his theoretic writings
Polyèdres et structures combinatoires
No full textUniversité : Université scientifique et médicale de GrenobleOn établit la dimension de l'enveloppe convexe des couplages maximums d'un graphe, avec un résultat sur le cas des couplages parfaits. On étudie le squelette des polytopes. On démontre que si chaque sommet du polytope peut être représenté par un vecteur à valeurs 0 ou 1 alors ce squelette est soit un hypercube soit Hamilton connexe. On considère le polyèdre associé au problème du voyageur de commerce. Une méthode de décomposition permet de décrire entièrement ce polyèdre dans un cas particulier. Pour une version dite graphique de ce problème, on donne un ensemble d'inéquations nécessaires a la description du polyèdre associé
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