66 research outputs found

    Planification multi-niveaux avec expertise humaine

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    La planification automatique est un domaine de recherche de l Intelligence Artificielle qui vise à calculer automatiquement une séquence d actions menant d un état initial donné à un but souhaité. Cependant, résoudre des problèmes réalistes est généralement difficile car trouver un chemin solution peut demander d explorer un nombre d états croissant exponentiellement avec le nombre de variables. Pour faire face à cette explosion combinatoire, les algorithmes performants ont recours aux heuristiques ou à des solutions hiérarchiques, décomposant le problème en sous-problèmes plus petits et plus simples. Dans une grande majorité des cas, le planificateur doit prendre en compte un certain nombre de contraintes telles que des phases d actions prédéfinies ou des protocoles. Ces contraintes aident à résoudre le problème en élaguant un grand nombre de branches de l arbre de recherche. Nous proposons alors une nouvelle méthode pour modéliser et résoudre des problèmes de planification déterministe en se basant sur une approche hiérarchique et heuristique. Nous nous sommes inspirés des formalismes de programmation structurée afin de fournir à l utilisateur un cadre de travail plus intuitif pour la modélisation des domaines de planification hiérarchique. D autre part, nous avons proposé un algorithme de planification capable d exploiter ce formalisme et composer des stratégies à différents niveaux de granularité, ce qui lui permet de planifier rapidement une stratégie globale, tout en étant en mesure de pallier aux difficultés rencontrées à plus bas niveau. Cet algorithme a fait ses preuves face au principal planificateur HTN, SHOP2, sur des problèmes de planification classique.Automated planning is a field of Artificial Intelligence which aims at automatically computing a sequence of actions that lead to some goals from a given initial state. However, solving realistic problems is challenging because finding a solution path may require to explore an exponential number of states with regard to the number of state variables. To cope with this combinatorial explosion, efficient algorithms use heuristics, which guide the search towards optimistic or approximate solutions. Remarkably, hierarchical methods iteratively decompose the planning problem into smaller and much simpler ones. In a vast majority of problems, the planner must deal with constraints, such as multiple predefined phases or protocols. Such constraints generally help solving the planning problem, because they prune lots of search paths where these constraints do not hold. In this thesis, we assume that these constraints are known and given to the planner. We thus propose a new method to model and solve a deterministic planning problem, based on a hierarchical and heuristic approach and taking advantage of these constraints. We inspired ourselves from structured programming formalisms in order to offer a more intuitive modeling framework in the domain of hierarchical planning to the user. We also proposed a planning algorithm able to exploit this formalism and build strategies at various levels of granularity, thus allowing to plan quickly a global strategy, while still being able to overcome the difficulties at lower level. This algorithm showed its performances compared with the main HTN planner, SHOP2, on classical planning problems.TOULOUSE-ISAE (315552318) / SudocSudocFranceF

    Laparoscopic Cholecystectomy in Cirrhotic Patient

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    Cholecystectomy is associated with increased risk in patients with liver cirrhosis. Moreover, cirrhosis and portal hypertension have been considered relative or absolute contraindication to laparoscopic cholecystectomy. As experience with laparoscopic cholecystectomy increased, we decided to treat cirrhotic patients via this approach. Between January 1994 and April 1995, nine patients with a Child-Pugh's stage A cirrhosis underwent elective laparoscopic cholecystectomy with intraoperative cholangiography. There was no significant per- or post-operative bleeding and no blood transfusion was necessary. There was no mortality and very low morbidity. Median hospital stay was 3 days. This series suggests that wellcompensated cirrhosis can not be considered a contraindication to laparoscopic cholecystectomy

    Aggregate demand, idle time, and unemployment

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    This paper develops a model of unemployment fluctuations. The model keeps the architecture of the Barro and Grossman [1971] general disequilibrium model but replaces the disequilibrium framework on the labor and product markets by a matching framework. On the product and labor markets, both price and tightness adjust to equalize supply and demand. There is one more variable than equilibrium condition on each market, so we consider various price mechanisms to close the model, from completely flexible to completely rigid. With some price rigidity, aggregate demand influences unemployment through a simple mechanism: higher aggregate demand raises the probability that firms find customers, which reduces idle time for firms’ employees and thus increases labor demand, which in turn reduces unemployment. We use the comparative-statics predictions of the model together with empirical measures of quantities and tightnesses to re-examine the origins of labor market fluctuations. We conclude that (1) price and real wage are not fully flexible because product and labor market tightness fluctuate significantly; (2) fluctuations are mostly caused by labor demand and not labor supply shocks because employment is positively correlated with labor market tightness; and (3) labor demand shocks mostly reflect aggregate demand and not technology shocks because output is positively correlated with product market tightness

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Résultats du traitement des fistules anales par fistulectomie-drainage-sphinctérotomie (thèse)

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    NICE-BU Médecine Odontologie (060882102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

    Résultats à long terme de la colectomie sub-totale avec anastomose cæco-rectale pour inertie colique (thèse)

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    NICE-BU Médecine Odontologie (060882102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

    Fenestration par voie coelioscopique trans-péritonéale des kystes simples du rein (thèse)

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    NICE-BU Médecine Odontologie (060882102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

    Traitement chirurgical de la hernie inguinale chez la femme

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    NICE-BU Médecine Odontologie (060882102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

    Fenestration du kyste hépatique par voie coelioscopique (résultats à moyen terme)

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    NICE-BU Médecine Odontologie (060882102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

    Cure de rectocèle par remplacement prothétique de la cloison recto-vaginale (thèse)

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    NICE-BU Médecine Odontologie (060882102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF
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