2,958,149 research outputs found

    L’entrĂ©e dans l’écrit grĂące au nouveau moyen romand "des albums pour dire, lire, Ă©crire" et son appropriation par les enseignants de 1ere- 2e Harmos

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    Ce travail aborde l’entrĂ©e dans le monde de l’écrit chez les enfants de premiĂšre et de deuxiĂšme annĂ©e HarmoS. La sociĂ©tĂ© et l’école ont Ă©voluĂ© parallĂšlement. Ce qui Ă©tait appelĂ© « Ă©cole enfantine » fait maintenant, depuis l’introduction d’HarmoS, partie de la scolaritĂ© « primaire » et constitue les degrĂ©s un et deux, obligatoires pour les enfants dĂšs quatre ans. L’apprentissage de la lecture suscite de nombreux dĂ©bats depuis plusieurs dĂ©cennies. Plusieurs thĂ©ories se sont opposĂ©es durant le dernier siĂšcle pour arriver aujourd’hui aux approches interactives, qui concilient l’apprentissage de la lecture et de l’écriture. DĂšs le mois d’aoĂ»t 2012, les enseignants romands des deux premiers degrĂ©s ont dĂ» intĂ©grer dans leur classe le nouveau moyen en didactique du français : « Des albums pour dire, Ă©crire, lire. SĂ©quences didactiques » (Auvergne et al., 2011) (ci-aprĂšs « DEL »). Cette dĂ©marche rĂ©pond aux besoins de formation des jeunes Ă©lĂšves prĂ©vus par le Plan d’études romand (2010). « DEL » (2011) prĂ©sente l’entrĂ©e dans l’écrit sous un nouveau jour, en plaçant notamment l’élĂšve en situation d’écrivain. Ma recherche s’intĂ©resse particuliĂšrement Ă  l’appropriation de ce moyen par les enseignantes, ainsi qu’à la situation-problĂšme « Lecture/Ă©criture Ă©mergente » de la phase d’entrĂ©e dans l’écrit

    Elation KM-arcs

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    In this paper, we study KM-arcs in PG(2, q), the Desarguesian projective plane of order q. A KM-arc A of type t is a natural generalisation of a hyperoval: it is a set of q+t points in PG(2, q) such that every line of PG(2, q) meets A in 0, 2 or t points. We study a particular class of KM-arcs, namely, elation KM-arcs. These KM-arcs are highly symmetrical and moreover, many of the known examples are elation KM-arcs. We provide an algebraic framework and show that all elation KM-arcs of type q/4 in PG(2, q) are translation KM-arcs. Using a result of [2], this concludes the classification problem for elation KM-arcs of type q=4. Furthermore, we construct for all q = 2(h), h > 3, an infinite family of elation KM-arcs of type q/8, and for q=2(h), where 4, 6, 7 | h an infinite family of KM-arcs of type q/16. Both families contain new examples of KM-arcs

    Matheuristics for robust optimization: application to real-world problems

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    In the field of optimization, the perspective that the problem data are subject to uncertainty is gaining more and more interest. The uncertainty in an optimization problem represents the measurement errors during the phase of collecting data, or unforeseen changes in the environment while implementing the optimal solution in practice. When the uncertainty is ignored, an optimal solution according to the mathematical model can turn out to be far from optimal, or even infeasible in reality. Robust optimization is an umbrella term for mathematical modelling methodologies focused on finding solutions that are reliable against the data perturbations caused by the uncertainty. Among the relatively more recent robust optimization methodologies, an important concept studied is the degree of conservativeness, which can be explained as the amount of targeted reliability against the uncertainty while looking for a solution. Because the reliability and solution cost usually end up being conflicting objectives, it is important for the decision maker to be able to configure the conservativeness degree, so that the desired balance between the cost and reliability can be obtained, and the most practical solution can be found for the problem at hand. The robust optimization methodologies are typically proposed within the framework of mathematical programming (i.e. linear programming, integer programming). Thanks to the nature of mathematical programming, these methodologies can find the exact optimum, according to the various solution evaluation perspectives they have. However, dependence on mathematical programming might also mean that such methodologies will require too much memory from the computer, and also too much execution time, when large-scale optimization problems are considered. A common strategy to avoid the big memory and execution time requirements of mathematical programming is to use metaheuristic optimization algorithms for solving large problem instances.In this research, we propose an approach for solving medium-to-large-sized robust optimization problem instances. The methodology we propose is a matheuristic (i.e. a hybridization of mathematical programming and metaheuristic). In the matheuristic approach we propose, the mathematical programming part handles the uncertainty, and the metaheuristic part handles the exploration of the solution space. Since the exploration of the solution space is entrusted onto the metaheuristic search, we can obtain practical near-optimal solutions while avoiding the big memory and time requirements that might be brought by pure mathematical programming methods. The mathematical programming part is used for making the metaheuristic favor the solutions which have more protections against the uncertainty. Another important characteristic of the methodology we propose is concurrency with information exchange: we concurrently execute multiple processes of the matheuristic algorithm, each process taking the uncertainty into account with a different degree of conservativeness. During the execution, these processes exchange their best solutions. So, if a process is stuck on a bad solution, it can realize that there is a better solution available thanks to the information exchange, and it can get unstuck. In the end, the solutions of these processes are collected into a solution pool. This solution pool provides the decision maker with alternative solutions with different costs and conservativeness degrees. Having a solution pool available at the end, the decision maker can make the most practical choice according to the problem at hand. In this thesis, we first discuss our studies in the field of robust optimization: a heuristic approach for solving a minimum power multicasting problem in wireless actuator networks under actuator distance uncertainty, and a linear programming approach for solving an aggregate blending problem in the construction industry, where the amounts of components found in aggregates are subject to uncertainty. These studies demonstrate the usage of mathematical programming for handling the uncertainty. We then discuss our studies in the field of matheuristics: a matheuristic approach for solving a large-scale energy management problem, and then a matheuristic approach for solving large instances of minimum power multicasting problem. In these studies, the usage of metaheuristics for handling the large problem instances is emphasized. In our study of solving minimum power multicasting problem, we also incorporate the mechanism of information exchange between different solvers. Later, we discuss the main matheuristic approach that we propose in this thesis. We first apply our matheuristic approach on a well-known combinatorial optimization problem: capacitated vehicle routing problem, by using an ant colony optimization as the metaheuristic part. Finally, we discuss the generality of the methodology that we propose: we suggest that it can be used as a general framework on various combinatorial optimization problems, by choosing the most appropriate metaheuristic algorithm according to the nature of the problem

    Les Archives de l'Etat en 1975

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    Les mĂšres cĂ©libataires et l’insertion professionnelle

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    La monoparentalitĂ© est devenue chose courante. Environ 183'000 mĂ©nages en Suisse sont tenus par un parent seul, soit environ 5% des mĂ©nages selon la FĂ©dĂ©ration suisse des familles monoparentales (svamv.ch, 2013). Mais comment font ces parents pour alterner vie professionnelle et vie privĂ©e? Ces mĂ©nages sont souvent considĂ©rĂ©s comme prĂ©caires et leur taux de perception Ă  l’aide sociale est trĂšs Ă©levĂ©. Dans mon travail, j’ai identifiĂ© les facteurs qui freinent l’insertion dans le monde du travail des mĂšres cĂ©libataires. En effet, ces femmes sont trĂšs peu reprĂ©sentĂ©es sur le marchĂ© de l’emploi. Afin de trouver des Ă©lĂ©ments de rĂ©ponse, j’ai contactĂ© des employeurs du Valais romand, interviewĂ© des mĂšres cĂ©libataires et effectuĂ© une recherche documentaire. De plus, j’ai Ă©laborĂ© une mĂ©thodologie de coaching pour aider les mĂšres cĂ©libataires Ă  trouver un emploi satisfaisant.Die Einelternfamilie ist in der Gesellschaft immer hĂ€ufiger. UngefĂ€hr 183‘000 Haushalte. In der Schweiz haben einen einzigen Familienvorstand, das sind ungefĂ€hr 5% alle Haushalte (svamv.ch, 2013). Wie organisieren diese Eltern sich, um Berufs-­‐ und Privatleben in Einklang zu bringen? Diese Haushalte werden hĂ€ufig als gefĂ€hrdet angesehen und der Prozentsatz der SozialhilfeempfĂ€nger in dieser Bevölkerungsgruppe ist besonders hoch. In dieser Arbeit habe ich die Hauptfaktoren, die die Eingliederung alleinerziehende MĂŒtter in die Arbeitswelt hemmen, identifiziert. In der Tat sind diese Frauen in der Arbeitswelt unterreprĂ€sentiert. Um Teilantworten zu finden, habe ich mit Unterwalliser Arbeit gebern Kontakt aufgenommen, alleinerziehende MĂŒtter befragt und eine dokumentarische Befragung durchgefĂŒhrt. Schliesslich habe ich eine Coachingmethode erarbeitet, um alleinerziehenden MĂŒttern zu helfen, eine befriedigende Arbeitsstelle zu finden

    Tourisme rural: un potentiel à développer dans la région de Nyon

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    Ce travail rĂ©pond Ă  trois objectifs : le premier est de prĂ©senter le tourisme rural, connaĂźtre son historique et l’importance de ce secteur touristique aujourd’hui, le deuxiĂšme est de prendre connaissance du potentiel de la rĂ©gion de Nyon pour rĂ©pondre au troisiĂšme qui est de proposer une nouvelle offre touristique sur le tourisme rural. Les principaux rĂ©sultats montrent que le district de Nyon est pauvre en tourisme rural, plus spĂ©cialement dans le tourisme en zone agricole nommĂ© agritourisme. C’est donc un potentiel Ă  dĂ©velopper. Cependant, rĂ©ussir Ă  convaincre des agriculteurs de faire de l’agritourisme n’est pas une tĂąche aisĂ©e et les lois Ă  ce sujet ne sont pas incitatives
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