Search results for "Modèle de simulation"
showing 3 items of 3 documents
Les modèles de simulation pour la planification de l'éducation en Afrique subsaharienne. Une simplicité appauvrissante et inféconde
2014
More than elsewhere, the issues covering educational planning are important in sub-Saharan Africa. Simulation models are the main tool of this type of planning. Most were designed or inspired by the World Bank or UNESCO. Yet, these models are too simplistic. This simplicity is a choice, although it is badly argued. The resulting vagueness is totally unacceptable, although imperceptible due to the simplicity of the models, which are not testable by facts. The simulation models are thus a sham and African educational systems continue to suffer grave imbalance in the allocation of resources. The conception of quality models, designed with a genuine concern to guide action, is possible and urge…
Morphological characterisation of soil structure in tilled fields: from a diagnosis method to the modelling of structural changes over time
2004
Characterisation of soit structure within the tilled layer of cultivated fields is crucial because the importance of this soil characteristic on the biological, chemical and physical properties of the soil and its repercussions on water cycle, root growth and functioning. We present in this paper a method for field characterisation of soil structure. This method, practised since the 1970s, was designed for field diagnosis of the effects of cropping systems on soil structure. It is based on a stratification of the observation face of a pit dug perpendicular to the direction of tillage and traffic: spatial compartments are distinguished, according to the nature of the mechanical stresses they…
La gestion des betteraves adventices résistantes à un herbicide: une approche par simulation
2007
National audience; Les variétés de betteraves sucrières génétiquement modifiées (GM) résistantes à un herbicide sont, a priori, intéressantes dans des champs fortement infestés par la betterave adventice. Cependant, la montée à fleurs de ces betteraves GM peut entraîner l’apparition d’individus résistants, via la dispersion de pollen. Nous avons développé et utilisé le modèle GENESYS-Betterave pour simuler, à l’échelle d’une petite région agricole, l’impact des pratiques culturales sur la dispersion du transgène. Il permet d'identifier des stratégies pour contrôler les adventices et limiter l'apparition de populations résistantes en zone de production de betterave sucrière. L’utilisation de…