288 research outputs found
Une analyse des écrits sur les impacts du jeu sur l’apprentissage
Cet article présente une synthèse des publications récentes (1998-2005) qui traitent des impacts du jeu, en tant que formule pédagogique, sur l’apprentissage. Constatant une grande variété d’approches, une certaine disparité dans la manière de présenter et d’interpréter les résultats, et souhaitant vérifier si les jeux éducatifs ont un impact réel sur l’apprentissage, les auteurs ont procédé à une recension des écrits sur le sujet à partir d’une grille d’analyse validée. Ces impacts sont détaillés après un résumé des attributs essentiels du jeu, attributs sur lesquels cette recherche a été fondée pour être menée à bien. L’analyse des écrits montre que le jeu a des impacts positifs sur l’apprentissage.This article presents a synthesis of recent (1998-2005) publications on the impact of play, as a pedagogical technique, on learning. While confirming that there are a great number of approaches, a certain disparity in the way of presenting and interpreting results, and hoping to verify if educational games have a real impact on learning, the authors used a validated analysis grid to produce a review of the literature in this area. The authors present a summary of the essential attributes of games, these attributes being used to frame this research, as well as details regarding the impacts noted. The analysis shows that play has positive impacts on learning.Este artÃculo presenta una sÃntesis de las publicaciones recientes (1998-2005) que tratan de los impactos del juego, como formula pedagógica, sobre el aprendizaje. Al observar una gran variedad de enfoques, una cierta disparidad en la manera de presentar y de interpretar los resultados, y con el deseo de comprobar si los juegos educativos tienen un real impacto sobre el aprendizaje, los autores procedieron a una recensión de los escritos sobre el tema a partir de una matriz de análisis validada. Estos impactos se detallan a continuación de un resumen de los atributos esenciales del juego, atributos que fundamentaron esta investigación para poder llevarla a cabo. El análisis de los escritos muestra que el juego tiene impactos positivos sobre el aprendizaje
The nature of damped HI absorbers probed by cosmological simulations: satellite accretion and outflows
We use state-of-the-art cosmological zoom simulations to explore the
distribution of neutral gas in and around galaxies that gives rise to high
column density \ion{H}{i} \mbox{Ly-} absorption (formally, sub-DLAs and
DLAs) in the spectra of background quasars. Previous cosmological hydrodynamic
simulations under-predict the mean projected separations of these
absorbers relative to the host, and invoke selection effects to bridge the gap
with observations. On the other hand, single lines of sight (LOS) in absorption
cannot uniquely constrain the galactic origin. Our simulations match all
observational data, with DLA and sub-DLA LOS existing over the entire probed
parameter space ([M/H], kpc) at all redshifts
(). We demonstrate how the existence of DLA LOS at kpc from a massive host galaxy require high numerical resolution, and
that these LOS are associated with dwarf satellites in the main halo, stripped
metal-rich gas and outflows. Separating the galaxy into interstellar
("\ion{H}{i} disc") and circumgalactic ("halo") components, we find that both
components significantly contribute to damped \ion{H}{i} absorption LOS. Above
the sub-DLA (DLA) limits, the disc and halo contribute with and
per cent, respectively. Our simulations confirm analytical
model-predictions of the DLA-distribution at . At high redshift
() sub-DLA and DLAs occupy similar spatial scales, but on average
separate by a factor of two by . On whether sub-DLA and DLA LOS
sample different stellar-mass galaxies, such a correlation can be driven by a
differential covering-fraction of sub-DLA to DLA LOS with stellar mass. This
preferentially selects sub-DLA LOS in more massive galaxies in the low-
universe.Comment: 12 pages, 5 figures, submitted to MNRAS 29/01/201
Points chauds sur la ville. La géographie urbaine au défi de la métropolisation ?
National audienceThis paper aims at identifying and discussing, within the theoretical framework of metropolisation, some issues that might be part of a renewed urban geography teaching, and thus research. Among other issues : How to deal with a growing complexity of phenomena linked to metropolisation ? How do we integrate the issues ofexplicit causality in explaining social urban patterns, asexplained by the dual city hypothesis (S. Sassen) ? Howcan we put forward the complexity of actors interplays ?Cette contribution vise à identifier, dans le contexte de la métropolisation, quelques problématiques sur la ville à approfondir dans l'enseignement, et par là même dans la recherche, selon trois axes : comment rendre compte de la complexité des phénomènes liés à la métropolisation ? comment expliciter une division sociale de l'espace souvent rattachées à la métropolisation par des causalités directes (dualisation sociale, comme le propose S. Sassen) ? comment enfin mettre en évidence la complexité des jeux d'acteurs
Urban damage assessment using multimodal QuickBird images and ancillary data: the Bam and the Boumerdes earthquakes
International audienceRemote sensing has proved its usefulness for the crisis mitigation through situation report and damage assessment. Visual analysis of satellite images is conducted by analysts, however automatic or decision aid method are desired. We propose a semi-automatic damage assessment method based on a pair of very high spatial resolution (VHR) images and some ancillary data. It is applied to two disaster cases, for which the QuickBird images acquisition conditions differ. For each case, the two images also have very different viewing and illumination angles. Hence their comparison requires a preliminary registration; an automatic method adapted to VHR images is described. Then several change features are extracted from the buildings, and their relevance to assess damage on buildings is evaluated. Some textural features allow a damage assessment, but correlation coefficients are more efficient. Finally, a step toward the full automation of the method is done, skipping the supervision step of the classification process. We show the robustness of the global approach for both disaster cases with average performances closed to 75 % when 4 damage classes are discriminated, up to 90 % for a intact/damaged detection
An object oriented approach for quantitative assessment of building damage in urban areas using very high resolution images
ISBN 1-4244-0712-5International audienceVery high resolution images are particularly well adapted to damage assessment methodology in urban area because on one hand it allows an analysis focused on the buildings solely through an object-oriented analysis, and on the other hand it permits a quantitative evaluation of this damage assessment using a visually established ground truth. We propose in this paper a method of damage assessment that uses these two benefits. First an original object oriented approach to register the images is presented. Then a simple and fast damage assessment method based on correlation is proposed and tested on the test-case of the earthquake of Bam in December 2003. Each building of a test-area is classified using Support Vector Machines. The performance of the method in each case is evaluated thanks to a manually constructed reference database that uses the European Macroseismic Scale. As a result, 75% of buildings are well classified among four different EMS damage grades
Damage assessment on buildings using very high resolution multimodal images and GIS
Satellite images are more and more used to prevent natural disasters and mitigate their impact on populations. Their analysis is usually manually conducted by operators. Automatic processing of very high resolution (VHR) images is critical when the images to analyse are acquired with very different acquisition angles; however, this situation is frequent in an operational scope of a natural disaster. We propose a method to assess damage on buildings using a pair of VHR images whose dates of acquisition encompass the disaster, and a geographical information system that contains the buildings footprints. It takes into account the acquisition parameters of the images. We assess its robustness as a function of the difference between the acquisition angles of the images. For this purpose, we adopt the framework of an operational scope and use six different VHR images that have been acquired successively before and during the period of interest. We show that the rate of false-alarms increases with this difference of acquisition angles. However, even in extreme conditions, damaged buildings are well detected. Our methodology leads to a global performance of the damage detection from 69 % with a difference angle of 80o, to 90 % for a difference angle around 24o
Object oriented assessment of damage due to natural disaster using very high resolution images
ISBN 978-1-4244-1211-2International audienceA building damage assessment method applied to the case of the earthquake of Bam is proposed in this paper. It uses two very high resolution images and focuses on the footprints of the buildings. The need of an accurate registration of the buildings is demonstrated; a registration method that improved the damage assessment is proposed. It allows a classification performance of the buildings among four damage grades up to 78%. The impact of a lower accuracy of the buildings roofs segmentation is evaluated; we show that it mainly leads to a decrease of the capacity to identify the partial damage on buildings
Introduction
Considérer les médias numériques comme des techniques susceptibles de générer de l’innovation est un argument régulièrement convoqué par les institutions patrimoniales pour présenter et soutenir le déploiement de politiques de numérisation ou de mise en place d’outils et de logiciels informatiques de médiation patrimoniale. Pour exemple, les appels d’offre concernant la mise en place de services culturels innovants accordent une large place à ces techniques, devenant quasi-incontournables lor..
Introduction
Considérer les médias numériques comme des techniques susceptibles de générer de l’innovation est un argument régulièrement convoqué par les institutions patrimoniales pour présenter et soutenir le déploiement de politiques de numérisation ou de mise en place d’outils et de logiciels informatiques de médiation patrimoniale. Pour exemple, les appels d’offre concernant la mise en place de services culturels innovants accordent une large place à ces techniques, devenant quasi-incontournables lor..
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