TaCS : une plate-forme collaborative à base de tags pour l'apprentissage

Cet article s'intéresse à l'usage des tags en éducation et notamment aux processus d'apprentissage qu'ils peuvent soutenir. Nous étudions les systèmes à base de tags existants pour montrer qu'ils n'exploitent pas toutes leurs possibilités pour favoriser l'apprentissage cognitif et social. Nous appuyant sur cette étude, nous proposons ensuite la plate-forme TaCS support à des activités d'apprentissage collaboratives et explicitons les processus d'apprentissage attendus lors de son utilisation. Nous présentons finalement les premiers résultats d'une expérimentation mettant en application un scénario d'apprentissage articulé avec les fonctionnalités de TaCS. Nous concluons par différentes perspectives d'utilisation des tags pour le développement d'EIAH

Modeling and Dimensioning Ground Heat Exchangers Principles: Influence of the soil's thermal proprieties

International audienceIn the context of energy crisis and global warming, heating buildings with the solar energy stored in the soil rep- resents a very interesting alternative. Moreover, cooling buildings can also use the soil damping capacity. This paper presents our reflexion about the modeling and dimensioning of the ground heat exchanger part of ground-coupled heat pumps (GCHP). After a physical overview of the ground heat exchanger, we extract from analytical solutions practical consequences of the soil damping behavior and limits that provide guidelines for the dimensioning. We then question the default values of the numerical tools thermal parameters used for the simulation of GCHP. We illustrate this issue through a TRNSYS dynamic simulation of GCHP, demonstrating that soil's thermal parameters have a strong impact on the results. Finally, we give some perspectives for the determination of soil's characteristics in situ, but indirectly, thanks to geophysical prospection methods as ground penetrating radar, electromagnetic induction, or electrical resistivity tomography.Dans un contexte de crise e ́nerge ́tique et de re ́chauffement climatique, le chauffage des baˆtiments graˆce a` l'e ́nergie solaire stocke ́e dans le sol est un principe inte ́ressant. De plus, les sondes ge ́othermiques utilise ́es pour extraire la chaleur du sol permettent aussi de l'y re ́injecter, et donc de refroidir les baˆtiments graˆce a` l'inertie thermique du sol. Cet article pre ́sente nos re ́flexions sur la mode ́lisation et le dimensionnement des e ́changeurs thermiques en faible profondeur couple ́s a` des pompes a` chaleur (PAC ge ́othermique). Apre`s une pre ́sentation de la physique sous-jacente aux e ́changeurs thermiques et des me ́thodes de re ́solution analytiques et nume ́riques, nous soulignons l'importance des valeurs des parame`tres thermiques du sol utilise ́es par les outils nume ́riques pour simuler les PAC ge ́othermiques. Nous illustrons cette question a` partir de re ́sultats de simulation dynamique TRNSYS : ceux-ci sont fortement influence ́s par les valeurs de conductivite ́ thermique du sol. Enfin, nous pre ́sentons un e ́tat de l'art des mesures de ces parame`tres thermiques in situ et sugge ́rons quelques me ́thodes ge ́ophysiques pour les de ́terminer indirectement, parmi lesquelles le ge ́oradar, l'induction e ́lectromagne ́tique et la tomographie e ́lectrique. La forte empreinte de la teneur en eau sur la thermique des sols permettrait en effet d'estimer leurs caracte ́ristiques thermiques via des mesures de conductivite ́ e ́lectrique ou de permittivite ́ die ́lectrique, elles aussi relie ́es a` la teneur en eau du milieu

Factors to Consider for Tailored Gamification

International audienceGamification is widely used to foster user motivation. Recent studies show that users can be more or less receptive to different game elements, based on their personality or player profile. Consequently, recent work on tailored gamification tries to identify links between user types and motivating game elements. However findings are very heterogeneous due to different contexts, different typologies to characterize users, and different implementations of game elements. Our work seeks to obtain more generalizable findings in order to identify the main factors that will support design choices when tailoring gamification to users' profiles and provide designers with concrete recommendations for designing tailored gamification systems. For this purpose, we ran a crowdsourced study with 300 participants to identify the motivational impact of game elements. Our study differs from previous work in three ways: first, it is independent from a specific user activity and domain; second, it considers three user typologies; and third, it clearly distinguishes motivational strategies and their implementation using multiple different game elements. Our results reveal that (1) different implementations of a same motivational strategy have different impacts on motivation, (2) dominant user type is not sufficient to differentiate users according to their preferences for game elements, (3) Hexad is the most appropriate user typology for tailored gamification and (4) the motiva-tional impact of certain game elements varies with the user activity or the domain of gamified systems

Efficient Decomposition of Image and Mesh Graphs by Lifted Multicuts

Formulations of the Image Decomposition Problem as a Multicut Problem (MP) w.r.t. a superpixel graph have received considerable attention. In contrast, instances of the MP w.r.t. a pixel grid graph have received little attention, firstly, because the MP is NP-hard and instances w.r.t. a pixel grid graph are hard to solve in practice, and, secondly, due to the lack of long-range terms in the objective function of the MP. We propose a generalization of the MP with long-range terms (LMP). We design and implement two efficient algorithms (primal feasible heuristics) for the MP and LMP which allow us to study instances of both problems w.r.t. the pixel grid graphs of the images in the BSDS-500 benchmark. The decompositions we obtain do not differ significantly from the state of the art, suggesting that the LMP is a competitive formulation of the Image Decomposition Problem. To demonstrate the generality of the LMP, we apply it also to the Mesh Decomposition Problem posed by the Princeton benchmark, obtaining state-of-the-art decompositions

KM and WEB 2.0 methods for project-based learning. MESHAT : a monitoring and experience sharing tool

Our work aims at studying tools offered to learners and tutors involved in face-to-face or blended project-based learning activities. To understand better the needs and expectations of each actor, we are especially interested in the specific case of project management training. The results of a course observation show that the lack of monitoring and expertise transfer tools involves important dysfunctions in the course organisation and therefore dissatisfaction for tutors and students (in particular about the acquisition of knowledge and expertise). So as to solve this problem, we propose a personalised platform (according to the actor: project group, student or tutor), which gives information to monitor activities and supports the acquisition and transfer of expertise. This platform is based on Knowledge Management (KM) and Web 2.0 concepts to support the dynamic building of knowledge. KM is used to define the learning process (based on the experiential learning theory) and the way the individual knowledge building is monitored (based on metacognitive concepts). Web 2.0 is used to define the way the experience is shared. We make the hypothesis that this approach improves the acquisition of complex skills (e.g. management, communication and collaboration), which requires a behavioural evolution. We aim at making the students become able 'to learn to learn' and evolve according to contexts. We facilitate their ability to have a critical analysis of their actions according to the situations they encounter.Comment: arXiv admin note: substantial text overlap with arXiv:0911.031

Meshat: Monitoring and Experience Sharing Tool for Project-Based Learning

Our work aims at studying tools offered to learners and tutors involved in face-to-face or blended project-based learning activities. To understand better the needs and expectations of each actor, we are especially interested in the specific case of project management training. The results of a course observation show that the lack of monitoring and expertise transfer tools involves important dysfunctions in the course organisation and therefore dissatisfaction for tutors and students (in particular about the acquisition of knowledge and expertise). So as to solve this problem, we propose a personalised platform (according to the actor: project group, student or tutor) which gives information to monitor activities and supports the acquisition and transfer of expertise. This platform is meant for the complex educational context of project-based learning. Indeed, as for the majority of project-based learning activities, the articulation conceptualisation-experiment is an important part of the process. The originality of our approach relies on also supporting the articulation between action (experiment or conceptualisation) and reflection. This approach so improves the acquisition of complex skills (e.g. management, communication and collaboration), which requires a behavioural evolution. We aim at making the students become able ?to learn to learn' and evolve according to contexts. We facilitate their ability to have a critical analysis of their actions according to the situations they encounter.Comment: 8

Defining Engagement and Characterizing Engaged-Behaviors in Digital Gaming

International audienceBackground. Although the analysis of engagement is crucial for digital entertainment or learning games, the concept of players' or learners' engagement is still confusing. Indeed, in digital games research, several concepts referring to the idea of engagement such as immersion, involvement, presence, and flow are used. Also, while the characterization of engaged-behaviors may be useful for designers or teachers in assessing players' or learners' engagement, the nature and the scope of these behaviors are still unclear. Aim. In this article, based on a multidisciplinary state of the art on the concept of engagement, we define and delineate the concepts related to digital gaming engagement. Results. We characterize engaged-behaviors by identifying four types of engagement: environmental, social, self, and action. We thus refine, disambiguate, and characterize the concepts of engagement and engaged-behaviors. This work therefore constitutes an effective support for analyzing, designing, assessing, and personalizing engaging activities in digital games

Adaptive coarse-to-fine quantization for optimizing rate-distortion of progressive mesh compression

International audienceWe propose a new connectivity-based progressivecompression approach for triangle meshes. The keyidea is to adapt the quantization precision to the resolutionof each intermediate mesh so as to optimizethe rate-distortion trade-off. This adaptation is automaticallydetermined during the encoding processand the overhead is efficiently encoded using geometricalprediction techniques. We also introducean optimization of the geometry coding by usinga bijective discrete rotation. Results show that ourapproach delivers a better rate-distortion behaviorthan both connectivity-based and geometry-basedcompression state of the art method