Denis Gillet

Turning Web 2.0 Social Software into Versatile Collaborative Learning Solutions

In the framework of the European Integrated Project PALETTE, the Ecole Polytechnique Federale de Lausanne (EPFL) is developing the eLogbook Web 2.0 social software. The purpose of eLogbook is to support tacit and explicit knowledge management in communities of practice. It can be customized by the users to serve as an asset management system, as a task management system or as a discussion platform. In this paper, the innovative Computer-Human Interaction features of eLogbook are introduced and its deployment scenario to support collaborative laboratory activities in engineering education is described. The main idea is to sustain interaction for learning purpose within self-organized teams that integrate -on a seamless level- both human actors (students, teaching assistants) and non-human actors such as laboratory equipments or software agents.

Towards Ubiquitous Learning

This paper explores the effect of computerized scaffolding and different forms of scaffolds on small groups’ collaborative discourse. We developed a computerized scaffolding system that uses an attention management system to support metacognitive activities in small groups. We previously found that the scaffolding stimulates the group’ metacognitive activities and enhances individual metacognitive knowledge. Moreover different forms of scaffolds have differential effects on learning that cannot be explained by quantitative differences in the groups’ metacognitive activities. Therefore, we investigate to qualitative differences in the groups’ collaborative discourse in this study. We found that groups receiving scaffolding had significantly less ignored metacognitive episodes. Groups receiving problematizing scaffolds had significantly less ignored metacognitive episodes and more co-constructed metacognitive episodes compared to groups receiving structuring scaffolds. These findings indicate that scaffolding indeed positively influenced collaborative discourse and intensive collaborative discourse seems to explain the differential learning effects of different forms of scaffolds.

A social media platform in higher education

This paper reports on the successful use of Graasp, a social media platform, by university students for their collaborative work. Graasp features a number of innovations, such as administrator-free creation of collaborative spaces, a context-aware recommendation and privacy management. In the context of a EU-funded project involving large test beds, we have been able to extend this platform with lightweight tools (widgets) aimed for learning and competence development and to validate its usefulness in a collaborative learning context.

Towards an Online Lab Portal for Inquiry-Based STEM Learning at School

Nowadays, the knowledge economy is growing rapidly. To sustain future growth, more well educated people in STEM science, technology, engineering and mathematics are needed. In the Go-Lab project we aim to motivate and orient students from an early age on to study STEM fields in their future educational path by applying inquiry learning using online labs. This paper presents an inquiry learning portal where teachers can discover, use and enhance online labs appropriate for their courses and students can acquire scientific methodology skills while doing experiments using the labs. The Go-Lab portal architecture is presented, which contains a repository of online labs, inquiry learning spaces and complementary services. The paper discusses a first version of the portal and our future plans.

Perceiving Learning at a Glance: A Systematic Literature Review of Learning Dashboard Research

This paper presents a systematic literature review of the state-of-the-art of research on learning dashboards in the fields of Learning Analytics and Educational Data Mining. Research on learning dashboards aims to identify what data is meaningful to different stakeholders and how data can be presented to support sense-making processes. Learning dashboards are becoming popular due to the increased use of educational technologies, such as Learning Management Systems (LMS) and Massive Open Online Courses (MOOCs). The initial search of five main academic databases and GScholar resulted in 346 papers out of which 55 papers were included in the final analysis. Our review distinguishes different kinds of research studies as well as various aspects of learning dashboards and their maturity regarding evaluation. As the research field is still relatively young, most studies are exploratory and proof-of-concept. The review concludes by offering a definition for learning dashboards and by outlining open issues and future lines of work in the area of learning dashboards. There is a need for longitudinal research in authentic settings and studies that systematically compare different dashboard designs.

A recommender system for job seeking and recruiting website

In this paper, a hybrid recommender system for job seeking and recruiting websites is presented. The various interaction features designed on the website help the users organize the resources they need as well as express their interest. The hybrid recommender system exploits the job and user profiles and the actions undertaken by users in order to generate personalized recommendations of candidates and jobs. The data collected from the website is modeled using a directed, weighted, and multi-relational graph, and the 3A ranking algorithm is exploited to rank items according to their relevance to the target user. A preliminary evaluation is conducted based on simulated data and production data from a job hunting website in Switzerland.

Towards Portable Learning Analytics Dashboards

This paper proposes a novel approach to build and deploy learning analytics dashboards in multiple learning environments. Existing learning dashboards are barely portable: once deployed on a learning platform, it requires considerable effort to deploy the dashboard elsewhere. We suggest constructing dashboards from lightweight web applications, namely widgets. Our approach allows to port dashboards with no additional cost between learning environments that implement open specifications (Open Social and Activity Streams) for data access and use widget APIs. We propose to facilitate reuse by sharing the dashboards and widgets via a centralized analytics repository.

A musculoskeletal shoulder model based on pseudo-inverse and null-space optimization

The goal of the present work was assess the feasibility of using a pseudo-inverse and null-space optimization approach in the modeling of the shoulder biomechanics. The method was applied to a simplified musculoskeletal shoulder model. The mechanical system consisted in the arm, and the external forces were the arm weight, 6 scapulo-humeral muscles and the reaction at the glenohumeral joint, which was considered as a spherical joint. The muscle wrapping was considered around the humeral head assumed spherical. The dynamical equations were solved in a Lagrangian approach. The mathematical redundancy of the mechanical system was solved in two steps: a pseudo-inverse optimization to minimize the square of the muscle stress and a null-space optimization to restrict the muscle force to physiological limits. Several movements were simulated. The mathematical and numerical aspects of the constrained redundancy problem were efficiently solved by the proposed method. The prediction of muscle moment arms was consistent with cadaveric measurements and the joint reaction force was consistent with in vivo measurements. This preliminary work demonstrated that the developed algorithm has a great potential for more complex musculoskeletal modeling of the shoulder joint. In particular it could be further applied to a non-spherical joint model, allowing for the natural translation of the humeral head in the glenoid fossa.

Envelope tomography of long-period variable stars ?;?? III. Line-doubling frequency among Mira stars

This paper presents statistics of the line-doubling phenomenon in a sample of 81 long-period variable (LPV) stars of various periods, spectral types and brightness ranges. The set of observations consists of 315 high- resolution optical spectra collected with the spectrograph ELODIE at the Haute-Provence Observatory, during 27 observing nights at one-month intervals and spanning two years. When correlated with a mask mimicking a K0III spectrum, 54% of the sample stars clearly showed a double-peaked cross-correlation prole around maximum light, reflecting double absorption lines. Several pieces of evidence are presented that point towards the double absorption lines as being caused by the propagation of a shock wave through the photosphere. The observation of the Balmer lines appearing in emission around maximum light in these stars corroborates the presence of a shock wave. The observed velocity discontinuities, ranging between 10 and 25 km s 1 , are not correlated with the brightness ranges. A comparison with the center-of-mass (COM) velocity obtained from submm CO lines originating in the circumstellar envelope reveals that the median velocity between the red and blue peaks is blueshifted with respect to the COM velocity, as expected if the shock moves upwards. The LPVs clearly exhibiting line-doubling around maximum light with the K0III mask appear to be the most compact ones, the stellar radius being estimated from their eective temperatures (via the spectral type) and luminosities (via the period-luminosity relationship). It is not entirely clear whether or not this segregation between compact and extended LPVs is an artefact of the use of the K0III mask. Warmer masks (F0V and G2V) applied to the most extended and coolest LPVs yield asymmetric cross-correlation functions which suggest that line doubling is occurring in those stars as well. Although a rm conclusion on this point is hampered by the large correlation noise present in the CCFs of cool LPVs obtained with warm masks, the occurrence of line doubling in those stars is conrmed by the double CO v = 3 lines observed around 1.6 m by Hinkle et al. (1984, ApJS, 56, 1). Moreover, the H line in emission, which is another signature of the presence of shocks, is observed as well in the most extended stars, although with a somewhat narrower prole. This is an indication that the shock is weaker in extended than in compact LPVs, which may also contribute to the diculty of detecting line doubling in cool, extended LPVs.

Model predictive coordination of autonomous vehicles crossing intersections

This paper presents a decentralized model predictive control approach for the coordination of autonomous vehicles at intersections. A linear quadratic optimal controller is introduced for each vehicle with predefined path, in order to minimize energy as well as to pass intersection smoothly. We guarantee collision avoidance by adding linear constraints to the optimization problem. We apply the so-called soft constraints for the collision avoidance problem to reduce the computation time in order to be able to run the simulations in real-time. In addition, the method can take into account crossing of vehicles in platoons by extending the linear quadratic cost functions.