Designing and Assessing Interactive Systems Using Task Models (2015)

International audienceThis two-part course takes a practical approach to introduce the principles, methods and tools in task modelling. Part 1: A non-technical introduction demonstrates that task models support successful design of interactive systems. Part 2: A more technical interactive hands-on exercise of how to "do it right", such as: How to go from task analysis to task models? How to assess (through analysis and simulation) that a task model is correct? How to identify complexity of user tasks

Études de cas et benchmarks pour la modélisation des tâches

International audienceLes modèles de tâches occupent une place croissante en conception centrée utilisateur car ils permettent de représenter de façon détaillée les activités que les opérateurs doivent mettre en oeuvre pour atteindre leurs buts. Ces concepts étant de nos jours matures, la question de la comparaison des approches, de leur enseignement et de leur diffusion dans le tissu industriel correspond aux activités du groupe de travail modèles de tâches de l'AFIHM. http://gtmdt.afihm.or

Magnitude bias of microlensed sources towards the Large Magellanic Cloud

There are lines of evidence suggesting that some of the observed microlensing events in the direction of the Large Magellanic Cloud (LMC) are caused by ordinary star lenses as opposed to dark Machos in the Galactic halo. Efficient lensing by ordinary stars generally requires the presence of one or more additional concentrations of stars along the line of sight to the LMC disk. If such a population behind the LMC disk exists, then the source stars (for lensing by LMC disk objects) will be drawn preferentially from the background population and will show systematic differences from LMC field stars. One such difference is that the (lensed) source stars will be farther away than the average LMC field stars, and this should be reflected in their apparent baseline magnitudes. We focus on red clump stars: these should appear in the color-magnitude diagram at a few tenths of a magnitude fainter than the field red clump. Suggestively, one of the two near-clump confirmed events, MACHO-LMC-1, is a few tenths of magnitude fainter than the clump.Comment: To appear in ApJ Letters. Shortened to match the accepted version, 8 pages plus 1 ps figur

Microlens Parallax Asymmetries Toward the LMC

If the microlensing events now being detected toward the Large Magellanic Cloud (LMC) are due to lenses in the Milky Way halo, then the events should typically have asymmetries of order 1% due to parallax from the reflex motion of the Earth. By contrast, if the lenses are in the LMC, the parallax effects should be negligible. A ground-based search for such parallax asymmetries would therefore clarify the location of the lenses. A modest effort (2 hours per night on a 1 m telescope) could measure 15 parallax asymmetries over 5 years and so marginally discriminate between the halo and the LMC as the source of the lenses. A dedicated 1 m telescope would approximately double the number of measurements and would therefore clearly distinguish between the alternatives. However, compared to satellite parallaxes, the information extracted from ground-based parallaxes is substantially less useful for understanding the nature of the halo lenses (if that is what they are). The backgrounds of asymmetries due to binary-source and binary-lens events are estimated to be approximately 7% and 12% respectively. These complicate the interpretation of detected parallax asymmetries, but not critically.Comment: Submitted to ApJ, 17 pages, including 2 embedded figure

HAMSTERS : un environnement d’édition et de simulation de modèles de tâches

National audienceCet article décrit une démonstration concernant l’outil logiciel HAMSTERS (Human-centered Assessment and Modeling to Support Task Engineering for Resilient Systems). HAMSTERS est un outil logiciel de modélisation permettant d’éditer, de simuler et d’analyser des modèles de tâches basés sur la notation éponyme. HAMSTERS a été conçu et développé pour les besoins de projets de recherche industriels principalement dans les domaines de l’aéronautique et de l’espace