104 research outputs found
Multi-scenario modelling of learning
International audienceDesigning an educational scenario is a sensitive and challenging activity because it is the vector of learning. However, the designed scenario may not correspond to some learners’ characteristics (pace of work, cognitive styles, emotional factors, prerequisite knowledge, …). To personalize the learning task and adapt it gradually to each learner, several scenarios are needed. Adaptation and personalization are difficult because it is necessary on the one hand to know in advance the profiles and on the other hand to produce the multiple scenarios corresponding to these profiles. Our model allows to design many scenarios without knowing the learner profiles beforehand. Furthermore, it offers each learner opportunities to choose a scenario and to change it during their learning process. The model ensures that all announced objectives have enough resources for acquiring knowledge and activities for evaluation
Thermal and Non-thermal X-Rays from the LMC Super Bubble 30 Dor C
We report on the discovery of thermal and non-thermal X-rays from the shells
of the super bubble (SB) 30 Dor C in the Large Magellanic Cloud (LMC). The
X-ray morphology is a nearly circular shell with a radius of about 40 pc, which
is bright on the northern and western sides. The spectra of the shells are
different from region to region. The southern shell shows clear emission lines,
and is well fitted with a model of a thin-thermal plasma (kT = 0.21keV) in
non-equilibrium ionization (NEI) plus a power-law component. This thermal
plasma is located inside of the H alpha emission, which is the outer edge of
the shell of the SB. The northern and western sides of the SB are dim in H
alpha emission, but are bright in non-thermal (power-law) X-rays with a photon
index of 2.1-2.9. The non-thermal X-ray shell traces the outer boundary of the
radio shell. These features of thin-thermal and non-thermal X-rays are similar
to those of SN 1006, a prototype of synchrotron X-ray shell, but the
non-thermal component of 30 Dor C is about ten-times brighter than that of SN
1006. 30 Dor C is the first candidate of an extragalactic SB, in which
energetic electrons are accelerating in the shell. The age is much older than
that of SN 1006, and hence the particle acceleration time in this SB may be
longer than those in normal shell-like SNRs. We found point-like sources
associated with some of tight star clusters. The X-ray luminosity and spectrum
are consistent with those of young clusters of massive stars. Point-like
sources with non-thermal spectra are also found in the SB. These may be
background objects (AGNs) or stellar remnants (neutron stars or black holes).Comment: 11 pages, 6 figures, Accepted for publication in ApJ, the paper with
full resolution images in
http://www-cr.scphys.kyoto-u.ac.jp/member/bamba/Paper/30DorC.pd
Spitzer observations of the N157B supernova remnant and its surroundings
(Aims): We study the LMC interstellar medium in the field of the nebula
N157B, which contains a supernova remnant, an OB association, ionized gas, and
high-density dusty filaments in close proximity. We investigate the relative
importance of shock excitation by the SNR and photo-ionization by the OB stars,
as well as possible interactions between the supernova remnant and its
environment. (Methods): We apply multiwavelength mapping and photometry, along
with spatially resolved infrared spectroscopy, to identifying the nature of the
ISM using new infrared data from the Spitzer space observatory and X-ray,
optical, and radio data from the literature. (Results): The N157B SNR has no
infrared counterpart. Infrared emission from the region is dominated by the
compact blister-type HII region associated with 2MASS J05375027-6911071 and
excited by an O8-O9 star. This object is part of an extended infrared emission
region that is associated with a molecular cloud. We find only weak emission
from the shock-indicator [FeII], and both the excitation and the heating of the
extended cloud are dominated by photo-ionization by the early O stars of LH99.
(Conclusions): Any possible impact by the expanding SNR does not now affect the
extended cloud of molecules and dust, despite the apparent overlap of SNR X-ray
emission with infrared and Ha emission from the cloud. This implies that the
supernova progenitor cannot have been more massive than about 25 solar masses.Comment: 10 pages, 8 figures, published in A&
Integrating health behavior theory and design elements in serious games.
Background: Internet interventions for improving health and well-being have the potential to reach many people and fill gaps in service provision. Serious gaming interfaces provide opportunities to optimize user adherence and impact. Health interventions based in theory and evidence and tailored to psychological constructs have been found to be more effective to promote behavior change. Defining the design elements which engage users and help them to meet their goals can contribute to better informed serious games.
Objective: To elucidate design elements important in SPARX, a serious game for adolescents with depression, from a user-centered perspective.
Methods: We proposed a model based on an established theory of health behavior change and practical features of serious game design to organize ideas and rationale. We analyzed data from 5 studies comprising a total of 22 focus groups and 66 semistructured interviews conducted with youth and families in New Zealand and Australia who had viewed or used SPARX. User perceptions of the game were applied to this framework.
Results: A coherent framework was established using the three constructs of self-determination theory (SDT), autonomy, competence, and relatedness, to organize user perceptions and design elements within four areas important in design: computer game, accessibility, working alliance, and learning in immersion. User perceptions mapped well to the framework, which may assist developers in understanding the context of user needs. By mapping these elements against the constructs of SDT, we were able to propose a sound theoretical base for the model.
Conclusions: This study’s method allowed for the articulation of design elements in a serious game from a user-centered perspective within a coherent overarching framework. The framework can be used to deliberately incorporate serious game design elements that support a user’s sense of autonomy, competence, and relatedness, key constructs which have been found to mediate motivation at all stages of the change process. The resulting model introduces promising avenues for future exploration. Involving users in program design remains an imperative if serious games are to be fit for purpose
First absolute measurements of fast-ion losses in the ASDEX Upgrade tokamak
A new diagnostic technique that allows to obtain absolute fluxes of fast-ion losses measured with absolutely calibrated scintillator based fast-ion loss detectors (FILD) is presented here. First absolute fluxes of fast-ion losses have been obtained in the ASDEX Upgrade tokamak. An instrument function that includes the scintillator efficiency, collimator geometry, optical transmission and camera efficiency has been constructed. The scintillator response to deuterium ions in the relevant energy range of fast-ions has been characterized using a tandem accelerator. Absolute flux of neutral beam injection (NBI) prompt losses has been obtained in magnetohydrodynamic quiescent plasmas. The temporal evolution of the heat load measured with FILD follows that measured at the FILD entrance obtained with an Infra-Red camera looking at the FILD detector head. ASCOT simulations are in good agreement with the absolute heat load of NBI prompt losses measured with FILD.Ministerio de Economía, Industria y Competitividad RYC-2011-09152, FIS2015-69362-P, ENE2012-31087EUROfusion Consortium PCIG11-GA-2012- 321455Comunidad Europea de la Energía Atómica 63305
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