Flexibility in MDE for scaling up from simple applications to real case studies: illustration on a Nuclear Power Plant

International audienceModel Driven Engineering provides powerful solutions for the development of User Interfaces. However, concepts and techniques are difficult to master and to apply: the threshold of use is said to be high, making designers and developers reluctant to use it. This paper investigates process model flexibility as a solution. We present three kinds of flexibility for improving design and development process models: (1) variability for equivalent choices, (2) granularability for several levels of details, (3) completeness for possibly optional and pre-defined reusable components. Flexibility decreases the threshold of use by reusability of knowledge, know-how and pieces of code. We illustrate these forms of flexibility on an industrial case study from the nuclear power plant domain. We explain how they are implemented in FlexiLab, a running prototype based on OSGi. The innovation is twofold: on one hand, the operationalization of flexibility; on the other hand, the jump from simple applications to real case studies thanks to flexibility

Comparison of XH_2O Retrieved from GOSAT Short-Wavelength Infrared Spectra with Observations from the TCCON Network

Understanding the atmospheric distribution of water (H_2O) is crucial for global warming studies and climate change mitigation. In this context, reliable satellite data are extremely valuable for their global and continuous coverage, once their quality has been assessed. Short-wavelength infrared spectra are acquired by the Thermal And Near-infrared Sensor for carbon Observation-Fourier Transform Spectrometer (TANSO-FTS) aboard the Greenhouse gases Observing Satellite (GOSAT). From these, column-averaged dry-air mole fractions of carbon dioxide, methane and water vapor (XH_2O) have been retrieved at the National Institute for Environmental Studies (NIES, Japan) and are available as a Level 2 research product. We compare the NIES XH_2O data, Version 02.21, with retrievals from the ground-based Total Carbon Column Observing Network (TCCON, Version GGG2014). The datasets are in good overall agreement, with GOSAT data showing a slight global low bias of −3.1% ± 24.0%, good consistency over different locations (station bias of −1.53% ± 10.35%) and reasonable correlation with TCCON (R = 0.89). We identified two potential sources of discrepancy between the NIES and TCCON retrievals over land. While the TCCON XH_2O amounts can reach 6000–7000 ppm when the atmospheric water content is high, the correlated NIES values do not exceed 5500 ppm. This could be due to a dry bias of TANSO-FTS in situations of high humidity and aerosol content. We also determined that the GOSAT-TCCON differences directly depend on the altitude difference between the TANSO-FTS footprint and the TCCON site. Further analysis will account for these biases, but the NIES V02.21 XH_2O product, after public release, can already be useful for water cycle studies

La préparation et le passage du recensement du Soudan 2008

Les opérations de comptage du 5e recensement de la population du Soudan viennent de s'achever. Elles se devaient d'aller à la rencontre des quelques 38 millions d'habitants du plus étendu des pays d'Afrique avec un questionnaire unique. Elles étaient conduites par deux institutions statistiques, l'une au Nord et l'autre au Sud. Le principe du recensement  a été scellé dans les accords de paix qui ont mis fin à la guerre civile entre le Sud et le Nord Soudan en 2005. Les résultats sont extrêmement attendus puisqu'ils doivent servir de base pour déterminer le partage des revenus pétroliers, préparer les élections législatives de 2009 et le référendum d'auto-détermination du Sud en 2011. Autant d'enjeux, les multiples conflits identitaires et pour l'accès, le contrôle et la redistribution des ressources à toutes les échelles et sur toutes les marges du Soudan font du recensement un catalyseur et finalement un révélateur des limites tragiques de la gouvernance ethnocratique.The Fith population census enumeration operations have just been achieved. They have to meet the 38 millions inhabitants of the largest countries of Africa with a unique questionnaire shared by two statistical institutions, one in the North and a second for the South. The census is a milestone of the peace agreement of 2005 that put an end to the civil war between the Nord and the South. The census results are extremely waited as they will determine the petrol dividend sharing, the parlement election of 2009 and the independence referendum of 2011. So much stakes, identity and ressources access, control and redistribution conflicts at all scales and in every sudanese margin are pushing the census to catalyse and finally reveal the tragical limits of an ethnocratic governance

Feeding ecology of Liza spp. in a tidal flat: Evidence of the importance of primary production (biofilm) and associated meiofauna

International audienceGrey mullets are unique among temperate-region fish species in their ability to feed on mudflat biofilm. In this study, we examined mullet feeding strategies on biofilm and associated meiofauna by using a diet study and stable isotope analysis to explore functional interactions between mullets and tidal flats. A stomach vacuity investigation showed that mullets did not import any materials from subtidal areas into the mudflat but exported mud, biofilm, and associated meiofauna. The results of mullet stomach content and fecal analyses, when compared to the availability of tidal flat resources, showed evidence of mullets' ability to ingest and assimilate biofilm and to concentrate major meiofauna grazers such as nematodes, copepods and, secondarily, foraminifers and ostracods. Isotopic ratios confirmed diet investigations, and as recently shown in salt marsh habitats, mullets exhibited an intermediate trophic position, supporting the hypothesis that they can assimilate both biofilm and major meiofauna grazers. The function of the tidal flat as a feeding habitat for gray mullets and the role of mullets as the main export pathway of biofilm from tidal flat ecosystems are discussed

Linear Efficient Antialiased Displacement and Reflectance Mapping

International audienceWe present Linear Efficient Antialiased Displacement and Reflectance (LEADR) mapping, a reflectance filtering technique for displacement mapped surfaces. Similarly to LEAN mapping, it employs two mipmapped texture maps, which store the first two moments of the displacement gradients. During rendering, the projection of this data over a pixel is used to compute a noncentered anisotropic Beckmann distribution using only simple, linear filtering operations. The distribution is then injected in a new, physically based, rough surface microfacet BRDF model, that includes masking and shadowing effects for both diffuse and specular reflection under directional, point, and environment lighting. Furthermore, our method is compatible with animation and deformation, making it extremely general and flexible. Combined with an adaptive meshing scheme, LEADR mapping provides the very first seamless and hardware-accelerated multi-resolution representation for surfaces. In order to demonstrate its effectiveness, we render highly detailed production models in real time on a commodity GPU, with quality matching supersampled ground-truth images

The Impact of Bayesian Hyperpriors on the Population-Level Eccentricity Distribution of Imaged Planets

Orbital eccentricities directly trace the formation mechanisms and dynamical histories of substellar companions. Here, we study the effect of hyperpriors on the population-level eccentricity distributions inferred for the sample of directly imaged substellar companions (brown dwarfs and cold Jupiters) from hierarchical Bayesian modeling (HBM). We find that the choice of hyperprior can have a significant impact on the population-level eccentricity distribution inferred for imaged companions, an effect that becomes more important as the sample size and orbital coverage decrease to values that mirror the existing sample. We reanalyse the current observational sample of imaged giant planets in the 5-100 AU range from Bowler et al. (2020) and find that the underlying eccentricity distribution implied by the imaged planet sample is broadly consistent with the eccentricity distribution for close-in exoplanets detected using radial velocities. Furthermore, our analysis supports the conclusion from that study that long-period giant planets and brown dwarf eccentricity distributions differ by showing that it is robust to the choice of hyperprior. We release our HBM and forward modeling code in an open-source Python package, ePop!, and make it freely available to the community.Comment: 18 pages, 11 figures. Accepted for publication in The Astronomical Journa