136 research outputs found
Contribution à la modélisation explicite des plates-formes d'exécution pour l'IDM
23 pagesNational audienceOne foundation of the model driven engineering (MDE) is to separate the modelling application description from its technological implementation (i.e. platform). Some of them are dedicated to the system execution. Hence, one promise solution of the MDE is to automate transformations from platform independent models to platform specific models. Little work has explicitly described platform characteristics. Yet, an explicit modelling allows taking in account their characteristics more easily (par ex., performances, maintainability,portability). This paper presents both an execution platform modelling state of art and a pattern to describe execution platform modelling framework. It intends to confirm the feasibility and the interests in describing an execution platform metamodel
Multilevel Modeling Paradigm in Profile Definition
Building a UML profile entails defining concepts required to cover a specific domain, and then, using stereotypes to map domain concepts onto UML metaclasses. Capture of domain concepts with an object-oriented language (like UML) may be inappropriate, and may impede the mapping, where more than two modeling levels are required. Use of only classes and objects may introduce accidental complexity into the domain model if other modeling levels (e.g. metatype level) are necessary. In such situations, a multilevel paradigm with deep characterization and deep instantiation is recommended to reduce complexity. However, this paradigm deserves to be further explored, and its value for definition of UML profiles assessed. We therefore propose a solution to put in practice the multi-level paradigm within a standard UML 2.x tool. Our solution involves a semi-automatic process that transforms a model annotated with multi-level characteristics into a profile-based implementation. Such automation lessens the gap between domain model and implementation and ensures consistency. As an example, we have taken an excerpt from the MARTE time profile. We then describe the new design opportunities inherent in our process and show how this process facilitates both domain specification and profile definition
Dynamic sizing of required balancing capacities: the operational approach in France
System operators employ operating reserves to deal with unexpected variations
of demand and generation and guarantee the security of supply. However, they
face new challenges to ensure this mission with the increasing share of
renewable generation. This article focuses on the operational approach adopted
by the French transmission system operator RTE for dynamically sizing the
required margins in the dynamic margin monitoring strategy context. It relies
on continuous forecasts of the main drivers of the uncertainties of the system
imbalance. Four types of forecast errors, assumed to be independent, are
considered in this approach: the errors in the wind and photovoltaic power
generation, production of conventional power units, and electricity
consumption. Then, the required margin is the result of comparing the global
forecast error, computed as the convolution of these independent errors, with a
security of supply criterion. This study presents the results of this method
implemented at RTE and used in real-time operation.Comment: Preprint version of the paper accepted for EEM 23 conferenc
Target detection with a liquid crystal-based passive Stokes polarimeter
International audienceWe present an imaging system that measures the polarimetric state of the light coming from each point of a scene. This system, which determines the four components of the Stokes vector at each spatial location, is based on a liquid-crystal polarization modulator, which makes it possible to acquire fourdimensional Stokes parameter images at a standard video rate. We show that using such polarimetric images instead of simple intensity images can improve target detection and segmentation performance
Evaluation of head-free eye tracking as an input device for air traffic control
International audienceThe purpose of this study was to investigate the possibility to integrate a free head motion eye-tracking system as input device in air traffic control (ATC) activity. Sixteen participants used an eye tracker to select targets displayed on a screen as quickly and accurately as possible. We assessed the impact of the presence of visual feedback about gaze position and the method of target selection on selection performance under different difficulty levels induced by variations in target size and target-to-target separation. We tend to consider that the combined use of gaze dwell-time selection and continuous eye-gaze feedback was the best condition as it suits naturally with gaze displacement over the ATC display and free the hands of the controller, despite a small cost in terms of selection speed. In addition, target size had a greater impact on accuracy and selection time than target distance. These findings provide guidelines on possible further implementation of eye tracking in ATC everyday activity
Dissecting genetic architecture of grape proanthocyanidin composition through quantitative trait locus mapping
<p>Abstract</p> <p>Background</p> <p>Proanthocyanidins (PAs), or condensed tannins, are flavonoid polymers, widespread throughout the plant kingdom, which provide protection against herbivores while conferring organoleptic and nutritive values to plant-derived foods, such as wine. However, the genetic basis of qualitative and quantitative PA composition variation is still poorly understood. To elucidate the genetic architecture of the complex grape PA composition, we first carried out quantitative trait locus (QTL) analysis on a 191-individual pseudo-F1 progeny. Three categories of PA variables were assessed: total content, percentages of constitutive subunits and composite ratio variables. For nine functional candidate genes, among which eight co-located with QTLs, we performed association analyses using a diversity panel of 141 grapevine cultivars in order to identify causal SNPs.</p> <p>Results</p> <p>Multiple QTL analysis revealed a total of 103 and 43 QTLs, respectively for seed and skin PA variables. Loci were mainly of additive effect while some loci were primarily of dominant effect. Results also showed a large involvement of pairwise epistatic interactions in shaping PA composition. QTLs for PA variables in skin and seeds differed in number, position, involvement of epistatic interaction and allelic effect, thus revealing different genetic determinisms for grape PA composition in seeds and skin. Association results were consistent with QTL analyses in most cases: four out of nine tested candidate genes (<it>VvLAR1</it>, <it>VvMYBPA2</it>, <it>VvCHI1</it>, <it>VvMYBPA1</it>) showed at least one significant association with PA variables, especially <it>VvLAR1 </it>revealed as of great interest for further functional investigation. Some SNP-phenotype associations were observed only in the diversity panel.</p> <p>Conclusions</p> <p>This study presents the first QTL analysis on grape berry PA composition with a comparison between skin and seeds, together with an association study. Our results suggest a complex genetic control for PA traits and different genetic architectures for grape PA composition between berry skin and seeds. This work also uncovers novel genomic regions for further investigation in order to increase our knowledge of the genetic basis of PA composition.</p
Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.
RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Contribution à la prise en compte des plates-formes logicielles d'exécution dans une ingénierie générative dirigée par les modèles
Face à la complexité des applications logicielles multitâches, une approche prometteuse est l'automatisation des développements. En pratique, cela se concrétise par des générateurs capables de produire les implantations propres aux plates-formes logicielles d exécution multitâche. Ces générateurs sont figés autour d'heuristiques d'implantations propres à chaque plate-forme visée. En vue d'obtenir des solutions plus flexibles, cette étude a pour objectif d'externaliser les formalismes propres aux plates-formes d'exécution dans des modèles explicites. Ces modèles sont alors utilisés en entrée des ingénieries ce qui permet de capitaliser et de réutiliser les générateurs. Pour y parvenir, cette étude définit un motif générique pour la modélisation des plates-formes logicielles d'exécution, une extension au langage UML pour la modélisation des plates-formes multitâches et une infrastructure de transformation intégrant ces modèles de plates-formes.To minimize the inherent complexity of multitasking programs, a promising approach is to automate developments. In practice, automation is achieved by generators. Those generators produce applications which execute on software multitasking platforms (for example multitasking operating systems). Such generators are in fact specific to selected platforms. They are made of implementation rules which are specific to each platform. In order to cope with adaptable and flexible solutions, this study aims to explicitly describe executing platforms as parameters of generators. For that, it defines, firstly, a generic pattern dedicated to modelling software execution platforms, secondly, an extension to the UML language for modelling multitasking software execution platforms (the Software Resource Modeling profile) and, thirdly, a transformation framework based on explicit platform models.EVRY-Bib. électronique (912289901) / SudocSudocFranceF
Comparison of the ALPS and PHILOS plating systems in proximal humeral fracture fixation – a retrospective study
Abstract Background Open reduction and plate osteosynthesis are considered as a successful technique for the treatment of proximal humerus fracture (PHF) despite high complication rates. The objective of our study was to review the clinical outcome and complications of the Anatomic Locking Plate System (ALPS) and compare it to the Proximal Humeral Internal Locking System (PHILOS). Our hypothesis was that ranges of motion (ROM) were superior and complication rates were lower with ALPS. Methods Twenty patients treated with ALPS for PHF were retrospectively compared to 27 patients treated with PHILOS. Union, ROM and complications were clinically and radiologically assessed at 6 weeks, 3, 6, 12 and 18–24 months post-operatively. Results Mean age was 52 ± 14 in the ALPS group and 58 ± 13 in the PHILOS group. Last follow-ups were conducted at a mean of 20.6 ± 4.8 months. Mean shoulder abduction was superior with ALPS by 14° (p-value = 0.036), 15° (p-value = 0.049), and 15° (p-value = 0.049) at 3, 6, and 12 months respectively. Mean shoulder external rotation was superior with ALPS by 11° (p-value = 0.032), 15° (p-value = 0.010) and 12° (p-value = 0.016) at 6 weeks, 3 and 6 months respectively. At the end of the follow-up, ROM remained better with ALPS, but not significantly. Complication rates over 21 months reached 20% with ALPS and 48% with PHILOS (p-value = 0.045). Implant removal rates reached 10% with ALPS and 37% with PHILOS (p-value = 0.036). Avascular necrosis was the only cause for hardware removal in the ALPS group. Conclusion The ALPS group showed better clinical outcomes with faster recovery in abduction and external rotation, although no difference in ROM remained after 21 months. Additionally, the complications rate was lower at last follow up. In our experience, the ALPS plating system is an effective management option in some PHF
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