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Modelling of micrometeorology, canopy transpiration and photosynthesis in a closed greenhouse using computational fluid dynamics
No full textClosed greenhouse systems allow micrometeorological conditions to be optimised for both energy saving and high quality yields. However, micrometeorological parameters need to be accurately monitored as a response to daily environmental conditions changes. A Computational Fluid Dynamics (CFD) model was developed to predict the distribution of temperature, water vapour and CO2 occurring in a Venlo-type semi-closed glass greenhouse equipped with air conditioners. Sensible and latent heat fluxes in the crop rows were included in the model along with radiation through a Discrete Ordinates (DO) model. A model for photosynthesis was also included to predict the evolution of the CO2 concentrations inside the greenhouse. Comparisons between simulated and measured values showed a good agreement for temperature and humidity. Good agreement was found also between simulated and experimental CO2 concentration values determined during a sunny summer day. Simulations were also performed to investigate the vertical distribution of temperature and humidity for two different Leaf Area Density (LAD) values (2.95 m(-1) and 5.9 m(-1)) and for different arrangements of the air conditioners. Simulation results showed that tall canopies, with high LAD, simultaneously induce a stronger cooling of the interior air. They also enhance temperature stratification providing a substantial decrease at canopy level. Lower suction also enhances stratification of the interior air
State Aids granted by regional airports: a two-sided market analysis
No full textInternational audienceA lot of cases had arouse in the past decade about agreements between regional airports and low-cost carriers. These agreements are challenged on the basis of the State Aids European control as they rise concerns not only about competition distortions between airlines but also about fiscal competition risks among Member States or local governments. Such phenomena could be expected as regional airports are characterized by significant overcapacities and overlapping inducing a substitutability for airlines. Surprisingly, the new 2014 guidelines on State Aids granted to airlines open the way to transitory operating aid schemes, an option apparently at odds with the European longstanding principles. Our purpose in this paper is to demonstrate with the help of the development of a model, that such agreements can make sense from the economic point of view provided that the relationship between the carrier and the airport is no longer analyzed as a vertical chain, inducing an assessment in terms of economic dependence, but as a two-sided market. The favorable usage terms granted to low cost carriers generate additional flows on the other side, with commercial revenues from shops or parking. Consequently, subsidizing operating costs might be rational, even for a private investor in a market economy, and might be a perennial device
Urban Objects Classification by Spectral Library: Feasibility and Applications
No full textInternational audienceObjects recognition in urban environment using multiband imagery is a difficult process, implying the use of elaborated and complex image processing methods, which are used to enhance the detection efficiency. The urban mosaics are characterized by multiple materials (e.g. manmade, urban vegetation, bare soil, transport infrastructure, etc.), which are combined together to form a complex patchwork. This study aims to take advantage of the multiband imagery, to assess the feasibility degree of the urban objects detection, and to explore some of the applications related to the multiband hyperspectral imagery classification
CERTIFICATE OF ATTENDANCE AND PRESENTATION Ontology for a Voice Transcription of OpenStreetMap Data: Case of Space Apprehension by Visually Impaired Persons
No full textCertificat conférenceCertificat
Vocabulary Acquisition via Drama: Welsh as a second language in the primary school setting
No full textInternational audienceThis paper tests a new method of teaching vocabulary to young second language learners through the medium of drama, specifically the effect of drama teaching techniques on vocabulary acquisition among primary school learners of Welsh. Vocabulary Acquisition via Drama (VAD) is based on principles derived from both process drama and communicative and task-based approaches to language teaching, and involves three phases: pre-drama, drama and post-drama activities. The research design involves two experimental and one control group, and a pre-post-retention test format on three measures of vocabulary acquisition: picture naming, sentence formulation and improvisation tasks. Results show a beneficial effect for VAD. The discussion section of the paper addresses the potential contribution of this approach to teaching second/foreign language vocabulary
Parallel preconditioners for high order discretizations arising from full system modeling for brain microwave imaging
No full textInternational audienceThis paper combines the use of high order finite element methods with parallel preconditioners of domain decomposition type for solving electromagnetic problems arising from brain microwave imaging. The numerical algorithms involved in such complex imaging systems are computationally expensive since they require solving the direct problem of Maxwell's equations several times. Moreover, wave propagation problems in the high frequency regime are challenging because a sufficiently high number of unknowns is required to accurately represent the solution. In order to use these algorithms in practice for brain stroke diagnosis, running time should be reasonable. The method presented in this paper, coupling high order finite elements and parallel preconditioners, makes it possible to reduce the overall computational cost and simulation time while maintaining accuracy
Europa in der Konfrontation mit populistischen rechtsradikalen Parteien
No full textInternational audienceAus einer deutsch-französischen Perspektive setzen sich die Beiträge dieses Bandes mit dieser politisch wie wissenschaftlich gleichermaßen vielschichtigen und brisanten Thematik auseinander. Dabei werden zwei Forschungsstränge zusammengeführt, die bislang ein eher getrenntes Dasein führten: die europawissenschaftliche Forschung über europäische Identität und europäisierte Öffentlichkeiten und die Rechtspopulismus- und Rechtsextremismusforschung
New insights into the regulatory function of CYFIP1 in the context of WAVE- and FMRP-containing complexes
No full textInternational audienceCytoplasmic FMRP interacting protein 1 (CYFIP1) is a candidate gene for intellectual disability (ID), autism, schizophrenia and epilepsy. It is a member of a family of proteins that is highly conserved during evolution, sharing high homology with its Drosophila homolog, dCYFIP. CYFIP1 interacts with the Fragile X mental retardation protein (FMRP, encoded by the FMR1 gene), whose absence causes Fragile X syndrome, and with the translation initiation factor eIF4E. It is a member of the WAVE regulatory complex (WRC), thus representing a link between translational regulation and the actin cytoskeleton. Here, we present data showing a correlation between mRNA levels of CYFIP1 and other members of the WRC. This suggests a tight regulation of the levels of the WRC members, not only by post-translational mechanisms, as previously hypothesized. Moreover, we studied the impact of loss of function of both CYFIP1 and FMRP on neuronal growth and differentiation in two animal models – fly and mouse. We show that these two proteins antagonize each other's function not only during neuromuscular junction growth in the fly but also during new neuronal differentiation in the olfactory bulb of adult mice. Mechanistically, FMRP and CYFIP1 modulate mTor signaling in an antagonistic manner, likely via independent pathways, supporting the results obtained in mouse as well as in fly at the morphological level. Collectively, our results illustrate a new model to explain the cellular roles of FMRP and CYFIP1 and the molecular significance of their interaction
Non-iterative low-multilinear-rank tensor approximation with application to decomposition in rank-(1,L,L) terms
No full textSubmitted to SIAM Journal on Scientific ComputingComputing low-rank approximations is one of the most important and well-studied problems involving tensors. In particular, approximations of low multilinear rank (mrank) have long been investigated by virtue of their usefulness for subspace analysis and dimensionality reduction purposes. The first part of this paper introduces a novel algorithm which computes a low-mrank tensor approximation non-iteratively. This algorithm, called sequential low-rank approximation and projection (SeLRAP), generalizes a recently proposed scheme aimed at the rank-one case, SeROAP. We show that SeLRAP is always at least as accurate as existing alternatives in the rank-(1,L,L) approximation of third-order tensors. By means of computer simulations with random tensors, such a superiority was actually observed for a range of different tensor dimensions and mranks. In the second part, we propose an iterative deflationary approach for computing a decomposition of a tensor in low-mrank blocks, termed DBTD. It first extracts an initial estimate of the blocks by employing SeLRAP, and then iteratively refines them by recomputing low-mrank approximations of each block plus the residue. Our numerical results show that, in the rank-(1,L,L) case, this remarkably simple scheme outperforms existing algorithms if the blocks are not too correlated. In particular, it is much less sensitive to discrepancies among the block's norms
Temporal convergence analysis of a locally implicit discontinuous galerkin time domain method for electromagnetic wave propagation in dispersive media
No full textInternational audienceThis paper is concerned with the approximation of the time domain Maxwell's equations in a dispersive propagation media by a Discontinuous Galerkin Time Domain (DGTD) method. The Debye model is used to describe the dispersive behaviour of the media. We adapt the locally implicit time integration method from [1] and derive a convergence analysis to prove that the locally implicit DGTD method for Maxwell's equations in dispersive media retains its second-order convergence