Search results for "modelisation"
showing 10 items of 24 documents
A simple modelling of crop water balance for agrometeorological applications
1991
Abstract A simple agrometeorological model of crop water balance is presented. It aims at the best estimate possible of the water balance components with the simplest formulation and the minimum set of input data. The model works with a time step of one day and uses rainfall and the calculated evapotranspiration as the climatic inputs. Some soil and crop characteristics, such as the maximum available moisture and crop coefficients are required as input parameters. The model is tested using experimental data obtained on wheat and lucerne crops in the Paris region. The sensitivity of the model is discussed and some possible applications to rainfed crop management are presented.
Degradation mechanisms under hydro-thermo-mechanical loads of natural fibers-reinforced biocomposites : application to the development of lightweight…
2018
With the current environmental concerns, research turns to alternative solutions to synthetic fibres. Vegetal fibers appears as good candidates, with good mechanical properties. However, their low durability is a major issue, especially when the composites are exposed to hydro(hygro)thermal loadings.The purpore of this thesis is to analyse and understand the degradation mechanisms when hydro-thermo-mechanical loadings are applied, in order to implement a predictive modelisation of the composite durability.The manufacturing process wasstudied and optimised to produce reproducible and strong composites. Two materials were produced. Their only difference is their volumetric fiber contents (37.…
Radiative surface temperature and convective flux calculation over crop canopies
1988
The analysis presented in this paper aims at a better understanding of the potential role of radiative temperature, as measured by a radiometer over crops, in sensible heat flux calculation. Defining radiative temperature as the mean temperature of the surfaces viewed by the radiometer (leaves and soil surface) and assuming that an Ohm's law type formula can be used to express sensible heat flux as a function of the difference between air temperature and radiative temperature, the aerodynamic resistance which divides this temperature difference has been analytically defined. The parameters which appear in the resistance expression depend essentially on wind velocity and canopy structure but…
Interactions surface continentale/atmosphère : l'expérience HAPEX-Sahel
1994
L'évolution saisonnière des termes du bilan radiatif, du bilan d'énergie et la production primaire d'une savane humide d'Afrique de l'Ouest (Lamto, Côte d'Ivoire) a été suivie dans le cadre du programme SAvanes à Long Terme (SALT). Ces données ont permis de développer un modèle de simulation des échanges surface/atmosphère en savane humide, basé sur les relations fonctionnelles existant entre la production et la phénologie de la savane d'une part, et les bilans d'énergie et hydrique de ce type de surface d'autre part. Ce modèle est issu du couplage de deux sous-modèles fonctionnant au pas de temps journalier et utilisant des variables climatiques standard en entrée : le modèle de bilan d'én…
Intégration d'une bouche artificielle dans un système de prélèvement Gilson
2007
Les graphes paysagers pour la modélisation et la gestion des pullulations de campagnols terrestres.
2016
International audience; Les prairies d’Auvergne et de Franche-Comté sont régulièrement envahies par un rongeur, le campagnol terrestre. Le projet CAMPAGRAPHE vise à fournir un appui pour la mise en place d’un dispositif agro-écologique limitant sa diffusion grâce à une modélisation des réseaux de prairies.Le graphe obtenu permet de localiser des actions de terrain et orienter le suivi des populations.
Using fractal objects as primitives for spatial modelling
2019
ECTQG 2019, European Colloquium of Theoretical and Quantitative Geography, Mondorf-les-Bains, LUXEMBOURG, 05-/09/2019 - 09/09/2019
Estimation des performances, test et contrôle des systèmes cyber-physiques employant des réseaux de communication non idéaux
2020
Wireless technology is a key enabler of the promises of Industry 4.0 (Smart Manufacturing). As such, wireless technology will be adopted as a principal mode of communication within the factory beginning with the factory enterprise and eventually being adopted for use within the factory workcell. Factory workcell communication has particular requirements on latency, reliability, scale, and security that must first be met by the wireless communication technology used. Wireless is considered a non-ideal form of communication in that when compared to its wired counterparts, it is considered less reliable (lossy) and less secure. These possible impairments lead to delay and loss of data in indus…
A multilight approach for documenting and modeling the appearance of large cultural heritage objects
2022
In recent years, Computer Vision has played a major role in the investigation of sur-face appearance, particularly with the introduction of image-based rendering algorithms. Reflectance transformation Imaging (RTI) is one of these approaches. The RTI is a multi-light imaging technique that involves taking a series of images of an item using a stationary camera, while the location of the incident light varies in each photograph. Thanks to the information gathered from this type of acquisition, which is also defined as a Multi-light Image Collection (MLIC), it is possible to model the angular reflectance of a surface. The RTI is frequently employed in the documentation and study of architectu…
L'impact des formes urbaines dans la mise en place des politiques de transition énergétique : une approche par la modélisation
2019
Rencontres Francophones Transport Mobilité 2019, Montréal, CANADA, 11-/06/2019 - 13/06/2019