Search results for "couvert"
showing 10 items of 62 documents
Echo cancellation system for iso-frequency repeaters : contribution to the development of a new generation digital repeater
2014
On-frequency repeaters are a cost-effective solution to extend coverage and enhance wireless communications, especially in shadow areas. However, coupling between the receiving antenna and the transmitting antenna, called radio frequency echo, increases modulation errors and creates oscillations in the system when the echo power is high. According to the communication standards, extremely weak echoes decrease the transmission rate, while strong echoes damage electroni ccircuits because of power peaks. This thesis aims at characterizing the echo phenomenon under different modulations, and proposing an optimized solution directly integrated to industry. We have turned to digital solutions esp…
Evaluation of viticultural practices on arbuscular mycorrhizal fungi associated with grapevine
2021
Arbuscular mycorrhiza, a mutualistic symbiosis established between plants and arbuscular mycorrhizal fungi (AMF), provides many ecosystem services such as improved soil structure, increased plant growth and nutrition, and improved tolerance to biotic and abiotic stresses. However, intensive agricultural practices and the use of phytosanitary products as for example herbicide and fungicides, have a strong impact on communities of soil microorganisms, including arbuscular mycorrhizal fungi, as well as on biological mechanisms within the ecosystem. This thesis wotk is part of the European Biovine project supported by the European Commission through the CORE Organic Cofund. The aim of this rese…
L'assurance insolvabilité de l'employeur en France et en Italie
2012
Insurance insolvency of the employer guarantees workers against the risk of non-payment of sums due under the contract of employment, following the failure of their employer. The central concern of this work is the presentation, under a critical angle, of the discipline of this instrument of safeguarding the rights of workers in the laws of Italy and French in the light of Community law, particularly with regard to different methods of determining the claims covered by insurance insolvency
HAPEX-Sahel
1997
The variation in evaporative fraction and actual evaporation is examined for three sample days in the HAPEX-Sahel Intensive Observation Period (IOP), including data from all the vegetation types and sites. The trends in evaporative fraction over the IOP are also presented for eight sites. The high rate of evaporation from bare soil in the days following rainfall produces a variability in evaporation which makes differences between sites difficult to interpret on a day-to-day basis, but over the whole IOP it is shown that the millet uses a smaller proportion of the available energy for evaporation than the tiger bush or fallow savannah. The combined effect of differences in the total energy …
Design, Development and Evaluation of a System for the Detection of Aerial Parts and Measurement of Growth Indices of Bell Pepper Plant Based on Ster…
2022
During the growth of plants, monitoring them brings much benefits to the producers. This monitoring includes the measurement of physical properties, counting plants leaves, detection of plants and separation of them from weeds. All these can be done different techniques, however, the techniques are favorable that are non-destructive because plant is a very sensitive creature that any manipulation can put disorder in its growth or lead to losing leaves or branches. Imaging techniques are of the best solutions for plants growth monitoring and geometric measurements. In this regard, in this project the use of stereo imaging and multispectral data was studied. Active and passive stereo imaging …
Le contrôle des risques bancaires. Une approche historique des enjeux et des résistances lors du changement de référentiel comptable de 2005.
2023
Ce chapitre analyse pourquoi et comment l'adoption des normes comptables internationales dans leur forme initiale aurait conduit à une remise en cause de la pratique de la macro-couverture utilisée par les grandes banques françaises pour gérer leur risque de taux. Plus largement il étudie en quoi cette remise en cause était susceptible d'avoir une incidence sur leur modèle économique et leur politique de crédit ainsi que les résistances, notamment politiques, qui ont été à l'œuvre
A simple algorithm to estimate evapotranspiration from DAIS data: Application to the DAISEX campaigns
2005
DOI:10.1016/j.jhydrol.2005.03.027; The knowledge of evapotranspiration is of great interest in many applications such as assessing irrigation water use. In this paper, a methodology is presented to estimate evapotranspiration using the surface energy balance model S-SEBI (Simplified Surface Energy Balance Index) and the evaporative fraction. The method is applicable under the assumptions of constant atmospheric conditions and sufficient wet and dry pixels over the image. The model uses remotely sensed parameters such as albedo, MSAVI (Modified Soil Adjusted Vegetation Index) and surface temperature and emissivity images. The methodology has been applied over the Barrax test site, located in…
Multiscale study of rainfall and vegetation cover in Cameroon : spatial analysis, temporal trends, climatic and anthropogenic factors of NDVI variabi…
2011
Due to its shape and location (2°N-13°N – 8°E-16°E; proximity of the Atlantic Ocean), Cameroon is characterized by a panel of cross-regional climate encountered widely in tropical Africa. Over the region, the decrease rainfall during the second half of the last century has been shown to be associated with stronger recurrence of drier periods, specifically in the core of the rainy season. These conditions have favored the degradation of vegetation cover, driven by socioeconomic and demographic constraints. The substantial impacts on human activities and local society highlight the need to better understand how climate and environmental dynamics do interact locally. The aim of this study is t…
Comment évaluer et mesurer la conflictualité liée aux usages de l'espace ? Eléments de méthode et de repérage
2010
Cet article a pour objet de présenter le travail réalisé depuis quelques années par une équipe pluridisciplinaire sur la question des conflits d’usage de l’espace et de révéler la méthodologie d’enquête et de collecte de données, ainsi que la structure de la base de données qui en est issue. Dans un premier temps nous procédons à une définition du champ des investigations, en donnant une définition de ces conflits, de leurs caractéristiques, des mobiles et des manifestations de la conflictualité, ainsi que des acteurs impliqués (I). Nous exposons ensuite notre méthode de repérage des conflits, fondée sur un diagnostic de zone et la mise en commun de différentes méthodes de recueil de donnée…