Search results for "fer"
showing 10 items of 33109 documents
La necesaria rehabilitación del sistema representativo en las propuestas de reforma democrática
2010
In the debates on deliberative democracy it’s a common idea that the defenders of this theory argue for the direct participation of the citizens in the political issues and for the transformation of our current representative devices. However, in this work I argue that this conception is misguided, and that it’s the minority who defends the direct participation. The majority of the writers acknowledges the necessity of a representative device, although based on different premises to the liberal system. The deliberative democracy supports a responsible and compromised citizenship, against the model of self interested citizenship.<br><br>En los debates sobre la democracia delibera…
Radio and infrared interferometry of stellar and substellar objects
2020
En el trabajo presentado aquí hemos usado la interferometría a modo de navaja suiza, lo cual nos ha permitido hacer contribuciones relevantes a diversos campos donde una gran resolución angular proporciona una gran ventaja. Hemos estudiado tanto objetos estelares como sub-estelares: desde gigantes rojas con atmósferas muy extensas y frías hasta enanas ultra-frías con una actividad magnética extrema. Todo gracias a la gran resolución que proporcionan los instrumentos actuales, tanto en radio como en infrarrojo, junto con su gran sensibilidad. In the work presented here, we have used interferometry as a Swiss knife allowing us to make contributions in a number of relevant astrophysical scenar…
A Stochastic Decision Process Model for Optimization of Railway and Tramway Track Maintenance by means of Image Processing Technique
2013
One of the key targets for an efficient transport network management is the search for proper maintenance policies to guarantee acceptable safety and quality standards in the travel and to optimize available resource allocation. Methodologically, the proposed model presented in this paper uses the stochastic dynamic programming and in particular Markov decision processes applied to the rail wear conditions for the railway and tramway network. By performing the integrated analysis of the classes of variables which characterize the rail quality (in terms of safety), the proposed mathematical approach allows to find the solutions to the decision-making process related to the probability of det…
Determinants of the interannual relationships between remote sensed photosynthetic activity and rainfall in tropical Africa
2007
International audience; The response of photosynthetic activity to interannual rainfall variations in Africa South of the Sahara is examined using 20 years (1981-2000) of Normalised Difference Vegetation Index (NDVI) AVHRR data. Linear correlations and regressions were computed between annual NDVI and annual rainfall at a 0.5° latitude/longitude resolution, based on two gridded precipitation datasets (Climate Prediction Center Merged Analysis of Precipitation [CMAP] and Climatic Research Unit [CRU]). The spatial patterns were then examined to detect how they relate to the mean annual rainfall amounts, land-cover types as from the Global Land Cover 2000 data set, soil properties and soil typ…
Generalized wave propagation problems and discrete exterior calculus
2018
We introduce a general class of second-order boundary value problems unifying application areas such as acoustics, electromagnetism, elastodynamics, quantum mechanics, and so on, into a single framework. This also enables us to solve wave propagation problems very efficiently with a single software system. The solution method precisely follows the conservation laws in finite-dimensional systems, whereas the constitutive relations are imposed approximately. We employ discrete exterior calculus for the spatial discretization, use natural crystal structures for three-dimensional meshing, and derive a “discrete Hodge” adapted to harmonic wave. The numerical experiments indicate that the cumulat…
Decoupling on the Wiener space and variational estimates for BSDEs
2015
Global Estimation of Biophysical Variables from Google Earth Engine Platform
2018
This paper proposes a processing chain for the derivation of global Leaf Area Index (LAI), Fraction of Absorbed Photosynthetically Active Radiation (FAPAR), Fraction Vegetation Cover (FVC), and Canopy water content (CWC) maps from 15-years of MODIS data exploiting the capabilities of the Google Earth Engine (GEE) cloud platform. The retrieval chain is based on a hybrid method inverting the PROSAIL radiative transfer model (RTM) with Random forests (RF) regression. A major feature of this work is the implementation of a retrieval chain exploiting the GEE capabilities using global and climate data records (CDR) of both MODIS surface reflectance and LAI/FAPAR datasets allowing the global estim…
Performance Dissimilarities in European Union Manufacturing: The Effect of Ownership and Technological Intensity
2021
Our paper addresses the relevance of a set of continuous and categorical variables that describe industry characteristics to differences in performance between foreign versus locally owned companies in industries with dissimilar levels of technological intensity. Including data on manufacturing sector performance from 20 European Union member countries and covering the 2009–2016 period, we used the random forests methodology to identify the best predictors of EU manufacturing industries’ a priori classification based on two main attributes: ownership (foreign versus local) and technological intensity. We found that EU foreign-owned businesses dominate locally owned ones in terms of size, wh…