Search results for "Régression"

Interannual memory effects for spring NDVI in semi-arid South Africa

2008

[1] Almost 20 years of Normalized Difference Vegetative Index (NDVI) and precipitation (PPT) data are analysed to better understand the interannual memory effects on vegetation dynamics observed at regional scales in Southern Africa (SA). The study focuses on a semi-arid region (25°S–31°S; 21°E–26°E) during the austral early summer (September–December). The memory effects are examined using simple statistical approaches (linear correlations and regressions) which require the definition of an early summer vegetation predictand (December NDVI minus September NDVI) and a consistent set of potential predictors (rainfall amount, number of rainy days, rainfall intensity, NDVI and Rain-Use-Efficie…

Optimal extension of multispectral image demosaicking algorithms for setting up a one-shot camera video acquisition system

2022

Multispectral images are acquired using multispectral cameras equipped with CCD or CMOS sensors which sample the visible or near infrared spectrum according to specific spectral bands. A mosaic of multispectral MSFA filters is superimposed on the surface of the sensors to acquire a raw image called an MSFA image. In the MSFA image, only one spectral band is available per pixel, the demosaicking process is necessary to estimate the multispectral image at full spatio-spectral resolution. Motivated by the success of single-sensor cameras capturing the image in a single exposure that use CFA filters, we performed a comparative study of a few recent color image demosaicking algorithms and experi…

Les erreurs de mesure dans les modèles de régression

1973

Penalization and data reduction of auxiliary variables in survey sampling

2012

Survey sampling techniques are quite useful in a way to estimate population parameterssuch as the population total when the large dimensional auxiliary data setis available. This thesis deals with the estimation of population total in presenceof ill-conditioned large data set.In the first chapter, we give some basic definitions that will be used in thelater chapters. The Horvitz-Thompson estimator is defined as an estimator whichdoes not use auxiliary variables. Along with, calibration technique is defined toincorporate the auxiliary variables for sake of improvement in the estimation ofpopulation totals for a fixed sample size.The second chapter is a part of a review article about ridge re…

Estimation de la relation de salaires de Mincer : choix de specification et enjeux économétriques

2012

In the present doctoral thesis, we estimated Mincer’s (1974) semi logarithmic wage function for the French and Pakistani labour force data. This model is considered as a standard tool in order to estimate the relationship between earnings/wages and different contributory factors. Despite of its vide and extensive use, simple estimation of the Mincerian model is biased because of different econometric problems. The main sources of bias noted in the literature are endogeneity of schooling, measurement error, and sample selectivity. We have tackled the endogeneity and measurement error biases via instrumental variables two stage least squares approach for which we have proposed two new instrum…

Influence des facteurs socio-économiques et géographiques sur l'incidence, l'accès aux soins et la survie des femmes atteintes d'un cancer du sein

2012

In developed countries, breast cancer is currently the leading cancer in women in terms of incidence and mortality (standardized rate of 101.5 and 17.7 per 100,000 person-years in 2005, respectively). Many risk factors and prognostic factors have been studied and are well known. Research is under way with regard to every step in the development of breast cancer, but the impact of socio-economic and geographic factors, at the individual and environmental level with regard to the disease have never been studied in France.The general aim of this work was to explore the impact of these factors in different ways to build on our knowledge and to develop practical applications in the primary, seco…

Handover management in heterogenous mobile and wireless networks

2015

Since 1990, networking and mobile technologies have made a phenomenal unprecedented progress. This progress has been experienced on multiple fronts in parallel; especially on the application level and the user's needs one. This rapid evolution of the technology imposed a need for the existence of heterogeneous environments where the coverage is ensured throughout the different available networks. The challenge with such architecture would be to provide the user with the ability to navigate through the different available networks in a transparent and seamless fashion. However, the navigation among different types of networks is commonly referred to as vertical Handover. The IEEE 802.21 stan…

Ville et fortifications : de l'héritage à la production du territoire urbain

2015

A large number of french cities host military historical edifices (citadels, barracks, bastions, defensive walls, etc.). Although their initial defensive functions have been lost over time, these edifices remain deeply rooted in the urban fabric of their host cities. They continue exerting an impact on these cities’ urban morphology and modern-time functions as well as the way in which the concept of city is understood. Cities nowadays face some new challenges,the increasing awareness of urban sprawl and its consequences, coupled with an urge to promote a renewed and sustainable urbanism, invites us to adopt new approaches to study urban fortifications. In addition to their symbolic aspect,…

Robust estimation of mean electricity consumption curves by sampling for small areas in presence of missing values

2017

In this thesis, we address the problem of robust estimation of mean or total electricity consumption curves by sampling in a finite population for the entire population and for small areas. We are also interested in estimating mean curves by sampling in presence of partially missing trajectories.Indeed, many studies carried out in the French electricity company EDF, for marketing or power grid management purposes, are based on the analysis of mean or total electricity consumption curves at a fine time scale, for different groups of clients sharing some common characteristics.Because of privacy issues and financial costs, it is not possible to measure the electricity consumption curve of eac…

Rich regions, poor regions and bank branch deregulation in Spain

2016

Rich regions, poor regions and bank branch deregulation in Spain. Regional Studies. The links between financial deregulation and economic performance are evaluated in a European context. Specifically, the study analyses the relaxation of bank branching restrictions in Spain, which triggered a remarkable interregional expansion of savings banks that coincided with an unprecedented period of sustained economic expansion. Although related questions have been widely investigated for the United States, experiences in Europe have received far less research attention. An additional contribution of the paper lies in its use of quantile regression, which enables the investigation of the possibility …