Lecture et bibliothèques publiques : actes du colloque, Hénin-Beaumont, 20-21 novembre 1981

« Document numérisé pour l\u27ENSSIB » - Ce document s\u27adresse aux professionnels des bibliothèques, et plus largement, aux acteurs de la vie culturelle. Il s\u27agit des actes du colloque consacré à la lecture et aux bibliothèques publiques qui s\u27est tenu à Hénin-Beaumont les 20 et 21 novembre 1981. Ce document aborde l\u27ensemble des questions et problèmes liés au développement de la lecture et des bibliothèques publiques, spécialement en région Nord - Pas-de-Calais. Les différentes interventions dressent un état des lieux de la situation régionale en la matière afin de réfléchir aux actions à mener en faveur de la lecture publique et d\u27élaborer une stratégie de développement efficace avec la participation de tous les acteurs du monde culturel de la région. L\u27intérêt de cet ouvrage réside dans cette vocation régionale qui permet d\u27appréhender concrètement la question de la lecture publique dans un contexte donné. Certes, cette étude précise ne peut être généralisée au niveau national, mais elle offre l\u27opportunité de comprendre les enjeux de la lecture publique au niveau local, ainsi que les réflexions et problèmes qu\u27ils sous-tendent. Par ailleurs, quelques tableaux font référence à d\u27autres régions françaises, amenant des comparaisons intéressantes

Hyperspectral images segmentation: a proposal

Hyper-Spectral Imaging (HIS) also known as chemical or spectroscopic imaging is an emerging technique that combines imaging and spectroscopy to capture both spectral and spatial information from an object. Hyperspectral images are made up of contiguous wavebands in a given spectral band. These images provide information on the chemical make-up profile of objects, thus allowing the differentiation of objects of the same colour but which possess make-up profile. Yet, whatever the application field, most of the methods devoted to HIS processing conduct data analysis without taking into account spatial information.Pixels are processed individually, as an array of spectral data without any spatial structure. Standard classification approaches are thus widely used (k-means, fuzzy-c-means hierarchical classification...). Linear modelling methods such as Partial Least Square analysis (PLS) or non linear approaches like support vector machine (SVM) are also used at different scales (remote sensing or laboratory applications). However, with the development of high resolution sensors, coupled exploitation of spectral and spatial information to process complex images, would appear to be a very relevant approach. However, few methods are proposed in the litterature. The most recent approaches can be broadly classified in two main categories. The first ones are related to a direct extension of individual pixel classification methods using just the spectral dimension (k-means, fuzzy-c-means or FCM, Support Vector Machine or SVM). Spatial dimension is integrated as an additionnal classification parameter (Markov fields with local homogeneity constrainst [5], Support Vector Machine or SVM with spectral and spatial kernels combination [2], geometrically guided fuzzy C-means [3]...). The second ones combine the two fields related to each dimension (spectral and spatial), namely chemometric and image analysis. Various strategies have been attempted. The first one is to rely on chemometrics methods (Principal Component Analysis or PCA, Independant Component Analysis or ICA, Curvilinear Component Analysis...) to reduce the spectral dimension and then to apply standard images processing technics on the resulting score images i.e. data projection on a subspace. Another approach is to extend the definition of basic image processing operators to this new dimensionality (morphological operators for example [1, 4]). However, the approaches mentioned above tend to favour only one description either directly or indirectly (spectral or spatial). The purpose of this paper is to propose a hyperspectral processing approach that strikes a better balance in the treatment of both kinds of information....Cet article présente une stratégie de segmentation d’images hyperspectrales liant de façon symétrique et conjointe les aspects spectraux et spatiaux. Pour cela, nous proposons de construire des variables latentes permettant de définir un sous-espace représentant au mieux la topologie de l’image. Dans cet article, nous limiterons cette notion de topologie à la seule appartenance aux régions. Pour ce faire, nous utilisons d’une part les notions de l’analyse discriminante (variance intra, inter) et les propriétés des algorithmes de segmentation en région liées à celles-ci. Le principe générique théorique est exposé puis décliné sous la forme d’un exemple d’implémentation optimisé utilisant un algorithme de segmentation en région type split and merge. Les résultats obtenus sur une image de synthèse puis réelle sont exposés et commentés

Diaspora, Développement et Citoyenneté: Les Migrants Originaires du Bassin du Fleuve Sénégal

The author analyses the contribution of the diaspora on the development of their locality

Les missions catholiques françaises et le développement des études igbo dans l’Est du Nigeria, 1885 - 1930

Partly based on archives, this description of the progression of French Catholic missions from Senegal to Igboland emphasizes the crucial roles played by the Congrégation des Pères du Saint Esprit (Spiritains) and the Société des Missions Africaines (SMA) from Lyon in collecting folklore, diffusing the Onitsha dialect throughout Igboland, and developing a system of writing for the language. By comparison with their predecessors (the British Church Missionary Society), these two missionary organizations, through their prublications, opened the way for progress in Igbo studies. These authors can be considered to be harbingers of the current cooperation between France and Igboland in the context of Franco-Nigerian relation

Hydrochemistry and stable isotopes (δ 18 O and δ 2 H) tools applied to the study of karst aquifers in Southern Mediterranean basin (Teboursouk area, NW Tunisia)

Karst aquifers receive increasing attention in Mediterranean countries as they provide large supplies water used for drinkable and irrigation purposes as well as for electricity production. In Teboursouk basin, Northwestern Tunisia, characterized by a typical karst landscape, the water hosted in the carbonates aquifers provides large parts of water supply for drinkable water and agriculture purposes. Groundwater circulation in karst aquifers is characterized by short residence time and low water-rock interaction caused by high karstification processes in the study area. Ion exchange process, rock dissolution and rainfall infiltration are the principal factors of water mineralization and spatial distribution of groundwater chemistry. The present work attempted to study karstic groundwater in Teboursouk region using hydrochemistry and stable isotopes (δ18O and δ2H) tools. Karst aquifers have good water quality with low salinity levels expressed by TDS values largely below 1.5 g/l with Ca-SO4-Cl water type prevailing in the study area. The aquifers have been recharged by rainfall originating from a mixture of Atlantic and Mediterranean vapor masses