La Géographie française et le risque d'inondation: de la géographie physique à la géographie humaine

Les inondations, comme tous les risques naturels, ont été un thème qui est revenu souvent au long de l'histoire de la géographie française, mais toujours — et contrairement à ce qui se passe dans la géographie anglo-saxonne —, en relation à la géographie physique. Dans cet article, nous voulons expliquer les raisons de la présence de la géographie physique dans le traitement du risque d'inondation : nous mettons en relation les différents moments de la géographie française avec l'analyse du risque d'inondation et révisons le contenu des références aux inondations entre les géographes ou écoles géographiques les plus représentatifs

El Lloc dels riscos naturals als Annales de Géographie (1891-1991)

L'étude des risques naturels est devenu un sujet de débat entre les géographes physiques français, de plus en plus conscients de l'exposition croissante des sociétés aux risques naturels et du besoin d'évaluer leurs compétences et leurs moyens d'intervention. Mais l'étude des risques naturels a aussi été un sujet récurrent dans l'histoire de la géographie française. Cet article prétend être une approche au traitement qu'a reçu ce thème dans les Annales de Géographie depuis sa création jusqu'h aujourd’hui. Après avoir distingué trois étapes (1891-1930, 1930-1975 et 1975-1991) on a établi les rapports existants entre les différents moments de la géographie française et l'étude des risques naturels et on a analysé autant le contenu des notices sur les divers évènements catastrophiques que les travaux des auteurs les plus représentatifs. I1 s'agit, en résumé, de proposer une réflexion sur la façon dont la géographie française a abordé ce sujet

La Geografia política en Vidal de la Blanche: la France de l'Est

En 1979 Y. Lacoste a publié dans la revue "Hérodote" un article surprenant intitulé "A bas Vidal ... Viva Vidal" qui exhumait la dernière œuvre de Vidal de la Blache: La france de I'Est (Loraine-Alsace) (1917). Dans cet article, Lacoste faisait l'éloge de certains aspects économiques, sociaux et surtout géopolitiques, non traités dans le traditionnel modèle vidalien. Nous tenterons d'approfondir dans cet essai l'une des questions qu'a induite l'article de Lacoste, a savoir la place qu'occupe la Géographie Politique dans l'école vidalienne. Les différents travaux et actions des disciples de Vidal ont fait preuve d’un grand intérêt pour la Géographie Politique en abandonnant provisoirement le schéma descriptif prope à la géographie régionale française. À la fin de la première guerre mondiale, le problème frontalier de l'Alsace-Loraine devient l'axe central de La France de I'Est; On a fait ressortir les éléments géopolitiques de cette œuvre a fin de démontrer que l'aspect géopolitique de l'école vidalienne est méconnu

Estat de conservació i propostes de gestió per a Stachys martitima Gouan a la Península Ibèrica

Es documenta la disminució de l’àrea de distribució i del nombre d’individus i s’avalua l’extensió actual d’Stachys maritima a la península Ibèrica, restringida a menys de 200 individus amb una àrea d’ocupació de només 8 km2. L’espècie és requalificada com a CR (en perill crític) en aquest territori, incrementant l’anterior valoració com a VU (vulnerable). Se suggereixen les mesures de conservació adequades que permetin garantir simultàniament activitats de turisme sostenibles

One-sided jet at milliarcsecond scales in LS I +61˚ 303

We present Very Long Baseline Interferometry (VLBI) observations of the high mass X-ray binary LS I +61˚303, carried out with the European VLBI Network (EVN). Over the 11 hour observing run, performed ~10 days after a radio outburst, the radio source showed a constant flux density, which allowed sensitive imaging of the emission distribution. The structure in the map shows a clear extension to the southeast. Comparing our data with previous VLBI observations we interpret the extension as a collimated radio jet as found in several other X-ray binaries. Assuming that the structure is the result of an expansion that started at the onset of the outburst, we derive an apparent expansion velocity of 0:003 c, which, in the context of Doppler boosting, corresponds to an intrinsic velocity of at least 0:4 c for an ejection close to the line of sight. From the apparent velocity in all available epochs we are able to establish variations in the ejection angle which imply a precessing accretion disk. Finally we point out that LS I +61˚303, like SS 433 and Cygnus X-1, shows evidence for an emission region almost orthogonal to the relativistic jet

Vegetative and reproductive morphology of Kallymenia patens (Kallymeniaceae, Rhodophyta) in the Mediterranean Sea

Reproductive morphology of the Mediterranean red alga Kallymenia patens is described for the first time, confirming its position in the genus. K. patens is characterized by a non-procarpic female reproductive apparatus, carpogonial branch systems consisting of supporting cells bearing both three-celled carpogonial branches and subsidiary cells that lack a hypogynous cell and carpogonium; fusion cells develop numerous connecting filaments, and tetrasporangia are scattered over the thallus and are probably cruciately divided. Old fertile spathulate specimens of K. patens are morphologically similar to K. spathulata, but they can be distinguished by the length of spathulated proliferations (up to 0.6 cm and 6 cm, respectively), the length of inner cortical cells (up to 70 and 30 μm, respectively), and the gonimoblast location (in proliferations from the perennial part of the blade and over all the thallus surface, respectively)

An hybrid methodology for RL-based behavior coordination in a target following mission with an AUV

Proposes a behavior-based scheme for high-level control of autonomous underwater vehicles (AUVs). Two main characteristics can be highlighted in the control scheme. Behavior coordination is done through a hybrid methodology, which takes in advantages of the robustness and modularity in competitive approaches, as well as optimized trajectories

Multicast extension of unicast charging for QoS Services

In order to successfully deploy multicast services in QoS-aware networks, pricing architectures must take into account the particular characteristics of multicast sessions. With this objective, we propose a charging scheme for QoS multicast services, assuming that the unicast cost of each interconnecting link is determined and that such cost is expressed in terms of quality of service (QoS) parameters. Our scheme allows determining the cost distribution of a multicast session along a cost distribution tree (CDT), and basing such distribution in those pre-existing unicast cost functions. The paper discusses in detail the main characteristics of the problem in a realistic interdomain scenario and how the proposed scheme would contribute to its solution

Differential epipolar constraint in mobile robot egomotion estimation

The estimation of camera egomotion is a well established problem in computer vision. Many approaches have been proposed based on both the discrete and the differential epipolar constraint. The discrete case is mainly used in self-calibrated stereoscopic systems, whereas the differential case deals with a unique moving camera. The article surveys several methods for mobile robot egomotion estimation covering more than 0.5 million samples using synthetic data. Results from real data are also given

Local map update for large scale SLAM

A technique for simultaneous localisation and mapping (SLAM) for large scale scenarios is presented. This solution is based on the use of independent submaps of a limited size to map large areas. In addition, a global stochastic map, containing the links between adjacent submaps, is built. The information in both levels is corrected every time a loop is closed: local maps are updated with the information from overlapping maps, and the global stochastic map is optimised by means of constrained minimisation

Multidimensional Adaptations for Open Learning Management Systems

Our work is focused on alleviating the workload for designers of adaptive courses on the complexity task of authoring adaptive learning designs adjusted to specific user characteristics and the user context. We propose an adaptation platform that consists in a set of intelligent agents where each agent carries out an independent adaptation task. The agents apply machine learning techniques to support the user modelling for the adaptation process

Colour image processing

In the context of the round table the following topics related to image colour processing will be discussed: historical point of view. Studies of Aguilonius, Gerritsen, Newton and Maxwell. CIE standard (Commission International de lpsilaEclaraige). Colour models. RGB, HIS, etc. Colour segmentation based on HSI model. Industrial applications. Summary and discussion. At the end, video images showing the robustness of colour in front of B/W images will be presented

Using appearance and context for outdoor scene object classification

We propose a probabilistic object classifier for outdoor scene analysis as a first step in solving the problem of scene context generation. The method begins with a top-down control, which uses the previously learned models (appearance and absolute location) to obtain an initial pixel-level classification. This information provides us the core of objects, which is used to acquire a more accurate object model. Therefore, their growing by specific active regions allows us to obtain an accurate recognition of known regions. Next, a stage of general segmentation provides the segmentation of unknown regions by a bottom-strategy. Finally, the last stage tries to perform a region fusion of known and unknown segmented objects. The result is both a segmentation of the image and a recognition of each segment as a given object class or as an unknown segmented object. Furthermore, experimental results are shown and evaluated to prove the validity of our proposal

Modeling and Classifying Breast Tissue Density in Mammograms

We present a new approach to model and classify breast parenchymal tissue. Given a mammogram, first, we will discover the distribution of the different tissue densities in an unsupervised manner, and second, we will use this tissue distribution to perform the classification. We achieve this using a classifier based on local descriptors and probabilistic Latent Semantic Analysis (pLSA), a generative model from the statistical text literature. We studied the influence of different descriptors like texture and SIFT features at the classification stage showing that textons outperform SIFT in all cases. Moreover we demonstrate that pLSA automatically extracts meaningful latent aspects generating a compact tissue representation based on their densities, useful for discriminating on mammogram classification. We show the results of tissue classification over the MIAS and DDSM datasets. We compare our method with approaches that classified these same datasets showing a better performance of our proposal

Object and Scene Classification: what does a Supervised Approach Provide us?

Given a set of images of scenes containing different object categories (e.g. grass, roads) our objective is to discover these objects in each image, and to use this object occurrences to perform a scene classification (e.g. beach scene, mountain scene). We achieve this by using a supervised learning algorithm able to learn with few images to facilitate the user task. We use a probabilistic model to recognise the objects and further we classify the scene based on their object occurrences. Experimental results are shown and evaluated to prove the validity of our proposal. Object recognition performance is compared to the approaches of He et al. (2004) and Marti et al. (2001) using their own datasets. Furthermore an unsupervised method is implemented in order to evaluate the advantages and disadvantages of our supervised classification approach versus an unsupervised one