La reconstitution de l'offre dans les opérations de renouvellement urbain de 2000 à 2004

Contexte :Cette démarche fait suite à une première analyse conduite en 2002 - 2003, par le Certu et quatre cete, ayant abouti à l’élaboration d'un ouvrage intitulé : « Renouvellement urbain - Enseignements de 15 opérations de démolition/reconstruction " . Ce document, destiné aux acteurs du renouvellement urbain et en particulier aux DDE, a souligné la difficulté de reconstituer une offre sociale à l'échelle des agglomérations . Il a également pointé la nécessité d'une meilleure utilisation des PLH pour décliner des politiques de re-développement de l'offre plus équilibrées au sein des Communautés d'Agglomération. C'est pourquoi la DGUHC a souhaité qu'une nouvelle investigation soit réalisée autour de cette double question. Résumé : Au travers des analyses de sites concernant dix agglomérations, l'objectif poursuivi est :- d'analyser la définition, le contenu et la mise en œuvre des politiques de reconstitution de l'offre dans les opérations de renouvellement urbain, à l'échelle de l'agglomération. n - d'apprécier l'articulation entre la reconstitution de l'offre des opérations de renouvellement urbain et les politiques locales de l'habitat. - de favoriser la connaissance des pratiques au regard de la problématique formulée, en premier lieu dans le réseau de l'Équipement, mais aussi auprès des collectivités ou auprès d'autres acteurs du renouvellement urbain. L'étude a été conduite dans un contexte très évolutif en matière de réglementations, de financements et de stratégies institutionnelles avec, d'une part, la création de l'Agence Nationale de la Rénovation Urbaine et, d'autre part, la délégation de compétence aux collectivités locales en matière d'attribution d'aides à la pierre, ouverte par la loi du 13 août 2004 relative aux libertés et responsabilités locales . Elle n'a donc pas vocation à édicter des éléments de doctrine, elle rend compte d'intentions locales, dresse un certain nombre de constats, et tente d'en tirer de premiers enseignements dans le cadre de processus opérationnels, souvent à des stades très amon

IRIM at TRECVID 2011: Semantic Indexing and Instance Search

12 pages - TRECVID workshop notebook papers/slides available at http://www-nlpir.nist.gov/projects/tvpubs/tv.pubs.org.htmlInternational audienceThe IRIM group is a consortium of French teams work- ing on Multimedia Indexing and Retrieval. This paper describes its participation to the TRECVID 2011 se- mantic indexing and instance search tasks. For the semantic indexing task, our approach uses a six-stages processing pipelines for computing scores for the likeli- hood of a video shot to contain a target concept. These scores are then used for producing a ranked list of im- ages or shots that are the most likely to contain the tar- get concept. The pipeline is composed of the following steps: descriptor extraction, descriptor optimization, classification, fusion of descriptor variants, higher-level fusion, and re-ranking. We evaluated a number of dif- ferent descriptors and tried different fusion strategies. The best IRIM run has a Mean Inferred Average Pre- cision of 0.1387, which ranked us 5th out of 19 partic- ipants. For the instance search task, we we used both object based query and frame based query. We formu- lated the query in standard way as comparison of visual signatures either of object with parts of DB frames or as a comparison of visual signatures of query and DB frames. To produce visual signatures we also used two apporaches: the first one is the baseline Bag-Of-Visual- Words (BOVW) model based on SURF interest point descriptor; the second approach is a Bag-Of-Regions (BOR) model that extends the traditional notion of BOVW vocabulary not only to keypoint-based descrip- tors but to region based descriptors

IRIM at TRECVID 2010: Semantic Indexing and Instance Search

International audienceThe IRIM group is a consortium of French teams working on Multimedia Indexing and Retrieval. This paper describes our participation to the TRECVID 2010 semantic indexing and instance search tasks. For the semantic indexing task, we evaluated a number of different descriptors and tried different fusion strategies, in particular hierarchical fusion. The best IRIM run has a Mean Inferred Average Precision of 0.0442, which is above the task median performance. We found that fusion of the classification scores from different classifier types improves the performance and that even with a quite low individual performance, audio descriptors can help. For the instance search task, we used only one of the example images in our queries. The rank is nearly in the middle of the list of participants. The experiment showed that HSV features outperform the concatenation of HSV and Edge histograms or the Wavelet features

Theories of schizophrenia: a genetic-inflammatory-vascular synthesis

BACKGROUND: Schizophrenia, a relatively common psychiatric syndrome, affects virtually all brain functions yet has eluded explanation for more than 100 years. Whether by developmental and/or degenerative processes, abnormalities of neurons and their synaptic connections have been the recent focus of attention. However, our inability to fathom the pathophysiology of schizophrenia forces us to challenge our theoretical models and beliefs. A search for a more satisfying model to explain aspects of schizophrenia uncovers clues pointing to genetically mediated CNS microvascular inflammatory disease. DISCUSSION: A vascular component to a theory of schizophrenia posits that the physiologic abnormalities leading to illness involve disruption of the exquisitely precise regulation of the delivery of energy and oxygen required for normal brain function. The theory further proposes that abnormalities of CNS metabolism arise because genetically modulated inflammatory reactions damage the microvascular system of the brain in reaction to environmental agents, including infections, hypoxia, and physical trauma. Damage may accumulate with repeated exposure to triggering agents resulting in exacerbation and deterioration, or healing with their removal. There are clear examples of genetic polymorphisms in inflammatory regulators leading to exaggerated inflammatory responses. There is also ample evidence that inflammatory vascular disease of the brain can lead to psychosis, often waxing and waning, and exhibiting a fluctuating course, as seen in schizophrenia. Disturbances of CNS blood flow have repeatedly been observed in people with schizophrenia using old and new technologies. To account for the myriad of behavioral and other curious findings in schizophrenia such as minor physical anomalies, or reported decreased rates of rheumatoid arthritis and highly visible nail fold capillaries, we would have to evoke a process that is systemic such as the vascular and immune/inflammatory systems. SUMMARY: A vascular-inflammatory theory of schizophrenia brings together environmental and genetic factors in a way that can explain the diversity of symptoms and outcomes observed. If these ideas are confirmed, they would lead in new directions for treatments or preventions by avoiding inducers of inflammation or by way of inflammatory modulating agents, thus preventing exaggerated inflammation and consequent triggering of a psychotic episode in genetically predisposed persons

A cycle of sand spit nourishment by swash bars on macrotidal ebb-tidal delta

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Bar Migrations on a Macrotidal Ebb Delta over a Period of Six Years Using Lidar Survey

(IF 1.05; Q2)International audienceThe migration rates of two swash bars on an ebb delta are studied in a macrotidal environment. A dataset of 12 LiDAR surveys, from 2011 to 2017 is used to compute the movement of the swash bar crests using Digital Shoreline Analysis System (DSAS) version 4.3. Hydrodynamic data are acquired near the ebb-tidal delta during the same period. The relationship between bar migration rate and wave energy flux is analyzed. The correlation is high (r2 = 0.71), but a specific migration rate of the two bars weaken this result. Furthermore, the two swash bars have two different behaviors under the same hydrodynamic conditions. Other analyses are conducted concerning the relationships between the migration of the bar and its volume or the water depth. The correlations are too weak to explain the different behaviors of the bars. Another parameter is highlighted, the number of swash bars in the immediate vicinity of the two bars

The formation and morphodynamics of complex multi-hooked spits and the contribution of swash bars

International audienceNumerous studies have been devoted to recurved and hooked spits in micro- and meso-tidal environments, but none have really focused on the peculiar right-angle plan shape exhibited by some spit hooks. The morphodynamics of a complex multi-hooked spit in a macrotidal inlet in Normandy, France, have been investigated using aerial photographs and 12 topographic LiDAR surveys from 2000 to 2017, complemented by hydrodynamic data. Merville Spit is a 2.5 km-long hooked spit, composed of four ‘nested’ ridges each with a right-angle hook at its tip, that has developed in the vicinity of the sand-rich outlet of the Orne River. Monitoring of the two last ridges shows that ridge formation starts with the attachment of the tip of a swash bar to the fulcrum point of the previous ridge, and ends following its westward elongation and counter-clockwise rotation when its hook impinges on the Orne outlet. The main factor controlling ridge plan-view shape is swash bar dynamics in the vicinity of the spit. The offshore wave direction has no significant impact on ridge and hook behaviour due to the large number of swash bars on the ebb-tidal delta. Over the study period, between 5 and 10 swash bars massively assured sand supply to the upper foreshore, favouring the growth of existing ridges, but also enabling the building of a new ridge. The bars contribute to imparting hook right angles at the tips of the ridges by creating local wave refraction or by providing a sheltering effect. Strong tidal currents in the Orne channel act as a hydrodynamic barrier that stops hook elongation at the edge of the river's outlet. The similar behaviour of the two studied ridges has been synthesized into a new and original conceptual model of complex multi-hooked spit formation and evolution under the influence of swash bars

The formation and morphodynamics of complex multi-hooked spits and thecontribution of swash bars

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