719 research outputs found

    Ability of the e-TellTale sensor to detect flow features over wind turbine blades: flow separation/reattachment dynamics

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    Monitoring the flow features over wind turbine blades is a challenging task that has become more and more crucial. This paper is devoted to demonstrate the ability of the e-TellTale sensor to detect the flow separation/reattachment dynamics over wind turbine blades. This sensor is made of a strip with a strain gauge sensor at its base. The velocity field was acquired using TR- PIV measurements over an oscillating thick blade section equipped with an e-TellTale sensor. PIV images were post-processed to detect movements of the strip, which was compared to movements of flow. Results show good agreement between the measured velocity field and movements of the strip regarding the separation/reattachment dynamics

    Trame écologique agropastorale du Massif central : de l’approche cartographique globale par grands types de milieux à une approche cartographique affinée des végétations agropastorales.

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    Les milieux ouverts herbacés représentent sur l’ensemble du Massif central une composante majeure et une richesse en terme de biodiversité. Ces milieux sont hérités d’une longue pratique agropastorale à laquelle ils doivent leur maintien. L’évolution récente et rapide de cette pratique, se traduit par une perte massive de diversité végétale. L’objet de cette étude est de mettre au point une méthode d’inventaire et de suivi de ces milieux à l’aide d’images optiques THR et de données Lidar, applicable à de larges superficies. Cette recherche est portée par la fédération des parcs naturels du Massif central (IPAMAC). Trois territoires expérimentaux (zones de 3000 ha) et représentatifs de la diversité du Massif central ont été définis : les Monts du Forez (secteur cristallin), le Massif du Sancy et du Cézallier (secteur volcanique) et le Causse noir (secteur calcaire). Dans chacun de ces territoires, une cartographie de terrain des végétations a été menée par les conservatoires botaniques sur des zones-tests de 300 ha environ. Cette cartographie rassemble des informations phytosociologiques, physionomiques, environnementales et sur les pratiques agropastorales, afin de prendre en compte les nombreux facteurs impactant l’information spectrale. Le choix des données image répond aux objectifs suivants : explorer les potentialités de la très haute résolution pour restituer le plus finement possible la diversité du tapis végétal et, suivre le développement phénologique des végétations à des dates différentes de la saison végétative. Trois types d’images aériennes et satellites (visible et proche infrarouge) ont été acquises sur chaque territoire sur la période végétative entre 2010 et 2013

    Fault Diagnosis in Fuzzy Discrete Event System: Incomplete Models and Learning

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    Nowadays, determining faults in non-stationary environment and that can deal with the problems of fuzziness impreciseness and subjectivity is a challenging task in complex systems such as nuclear center, or wind turbines, etc. Our objective in this paper is to develop models based on fuzzy finite state automaton with fuzzy variables describing the industrial process in order to detect anomalies in real time and possibly in anticipation. A diagnosis method has for goal to alert actors responsible for managing operations and resources, able to adapt to the emergence of new procedures or improvisation in the case of unexpected situations. The diagnoser module use the outputs events and membership values of each active state of the model as input events

    Estimation of conditional laws given an extreme component

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    Let (X,Y)(X,Y) be a bivariate random vector. The estimation of a probability of the form P(YyX>t)P(Y\leq y \mid X >t) is challenging when tt is large, and a fruitful approach consists in studying, if it exists, the limiting conditional distribution of the random vector (X,Y)(X,Y), suitably normalized, given that XX is large. There already exists a wide literature on bivariate models for which this limiting distribution exists. In this paper, a statistical analysis of this problem is done. Estimators of the limiting distribution (which is assumed to exist) and the normalizing functions are provided, as well as an estimator of the conditional quantile function when the conditioning event is extreme. Consistency of the estimators is proved and a functional central limit theorem for the estimator of the limiting distribution is obtained. The small sample behavior of the estimator of the conditional quantile function is illustrated through simulations.Comment: 32 pages, 5 figur

    An unusual presentation of Castleman's Disease:a case report

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    BACKGROUND: Castleman's disease (CD), a rare condition of uncertain etiology, involves a massive proliferation of lymphoid tissues and typically presents as mediastinal masses. We describe a patient with CD who presented with diffuse adenopathy involving the inguinal, paratracheal, retroperitoneal, axillary, and pelvic regions. CASE PRESENTATION: Case report describing presentation, work-up, management and clinical course of a patient with Castleman's disease in the setting of a county hospital in metropolitan area. Patient was treated with chemotherapeutic agents. CONCLUSIONS: To our knowledge, this represents the first case of CD involving an HIV-positive patient with a negative Human Herpes Virus (HHV-8) viral panel. Because patients with similar clinical histories are at high risk for the development of non-Hodgkin's lymphoma and Kaposi sarcoma, regular medical surveillance is recommended

    Hepatitis C virus cell-cell transmission and resistance to direct-acting antiviral agents

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    Hepatitis C virus (HCV) is transmitted between hepatocytes via classical cell entry but also uses direct cell-cell transfer to infect neighboring hepatocytes. Viral cell-cell transmission has been shown to play an important role in viral persistence allowing evasion from neutralizing antibodies. In contrast, the role of HCV cell-cell transmission for antiviral resistance is unknown. Aiming to address this question we investigated the phenotype of HCV strains exhibiting resistance to direct-acting antivirals (DAAs) in state-of-the-art model systems for cell-cell transmission and spread. Using HCV genotype 2 as a model virus, we show that cell-cell transmission is the main route of viral spread of DAA-resistant HCV. Cell-cell transmission of DAA-resistant viruses results in viral persistence and thus hampers viral eradication. We also show that blocking cell-cell transmission using host-targeting entry inhibitors (HTEIs) was highly effective in inhibiting viral dissemination of resistant genotype 2 viruses. Combining HTEIs with DAAs prevented antiviral resistance and led to rapid elimination of the virus in cell culture model. In conclusion, our work provides evidence that cell-cell transmission plays an important role in dissemination and maintenance of resistant variants in cell culture models. Blocking virus cell-cell transmission prevents emergence of drug resistance in persistent viral infection including resistance to HCV DAAs

    Sistemas dinámicos y aplicaciones

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    La Teoría de sistemas dinámicos abarca una gran variedad de problemas, técnicas y aplicaciones, y ha crecido en estrecha vinculación con otras disciplinas. Este proyecto se propone avanzar en el conocimiento referido a algunas líneas de investigación y sus aplicaciones: - Análisis de oscilaciones en sistemas dinámicos. - Modelos no lineales y dinámica de poblaciones. - Sistemas dinámicos no lineales, discretos y determinísticos, vinculados a sistemas de tiempo real.Eje: Procesamiento de señales y sistemas en tiempo realRed de Universidades con Carreras en Informática (RedUNCI
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