331 research outputs found

    Log Pre-Processing and Grammatical Inference for Web Usage Mining

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    International audienceIn this paper, we propose a Web Usage Mining pre-processing method to retrieve missing data from the server log files. Moreover, we propose two levels of evaluation: directly on reconstructed data, but also after a machine learning step by evaluating inferred grammatical models. We conducted some experiments and we showed that our algorithm improves the quality of user data

    Quelles distributions spatiales des systÚmes de culture pour limiter l'occurence des crises de gestion quantitative de l'eau ? Une démarche de conception évaluation sur le territoire irrigué de l'Aveyron aval

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    Dans les territoires irriguĂ©s exposĂ©s aux crises de gestion quantitative de l’eau, la sĂ©vĂ©ritĂ© des Ă©tiages dĂ©pend des interactions entre systĂšmes de culture, situations pĂ©doclimatiques, hydrologie, lĂąchers d’eau et restriction d’irrigation. Dans de nombreuses situations, l’absence de nouvelles solutions de stockage et les tensions entre gestionnaires et usagers de l’eau rendent nĂ©cessaire la planification des Ă©tiages. Mes travaux explorent le potentiel de « la gestion spatiale » de l’eau pour mettre en adĂ©quation la dynamique des prĂ©lĂšvements pour l’irrigation avec celle de l’offre en eau disponible (naturelle et stockĂ©e). Je propose une mĂ©thodologie participative de conception-Ă©valuation d’organisations territoriales des activitĂ©s agricoles, dĂ©ployĂ©e sur l’aval du bassin versant de l’Aveyron (800 kmÂČ), en trois Ă©tapes: (1) modĂ©liser le systĂšme socio-agro-hydrologique, (2) concevoir des alternatives de distribution spatiale des systĂšmes de culture, (3) conduire une Ă©valuation intĂ©grĂ©e des alternatives face Ă  la variabilitĂ© climatique observĂ©e. Ces travaux combinent des mĂ©thodes, connaissances et outils « hard and soft », et font usage de la plateforme de simulation multi-agent MAELIA. Le processus a permis de formaliser des visions d’acteurs et de poser les bases d’une concertation multi acteur. Cependant la simulation des impacts de ces alternatives a montrĂ© leurs limites pour rĂ©gler le problĂšme de dĂ©ficit structurel en eau. Cette dĂ©marche pourrait ĂȘtre prolongĂ©e pour aboutir Ă  des propositions opĂ©rationnelles

    Quelles distributions spatiales des systÚmes de culture pour limiter l'occurence des crises de gestion quantitative de l'eau ? Une démarche de conception évaluation sur le territoire irrigué de l'Aveyron aval

    Get PDF
    Dans les territoires irriguĂ©s exposĂ©s aux crises de gestion quantitative de l’eau, la sĂ©vĂ©ritĂ© des Ă©tiages dĂ©pend des interactions entre systĂšmes de culture, situations pĂ©doclimatiques, hydrologie, lĂąchers d’eau et restriction d’irrigation. Dans de nombreuses situations, l’absence de nouvelles solutions de stockage et les tensions entre gestionnaires et usagers de l’eau rendent nĂ©cessaire la planification des Ă©tiages. Mes travaux explorent le potentiel de « la gestion spatiale » de l’eau pour mettre en adĂ©quation la dynamique des prĂ©lĂšvements pour l’irrigation avec celle de l’offre en eau disponible (naturelle et stockĂ©e). Je propose une mĂ©thodologie participative de conception-Ă©valuation d’organisations territoriales des activitĂ©s agricoles, dĂ©ployĂ©e sur l’aval du bassin versant de l’Aveyron (800 kmÂČ), en trois Ă©tapes: (1) modĂ©liser le systĂšme socio-agro-hydrologique, (2) concevoir des alternatives de distribution spatiale des systĂšmes de culture, (3) conduire une Ă©valuation intĂ©grĂ©e des alternatives face Ă  la variabilitĂ© climatique observĂ©e. Ces travaux combinent des mĂ©thodes, connaissances et outils « hard and soft », et font usage de la plateforme de simulation multi-agent MAELIA. Le processus a permis de formaliser des visions d’acteurs et de poser les bases d’une concertation multi acteur. Cependant la simulation des impacts de ces alternatives a montrĂ© leurs limites pour rĂ©gler le problĂšme de dĂ©ficit structurel en eau. Cette dĂ©marche pourrait ĂȘtre prolongĂ©e pour aboutir Ă  des propositions opĂ©rationnelles. ABSTRACT : In irrigated landscapes exposed to quantitative water management crisis, the intensity of low flows depends on interactions between cropping systems, pedoclimatic situation hydrology, water releases and withdrawal restrictions. In many situations there are no opportunities for more water storage, thus tensions occur between water managers and users, which makes the planning of water demand dynamics necessary. My work explores the potentials in the “spatial management of water” to align the water demand dynamics with natural and stored water availability. I present a 3 step, participatory method to design and assess agricultural landscapes: (1) model the Social-Agro Hydrological system, (2) design alternative spatial distribution of the cropping systems, (3) carry an integrated assessment of those alternatives based on observed climatic variability. This method combines “hard” and “soft” methods, knowledge and tools, and uses the MAELIA multi-agent simulation platform. I tested the method tested in the downstream area of the Aveyron River (800 kmÂČ Southwestern France). It allowed to formalize the actors’ visions on alternative distributions of the cropping systems. However they showed to be limited in solving the water deficit issue. The method could be continued to reach operational proposals

    Outbreak of West Nile virus causing severe neurological involvement in children, Nuba Mountains, Sudan, 2002.

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    An atypical outbreak of West Nile virus (WNV) occurred in Ngorban County, South Kordophan, Sudan, from May to August 2002. We investigated the epidemic and conducted a case-control study in the village of Limon. Blood samples were obtained for cases and controls. Patients with obvious sequelae underwent cerebrospinal fluid (CSF) sampling as well. We used enzyme-linked immunosorbent assay (ELISA) and neutralization tests for laboratory diagnosis and identified 31 cases with encephalitis, four of whom died. Median age was 36 months. Bivariate analysis did not reveal any significant association with the risk factors investigated. Laboratory analysis confirmed presence of IgM antibodies caused by WNV in eight of 13 cases, indicative of recent viral infection. The unique aspects of the WNW outbreak in Sudan, i.e. disease occurrence solely among children and the clinical domination of encephalitis, involving severe neurological sequelae, demonstrate the continuing evolution of WNV virulence. The spread of such a virus to other countries or continents cannot be excluded

    West Nile outbreak in horses in southern France, 2000: the return after 35 years.

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    On September 6, 2000, two cases of equine encephalitis caused by West Nile (WN) virus were reported in southern France (HĂ©rault Province), near Camargue National Park, where a WN outbreak occurred in 1962. Through November 30, 76 cases were laboratory confirmed among 131 equines with neurologic disorders. The last confirmed case was on November 3, 2000. All but three cases were located in a region nicknamed "la petite Camargue," which has several large marshes, numerous colonies of migratory and resident birds, and large mosquito populations. No human case has been confirmed among clinically suspected patients, nor have abnormal deaths of birds been reported. A serosurvey has been undertaken in horses in the infected area, and other studies are in progress
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