2,821 research outputs found

    RBF neural net based classifier for the AIRIX accelerator fault diagnosis

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    The AIRIX facility is a high current linear accelerator (2-3.5kA) used for flash-radiography at the CEA of Moronvilliers France. The general background of this study is the diagnosis and the predictive maintenance of AIRIX. We will present a tool for fault diagnosis and monitoring based on pattern recognition using artificial neural network. Parameters extracted from the signals recorded on each shot are used to define a vector to be classified. The principal component analysis permits us to select the most pertinent information and reduce the redundancy. A three layer Radial Basis Function (RBF) neural network is used to classify the states of the accelerator. We initialize the network by applying an unsupervised fuzzy technique to the training base. This allows us to determine the number of clusters and real classes, which define the number of cells on the hidden and output layers of the network. The weights between the hidden and the output layers, realising the non-convex union of the clusters, are determined by a least square method. Membership and ambiguity rejection enable the network to learn unknown failures, and to monitor accelerator operations to predict future failures. We will present the first results obtained on the injector.Comment: 3 pages, 4 figures, LINAC'2000 conferenc

    Un nuevo Eurydema Lp. ibérico (Heteroptera, Pentatomidae)

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    Formación del profesorado : asesoramiento sobre educación emocional en centros escolares de infantil y primaria

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    En este artículo presentamos el desarrollo de un asesoramiento sobre educación emocional que se está llevando a cabo en los centros de educación infantil y primaria «Doctor Serés», de Alpicat, y «Pinyana», de Alfarràs (Lleida). Desde el marco teórico de la educación emocional y desde el modelo de consulta colaborativa, el asesoramiento tiene la finalidad de formar al profesorado para la implementación de un programa de educación emocional en todos los ciclos de infantil y primaria.En aquest article presentem el desenvolupament d'un assessorament sobre educació emocional que es du a terme en el centres d'educació infantil i primària «Doctor Serés», de Alpicat, i «Pinyana», de Alfarràs (Lleida). Des del marc teòric de l'educació emocional i des del model de consulta col·laborativa, l'assessorament té la finalitat de formar al professorat per a l'aplicació d'un programa d'educació emocional a tots els cicles d'infantil i primària.In this article we introduce the development of an advice-study about Emotional education which is put into practice in the children's Education Centres and Primary Schools «Doctor Serés», in Alpicat, and «Pinyana», in Alfarràs (Lleida). From the Emotional Education framework and from collaborative consulting model, the aim of this advice-study is to train the teaching staff to implement an emotional education program in all courses of children's and Primary Schools

    On the novel free porphyrins corallistin B, C, D, and E : isolation from the demosponge Corallistes sp. of the Coral Sea and reactivity of their nickel (2) complexes toward formylating reagents

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    Reported here are the novel free corallistin B, C, D, and E, isolated as methyl esters 2a, 3a, 4a, and 5a, respectively, from the sponge #Corallistes sp.(#Lithistida) collected at the basis of the South New Caledonian coral reef. A protocol is also established for formulation of their NiII complexes, which show a different reactivity pattern toward DMF/POCI3 from metal complexes of deuteroporphyrin IX (isolate as 6a) also present in the sponge, the new corallistins, which may be thought to derive from protoporphyrin via heme, account for an amazing 60% of the etOH extract from the sponge. (Résumé d'auteur

    The Dynamic Formation of Prominence Condensations

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    We present simulations of a model for the formation of a prominence condensation in a coronal loop. The key idea behind the model is that the spatial localization of loop heating near the chromosphere leads to a catastrophic cooling in the corona (Antiochos & Klimchuk 1991). Using a new adaptive grid code, we simulate the complete growth of a condensation, and find that after approx. 5,000 s it reaches a quasi-steady state. We show that the size and the growth time of the condensation are in good agreement with data, and discuss the implications of the model for coronal heating and SOHO/TRACE observations.Comment: Astrophysical Journal latex file, 20 pages, 7 b-w figures (gif files

    Agelastatin A, a new skeleton cytotoxic alkaloid of the oroidin family : isolation from the Axinellid sponge Agelas dendromorpha of the Coral Sea

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    Agelastatin A, isolated from the axinellid sponge #Agelas dendromorpha$ of the Coral Sea, is a new skeleton alkaloid with, unusually for the oroidin family to which it belongs, marked cytototoxicity toward tumour cells in culture. (Résumé d'auteur
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