The Virgo data acquisition system

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The gravitational wave detector VIRGO

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Towards the petaflop for Lattice QCD simulations the PetaQCD project

International audienceThe study and design of a very ambitious petaflop cluster exclusively dedicated to Lattice QCD simulations started in early '08 among a consortium of 7 laboratories (IN2P3, CNRS, INRIA, CEA) and 2 SMEs. This consortium received a grant from the French ANR agency in July '08, and the PetaQCD project kickoff took place in January '09. Building upon several years of fruitful collaborative studies in this area, the aim of this project is to demonstrate that the simulation of a 256 x 1283 lattice can be achieved through the HMC/ETMC software, using a machine with efficient speed/cost/reliability/power consumption ratios. It is expected that this machine can be built out of a rather limited number of processors (e.g. between 1000 and 4000), although capable of a sustained petaflop CPU performance. The proof-of-concept should be a mock-up cluster built as much as possible with off-the-shelf components, and 2 particularly attractive axis will be mainly investigated, in addition to fast all-purpose multi-core processors: the use of the new brand of IBM-Cell processors (with on-chip accelerators) and the very recent Nvidia GP-GPUs (off-chip co-processors). This cluster will obviously be massively parallel, and heterogeneous. Communication issues between processors, implied by the Physics of the simulation and the lattice partitioning, will certainly be a major key to the project

Objeto, sujeito, inimigo, vovô: um estudo em etnomuseologia comparada entre os Mebêngôkre-Kayapó e Baniwa do Brasil

International audienceAbstract Ethnomuseology seeks to put indigenous people in dialog with their own material culture heritage. This article reflects on collaborative research carried out with Mebêngôkre-Kayapó and Baniwa consultants on important collections of both groups from the early twentieth century. In addition to noting differences between museological or scientific and indigenous concepts about museum objects, we also noticed a number of cultural differences in the way the two indigenous groups related to objects from their past. While both cultural groups attributed subjective characteristics to museum objects, for the Mebêngôkre-Kayapó this subjectivity expressed itself mostly in terms of possible threats to visitors of the museum collections, leading to a hesitancy to handle museum objects, assumed to be war trophies captured in the past from dangerous enemies. The Baniwa, by contrast, expressed great affection for ‘grandpa’s things’, and they felt they had a right to handle objects that represent the heritage of patrilineal clans. This experience in ethnomuseology highlights the diversity of indigenous concepts, attitudes and expectations about museum collections and the need for the dialogical approach to collaborative research.Resumo A etnomuseologia visa engajar os povos indígenas em um diálogo com a sua cultura material. Este artigo reflete sobre uma experiência efetuada no acervo etnográfico do Museu Paraense Emílio Goeldi com interlocutores Mebêngôkre-Kayapó e Baniwa sobre importantes coleções de seus respectivos povos, as quais datam do início do século XX. Além de perceber diferenças entre conceitos museológicos, ou científicos, e indígenas sobre as peças e os processos de musealização, também foi possível observar uma série de diferenças culturais entre os Mebêngôkre-Kayapó e os Baniwa no que concerne à maneira de se relacionar com os objetos de seu passado. Ambos os grupos atribuíram características subjetivas aos objetos no acervo, mas, no caso dos Mebêngôkre-Kayapó, a subjetividade das peças antigas representava uma ameaça aos visitantes do acervo, levando a um certo receio em manusear as peças, concebidas com troféus de guerra capturados de inimigos perigosos. Os Baniwa, ao contrário, expressavam grande carinho com os ‘objetos do vovô’ e sentiam-se no direito de manusear as peças que representam o patrimônio de clãs patrilineais. Esta experiência em etnomuseologia comparada ressalta a diversidade de conceitos, atitudes e expectativas dos povos indígenas perante às coleções museológicas, e a necessidade desta nova abordagem de pesquisa colaborativa