Performance Models for Data Transfers: A Case Study with Molecular Chemistry Kernels

With increasing complexity of hardwares, systems with different memory nodes are ubiquitous in High Performance Computing (HPC). It is paramount to develop strategies to overlap the data transfers between memory nodes with computations in order to exploit the full potential of these systems. In this article, we consider the problem of deciding the order of data transfers between two memory nodes for a set of independent tasks with the objective to minimize the makespan. We prove that with limited memory capacity, obtaining the optimal order of data transfers is a NP-complete problem. We propose several heuristics for this problem and provide details about their favorable situations. We present an analysis of our heuristics on traces, obtained by running 2 molecular chemistry kernels, namely, Hartree-Fock (HF) and Coupled Cluster Single Double (CCSD) on 10 nodes of an HPC system. Our results show that some of our heuristics achieve significant overlap for moderate memory capacities and are very close to the lower bound of makespan

The partition function of the two-matrix model as an isomonodromic tau-function

We consider the Itzykson-Zuber-Eynard-Mehta two-matrix model and prove that the partition function is an isomonodromic tau function in a sense that generalizes Jimbo-Miwa-Ueno's. In order to achieve the generalization we need to define a notion of tau-function for isomonodromic systems where the ad-regularity of the leading coefficient is not a necessary requirement.Comment: 22 pages, 1 figur

Gravitational wave forms for a three-body system in Lagrange's orbit: parameter determinations and a binary source test

Continuing work initiated in an earlier publication [Torigoe et al. Phys. Rev. Lett. {\bf 102}, 251101 (2009)], gravitational wave forms for a three-body system in Lagrange's orbit are considered especially in an analytic method. First, we derive an expression of the three-body wave forms at the mass quadrupole, octupole and current quadrupole orders. By using the expressions, we solve a gravitational-wave {\it inverse} problem of determining the source parameters to this particular configuration (three masses, a distance of the source to an observer, and the orbital inclination angle to the line of sight) through observations of the gravitational wave forms alone. For this purpose, the chirp mass to a three-body system in the particular configuration is expressed in terms of only the mass ratios by deleting initial angle positions. We discuss also whether and how a binary source can be distinguished from a three-body system in Lagrange's orbit or others.Comment: 21 pages, 3 figures, 1 table; text improved, typos corrected; accepted for publication in PR

Thermal stability of titanium hydride thin films

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Local hydrogen environments in Gd 1− x Fe x thin films amorphous alloys from effusion experiments

International audienceThin films of hydrogenated Gd,-XFeX (0.25 =%< 0.90) amorphous-alloys were prepared by reactive evaporation. Effusion experiments, showing several hydrogen release peaks, allowed us to describe the site distribution of hydrogen in these alloys. The different local environments correspond to tetrahedral sites and the stability of these sites increases with the number of rare-earth neighbors

Análisis de la flora vascular endémica y amenazada de los medios salinos de Andalucía (S. España)

Se analiza la flora vascular halófila endémica y amenazada presente en los medios salinos de Andalucía, a partir del catálogo florístico elaborado en el territorio entre los años 2003 y 2008. De un total de 162 especies y subespecies de plantas vasculares que fueron detectados en los ecosistemas halófilos andaluces, 43 taxones son endémicos y 41 taxones están amenazados y/o protegidos por la legislación a un nivel local, regional o nacional.Analysis of endemic and threatened vascular flora in saline environments of Andalusia (S. Spain). An analysis on the endemic and endangered halophyte vascular flora of saline environments of Andalusia is carried out, starting out from the catalog of flora recorded in the territory between the years 2003 and 2008. A total amount of 162 species and subspecies of vascular plants were detected in Andalusian saline environ - ments, 43 of them being endemics and 41 threatened and/or protected by law at different levels: local, regional and nationalConsejería de Economía, Innovación y Ciencia de la Junta de Andalucí

Magnetic behavior of Fe x Sn 1 − x amorphous alloys near the critical composition

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Estudio florístico de los medios húmedos salinos de Andalucía (S. de España). Catálogo y análisis de la flora vascular halófila

El objetivo del presente estudio es el conocimiento de la composición florística de los medios húmedos salinos andaluces. Entre 2003 y 2008 se han inventariado un total de 162 especies y subespecies de plantas vasculares que son propias de los medios salinos andaluces, entre las que se encuentran 41 taxones amenazados y/o protegidos y 6 taxones alóctonos. Para cada uno de los taxones se indica el nombre aceptado, sinónimos más usados, familia a la que pertenece, tipo de vegetación en el que suele aparecer, afinidad fitosociológica, ecología, biotipo, termotipo, distribución general y distribución en el área de estudio por unidades fitogeográficas. Finalmente se indica si la especie es invasora en el territorio o si la especie se considera amenazada.Floristic study of the Andalusian saline wetlands (S. Spain). Checklist and floristic analysis of the halophytic vascular flora. The aim of this study is to contribute to the knowledge of the floristic composition of Andalusian saline wetlands. A total of 162 halophytic vascular plant species and subspecies has been recorded between 2003 and 2008, comprising 41 threatened and/or protected taxa and 6 allochthonous species. For each taxon the accepted name, most usual synonyms, botanic family, vegetation type where it usually appears, phytosociologic affinity, ecology, biotype, termotype, general distribution and phytogeographic distribution in the study area is provided. Finally, it is pointed out whether the species is considered invasive or threatened in the territory.Junta de Andalucía. Consejería de Economía, Innovación y CienciaEmpresa de Gestión Medioambiental (EGMASA

Una nueva asociación de vegetación halófila en el sureste de la península ibérica (España): Limonio Majoris-Sarcocornietum fruticosae

Como resultado del estudio de la vegetación de los humedales salinos en Andalucía, se muestra la descripción y caracterización de una nueva asociación halófila desarrollada en los saladares de la Hoya de Baza (Granada). Se trata de una fitocenosis dominada por Sarcocornia fruticosa (L.) A. J. Scott, junto a otros nanofanerófitos suculentos y hemicriptófitos rosulados entre los que destaca el endemismo local Limonium majus (Boiss.) Erben. La asociación Limonio majoris-Sarcocornietum fruticosae ass. nova es propia del distrito Guadiciano-Bastetano (sector Guadiciano-Bacense, provincia Bética) en el piso bioclimático mesomediterráneo semiárido.A new halophytic vegetation association in southeastern Iberian Peninsula (Spain): Limonio majoris-Sarcocornietum fruticosae. As a result of the research on the vegetation of Andalusian saline wetlands, a new halophytic association in the Baza depression (Granada) is characterized and described. This phytocoenoses is mainly dominated by Sarcocornia fruticosa (L.) A. J. Scott, together with other succulent nanophanerophytes and rosulate hemicryptophytes, highlighting the existence of the local endemic taxon Limonium majus (Boiss.) Erben. The new association is named Limonio majoris-Sarcocornietum fruticosae ass. Nova being exclusive of the Guadician-Bastetan district territories (Guadician-Bacensean sector, Baetic province) and developing in the Mesomediterranean semiarid bioclimatic belt.Junta de Andalucía. Consejería de Economía, Innovación y CienciaJunta de Andalucía. Consejería de Medio Ambient

Optical studies of bonding in coevaporated amorphous silicon-tin alloys

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