9,324 research outputs found
Towards a Swiss National Research Infrastructure
In this position paper we describe the current status and plans for a Swiss
National Research Infrastructure. Swiss academic and research institutions are
very autonomous. While being loosely coupled, they do not rely on any
centralized management entities. Therefore, a coordinated national research
infrastructure can only be established by federating the various resources
available locally at the individual institutions. The Swiss Multi-Science
Computing Grid and the Swiss Academic Compute Cloud projects serve already a
large number of diverse user communities. These projects also allow us to test
the operational setup of such a heterogeneous federated infrastructure
Large Scale In Silico Screening on Grid Infrastructures
Large-scale grid infrastructures for in silico drug discovery open
opportunities of particular interest to neglected and emerging diseases. In
2005 and 2006, we have been able to deploy large scale in silico docking within
the framework of the WISDOM initiative against Malaria and Avian Flu requiring
about 105 years of CPU on the EGEE, Auvergrid and TWGrid infrastructures. These
achievements demonstrated the relevance of large-scale grid infrastructures for
the virtual screening by molecular docking. This also allowed evaluating the
performances of the grid infrastructures and to identify specific issues raised
by large-scale deployment.Comment: 14 pages, 2 figures, 2 tables, The Third International Life Science
Grid Workshop, LSGrid 2006, Yokohama, Japan, 13-14 october 2006, to appear in
the proceeding
Searches for New Heavy Resonances in Final States with Leptons and Photons in ATLAS and CMS
Searches for resonances in final states with leptons and photons have always
been a powerful tool for discovery in high energy physics. We present here the
latest results from the ATLAS and CMS experiments, based on up to 36.1
fb of 13 TeV proton-proton collisions produced at the Large Hadron
Collider. Detailed results on single lepton, dilepton, diphoton and Z
resonances are included
Spectroscopic [Fe/H] for 98 extra-solar planet-host stars: Exploring the probability of planet formation
We present stellar parameters and metallicities, obtained from a detailed
spectroscopic analysis, for a large sample of 98 stars known to be orbited by
planetary mass companions (almost all known targets), as well as for a
volume-limited sample of 41 stars not known to host any planet. For most of the
stars the stellar parameters are revised versions of the ones presented in our
previous works. However, we also present parameters for 18 stars with planets
not previously published, and a compilation of stellar parameters for the
remaining 4 planet-hosts for which we could not obtain a spectrum. A comparison
of our stellar parameters with values of Teff, log(g), and [Fe/H] available in
the literature shows a remarkable agreement. The derived [Fe/H] values are then
used to confirm the previously known result that planets are more prevalent
around metal-rich stars. Furthermore, we confirm that the frequency of planets
is a strongly rising function of the stellar metallicity, at least for stars
with [Fe/H]>0. While only about 3% of the solar metallicity stars in the
CORALIE planet search sample were found to be orbited by a planet, this number
increases to more than 25% for stars with [Fe/H] above +0.3. Curiously, our
results also suggest that these percentages might remain relatively constant
for values of [Fe/H] lower than about solar, increasing then linearly with the
mass fraction of heavy elements. These results are discussed in the context of
the theories of planetary formation.Comment: 15 pages, 9 figures, Accepted for publication in A&A; Replaced after
language editin
Towards a Mini-App for Smoothed Particle Hydrodynamics at Exascale
The smoothed particle hydrodynamics (SPH) technique is a purely Lagrangian
method, used in numerical simulations of fluids in astrophysics and
computational fluid dynamics, among many other fields. SPH simulations with
detailed physics represent computationally-demanding calculations. The
parallelization of SPH codes is not trivial due to the absence of a structured
grid. Additionally, the performance of the SPH codes can be, in general,
adversely impacted by several factors, such as multiple time-stepping,
long-range interactions, and/or boundary conditions. This work presents
insights into the current performance and functionalities of three SPH codes:
SPHYNX, ChaNGa, and SPH-flow. These codes are the starting point of an
interdisciplinary co-design project, SPH-EXA, for the development of an
Exascale-ready SPH mini-app. To gain such insights, a rotating square patch
test was implemented as a common test simulation for the three SPH codes and
analyzed on two modern HPC systems. Furthermore, to stress the differences with
the codes stemming from the astrophysics community (SPHYNX and ChaNGa), an
additional test case, the Evrard collapse, has also been carried out. This work
extrapolates the common basic SPH features in the three codes for the purpose
of consolidating them into a pure-SPH, Exascale-ready, optimized, mini-app.
Moreover, the outcome of this serves as direct feedback to the parent codes, to
improve their performance and overall scalability.Comment: 18 pages, 4 figures, 5 tables, 2018 IEEE International Conference on
Cluster Computing proceedings for WRAp1
Land cover maps for environmental modeling at multiple scales
As described in the ECOCHANGE proposal, Task01.02.02 “Map production and aggregation”, two major products are generated within this WP. Firstly, land cover maps at high spatial resolutions will be produced for the European Union and for the reference years of 1960, 1990 and 2000. Secondly, thematic and spatial aggregated products will be derived at coarser spatial resolutions in order to synthesize the fragmentation and variability within coarser cells for biodiversity assessment and modelling. The name of the official deliverable is D01.02.01 “Land cover maps for environmental modelling at multiple scales” and includes this report, the digital land cover products and an interactive website to view the data at all thematic and spatial scales
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