99,417 research outputs found
The Joint COntrols Project Framework
The Framework is one of the subprojects of the Joint COntrols Project (JCOP),
which is collaboration between the four LHC experiments and CERN. By sharing
development, this will reduce the overall effort required to build and maintain
the experiment control systems. As such, the main aim of the Framework is to
deliver a common set of software components, tools and guidelines that can be
used by the four LHC experiments to build their control systems. Although
commercial components are used wherever possible, further added value is
obtained by customisation for HEP-specific applications. The supervisory layer
of the Framework is based on the SCADA tool PVSS, which was selected after a
detailed evaluation. This is integrated with the front-end layer via both OPC
(OLE for Process Control), an industrial standard, and the CERN-developed DIM
(Distributed Information Management System) protocol. Several components are
already in production and being used by running fixed-target experiments at
CERN as well as for the LHC experiment test beams. The paper will give an
overview of the key concepts behind the project as well as the state of the
current development and future plans.Comment: Paper from the 2003 Computing in High Energy and Nuclear Physics
(CHEP03), La Jolla, Ca, USA, March 2003, 4 pages, PDF. PSN THGT00
Interplay between the ionic and electronic density profiles in liquid metal surfaces
First principles molecular dynamics simulations have been performed for the
liquid-vapor interfaces of liquid Li, Mg, Al and Si. We analize the oscillatory
ionic and valence electronic density profiles obtained, their wavelengths and
the mechanisms behind their relative phase-shift.Comment: Accepted for publication in Journal of Chemical Physic
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The Supply of Social Insurance
We propose a theory of the welfare state, in which social transfers are chosen by a governing group interacting with non-governing groups repeatedly. Social demands from the non-governing groups are credible because these groups have the ability to generate social conflict. In this context social insurance is supplied as an equilibrium response to income risks within a self-enforcing social contract. When we explore the implications of such a view of the social contract, we find four main determinants of the welfare state: the degree of aggregate income risk; the heterogeneity of group-specific income risks; the public administration’s ability to implement group-specific transfers; and the ability of the non-governing groups to coordinate their social demands. We also analyze the link between public good provision and social insurance
Parent Stars of Extrasolar Planets. XI. Trends with Condensation Temperature Revisited
We report the results of abundance analyses of new samples of stars with
planets and stars without detected planets. We employ these data to compare
abundance-condensation temperature trends in both samples. We find that stars
with planets have more negative trends. In addition, the more metal-rich stars
with planets display the most negative trends. These results confirm and extend
the findings of Ramirez et al. (2009) and Melendez et al. (2009), who
restricted their studies to solar analogs. We also show that the differences
between the solar photospheric and CI meteoritic abundances correlate with
condensation temperature.Comment: 7 pages, 11 figures; to be published in MNRA
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