787 research outputs found
Managing Dynamic User Communities in a Grid of Autonomous Resources
One of the fundamental concepts in Grid computing is the creation of Virtual
Organizations (VO's): a set of resource consumers and providers that join
forces to solve a common problem. Typical examples of Virtual Organizations
include collaborations formed around the Large Hadron Collider (LHC)
experiments. To date, Grid computing has been applied on a relatively small
scale, linking dozens of users to a dozen resources, and management of these
VO's was a largely manual operation. With the advance of large collaboration,
linking more than 10000 users with a 1000 sites in 150 counties, a
comprehensive, automated management system is required. It should be simple
enough not to deter users, while at the same time ensuring local site autonomy.
The VO Management Service (VOMS), developed by the EU DataGrid and DataTAG
projects[1, 2], is a secured system for managing authorization for users and
resources in virtual organizations. It extends the existing Grid Security
Infrastructure[3] architecture with embedded VO affiliation assertions that can
be independently verified by all VO members and resource providers. Within the
EU DataGrid project, Grid services for job submission, file- and database
access are being equipped with fine- grained authorization systems that take VO
membership into account. These also give resource owners the ability to ensure
site security and enforce local access policies. This paper will describe the
EU DataGrid security architecture, the VO membership service and the local site
enforcement mechanisms Local Centre Authorization Service (LCAS), Local
Credential Mapping Service(LCMAPS) and the Java Trust and Authorization
Manager.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics
(CHEP03), La Jolla, Ca, USA, March 2003, 7 pages, LaTeX, 5 eps figures. PSN
TUBT00
Storage Infrastructure at the INFN LHC Tier-1
In this paper we will describe the Storage Infrastructure of the INFN-CNAF Tier-1, used to store data of High Energy Physics experiments, in particular those operating at the Large Hadron Collider
LARES/WEBER-SAT and the equivalence principle
It has often been claimed that the proposed Earth artificial satellite
LARES/WEBER-SAT-whose primary goal is, in fact, the measurement of the general
relativistic Lense-Thirring effect at a some percent level-would allow to
greatly improve, among (many) other things, the present-day (10^-13) level of
accuracy in testing the equivalence principle as well. Recent claims point
towards even two orders of magnitude better, i.e. 10^-15. In this note we show
that such a goal is, in fact, unattainable by many orders of magnitude being,
instead, the achievable level of the order of 10^-9.Comment: LaTex, 4 pages, no figures, no tables, 26 references. Proofs
corrections included. To appear in EPL (Europhysics Letters
Migraine-attributed burden, impact and disability, and migraine-impacted quality of life : Expert consensus on definitions from a Delphi process
Migraine-attributed burden, impact, disability and migraine-impacted quality of life are important concepts in clinical management, clinical and epidemiological research, and health policy, requiring clear and agreed definitions. We aimed to formulate concise and precise definitions of these concepts by expert consensus. We searched the terms migraine-attributed burden, impact, disability and migraine-impacted quality of life in Embase and Medline from 1974 and 1946 respectively. We followed a Delphi process to reach consensus on definitions. We found widespread conflation of concepts and inconsistent terminology within publications. Following three Delphi rounds, we defined migraine-attributed burden as "the summation of all negative consequences of the disease or its diagnosis"; migraine-attributed impact as "the effect of the disease, or its diagnosis, on a specified aspect of life, health or wellbeing"; migraine-attributed disability as "physical, cognitive and mental incapacities imposed by the disease"; and migraine-impacted quality of life as "the subjective assessment by a person with the disease of their general wellbeing, position and prospects in life". We complemented each definition with a detailed description. These definitions and descriptions should foster consistency and encourage more appropriate use of currently available quantifying instruments and aid the future development of other
Migraine-attributed burden, impact and disability, and migraine-impacted quality of life : Expert consensus on definitions from a Delphi process
Migraine-attributed burden, impact, disability and migraine-impacted quality of life are important concepts in clinical management, clinical and epidemiological research, and health policy, requiring clear and agreed definitions. We aimed to formulate concise and precise definitions of these concepts by expert consensus. We searched the terms migraine-attributed burden, impact, disability and migraine-impacted quality of life in Embase and Medline from 1974 and 1946 respectively. We followed a Delphi process to reach consensus on definitions. We found widespread conflation of concepts and inconsistent terminology within publications. Following three Delphi rounds, we defined migraine-attributed burden as "the summation of all negative consequences of the disease or its diagnosis"; migraine-attributed impact as "the effect of the disease, or its diagnosis, on a specified aspect of life, health or wellbeing"; migraine-attributed disability as "physical, cognitive and mental incapacities imposed by the disease"; and migraine-impacted quality of life as "the subjective assessment by a person with the disease of their general wellbeing, position and prospects in life". We complemented each definition with a detailed description. These definitions and descriptions should foster consistency and encourage more appropriate use of currently available quantifying instruments and aid the future development of other
VOMS, an Authorization System for Virtual Organizations
We briefly describe the authorization requirements, focusing on the framework of the DataGrid and DataTAG Projects and illustrate the architecture of a new service we have developed, the Virtual Organization Membership Service (VOMS), to manage authorization information in Virtual Organization scope
long term data preservation for cdf at infn cnaf
Long-term preservation of experimental data (intended as both raw and derived formats) is one of the emerging requirements coming from scientific collaborations. Within the High Energy Physics community the Data Preservation in High Energy Physics (DPHEP) group coordinates this effort. CNAF is not only one of the Tier-1s for the LHC experiments, it is also a computing center providing computing and storage resources to many other HEP and non-HEP scientific collaborations, including the CDF experiment. After the end of data taking in 2011, CDF is now facing the challenge to both preserve the large amount of data produced during several years of data taking and to retain the ability to access and reuse it in the future. CNAF is heavily involved in the CDF Data Preservation activities, in collaboration with the Fermilab National Laboratory (FNAL) computing sector. At the moment about 4 PB of data (raw data and analysis-level ntuples) are starting to be copied from FNAL to the CNAF tape library and the framework to subsequently access the data is being set up. In parallel to the data access system, a data analysis framework is being developed which allows to run the complete CDF analysis chain in the long term future, from raw data reprocessing to analysis-level ntuple production. In this contribution we illustrate the technical solutions we put in place to address the issues encountered as we proceeded in this activity
Fundamental physics and absolute positioning metrology with the MAGIA lunar orbiter
MAGIA is a mission approved by the Italian Space Agency (ASI) for Phase A study. Using a single large-diameter laser retroreflector, a large laser retroreflector array and an atomic clock onboard MAGIA we propose to perform several fundamental physics and absolute positioning metrology experiments: VESPUCCI, an improved test of the gravitational redshift in the Earth–Moon system predicted by General Relativity; MoonLIGHT-P, a precursor test of a second generation Lunar Laser Ranging (LLR) payload for precision gravity and lunar science measurements under development for NASA, ASI and robotic missions of the proposed International Lunar Network (ILN); Selenocenter (the center of mass of the Moon), the determination of the position of the Moon center of mass with respect to the International Terrestrial Reference Frame/System (ITRF/ITRS); this will be compared to the one from Apollo and Lunokhod retroreflectors on the surface; MapRef, the absolute referencing of MAGIA's lunar altimetry, gravity and geochemical maps with respect to the ITRF/ITRS. The absolute positioning of MAGIA will be achieved thanks to: (1) the laboratory characterization of the retroreflector performance at INFN-LNF; (2) the precision tracking by the International Laser Ranging Service (ILRS), which gives two fundamental contributions to the ITRF/ITRS, i.e. the metrological definition of the geocenter (the Earth center of mass) and of the scale of length; (3) the radio science and accelerometer payloads; (4) support by the ASI Space Geodesy Center in Matera, Italy. Future ILN geodetic nodes equipped with MoonLIGHT and the Apollo/Lunokhod retroreflectors will become the first realization of the International Moon Reference Frame (IMRF), the lunar analog of the ITRF
Determination of CP and CPT violation parameters in the neutral kaon system using the Bell-Steinberger relation and data from the KLOE experiment
We present an improved determination of the CP and CPT violation parameters
Re(epsilon) and Im(delta) based on the unitarity condition (Bell-Steinberger
relation) and on recent results from the KLOE experiment. We find Re(epsilon) =
(159.6 \pm 1.3)10^-5 and Im(delta) = (0.4 \pm 2.1)10^-5, consistent with no CPT
violation.Comment: Submitted to JHE
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