| 1. |
- Abelev, Betty, et al.
(författare)
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Long-range angular correlations on the near and away side in p-Pb collisions at root S-NN=5.02 TeV
- 2013
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 719:1-3, s. 29-41
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Tidskriftsartikel (refereegranskat)abstract
- Angular correlations between charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV for transverse momentum ranges within 0.5 < P-T,P-assoc < P-T,P-trig < 4 GeV/c. The correlations are measured over two units of pseudorapidity and full azimuthal angle in different intervals of event multiplicity, and expressed as associated yield per trigger particle. Two long-range ridge-like structures, one on the near side and one on the away side, are observed when the per-trigger yield obtained in low-multiplicity events is subtracted from the one in high-multiplicity events. The excess on the near-side is qualitatively similar to that recently reported by the CMS Collaboration, while the excess on the away-side is reported for the first time. The two-ridge structure projected onto azimuthal angle is quantified with the second and third Fourier coefficients as well as by near-side and away-side yields and widths. The yields on the near side and on the away side are equal within the uncertainties for all studied event multiplicity and p(T) bins, and the widths show no significant evolution with event multiplicity or p(T). These findings suggest that the near-side ridge is accompanied by an essentially identical away-side ridge. (c) 2013 CERN. Published by Elsevier B.V. All rights reserved.
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| 2. |
- Abelev, Betty, et al.
(författare)
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Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :11
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Tidskriftsartikel (refereegranskat)abstract
- The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.
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| 3. |
- Abelev, Betty, et al.
(författare)
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Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :7
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Tidskriftsartikel (refereegranskat)abstract
- We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.
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| 4. |
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| 6. |
- Fritzson, Peter, 1952-, et al.
(författare)
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Modelica - A Strongly Typed System Specification Language for Safe Engineering Practices
- 2004
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Ingår i: Proceedings of the SimSAFE Conference, Karlskoga, Sweden, June 15-17, 2004.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Recent years have witnessed a significant growth of interest in modeling and simulation of engineering application systems. A key factor in this growth has been the development of efficient equation-based simulation languages, with Modelica as one of the prime examples. Such languages have been designed to allow automatic generation of efficient simulation code from declarative specifications. A major objective is to facilitate reuse and exchange of models, model libraries, and simulation specifications.The Modelica language and its associated support technologies have achieved considerable success through the development of domain libraries in a number of technical areas. By using domain-libraries complex simulation models can be built by aggregating and combining submodels and components from various physical domains.The concept of safe engineering practices has been one of the most important guidelines when designing Modelica. This made it natural to make Modelica a statically strongly typed language, which allows the compiler to check the consistency of a design before it is executed, in contrast to dynamically typed languages such as Matlab.The ability of static checking has also influenced the design of conditional equations and the ongoing the design of variant handling features in Modelica. Moreover, the language allows support for standardized physical units, thus enabling tools for unit checking of relationships and connections between interfaces. A third possible level of checking is through design rules within application-specific libraries, which can be enforced via assert statements. These properties taken together gives a good foundation for safe engineering practices, even though more work is needed to further increase the safety quality level.
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| 7. |
- Fritzson, Peter, et al.
(författare)
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The Open Source Modelica Project
- 2002
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Ingår i: Proceedings from The 2nd International Modelica Conference was held March 18-19, 2002, Oberpfaffenhofen, Germany. - : Modelica Association. ; , s. 297-306
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Konferensbidrag (refereegranskat)abstract
- The open source software movement has received enormous attention in recent years. It is often characterized as a fundamentally new way to develop software. This paper describes an effort to develop an open source Modelica environment to a large extent based on a formal specification of Modelica, coordinated by PELAB, Department of Computer and Information Science, Linköping University, Sweden. The current version of the system provides an efficient interactive computational environment for most of the expression, algorithm, and function parts of the Modelica language as well as an almost complete static semantics for Modelica 2.0.The longer-term goal is to provide reasonable simulation execution support, at least for less complex models, also for the equation part of Modelica which is the real essence of the language. People are invited to contribute to this open source project, e.g. to provide implementations of numerical algorithms as Modelica functions, add-on tools to the environment, or contributions to compiler itself. The source code of the tool components of the open source Modelica environment is available under the Gnu Public License, GPL. The library components are available under the same conditions as the standard Modelica library. The system currently runs under Microsoft Windows, Linux, and Sun Sparc Solaris. A benchmark example of running a simplex algorithm shows that the performance of the current system is close to the performance of handwritten C code for the same algorithm.
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| 8. |
- Agardh, Emilie E., et al.
(författare)
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Disease Burden Attributed to Drug use in the Nordic Countries : a Systematic Analysis for the Global Burden of Diseases, Injuries, and Risk Factors Study 2019
- 2023
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Ingår i: International Journal of Mental Health and Addiction. - 1557-1874 .- 1557-1882.
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Tidskriftsartikel (refereegranskat)abstract
- The Nordic countries share similarities in many social and welfare domains, but drug policies have varied over time and between countries. We wanted to compare differences in mortality and disease burden attributed to drug use over time. Using results from the Global Burden of Disease (GBD) study, we extracted age-standardized estimates of deaths, DALYs, YLLs and YLDs per 100 000 population for Denmark, Finland, Iceland, Norway, and Sweden during the years 1990 to 2019. Among males, DALY rates in 2019 were highest in Finland and lowest in Iceland. Among females, DALY rates in 2019 were highest in Iceland and lowest in Sweden. Sweden have had the highest increase in burden since 1990, from 252 DALYs to 694 among males, and from 111 to 193 among females. Norway had a peak with highest level of all countries in 2001-2004 and thereafter a strong decline. Denmark have had the most constant burden over time, 566-600 DALYs among males from 1990 to 2010 and 210-240 DALYs among females. Strict drug policies in Nordic countries have not prevented an increase in some countries, so policies need to be reviewed.
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| 9. |
- Aronsson, Peter, et al.
(författare)
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A Task Merging Technique for Parallelization of Modelica Models
- 2005
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Ingår i: 4th International Modelica Conference. ; , s. -128
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Konferensbidrag (refereegranskat)abstract
- This paper presents improvements on techniques of merging tasks in task graphs generated in the ModPar automatic parallelization module of the OpenModelica compiler. Automatic parallelization is performed on Modelica models by building data dependency graphs called task graphs from the model equations. To handle large task graphs with fine granularity, i.e. low ratio of execution and communication cost, the tasks are merged. This is done by using a graph rewrite system(GRS), which is a set of graph transformation rules applied on the task graph. In this paper we have solved the confluence problem of the task merging system by giving priorities to the merge rules. A GRS is confluent if the application order of the graph transformations does not matter, i.e. the same result is gained regardless of application order. We also present a Modelica model suited for automatic parallelization and show results on this using the ModPar module in the OpenModelica compiler.
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| 10. |
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