1,263 research outputs found

    Reducing energy usage in resource-intensive Java-based scientific applications via micro-benchmark based code refactorings

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    In-silico research has grown considerably. Today's scientific code involves long-running computer simulations and hence powerful computing infrastructures are needed. Traditionally, research in high-performance computing has focused on executing code as fast as possible, while energy has been recently recognized as another goal to consider. Yet, energy-driven research has mostly focused on the hardware and middleware layers, but few efforts target the application level, where many energy-aware optimizations are possible. We revisit a catalog of Java primitives commonly used in OO scientific programming, or micro-benchmarks, to identify energy-friendly versions of the same primitive. We then apply the micro-benchmarks to classical scientific application kernels and machine learning algorithms for both single-thread and multi-thread implementations on a server. Energy usage reductions at the micro-benchmark level are substantial, while for applications obtained reductions range from 3.90% to 99.18%.Fil: Longo, Mathias. Consejo Nacional de Investigaciones CientĂ­ficas y TĂŠcnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Tandil. Instituto Superior de IngenierĂ­a del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de IngenierĂ­a del Software; Argentina. University of Southern California; Estados UnidosFil: Rodriguez, Ana Virginia. Consejo Nacional de Investigaciones CientĂ­ficas y TĂŠcnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Tandil. Instituto Superior de IngenierĂ­a del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de IngenierĂ­a del Software; ArgentinaFil: Mateos Diaz, Cristian Maximiliano. Consejo Nacional de Investigaciones CientĂ­ficas y TĂŠcnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Tandil. Instituto Superior de IngenierĂ­a del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de IngenierĂ­a del Software; ArgentinaFil: Zunino Suarez, Alejandro Octavio. Consejo Nacional de Investigaciones CientĂ­ficas y TĂŠcnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Tandil. Instituto Superior de IngenierĂ­a del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de IngenierĂ­a del Software; Argentin

    Towards integrating mobile devices into dew computing: A model for hour-wise prediction of energy availability

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    With self-provisioning of resources as premise, dew computing aims at providing computing services by minimizing the dependency over existing internetwork back-haul. Mobile devices have a huge potential to contribute to this emerging paradigm, not only due to their proximity to the end user, ever growing computing/storage features and pervasiveness, but also due to their capability to render services for several hours, even days,without being plugged to the electricity grid. Nonetheless,misusing the energy of their batteries can discourage owners to offer devices as resource providers in dew computing environments. Arguably, having accurate estimations of remaining battery would help to take better advantage of a device's computing capabilities. In this paper, we propose a model to estimate mobile devices battery availability by inspecting traces of real mobile device owner's activity and relevant device state variables. Themodel includes a feature extraction approach to obtain representative features/variables, and a prediction approach, based on regression models and machine learning classifiers. On average, the accuracy of our approach, measured with the mean squared error metric, overpasses the one obtained by a relatedwork. Prediction experiments at five hours ahead are performed over activity logs of 23 mobile users across several months.Fil: Longo, Mathias. University of Southern California; Estados UnidosFil: Hirsch JofrĂŠ, MatĂ­as Eberardo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂŠcnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Tandil. Instituto Superior de IngenierĂ­a del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de IngenierĂ­a del Software; ArgentinaFil: Mateos Diaz, Cristian Maximiliano. Consejo Nacional de Investigaciones CientĂ­ficas y TĂŠcnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Tandil. Instituto Superior de IngenierĂ­a del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de IngenierĂ­a del Software; ArgentinaFil: Zunino Suarez, Alejandro Octavio. Consejo Nacional de Investigaciones CientĂ­ficas y TĂŠcnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Tandil. Instituto Superior de IngenierĂ­a del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de IngenierĂ­a del Software; Argentin

    ASSESSING THE NUTRITIONAL CONDITION OF PREGNANT WOMEN IN THE CITY OF SANTO ANDRÉ THROUGH ROSSO’S GRAPH

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    A falta de vigilancia da condição nutricional da gestante durante o exame pré-natal tem dificultado intervenções adequadas no sentido de prevenir a ocorrência do baixo peso ao nascimento (BP). Foram avaliadas, prospectivamente, 95 gestantes de baixo nível sócio-econômico do Município de Santo André, para realização de exame pré-natal, utilizando-se a curva de Rosso para sua classificação nutricional. O percentual de mãe com baixo peso foi de 36,8%. As mães com mais de duas gestações apresentaram maior ocorrência de sobrepeso ou obesidade e as com menos de duas gestações, percentual significativamente maior de baixo peso. A anemia também se associou de maneira significativa às gestantes de baixo peso. O presente trabalho ressalta a importancia da implantação de instrumento na rede básica de saúde para controlar o ganho de peso da gestante, bem como da vigilancia de outros fatores de risco no intuito de reduzir os elevados percentuais de recém-nascidos com BP.The lack of monitoring ofthenutritional condition of pregnamtwomen during theprenatal exammat^lon has made it difficult for interventions aimir g at the prevention of low weight at birth (BP). 45 pregnmt women of low socio-economic levei registered m the posts of the FOUNDATION for ASSISTANCE to INFANCY (FAISA - Santo André, São Paulo) were evaluated, for accomplishment of prenatal exammation, using Rosso’s Graph for its nutritional classification. The achieved percentage of pregnantwomenwi^th low weightwas 36,8%. Mo^therswi^thmore thamtwo ges^tations and wi^th less than two presented greater occurrence of overweight obesi^ty amd low weight, respectively. Higher percentage of amemia in the pregmant women with low weight was verified. Therefore, it is evident that this instrument should be implemented as routine in ^the prenatal examinabon

    Searching for a Stochastic Background of Gravitational Waves with LIGO

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    The Laser Interferometer Gravitational-wave Observatory (LIGO) has performed the fourth science run, S4, with significantly improved interferometer sensitivities with respect to previous runs. Using data acquired during this science run, we place a limit on the amplitude of a stochastic background of gravitational waves. For a frequency independent spectrum, the new limit is ΩGW<6.5×10−5\Omega_{\rm GW} < 6.5 \times 10^{-5}. This is currently the most sensitive result in the frequency range 51-150 Hz, with a factor of 13 improvement over the previous LIGO result. We discuss complementarity of the new result with other constraints on a stochastic background of gravitational waves, and we investigate implications of the new result for different models of this background.Comment: 37 pages, 16 figure

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

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    A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

    Combined search for the quarks of a sequential fourth generation

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    Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO

    Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV

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    The azimuthal anisotropy of charged particles in PbPb collisions at nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS detector at the LHC over an extended transverse momentum (pt) range up to approximately 60 GeV. The data cover both the low-pt region associated with hydrodynamic flow phenomena and the high-pt region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0-60% most-central events, the observed v2 values are found to first increase with pt, reaching a maximum around pt = 3 GeV, and then to gradually decrease to almost zero, with the decline persisting up to at least pt = 40 GeV over the full centrality range measured.Comment: Replaced with published version. Added journal reference and DO
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