1,263 research outputs found
Reducing energy usage in resource-intensive Java-based scientific applications via micro-benchmark based code refactorings
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
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 ANDRĂ THROUGH ROSSOâS GRAPH
A falta de vigilancia da condição nutricional da gestante durante o exame prĂŠ-natal tem dificultado intervençþes adequadas no sentido de prevenir a ocorrĂŞncia do baixo peso ao nascimento (BP). Foram avaliadas, prospectivamente, 95 gestantes de baixo nĂvel sĂłcio-econĂ´mico do MunicĂpio de Santo AndrĂŠ, para realização de exame prĂŠ-natal, utilizando-se a curva de Rosso para sua classificação nutricional. O percentual de mĂŁe com baixo peso foi de 36,8%. As mĂŁes com mais de duas gestaçþes apresentaram maior ocorrĂŞncia de sobrepeso ou obesidade e as com menos de duas gestaçþes, percentual significativamente maior de baixo peso. A anemia tambĂŠm se associou de maneira significativa Ă s gestantes de baixo peso. O presente trabalho ressalta a importancia da implantação de instrumento na rede bĂĄsica de saĂşde 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 recĂŠm-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 AndrĂŠ, SĂŁo Paulo) were evaluated, for accomplishment of prenatal exammation, using Rossoâs 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
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
. 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
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
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
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
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
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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