Jan Balewski - Academia.edu (original) (raw)
Papers by Jan Balewski
2021 IEEE 28th International Conference on High Performance Computing, Data, and Analytics (HiPC), 2021
Recently, many scientific applications adopt deep learning methods to solve their classification ... more Recently, many scientific applications adopt deep learning methods to solve their classification or regression problems. However, for data-intensive scientific applications, I/O performance can be the major performance bottleneck. In order to effectively solve important real-world problems using deep learning methods on High-Performance Computing (HPC) systems, it is essential to address the poor I/O performance issue in parallel neural network training. In this paper, we propose an asynchronous I/O strategy that can be generally applied to deep learning applications. Our I/O strategy employs an I/O-dedicated thread per process, that performs I/O operations independently of the training progress. The I/O thread reads many training samples at once to reduce the total number of I/O operations per epoch. Given the fixed amount of training data, the fewer the I/O operations per epoch, the shorter the overall I/O time. The I/O operations are also overlapped with the computations using the double-buffering method. We evaluate our I/O strategy using two real-world scientific applications, CosmoFlow and Neuron-Inverter. Our experimental results demonstrate that the proposed I/O strategy significantly improves the scaling performance without affecting the regression performance.
2020 25th International Conference on Pattern Recognition (ICPR), 2021
❏ ERA-Interim reanalysis of the European Center for Medium-Range Weather Forecasting, and binary ... more ❏ ERA-Interim reanalysis of the European Center for Medium-Range Weather Forecasting, and binary masks (i.e., AB or non-AB labels) are provided by the Institute for Atmospheric and Climate Science at the ETH Zurich, Switzerland. ❏ We use temperature, meridional and zonal wind speed, geopotential height, and potential vorticity variables at eight pressure levels (150-500 millibars), 6-hourly at approx. 80 km spatial resolution in the period 1979-2018. ❏ Each geographic region of interest is roughly centered over a local maximum of blocking frequency and has a size of 60 px x 120 px x 40 channels.
15th International Workshop on Deep-Inelastic Scattering and Related Subjects DIS 2007, 2007
STAR Collaboration is reporting measurement of transverse single spin asymmetry (TSSA) for di-jet... more STAR Collaboration is reporting measurement of transverse single spin asymmetry (TSSA) for di-jet produced in collisions of transversely polarized protons at RHIC at √ s = 200 GeV. The measurement probes (Sivers) correlations between the transverse spin orientation of a proton and the transverse momentum directions of its partons. Measured TSSA are consistent with zero. It agrees with recent calculations basedon on non-zero HERMES results from DIS folded with contrabalancing ISI and FSI required to restore time reversal invariance, violated by postulated Sivers mechanism in p+p. With both beams polarized, the wide pseudorapidity (−1 ≤ η ≤ +2) coverage for jets permits separation of Sivers functions for the quark and gluon dominated kinematic regime.
AIP Conference Proceedings, 2009
Measurements of the gluon polarization are a fundamental piece of the experimental program that a... more Measurements of the gluon polarization are a fundamental piece of the experimental program that aims to form a deeper understanding of the origin of the proton spin. The STAR experiment at RHIC measured the longitudinal double-spin asymmetry A{sub LL} for inclusive charged and neutral pions and inclusive jet production. A recent global analysis of polarized DIS data and RHIC spin data disfavors extreme gluon polarization scenarios.
Physics Letters B, 2000
We have measured the longitudinal analyzing power A of the pp ™ppp 0 reaction at 375 MeV bombardi... more We have measured the longitudinal analyzing power A of the pp ™ppp 0 reaction at 375 MeV bombarding energy. We z find that for certain angle combinations of the outgoing particles the observed A is as large as 0.3, demonstrating that z sizeable longitudinal analyzing powers in reactions with multi-particle final states are possible. This result has implications for pp parity violation experiments above the pion threshold. The observed A is dominated by the interference between s z and p wave pions in conjunction with nucleon-nucleon P waves in the final state.
Proceedings of the XVII International Workshop on Deep-Inelastic Scattering and Related Topics, 2009
Journal of Physics: Conference Series, 2014
Proceedings of the XVI International Workshop on Deep-Inelastic Scattering and Related Topics, 2008
AIP Conference Proceedings, 2012
ABSTRACT The STAR experiment at the Relativistic Heavy-Ion Collider at Brookhaven National Labora... more ABSTRACT The STAR experiment at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory is providing fundamental measurements of the spin structure and dynamics of the proton. The STAR experiment has collected W-boson events from collisions of longitudinally polarized protons at s = 500 GeV in 2009 and 2011. In the standard model leadingorder W+/- production proceeds through u+d --> W+ and d+u -->W- These interactions are ideal tools to study the spin-flavor structure of the proton, because the spin-dependent W production cross section Δσ = σ(-->pp)-σ(<--pp) depends strongly on the polarization of the quark and anti-quark in the proton, with -->p (<--p) representing a proton with its spin aligned with (against) its momentum direction. The STAR Electromagnetic Calorimeter triggered on electrons/positrons from the weak decay of the W boson and provided information about energy of the lepton, while the STAR Time Projection Chamber allowed reconstruction of the lepton track and its charge sign. QCD physics background was suppressed by isolation cuts around a candidate lepton track as well as vetoing on transverse energy opposite in azimuth. We present results of the cross section and of the single-spin asymmetry, AL = Δσ/(-->pp)+σ(pp)), for mid-rapidity charge separated W+ and W- production from 2009 data set and a progress report on the 2011 set.
Analyzing powers Ay and spin-dependent total cross section ratios Deltasigma_T/sigma_tot and Delt... more Analyzing powers Ay and spin-dependent total cross section ratios Deltasigma_T/sigma_tot and Deltasigma_L/sigma_tot have been measured for pparrow pnpi^+ at the IUCF cooler ring with a polarized internal target at beam energies of 375 and 400 MeV. To eliminate monitoring errors the target polarization was switched rapidly between left, right (±x), up, down (±y) and along, opposite (±z) to the beam direction. The vertical and longitudinal components of the beam polarization at the target were about equal and were also switched. Reaction protons were detected for angles theta_lab > 6^circ by a system of wire-chambers and plastic scintillators. Reaction neutrons in coincidence with protons were detected in a large area hodoscope with an energy resolution of 20%. This arrangement permitted near complete sampling of all outgoing pion momenta. Analyzing powers and the spin-dependent total cross section ratios for this reaction are large and will be presented. Corrections for nonuniform...
Physics Letters B, 2003
Values of the ratios in the mid-rapidity yields of Λ/Λ = 0.71 ± 0.01(stat.) ± 0.04(sys.), Ξ + /Ξ ... more Values of the ratios in the mid-rapidity yields of Λ/Λ = 0.71 ± 0.01(stat.) ± 0.04(sys.), Ξ + /Ξ − = 0.83 ± 0.04(stat.) ± 0.05(sys.), Ω + /Ω − = 0.95 ± 0.15(stat.) ± 0.05(sys.) and K + /K − = 1.092 ± 0.023(combined) were obtained in central √ s NN = 130 GeV Au+Au collisions using the STAR detector. The ratios indicate that a fraction of the net-baryon number from the initial system is present in the excess of hyperons over anti-hyperons at mid-rapidity. The trend in the progression of the baryon ratios, with increasing strange quark content, is similar to that observed in heavy-ion collisions at lower energies. The value of these ratios may be related to the charged kaon ratio in the framework of simple quark-counting and thermal models.
Physics Letters B, 1998
The energy dependence of the total cross section for the pp −→ pK + Λ reaction was measured in th... more The energy dependence of the total cross section for the pp −→ pK + Λ reaction was measured in the threshold region covering the excess energy range up to 7 MeV. Existing model calculations describe the slope of the measured cross sections well, but are too low by a factor of two to three in rate. The data were used for a precise determination of the beam momentum of the COSY-synchrotron.
Physical Review Letters, 2004
Physical Review C, 2004
We report inclusive photon measurements about midrapidity ([y[ < 0.5) from 197 Au + 197 Au collis... more We report inclusive photon measurements about midrapidity ([y[ < 0.5) from 197 Au + 197 Au collisions at s NN = 130 GeV at RHIC. Photon pair conversions were reconstructed from electron and positron tracks mea sured with the Time Projection Chamber (TPC) of the STAR experiment. With this method, an energy reso lution of ME / E = 2% at 0.5 GeV has been achieved. Reconstructed photons have also been used to measure the transverse momentum (p t) spectra of 7 0 mesons about midrapidity ([y[ < 1) via the 7 0yy decay channel. The fractional contribution of the 7 0yy decay to the inclusive photon spectrum decreases by 20 % ± 5% between p t = 1.65 GeV / c and p t = 2.4 GeV / c in the most central events, indicating that relative to 7 0yy decay the contribution of other photon sources is substantially increasing.
Physical Review C, 2004
We report on the rapidity and centrality dependence of proton and antiproton transverse mass dist... more We report on the rapidity and centrality dependence of proton and antiproton transverse mass distributions from 197 Au+ 197 Au collisions at ͱ s NN = 130 GeV as measured by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). Our results are from the rapidity and transverse momentum range of ͉y͉ Ͻ 0.5 and 0.35Ͻ p t Ͻ 1.00 GeV/ c. For both protons and antiprotons, transverse mass distributions become more convex from peripheral to central collisions demonstrating characteristics of collective expansion. The measured rapidity distributions and the mean transverse momenta versus rapidity are flat within ͉y͉ Ͻ 0.5. Comparisons of our data with results from model calculations indicate that in order to obtain a consistent picture of the proton (antiproton) yields and transverse mass distributions the possibility of prehadronic collective expansion may have to be taken into account.
2021 IEEE 28th International Conference on High Performance Computing, Data, and Analytics (HiPC), 2021
Recently, many scientific applications adopt deep learning methods to solve their classification ... more Recently, many scientific applications adopt deep learning methods to solve their classification or regression problems. However, for data-intensive scientific applications, I/O performance can be the major performance bottleneck. In order to effectively solve important real-world problems using deep learning methods on High-Performance Computing (HPC) systems, it is essential to address the poor I/O performance issue in parallel neural network training. In this paper, we propose an asynchronous I/O strategy that can be generally applied to deep learning applications. Our I/O strategy employs an I/O-dedicated thread per process, that performs I/O operations independently of the training progress. The I/O thread reads many training samples at once to reduce the total number of I/O operations per epoch. Given the fixed amount of training data, the fewer the I/O operations per epoch, the shorter the overall I/O time. The I/O operations are also overlapped with the computations using the double-buffering method. We evaluate our I/O strategy using two real-world scientific applications, CosmoFlow and Neuron-Inverter. Our experimental results demonstrate that the proposed I/O strategy significantly improves the scaling performance without affecting the regression performance.
2020 25th International Conference on Pattern Recognition (ICPR), 2021
❏ ERA-Interim reanalysis of the European Center for Medium-Range Weather Forecasting, and binary ... more ❏ ERA-Interim reanalysis of the European Center for Medium-Range Weather Forecasting, and binary masks (i.e., AB or non-AB labels) are provided by the Institute for Atmospheric and Climate Science at the ETH Zurich, Switzerland. ❏ We use temperature, meridional and zonal wind speed, geopotential height, and potential vorticity variables at eight pressure levels (150-500 millibars), 6-hourly at approx. 80 km spatial resolution in the period 1979-2018. ❏ Each geographic region of interest is roughly centered over a local maximum of blocking frequency and has a size of 60 px x 120 px x 40 channels.
15th International Workshop on Deep-Inelastic Scattering and Related Subjects DIS 2007, 2007
STAR Collaboration is reporting measurement of transverse single spin asymmetry (TSSA) for di-jet... more STAR Collaboration is reporting measurement of transverse single spin asymmetry (TSSA) for di-jet produced in collisions of transversely polarized protons at RHIC at √ s = 200 GeV. The measurement probes (Sivers) correlations between the transverse spin orientation of a proton and the transverse momentum directions of its partons. Measured TSSA are consistent with zero. It agrees with recent calculations basedon on non-zero HERMES results from DIS folded with contrabalancing ISI and FSI required to restore time reversal invariance, violated by postulated Sivers mechanism in p+p. With both beams polarized, the wide pseudorapidity (−1 ≤ η ≤ +2) coverage for jets permits separation of Sivers functions for the quark and gluon dominated kinematic regime.
AIP Conference Proceedings, 2009
Measurements of the gluon polarization are a fundamental piece of the experimental program that a... more Measurements of the gluon polarization are a fundamental piece of the experimental program that aims to form a deeper understanding of the origin of the proton spin. The STAR experiment at RHIC measured the longitudinal double-spin asymmetry A{sub LL} for inclusive charged and neutral pions and inclusive jet production. A recent global analysis of polarized DIS data and RHIC spin data disfavors extreme gluon polarization scenarios.
Physics Letters B, 2000
We have measured the longitudinal analyzing power A of the pp ™ppp 0 reaction at 375 MeV bombardi... more We have measured the longitudinal analyzing power A of the pp ™ppp 0 reaction at 375 MeV bombarding energy. We z find that for certain angle combinations of the outgoing particles the observed A is as large as 0.3, demonstrating that z sizeable longitudinal analyzing powers in reactions with multi-particle final states are possible. This result has implications for pp parity violation experiments above the pion threshold. The observed A is dominated by the interference between s z and p wave pions in conjunction with nucleon-nucleon P waves in the final state.
Proceedings of the XVII International Workshop on Deep-Inelastic Scattering and Related Topics, 2009
Journal of Physics: Conference Series, 2014
Proceedings of the XVI International Workshop on Deep-Inelastic Scattering and Related Topics, 2008
AIP Conference Proceedings, 2012
ABSTRACT The STAR experiment at the Relativistic Heavy-Ion Collider at Brookhaven National Labora... more ABSTRACT The STAR experiment at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory is providing fundamental measurements of the spin structure and dynamics of the proton. The STAR experiment has collected W-boson events from collisions of longitudinally polarized protons at s = 500 GeV in 2009 and 2011. In the standard model leadingorder W+/- production proceeds through u+d --> W+ and d+u -->W- These interactions are ideal tools to study the spin-flavor structure of the proton, because the spin-dependent W production cross section Δσ = σ(-->pp)-σ(<--pp) depends strongly on the polarization of the quark and anti-quark in the proton, with -->p (<--p) representing a proton with its spin aligned with (against) its momentum direction. The STAR Electromagnetic Calorimeter triggered on electrons/positrons from the weak decay of the W boson and provided information about energy of the lepton, while the STAR Time Projection Chamber allowed reconstruction of the lepton track and its charge sign. QCD physics background was suppressed by isolation cuts around a candidate lepton track as well as vetoing on transverse energy opposite in azimuth. We present results of the cross section and of the single-spin asymmetry, AL = Δσ/(-->pp)+σ(pp)), for mid-rapidity charge separated W+ and W- production from 2009 data set and a progress report on the 2011 set.
Analyzing powers Ay and spin-dependent total cross section ratios Deltasigma_T/sigma_tot and Delt... more Analyzing powers Ay and spin-dependent total cross section ratios Deltasigma_T/sigma_tot and Deltasigma_L/sigma_tot have been measured for pparrow pnpi^+ at the IUCF cooler ring with a polarized internal target at beam energies of 375 and 400 MeV. To eliminate monitoring errors the target polarization was switched rapidly between left, right (±x), up, down (±y) and along, opposite (±z) to the beam direction. The vertical and longitudinal components of the beam polarization at the target were about equal and were also switched. Reaction protons were detected for angles theta_lab > 6^circ by a system of wire-chambers and plastic scintillators. Reaction neutrons in coincidence with protons were detected in a large area hodoscope with an energy resolution of 20%. This arrangement permitted near complete sampling of all outgoing pion momenta. Analyzing powers and the spin-dependent total cross section ratios for this reaction are large and will be presented. Corrections for nonuniform...
Physics Letters B, 2003
Values of the ratios in the mid-rapidity yields of Λ/Λ = 0.71 ± 0.01(stat.) ± 0.04(sys.), Ξ + /Ξ ... more Values of the ratios in the mid-rapidity yields of Λ/Λ = 0.71 ± 0.01(stat.) ± 0.04(sys.), Ξ + /Ξ − = 0.83 ± 0.04(stat.) ± 0.05(sys.), Ω + /Ω − = 0.95 ± 0.15(stat.) ± 0.05(sys.) and K + /K − = 1.092 ± 0.023(combined) were obtained in central √ s NN = 130 GeV Au+Au collisions using the STAR detector. The ratios indicate that a fraction of the net-baryon number from the initial system is present in the excess of hyperons over anti-hyperons at mid-rapidity. The trend in the progression of the baryon ratios, with increasing strange quark content, is similar to that observed in heavy-ion collisions at lower energies. The value of these ratios may be related to the charged kaon ratio in the framework of simple quark-counting and thermal models.
Physics Letters B, 1998
The energy dependence of the total cross section for the pp −→ pK + Λ reaction was measured in th... more The energy dependence of the total cross section for the pp −→ pK + Λ reaction was measured in the threshold region covering the excess energy range up to 7 MeV. Existing model calculations describe the slope of the measured cross sections well, but are too low by a factor of two to three in rate. The data were used for a precise determination of the beam momentum of the COSY-synchrotron.
Physical Review Letters, 2004
Physical Review C, 2004
We report inclusive photon measurements about midrapidity ([y[ < 0.5) from 197 Au + 197 Au collis... more We report inclusive photon measurements about midrapidity ([y[ < 0.5) from 197 Au + 197 Au collisions at s NN = 130 GeV at RHIC. Photon pair conversions were reconstructed from electron and positron tracks mea sured with the Time Projection Chamber (TPC) of the STAR experiment. With this method, an energy reso lution of ME / E = 2% at 0.5 GeV has been achieved. Reconstructed photons have also been used to measure the transverse momentum (p t) spectra of 7 0 mesons about midrapidity ([y[ < 1) via the 7 0yy decay channel. The fractional contribution of the 7 0yy decay to the inclusive photon spectrum decreases by 20 % ± 5% between p t = 1.65 GeV / c and p t = 2.4 GeV / c in the most central events, indicating that relative to 7 0yy decay the contribution of other photon sources is substantially increasing.
Physical Review C, 2004
We report on the rapidity and centrality dependence of proton and antiproton transverse mass dist... more We report on the rapidity and centrality dependence of proton and antiproton transverse mass distributions from 197 Au+ 197 Au collisions at ͱ s NN = 130 GeV as measured by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). Our results are from the rapidity and transverse momentum range of ͉y͉ Ͻ 0.5 and 0.35Ͻ p t Ͻ 1.00 GeV/ c. For both protons and antiprotons, transverse mass distributions become more convex from peripheral to central collisions demonstrating characteristics of collective expansion. The measured rapidity distributions and the mean transverse momenta versus rapidity are flat within ͉y͉ Ͻ 0.5. Comparisons of our data with results from model calculations indicate that in order to obtain a consistent picture of the proton (antiproton) yields and transverse mass distributions the possibility of prehadronic collective expansion may have to be taken into account.