Distributed computing is an important topic in the field of wireless communications and networking,and its high efficiency in handling large amounts of data is particularly noteworthy.Although distributed computing be...Distributed computing is an important topic in the field of wireless communications and networking,and its high efficiency in handling large amounts of data is particularly noteworthy.Although distributed computing benefits from its ability of processing data in parallel,the communication burden between different servers is incurred,thereby the computation process is detained.Recent researches have applied coding in distributed computing to reduce the communication burden,where repetitive computation is utilized to enable multicast opportunities so that the same coded information can be reused across different servers.To handle the computation tasks in practical heterogeneous systems,we propose a novel coding scheme to effectively mitigate the "straggling effect" in distributed computing.We assume that there are two types of servers in the system and the only difference between them is their computational capabilities,the servers with lower computational capabilities are called stragglers.Given any ratio of fast servers to slow servers and any gap of computational capabilities between them,we achieve approximately the same computation time for both fast and slow servers by assigning different amounts of computation tasks to them,thus reducing the overall computation time.Furthermore,we investigate the informationtheoretic lower bound of the inter-communication load and show that the lower bound is within a constant multiplicative gap to the upper bound achieved by our scheme.Various simulations also validate the effectiveness of the proposed scheme.展开更多
This paper presents a simulation study of the impact of energy straggle on a proton-induced single event upset （SEU） test in a commercial 65-nm static random access memory cell. The simulation results indicate that ...This paper presents a simulation study of the impact of energy straggle on a proton-induced single event upset （SEU） test in a commercial 65-nm static random access memory cell. The simulation results indicate that the SEU cross sections for low energy protons are significantly underestimated due to the use of degraders in the SEU test. In contrast, using degraders in a high energy proton test may cause the overestimation of the SEU cross sections. The results are confirmed by the experimental data and the impact of energy straggle on the SEU cross section needs to be taken into account when conducting a proton-induced SEU test in a nanodevice using degraders.展开更多
Monte Carlo simulations reveal considerable straggling of energy loss by the same ions with the same energy in fully-depleted silicon-on-insulator （FDSOI） devices with ultra-thin sensitive silicon layers down to 2.5...Monte Carlo simulations reveal considerable straggling of energy loss by the same ions with the same energy in fully-depleted silicon-on-insulator （FDSOI） devices with ultra-thin sensitive silicon layers down to 2.5 rim. The absolute straggling of deposited energy decreases with decreasing thickness of the active silicon layer. While the relative straggling increases gradually with decreasing thickness of silicon films and exhibits a sharp rise as the thickness of the silicon film descends below a threshold value of 50 nm, with the dispersion of deposited energy ascending above ~10%. Ion species and energy dependence of the energy-loss straggling are also investigated. For a given beam, the dispersion of deposited energy results in large uncertainty on the actual linear energy transfer （LET） of incident ions, and thus single event effect （SEE） responses, which pose great challenges for traditional error rate prediction methods.展开更多
Energy straggling for fast proton beams in Ni, Al, Ti, Cu, In and Sb solids and N, O, F, B, S, Cl and air gases were calculated using an effective IPM potential which contains an adjustable parameter. The energy and Z...Energy straggling for fast proton beams in Ni, Al, Ti, Cu, In and Sb solids and N, O, F, B, S, Cl and air gases were calculated using an effective IPM potential which contains an adjustable parameter. The energy and Z<sub>2</sub> （target atomic number） dependence of the energy straggling for proton in materials are Obtained when Bonderup and Hvelplund’s formulation is used. The results are compared with some experiments in detail, and show in good agreement with them.展开更多
The stopping and scattering of fast electrons in a dense plasma relevant to inertial confinement fusion （ICF） are investigated numerically with the latest improved cross section equations. Binary and collective effe...The stopping and scattering of fast electrons in a dense plasma relevant to inertial confinement fusion （ICF） are investigated numerically with the latest improved cross section equations. Binary and collective effects are considered to determine beam transport parameters such as range, penetration depth, spreading processes as straggling and blooming versus electron energy and plasma parameters. Blooming and straggling effects, which act as consequences of scattering with statistical assumption in collisions, lead to a non-uniform, extended region of energy deposition. Finally the mean angle of deflections is calculated for different plasma energies.展开更多
Based on the characteristics of the interactions between intermediate energy heavy-ion beam and target matter, a method to calculate the depth-dose distribution of heavy-ion beams with intermediate energy (10-100 MeV/...Based on the characteristics of the interactions between intermediate energy heavy-ion beam and target matter, a method to calculate the depth-dose distribution of heavy-ion beams with intermediate energy (10-100 MeV/u) is presented. By comparing high energy beams where projectile fragmentation is overwhelming with low energies where energy straggling is the sole factor instead, a crescent energy spread with increasing depth and a simple fragmentation assumption were included for the depth-dose calculation of the intermediate energy beam. Relative depth-dose curves of carbon and oxygen ion beams with intermediate energies were computed according to the method here. Comparisons between the calculated relative doses and measurements are shown. The calculated Bragg curves, especially the upstream and downstream Bragg peaks, agree with the measured data. Differences between the two results appear only around the peak regions because of the limitations of the calculation and experimental conditions, but the展开更多
The energy spreading of recorded ions is influenced by straggling,geometrical acceptance angles and detector energy resolution effects in neutron depth profiling(NDP)and a symmetric Gaussian function model was customa...The energy spreading of recorded ions is influenced by straggling,geometrical acceptance angles and detector energy resolution effects in neutron depth profiling(NDP)and a symmetric Gaussian function model was customarily applied before.In addition,the spectra of mono-energetic alpha particles show a well known asymmetric shape as well when measured by silicon detectors.This article presents a physical model predicting the observed energy spectrum of a sample ion with target nuclides in prearranged depths.It is expressed as the convolution of a Gaussian function with a left-hand double-exponential function.Experiment showed that the predicted ions spectrum derived from the asymmetric model matches the observed energy spectrum.Therefore,the model can be applied to produce matrix for inversion of NDP spectrum.展开更多
基金supported by NSF China(No.T2421002,62061146002,62020106005)。
文摘Distributed computing is an important topic in the field of wireless communications and networking,and its high efficiency in handling large amounts of data is particularly noteworthy.Although distributed computing benefits from its ability of processing data in parallel,the communication burden between different servers is incurred,thereby the computation process is detained.Recent researches have applied coding in distributed computing to reduce the communication burden,where repetitive computation is utilized to enable multicast opportunities so that the same coded information can be reused across different servers.To handle the computation tasks in practical heterogeneous systems,we propose a novel coding scheme to effectively mitigate the "straggling effect" in distributed computing.We assume that there are two types of servers in the system and the only difference between them is their computational capabilities,the servers with lower computational capabilities are called stragglers.Given any ratio of fast servers to slow servers and any gap of computational capabilities between them,we achieve approximately the same computation time for both fast and slow servers by assigning different amounts of computation tasks to them,thus reducing the overall computation time.Furthermore,we investigate the informationtheoretic lower bound of the inter-communication load and show that the lower bound is within a constant multiplicative gap to the upper bound achieved by our scheme.Various simulations also validate the effectiveness of the proposed scheme.
基金supported by the National Natural Science Foundation of China(Grant Nos.11690041 and 11675233)
文摘This paper presents a simulation study of the impact of energy straggle on a proton-induced single event upset （SEU） test in a commercial 65-nm static random access memory cell. The simulation results indicate that the SEU cross sections for low energy protons are significantly underestimated due to the use of degraders in the SEU test. In contrast, using degraders in a high energy proton test may cause the overestimation of the SEU cross sections. The results are confirmed by the experimental data and the impact of energy straggle on the SEU cross section needs to be taken into account when conducting a proton-induced SEU test in a nanodevice using degraders.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11179003 and 10975164)
文摘Monte Carlo simulations reveal considerable straggling of energy loss by the same ions with the same energy in fully-depleted silicon-on-insulator （FDSOI） devices with ultra-thin sensitive silicon layers down to 2.5 rim. The absolute straggling of deposited energy decreases with decreasing thickness of the active silicon layer. While the relative straggling increases gradually with decreasing thickness of silicon films and exhibits a sharp rise as the thickness of the silicon film descends below a threshold value of 50 nm, with the dispersion of deposited energy ascending above ~10%. Ion species and energy dependence of the energy-loss straggling are also investigated. For a given beam, the dispersion of deposited energy results in large uncertainty on the actual linear energy transfer （LET） of incident ions, and thus single event effect （SEE） responses, which pose great challenges for traditional error rate prediction methods.
基金Project was supported by Foundation of Analysis and Testing, Beijing 89K25E-123
文摘Energy straggling for fast proton beams in Ni, Al, Ti, Cu, In and Sb solids and N, O, F, B, S, Cl and air gases were calculated using an effective IPM potential which contains an adjustable parameter. The energy and Z<sub>2</sub> （target atomic number） dependence of the energy straggling for proton in materials are Obtained when Bonderup and Hvelplund’s formulation is used. The results are compared with some experiments in detail, and show in good agreement with them.
文摘The stopping and scattering of fast electrons in a dense plasma relevant to inertial confinement fusion （ICF） are investigated numerically with the latest improved cross section equations. Binary and collective effects are considered to determine beam transport parameters such as range, penetration depth, spreading processes as straggling and blooming versus electron energy and plasma parameters. Blooming and straggling effects, which act as consequences of scattering with statistical assumption in collisions, lead to a non-uniform, extended region of energy deposition. Finally the mean angle of deflections is calculated for different plasma energies.
基金This work was jointly supported by the Western Hope Project of the Chinese Academy of Sciences (Grant No. XB010612) the Director Foundation of the Institute of Modern Physics, the Chinese Academy of Sciences (Grant No. ZY010606).
文摘Based on the characteristics of the interactions between intermediate energy heavy-ion beam and target matter, a method to calculate the depth-dose distribution of heavy-ion beams with intermediate energy (10-100 MeV/u) is presented. By comparing high energy beams where projectile fragmentation is overwhelming with low energies where energy straggling is the sole factor instead, a crescent energy spread with increasing depth and a simple fragmentation assumption were included for the depth-dose calculation of the intermediate energy beam. Relative depth-dose curves of carbon and oxygen ion beams with intermediate energies were computed according to the method here. Comparisons between the calculated relative doses and measurements are shown. The calculated Bragg curves, especially the upstream and downstream Bragg peaks, agree with the measured data. Differences between the two results appear only around the peak regions because of the limitations of the calculation and experimental conditions, but the
文摘The energy spreading of recorded ions is influenced by straggling,geometrical acceptance angles and detector energy resolution effects in neutron depth profiling(NDP)and a symmetric Gaussian function model was customarily applied before.In addition,the spectra of mono-energetic alpha particles show a well known asymmetric shape as well when measured by silicon detectors.This article presents a physical model predicting the observed energy spectrum of a sample ion with target nuclides in prearranged depths.It is expressed as the convolution of a Gaussian function with a left-hand double-exponential function.Experiment showed that the predicted ions spectrum derived from the asymmetric model matches the observed energy spectrum.Therefore,the model can be applied to produce matrix for inversion of NDP spectrum.
