A novel and efficient method for decomposing a signal into a set of intrinsic mode functions （IMFs） and a trend is proposed. Unlike the original empirical mode decomposition （EMD）, which uses spline fits to extrac...A novel and efficient method for decomposing a signal into a set of intrinsic mode functions （IMFs） and a trend is proposed. Unlike the original empirical mode decomposition （EMD）, which uses spline fits to extract variations from the signal by separating the local mean from the fluctuations in the decomposing process, this new method being proposed takes advantage of the theory of variable finite impulse response （FIR） filtering where filter coefficients and breakpoint frequencies can be adjusted to track any peak-to-peak time scale changes. The IMFs are results of a multiple variable frequency response FIR filtering when signals pass through the filters. Numerical examples validate that in contrast with the original EMD, the proposed method can fine-tune the frequency resolution and suppress the aliasing effectively.展开更多
Purpose In the BESIII experiment,a conventional least square method is currently used to calibrate the time-of-flight(TOF)system,aiming to achieve optimal time resolution.However,it is intricate for conventional metho...Purpose In the BESIII experiment,a conventional least square method is currently used to calibrate the time-of-flight(TOF)system,aiming to achieve optimal time resolution.However,it is intricate for conventional methods to handle electronics saturation and boundary effect which affect the time resolution.Methods A novel method based on machine learning techniques for time calibration of barrel TOF system is implemented in this paper.Results and conclusion With the application of boosted decision tree(BDT)algorithm,the overall time resolution of barrel TOF is found to be 64 ps.Compared with conventional method,a notable improvement in time resolution is achieved in the boundary range of the scintillator bar using BDT method.展开更多
Purpose The end cap time of flight at Beijing Spectrometer is upgraded with multi-gap resistive plate chamber technology in order to improve the charged particle identification capability.The time-over-threshold is us...Purpose The end cap time of flight at Beijing Spectrometer is upgraded with multi-gap resistive plate chamber technology in order to improve the charged particle identification capability.The time-over-threshold is used for the time slewing correction instead of the signal amplitude.Methods The correlation of the multi-peak time-over-threshold and the hit position along the strip of the charged particle is investigated.Implementation of the off-line data calibration method is discussed in detail.Results and conclusion The overall time resolution for pions with momentum around 0.8 GeV/c is about 65 ps.展开更多
基金supported by the National Natural Science Foundation of China (60472021).
文摘A novel and efficient method for decomposing a signal into a set of intrinsic mode functions （IMFs） and a trend is proposed. Unlike the original empirical mode decomposition （EMD）, which uses spline fits to extract variations from the signal by separating the local mean from the fluctuations in the decomposing process, this new method being proposed takes advantage of the theory of variable finite impulse response （FIR） filtering where filter coefficients and breakpoint frequencies can be adjusted to track any peak-to-peak time scale changes. The IMFs are results of a multiple variable frequency response FIR filtering when signals pass through the filters. Numerical examples validate that in contrast with the original EMD, the proposed method can fine-tune the frequency resolution and suppress the aliasing effectively.
基金supported in part by National Key R&D Program of China under Contracts No.2020YFA0406304.
文摘Purpose In the BESIII experiment,a conventional least square method is currently used to calibrate the time-of-flight(TOF)system,aiming to achieve optimal time resolution.However,it is intricate for conventional methods to handle electronics saturation and boundary effect which affect the time resolution.Methods A novel method based on machine learning techniques for time calibration of barrel TOF system is implemented in this paper.Results and conclusion With the application of boosted decision tree(BDT)algorithm,the overall time resolution of barrel TOF is found to be 64 ps.Compared with conventional method,a notable improvement in time resolution is achieved in the boundary range of the scintillator bar using BDT method.
基金Supported in part by National Natural Science Foundation of China(U1232201,11575225,11605220)National Key Basic Research Program of China(2015CB856700)Chinese Academy of Sciences(1G201331231172010).
文摘Purpose The end cap time of flight at Beijing Spectrometer is upgraded with multi-gap resistive plate chamber technology in order to improve the charged particle identification capability.The time-over-threshold is used for the time slewing correction instead of the signal amplitude.Methods The correlation of the multi-peak time-over-threshold and the hit position along the strip of the charged particle is investigated.Implementation of the off-line data calibration method is discussed in detail.Results and conclusion The overall time resolution for pions with momentum around 0.8 GeV/c is about 65 ps.
