The author proves that if f ： C → C^n is a transcendental vector valued mero-morphic function of finite order and assume, This result extends the related results for meromorphic function by Singh and Kulkarni.
The output of charge sensitive amplifier(CSA) is a negative exponential signal with long decay time which will result in undershoot after C-R differentiator.Pole-zero cancellation(PZC) circuit is often applied to elim...The output of charge sensitive amplifier(CSA) is a negative exponential signal with long decay time which will result in undershoot after C-R differentiator.Pole-zero cancellation(PZC) circuit is often applied to eliminate undershoot in many radiation detectors.However,it is difficult to use a zero created by PZC circuit to cancel a pole in CSA output signal accurately because of the influences of electronic components inherent error and environmental factors.A novel recursive model for PZC circuit is presented based on Kirchhoff's Current Law(KCL) in this paper.The model is established by numerical differentiation algorithm between the input and the output signal.Some simulation experiments for a negative exponential signal are carried out using Visual Basic for Application(VBA) program and a real x-ray signal is also tested.Simulated results show that the recursive model can reduce the time constant of input signal and eliminate undershoot.展开更多
The Head-Related Transfer Function(HRTF)describes the effects of sound reflection and scattering caused by the environment and the human body when sound signals are transmitted from a source to the human ear.It contai...The Head-Related Transfer Function(HRTF)describes the effects of sound reflection and scattering caused by the environment and the human body when sound signals are transmitted from a source to the human ear.It contains a significant amount of auditory cue information used for sound localization.Consequently,HRTF renders 3D audio accurately in numerous immersive multimedia applications.Because HRTF is high-dimensional,complex,and nonlinear,it is a relatively large and intricate dataset,typically consisting of hundreds of thousands of samples.Storing HRTF requires a significant amount of storage space in practical applications.Based on this,high-dimensional,complex,and nonlinear HRTFs need to be compressed and reconstructed.In this study,inspired by the conventional common-pole/zero model,we propose a method for representing HRTF based on the common-pole/zero model and principal component analysis(PCA).Our method utilizes human auditory features and extends the traditional Common-Acoustical-Pole/Zero(CAPZ)method to estimate the common pole and zero coefficients across multiple subjects.Subsequently,the zero coefficients are compressed using the PCA procedure.Experimental results on the CIPIC database show that the compression ratio can reach 9.5%when the average spectral distortion is less than 2 dB.展开更多
Hilly terrain pipeline is a common form of pipeline in oil and gas storage and transportation industry.Due to the hilly terrain influence, the liquid at the elbow of the gathering pipeline is easy to flow back and acc...Hilly terrain pipeline is a common form of pipeline in oil and gas storage and transportation industry.Due to the hilly terrain influence, the liquid at the elbow of the gathering pipeline is easy to flow back and accumulate to form slug flow, so it is necessary to remove the accumulated liquid by gas purging. In this paper, experiment is carried out in hilly terrain pipelines. Three flow patterns of stratified flow, slug flow and stratified entrained flow are observed. The process of gas purging accumulated liquid is divided into four stages, namely liquid accumulation, liquid rising, continuous outflow and tail outflow. At the same time, the flow pattern maps of each stage are drawn. The pressure drop signal is analyzed in time domain and frequency domain, and the contour map of pressure drop distribution is drawn. It is found that the ratio of range to average value can well distinguish the occurrence range of each flow pattern.Based on visualization, the transition process of slug flow to stratified flow and stratified entrained flow is studied, and the transition boundary prediction model is established. An image processing method is proposed to convert the image signal into a similarity curve, and PSD analysis is performed to calculate the slug frequency. The normal distribution is used to fit the slug frequency, and the predicted correlation is in good agreement with the experimental data.展开更多
快反镜作为高精度光学系统的核心执行机构,其控制策略的优劣直接影响系统性能。传统的快反镜控制策略依赖独立的控制盒和线性功放模块,导致快反镜控制系统体积大、热量高、应用受限。而基于金属-氧化物半导体场效应晶体管(metal-oxide-s...快反镜作为高精度光学系统的核心执行机构,其控制策略的优劣直接影响系统性能。传统的快反镜控制策略依赖独立的控制盒和线性功放模块,导致快反镜控制系统体积大、热量高、应用受限。而基于金属-氧化物半导体场效应晶体管(metal-oxide-semiconductor field-effect transistor,MOSFET)开关量驱动的快反镜在控制上难以达到精度要求。通过对快反镜的建模扫频分析,提出了开环零极点配置与比例积分控制(proportional integral derivative,PID)相结合的控制策略,并在快反镜的硬件平台上进行了仿真验证。实验结果表明,该控制策略在不依赖额外控制器和驱动模块的前提下,能够保证快反镜控制的高精度要求。展开更多
基金supported by the National Natural Science Foundation of China(11201395)supported by the Science Foundation of Educational Commission of Hubei Province(Q20132801)
文摘The author proves that if f ： C → C^n is a transcendental vector valued mero-morphic function of finite order and assume, This result extends the related results for meromorphic function by Singh and Kulkarni.
基金Supported by National High Technology Research and Development Program of China(863 Program)(No 2012AA061804-03)
文摘The output of charge sensitive amplifier(CSA) is a negative exponential signal with long decay time which will result in undershoot after C-R differentiator.Pole-zero cancellation(PZC) circuit is often applied to eliminate undershoot in many radiation detectors.However,it is difficult to use a zero created by PZC circuit to cancel a pole in CSA output signal accurately because of the influences of electronic components inherent error and environmental factors.A novel recursive model for PZC circuit is presented based on Kirchhoff's Current Law(KCL) in this paper.The model is established by numerical differentiation algorithm between the input and the output signal.Some simulation experiments for a negative exponential signal are carried out using Visual Basic for Application(VBA) program and a real x-ray signal is also tested.Simulated results show that the recursive model can reduce the time constant of input signal and eliminate undershoot.
文摘The Head-Related Transfer Function(HRTF)describes the effects of sound reflection and scattering caused by the environment and the human body when sound signals are transmitted from a source to the human ear.It contains a significant amount of auditory cue information used for sound localization.Consequently,HRTF renders 3D audio accurately in numerous immersive multimedia applications.Because HRTF is high-dimensional,complex,and nonlinear,it is a relatively large and intricate dataset,typically consisting of hundreds of thousands of samples.Storing HRTF requires a significant amount of storage space in practical applications.Based on this,high-dimensional,complex,and nonlinear HRTFs need to be compressed and reconstructed.In this study,inspired by the conventional common-pole/zero model,we propose a method for representing HRTF based on the common-pole/zero model and principal component analysis(PCA).Our method utilizes human auditory features and extends the traditional Common-Acoustical-Pole/Zero(CAPZ)method to estimate the common pole and zero coefficients across multiple subjects.Subsequently,the zero coefficients are compressed using the PCA procedure.Experimental results on the CIPIC database show that the compression ratio can reach 9.5%when the average spectral distortion is less than 2 dB.
基金supported by the Basic Science Center Program for Ordered Energy Conversion of the National Natural Science Foundation of China(No.52488201)the National Natural Science Foundation of China(No.52422606).
文摘Hilly terrain pipeline is a common form of pipeline in oil and gas storage and transportation industry.Due to the hilly terrain influence, the liquid at the elbow of the gathering pipeline is easy to flow back and accumulate to form slug flow, so it is necessary to remove the accumulated liquid by gas purging. In this paper, experiment is carried out in hilly terrain pipelines. Three flow patterns of stratified flow, slug flow and stratified entrained flow are observed. The process of gas purging accumulated liquid is divided into four stages, namely liquid accumulation, liquid rising, continuous outflow and tail outflow. At the same time, the flow pattern maps of each stage are drawn. The pressure drop signal is analyzed in time domain and frequency domain, and the contour map of pressure drop distribution is drawn. It is found that the ratio of range to average value can well distinguish the occurrence range of each flow pattern.Based on visualization, the transition process of slug flow to stratified flow and stratified entrained flow is studied, and the transition boundary prediction model is established. An image processing method is proposed to convert the image signal into a similarity curve, and PSD analysis is performed to calculate the slug frequency. The normal distribution is used to fit the slug frequency, and the predicted correlation is in good agreement with the experimental data.
文摘快反镜作为高精度光学系统的核心执行机构,其控制策略的优劣直接影响系统性能。传统的快反镜控制策略依赖独立的控制盒和线性功放模块,导致快反镜控制系统体积大、热量高、应用受限。而基于金属-氧化物半导体场效应晶体管(metal-oxide-semiconductor field-effect transistor,MOSFET)开关量驱动的快反镜在控制上难以达到精度要求。通过对快反镜的建模扫频分析,提出了开环零极点配置与比例积分控制(proportional integral derivative,PID)相结合的控制策略,并在快反镜的硬件平台上进行了仿真验证。实验结果表明,该控制策略在不依赖额外控制器和驱动模块的前提下,能够保证快反镜控制的高精度要求。
