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FFT分析器作谱密度估计时的偏度误差分析
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作者 胡强 《振动与冲击》 EI CSCD 北大核心 1989年第2期12-18,共7页
本文提出了计算FFT分析器作潜密度估计时的偏度误差的离散化计算公式,并与积分计算进行了比较,给出了采用矩形窗和汉宁窗时FFT分析器对白噪声谱和单自由度系统响应谱的估计偏度误差分析的算例。
关键词 FFT 分析器 谱密函数 偏度误差
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传声器通道和位置失配误差对平面近场声全息的影响 被引量:3
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作者 毛荣富 朱海潮 《声学技术》 CSCD 2010年第1期1-8,共8页
在综合考虑偏度误差与随机误差的基础上,分析了传声器通道失配误差和位置失配误差对平面近场声全息(NAH)分析的影响,从实空间和波数域两方面对全息面和重建面上引起的统计误差进行了详细的理论推导,并以理想点源作为研究对象对理论结果... 在综合考虑偏度误差与随机误差的基础上,分析了传声器通道失配误差和位置失配误差对平面近场声全息(NAH)分析的影响,从实空间和波数域两方面对全息面和重建面上引起的统计误差进行了详细的理论推导,并以理想点源作为研究对象对理论结果进行了验证。理论推导与数值仿真均表明:在偏度误差和随机误差取值相当的条件下,在波数域内,它们在全息面及重建面上产生的统计误差的偏差都较小,且偏度误差引起的归一化偏差要大于随机误差引起的归一化偏差,但两者在全息面及重建面上产生的统计误差的方差大相径庭,偏度误差引起的归一化方差很小可以完全忽略不计,而随机误差引起的归一化方差在辐射圆外呈指数倍数放大,会对NAH的重建结果将会产生严重的影响,综合考虑后,随机误差比偏度误差对NAH重建精度的影响更大。 展开更多
关键词 近场声全息 通道失配误差 位置失配误差 偏度误差 随机误差
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Application of Monte Carlo method in rudder control precision 被引量:2
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作者 凡永磊 陈国光 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2015年第4期378-383,共6页
After the trajectory simulation model of rudder control rocket with six degrees of freedom is established by Matlab/ Simulink, the simulated targeting of rudder control rocket with rudder angle error and starting cont... After the trajectory simulation model of rudder control rocket with six degrees of freedom is established by Matlab/ Simulink, the simulated targeting of rudder control rocket with rudder angle error and starting control moment error is carried out respectively by means of Monte Carlo method and the distribution of impact points of rudder control rocket is counted from all the successful subsamples. In the case of adding interference errors associated with rudder angle error and starting time error, the simulation analysis of impact point dispersion is done and its lateral and longitudinal correction abilities at different targeting angles are simulated to identify the effects of these factors on characteristics and control precision of the rudder control rocket, which provides the relevant reference for high-precision design of rudder control system. 展开更多
关键词 rudder control precision rudder angle error starting control time error Monte Carlo method
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Dynamic load sharing behavior of transverse-torsional coupled planetary gear train with multiple clearances 被引量:4
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作者 盛冬平 朱如鹏 +2 位作者 靳广虎 陆凤霞 鲍和云 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第7期2521-2532,共12页
A new nonlinear transverse-torsional coupled model with backlash and bearing clearance was proposed for planetary gear set. Meanwhile, sun gear and planet's eccentricity errors, static transmission error, and time... A new nonlinear transverse-torsional coupled model with backlash and bearing clearance was proposed for planetary gear set. Meanwhile, sun gear and planet's eccentricity errors, static transmission error, and time-varying meshing stiffness were taken into consideration. The differential governing equations of motion were solved by employing variable step-size Rung-Kutta numerical integration method. The behavior of dynamic load sharing characteristics affected by the system parameters including input rate, sun gear's supporting stiffness and eccentricity error, planet's eccentricity error, sun gear's bearing clearance, backlashes of sun-planet and planet-ring meshes were investigated qualitatively and systematically. Some theoretical results are summarized at last which extend the current understanding of the dynamic load sharing behavior of planet gear train, enrich the related literature and provide references for the design of planetary gear train. 展开更多
关键词 planetary gear train dynamic load sharing time-varying stiffness backlash bearing clearance
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多台阶衍射光学元件的工艺优化 被引量:11
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作者 刘强 邬融 +2 位作者 张晓波 李永平 田杨超 《中国激光》 EI CAS CSCD 北大核心 2008年第8期1165-1168,共4页
通过对多台阶衍射光学元件(MDOE)刻蚀工艺中的误差分析,提出了一个反映整体刻蚀误差的参数———误差偏度.重点研究了误差偏度的变化对多台阶衍射光学元件光束整形效果的影响,发现在误差偏度曲线中存在一个能使刻蚀误差影响减弱的平坦区... 通过对多台阶衍射光学元件(MDOE)刻蚀工艺中的误差分析,提出了一个反映整体刻蚀误差的参数———误差偏度.重点研究了误差偏度的变化对多台阶衍射光学元件光束整形效果的影响,发现在误差偏度曲线中存在一个能使刻蚀误差影响减弱的平坦区间.提出了在刻蚀工艺上以控制刻蚀深度来改善多台阶衍射光学元件器件实际照明效果的一种方法.实验结果表明,经过工艺优化后的MDOE的光场参数峰值(PV)下降了近30%. 展开更多
关键词 衍射 离子束刻蚀 误差 光束整形
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