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基于过零点-极点估计的瞬时频率幅度算法 被引量:3
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作者 孙晖 朱善安 《电子与信息学报》 EI CSCD 北大核心 2006年第5期905-908,共4页
Itilbert.Huang变换(HHT)理论通过经验模态分解(EMD)提取信号的内蕴模态函数(IMF),并对IMF利用 Hilbert变换得到信号的时频幅度谱和边际谱。在总结}filbert变换理论和算法实现局限性的基础上,提出基于过零点.极点估计求取IMF?瞬时频... Itilbert.Huang变换(HHT)理论通过经验模态分解(EMD)提取信号的内蕴模态函数(IMF),并对IMF利用 Hilbert变换得到信号的时频幅度谱和边际谱。在总结}filbert变换理论和算法实现局限性的基础上,提出基于过零点.极点估计求取IMF?瞬时频率、幅度算法,通过对离散信号插值运算精确求取过零点和极点位置,并据此求出相应点的瞬时频率和幅度,最后采用三次样条求取信号的瞬时频率幅度曲线。通过几个典型的例子对该算法进行检验,结果表明,与}tilbert变换结果比较,借助该算法得到信号的时频幅度谱和边际谱结果更精确、频率分辨率更好。 展开更多
关键词 HILBERT-HUANG变换 经验模态分解 内蕴模态函数 过零点-极点估计
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噪声信号极点估计的一般方法
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作者 姜文利 唐白玉 柯有安 《北京理工大学学报》 EI CAS CSCD 1996年第6期643-648,共6页
建立了阻尼指数和信号的状态空间模型,提出了噪声中阻尼指数和信号极点估计的状态空间方法:基于输出方程和状态方程的估计算法.证明了矩阵预测方法等价于状态空间方法的算法二,从而使Prony方法、K-T(SVD-Prony)... 建立了阻尼指数和信号的状态空间模型,提出了噪声中阻尼指数和信号极点估计的状态空间方法:基于输出方程和状态方程的估计算法.证明了矩阵预测方法等价于状态空间方法的算法二,从而使Prony方法、K-T(SVD-Prony)方法、矩阵束方法以及矩阵预测方法在状态空间意义之下得到统一. 展开更多
关键词 阻尼指数 信号 状态空间 噪声 极点估计
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空间目标的联合矩阵束极点估计 被引量:1
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作者 邢煦然 赵宏钟 贾鑫 《电讯技术》 北大核心 2018年第7期768-773,共6页
极点作为谐振区雷达目标的最主要电磁特性,具有很大的空间目标识别前景。但是在使用频域观测数据提取目标极点时,存在虚假极点和估计精度问题。针对上述问题,首先通过加窗和截断改进了后时响应信号的获取流程,抑制了虚假极点影响;然后... 极点作为谐振区雷达目标的最主要电磁特性,具有很大的空间目标识别前景。但是在使用频域观测数据提取目标极点时,存在虚假极点和估计精度问题。针对上述问题,首先通过加窗和截断改进了后时响应信号的获取流程,抑制了虚假极点影响;然后采用最小描述长度法(MDL)估计极点个数,避免了定阶错误引起的虚假极点;最后采用联合矩阵束法估计极点,有效减少了单角度数据估计极点时存在的遗漏极点和虚假极点问题。FEKO软件验证表明,所提算法具有更高的精度和抗噪能力。 展开更多
关键词 空间目标 目标识别 谐振区 极点估计 联合矩阵束
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估计信号极点参数的逆预测SVD算法
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作者 赵涵 《声学与电子工程》 1999年第2期21-24,共4页
本文研究了一种逆预测SVD算法,在信噪比不太高的情况下,可有效估计噪声中复指数信号的极点参数。
关键词 极点参数估计 逆预测SVD算法 信号分析
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多模块中核四极矩共振信号参数估计新方法 被引量:1
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作者 朱凯然 何学辉 +1 位作者 郑纪彬 苏涛 《西安电子科技大学学报》 EI CAS CSCD 北大核心 2013年第3期36-41,共6页
针对核四极矩共振技术探测爆炸物中干扰信号的时变性,基于各信号采样模块包含有固定的核四极矩共振信号与时变干扰信号以及噪声的实际信号模型,提出改进的多模块HTLSstack算法.首先采用HTLS的方法确定出共有极点的个数;其次构造新的筛... 针对核四极矩共振技术探测爆炸物中干扰信号的时变性,基于各信号采样模块包含有固定的核四极矩共振信号与时变干扰信号以及噪声的实际信号模型,提出改进的多模块HTLSstack算法.首先采用HTLS的方法确定出共有极点的个数;其次构造新的筛选准则,确定所有模块的共有极点;最后结合核四极矩共振信号的先验信息,实现核四极矩共振信号参数的有效估计.该方法充分利用了原始数据的信息,在低信噪比下,避免了多模块HTLS方法在第一次奇异值分解时带来的性能损失.仿真数据和实测数据结果证明了该算法的有效性. 展开更多
关键词 核四极矩共振 自由感应衰减 子空间基共有极点估计 奇异值分解 HTLS
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分布式多频带雷达数据融合目标高分辨分析方法
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作者 王剑 《现代防御技术》 北大核心 2007年第6期102-105,138,共5页
宽带雷达接收的目标散射回波提供了目标散射点的散射类型及距离高分辨。由于条件限制,很难获得宽带及超宽带回波数据。采用状态空间法融合不同频带下的雷达回波数据得到目标高分辨分析。仿真证明,该方法能够有效地利用多部不同频带雷达... 宽带雷达接收的目标散射回波提供了目标散射点的散射类型及距离高分辨。由于条件限制,很难获得宽带及超宽带回波数据。采用状态空间法融合不同频带下的雷达回波数据得到目标高分辨分析。仿真证明,该方法能够有效地利用多部不同频带雷达的回波来获得目标的散射特征,明显优于同条件下单部雷达所得到的结果。该方法提供了一种以多部窄带雷达等效获得宽带、超宽带雷达的可行方法。 展开更多
关键词 目标散射中心 极点估计 多频带 数据融合 分布式雷达 超宽带雷达
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Percentiles Estimation for a Response Distribution 被引量:1
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作者 田玉斌 牟可典 《Journal of Beijing Institute of Technology》 EI CAS 2002年第4期424-428,共5页
To estimate percentiles of a response distribution, the transformed response rule of Wetherill and Robbins-Monro sequential design were proposed under Log-Logistic model. Based on responses data, a necessary and suffi... To estimate percentiles of a response distribution, the transformed response rule of Wetherill and Robbins-Monro sequential design were proposed under Log-Logistic model. Based on responses data, a necessary and sufficient condition for the existence of maximum likelihood estimators and then the calculating formula were presented. After a simulation study, the proposed approach was applied to 65# detonator. Numerical results showed that estimators of percentiles from the proposed approach are robust to the parametric models lacking information on the original response distribution. 展开更多
关键词 PERCENTILES maximum likelihood estimator sensitivity test transformed response
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Pole-placement self-tuning control of nonlinear Hammerstein system and its application to pH process control 被引量:1
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作者 邹志云 赵丹丹 +4 位作者 刘兴红 郭宇晴 管臣 冯文强 郭宁 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第8期1364-1368,共5页
By taking advantage of the separation characteristics of nonlinear gain and dynamic sector inside a Hammerstein model, a novel pole placement self tuning control scheme for nonlinear Hammerstein system was put forward... By taking advantage of the separation characteristics of nonlinear gain and dynamic sector inside a Hammerstein model, a novel pole placement self tuning control scheme for nonlinear Hammerstein system was put forward based on the linear system pole placement self tuning control algorithm. And the nonlinear Hammerstein system pole placement self tuning control(NL-PP-STC) algorithm was presented in detail. The identi fication ability of its parameter estimation algorithm of NL-PP-STC was analyzed, which was always identi fiable in closed loop. Two particular problems including the selection of poles and the on-line estimation of model parameters, which may be met in applications of NL-PP-STC to real process control, were discussed. The control simulation of a strong nonlinear p H neutralization process was carried out and good control performance was achieved. 展开更多
关键词 Nonlinear system Hammerstein model Pole placement Self tuning control pH control
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Analysis of seasonal signals and long-term trends in the height time series of IGS sites in China 被引量:12
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作者 MING Feng YANG YuanXi +1 位作者 ZENG AnMin JING YiFan 《Science China Earth Sciences》 SCIE EI CAS CSCD 2016年第6期1283-1291,共9页
The seasonal signal and long-term trend in the height time series of 10 IGS sites in China are investigated in this paper. The offset detection and outlier removal as well as the removal of common mode error are perfo... The seasonal signal and long-term trend in the height time series of 10 IGS sites in China are investigated in this paper. The offset detection and outlier removal as well as the removal of common mode error are performed on the raw GPS time-series data developed by the Scripps Orbit and Permanent Array Center(SOPAC). The seasonal-trend decomposition procedure based on LOESS(STL) is utilized to extract precise seasonal signals, followed by an estimation of the long-term trend with the application of maximum likelihood estimation(MLE) to the seasonally adjusted time series. The Up-compo- nents of all sites are featured by obvious seasonal variations, with significant phase and amplitude modulation on some sites. After Kendall's tau test, a significant trend(99% confidence interval) for all sites is achieved. Furthermore, the trends at sites TCMS and TNML have significant changes at epochs 2009.5384 and 2009.1493(95% confidence interval), respectively, using the Breaks For Additive Seasonal and Trend test. Finally, the velocities and their uncertainties for all sites are estimated using MLE with the white noise plus flicker noise model. And the results are analyzed and compared with those announced by SOPAC. The results obtained in this paper have a higher precision than the SOPAC results. 展开更多
关键词 GPS Height time series Seasonal signal Long-term trend STL filter Colored noise
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Weighted L^p Estimates for Maximal Commutators of Multilinear Singular Integrals
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作者 Dongxiang CHEN Jiecheng CHEN Suzhen MAO 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2013年第6期885-902,共18页
This paper is concerned with the pointwise estimates for the sharp function of two kinds of maximal commutators of multilinear singular integral operators T∑b^* and TПb^* which are generalized by a weighted BMO fu... This paper is concerned with the pointwise estimates for the sharp function of two kinds of maximal commutators of multilinear singular integral operators T∑b^* and TПb^* which are generalized by a weighted BMO function b and a multilinear singular integral operator T, respectively. As applications, some commutator theorems are established. 展开更多
关键词 Weighted BMO space Maximal commutator Multilinear singular integral Sharp maximal function
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