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一种有效的机载双频干涉地形高程重建方法 被引量:1
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作者 刘华有 郑明洁 +2 位作者 张衡 王宇 秦小芳 《雷达学报(中英文)》 CSCD 北大核心 2018年第4期475-486,共12页
双频联合解缠不需要满足Iton假设,因此双频干涉可以有效地提取地形起伏较大区域的高程信息。针对目前双频干涉处理中高程重建精度低的问题,该文提出了一种有效的双频干涉SAR地形高程重建方法。该方法对常规处理流程中的关键步骤进行了改... 双频联合解缠不需要满足Iton假设,因此双频干涉可以有效地提取地形起伏较大区域的高程信息。针对目前双频干涉处理中高程重建精度低的问题,该文提出了一种有效的双频干涉SAR地形高程重建方法。该方法对常规处理流程中的关键步骤进行了改进,首先在不同波段配准之前采用非局部参数估计(NL-InSAR)技术对幅度图、相干系数、干涉相位进行精确估计,利用各个波段滤波后的幅度信息来实现不同波段的干涉相位的配准。然后采用聚类分析技术对联合解缠相位标记有效点和噪点,并利用这些有效点对联合解缠相位进行均值滤波。用于实验的机载实测数据包括同一场景的C波段和X波段主、辅SAR图像复数据,在针对实测数据处理中,该方法取得了较好的高程重建结果。 展开更多
关键词 双频干涉 非局部参数估计(NL-InSAR) 干涉图配准 变分能量项最大后验估计 聚类分析
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Parametric modeling of carbon nanotubes and estimating nonlocal constant using simulated vibration signals-ARMA and ANN based approach 被引量:1
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作者 Saeed Lotfan Reza Fathi 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第3期461-472,共12页
Nonlocal continuum mechanics is a popular growing theory for investigating the dynamic behavior of Carbon nanotubes(CNTs).Estimating the nonlocal constant is a crucial step in mathematical modeling of CNTs vibration b... Nonlocal continuum mechanics is a popular growing theory for investigating the dynamic behavior of Carbon nanotubes(CNTs).Estimating the nonlocal constant is a crucial step in mathematical modeling of CNTs vibration behavior based on this theory.Accordingly,in this study a vibration-based nonlocal parameter estimation technique,which can be competitive because of its lower instrumentation and data analysis costs,is proposed.To this end,the nonlocal models of the CNT by using the linear and nonlinear theories are established.Then,time response of the CNT to impulsive force is derived by solving the governing equations numerically.By using these time responses the parametric model of the CNT is constructed via the autoregressive moving average(ARMA)method.The appropriate ARMA parameters,which are chosen by an introduced feature reduction technique,are considered features to identify the value of the nonlocal constant.In this regard,a multi-layer perceptron(MLP)network has been trained to construct the complex relation between the ARMA parameters and the nonlocal constant.After training the MLP,based on the assumed linear and nonlinear models,the ability of the proposed method is evaluated and it is shown that the nonlocal parameter can be estimated with high accuracy in the presence/absence of nonlinearity. 展开更多
关键词 nonlocal theory nonlocal parameter estimation autoregressive moving average artificial neural network feature reduction
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Local Polynomial-Brunk Estimation in Semi-Parametric Monotone Errors-in-Variables Model with Right-Censored Data 被引量:1
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作者 XIA Wei CHEN Zhao +1 位作者 WU Wuqing ZHOU Jianjun 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2015年第4期938-960,共23页
This paper introduces a semi-parametric model with right-censored data and a monotone constraint on the nonparametrie part. The authors study the local linear estimators of the parametric coefficients and apply B-spli... This paper introduces a semi-parametric model with right-censored data and a monotone constraint on the nonparametrie part. The authors study the local linear estimators of the parametric coefficients and apply B-spline method to approximate the nonparametric part based on grouped data. The authors obtain the rates of convergence for parametric and nonparametric estimators. Moreover, the authors also prove that the nonparametric estimator is consistent at the boundary. At last, the authors investigate the finite sample performance of the estimation. 展开更多
关键词 B-SPLINE grouped brunk local polynomial monotone regression right-censored semi-parametric model.
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