关于Hermite矩阵迹的不等式   总被引：2，自引：0，他引：2  

杨兴东 《南京气象学院学报》2000,23(1):130-132

获得不等式 :( 1 ) tr ( AB) m≤ tr ( Am Bm) ;( 2 ) tr ( A B) m≤ tr ( Am Bm)。其中 A、B为 Hermite矩阵 ,m为正偶数。  相似文献   

A least-squares penalty method algorithm for inverse problems of steady-state aquifer models     

Hailong Li  Qichang Yang 《Advances in water resources》2000,23(8)

Based on the generalized Gauss–Newton method, a new algorithm to minimize the objective function of the penalty method in (Bentley LR. Adv Wat Res 1993;14:137–48) for inverse problems of steady-state aquifer models is proposed. Through detailed analysis of the “built-in” but irregular weighting effects of the coefficient matrix on the residuals on the discrete governing equations, a so-called scaling matrix is introduced to improve the great irregular weighting effects of these residuals adaptively in every Gauss–Newton iteration. Numerical results demonstrate that if the scaling matrix equals the identity matrix (i.e., the irregular weighting effects of the coefficient matrix are not balanced), our algorithm does not perform well, e.g., the computation cost is higher than that of the traditional method, and what is worse is the calculations fail to converge for some initial values of the unknown parameters. This poor situation takes a favourable turn dramatically if the scaling matrix is slightly improved and a simple preconditioning technique is adopted: For naturally chosen simple diagonal forms of the scaling matrix and the preconditioner, the method performs well and gives accurate results with low computational cost just like the traditional methods, and improvements are obtained on: (1) widening the range of the initial values of the unknown parameters within which the minimizing iterations can converge, (2) reducing the computational cost in every Gauss–Newton iteration, (3) improving the irregular weighting effects of the coefficient matrix of the discrete governing equations. Consequently, the example inverse problem in Bentley (loc. cit.) is solved with the same accuracy, less computational effort and without the regularization term containing prior information on the unknown parameters. Moreover, numerical example shows that this method can solve the inverse problem of the quasilinear Boussinesq equation almost as fast as the linear one.In every Gauss–Newton iteration of our algorithm, one needs to solve a linear least-squares system about the corrections of both the parameters and the groundwater heads on all the discrete nodes only once. In comparison, every Gauss–Newton iteration of the traditional method has to solve the discrete governing equations as many times as one plus the number of unknown parameters or head observation wells (Yeh WW-G. Wat Resour Res 1986;22:95–108).All these facts demonstrate the potential of the algorithm to solve inverse problems of more complicated non-linear aquifer models naturally and quickly on the basis of finding suitable forms of the scaling matrix and the preconditioner.  相似文献   

加速度地震记录服从三维高斯分布的证明与应用     

马亮  卢建旗  程建武 《大地测量与地球动力学》2022,42(2):199-202

利用加速度记录分析P波质点的受力状态、P波质点随机震动的概率分布及其偏振现象,结果显示,P波质点随机震动的受力矢量服从三维高斯分布,其概率密度呈椭球状分布,可通过加速度记录的协方差矩阵求出偏振椭球的几何参数,从而求出震中方位角.  相似文献   

利用上行波进行VSP数据旅行时反演     

朱键  王永昌 《地球科学与环境学报》1999,21(3)

利用双层剥层法同时对层速度和界面形态参数进行反演,并采用最小二乘法迭代求解。为了消除局部极值的影响,减少病态方程的产生,利用了 Ｍｏｎｔｅ Ｃａｒｌｏ 方法调整参数初始值。通过改变参数单位以均衡微分系数矩阵元素等措施,使这种反演方法具有较快的速度和较好的稳定性。对井底以上地层和井底以下地层均适用。  相似文献   

有理函数模型下基础矩阵研究     

叶新魁  ;文贡坚  ;王继阳  ;回丙伟 《测绘信息与工程》2009,34(5):36-38

分析了线阵影像的核线关系,提出了有理函数模型下线阵扫描影像的基础矩阵求解方法,验证了线阵影像中精确共轭核线对是不存在的。  相似文献   

LZD模型多维粗差发现和定位能力分析     

张同刚  岑敏仪  杨容浩  任自珍 《测绘科学》2009,34(4)

不借助地面控制点的DEM匹配差异探测算法是多时相DEM分析的最新发展方向。现有的算法大多把DEM表面差异作为粗差进行处理,算法性能得到了较大的提高,但忽略了对DEM匹配模型多维粗差的可发现和可定位能力进行分析,而这是DEM差异探测算法的理论基础。本文采用测量误差和可靠性理论中的判断矩阵法,通过理论分析和模拟试验验证了对于实际DEM而言,LZD模型具备多维粗差发现和定位能力。基于LZD模型的DEM差异探测算法能够正确地探测表面变形,这就完善了DEM差异探测研究的理论基础。  相似文献   

基于影像序列的目标三维重构技术研究          下载免费PDF全文

山海涛  李海滨  李大卫  郝向阳 《海洋测绘》2009,29(3):41-44

从三维重构的概念和应用出发,给出了近年来国际上出现的一些较为成功的三维重构系统,但由于其较强的专业性和局限性并没有得到推广。因此,在分析和熟悉三维重构流程的基础上,对其中涉及的关键技术进行了深入的研究和探讨。在对上述关键技术的改进和创新的基础上,通过编程工具,设计并实现一个初步的基于影像序列的三维重构原型系统,从而实现对基于任意相机获取的影像（序列）实现场景的三维重构。  相似文献   

一种局地简正波快速求解方法——耦合简正波计算     

王好忠  王宁  高伟 《中国海洋大学学报(自然科学版)》2009,39(1)

通过求解低维矩阵问题替代简正波模型的差分算法,提出一种快速获得局地简正波本征波数和本征函数的方法.数值算例的结果表明:局地简正波本征波数和本征函数与KRAKAN的计算结果吻合较好,利用获得的局地简正波信息计算的相干传播损失与For3D的计算结果的均方误差为1.61 dB,从而验证了方法的可行性.  相似文献   

A Stability Criterion for Time-Delay Tension Leg Platform Systems Subjected to External Force     

Chien-wen SHEN  Kevin Fong-Rey LIU  Ming-Jen CHENG 《中国海洋工程》2009,23(1)

Stability analysis plays a central role in nonlinear system theory and engineering application.Over the past few yeats,the stability analysis of fuzzy systems has been proposed and there are many successful applications in practical engineering.Therefore,in this paper firstly proposed is the stability analysis on oceanic structure by fuzzy models.In the present study,Takagi-Sugeno (T-S) fuzzy model is proposed for a time delay tension leg platform (TLP) system subjected to an external wave force.In terms of stability analysis,linear matrix inequality (LMI) conditions are derived via Lyapunov theory to guarantee the stability of the TLP system.  相似文献   

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刘爽  张松林  童小华 《大地测量与地球动力学》2009,29(4):93-96

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