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探讨了卫星测高数据处理的共线秩亏平差算法,推求了消除秩亏的附加条件系数矩阵。用Topex测高数据对轨道误差模型进行了验证。 相似文献
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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
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对于增长曲线模型,在二次损失函数下,研究了当C为列满秩,而A为行秩亏矩阵时误差方差的二次型估计的容许性,用矩阵形式给出了二次型估计可容许的充要条件。 相似文献
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研究随机线性反馈控制系统的结构辨识问题。在已知时滞的下界和模型阶的上界的假定下,通过使修改的Bayesian信息准则最小化,推导出由多输入多输出CAN模型描述的系统的未知阶与时滞的估计算法,证明了算法是强一致收敛的,且能在有限步内达到其模型结构参数的真值。讨论了当模型的参数矩阵不满秩时减弱条件H’s的强一致估计算法。 相似文献
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对于增长曲线模型Y=ABC εEε=0,cov(vecε)=σ2(Ip(○X)G)在二次损失函数下,研究了当A为非行满秩矩阵时误差方差的二次型估计的容许性,并得出二次型估计可容许的必要条件. 相似文献
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研究扩展Sylvester共轭矩阵方程及更一般形式复矩阵方程的解,利用复矩阵的实形式方法得到求解方程的迭代算法.数值例子展示了该算法的有效性. 相似文献
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实测信号中的噪声,以及模型阶次的不确定性给模态参数的准确识别带来困难.以提高模态参数识别精度为目标,提出基于模30-定阶和信噪分离的复指数模态参数识别方法.该方法借助奇异值分解技术确定模型阶次,采用结构低秩逼近方法进行信噪分离.在此基础上.利用复指数法进行模态参数识别.分别选取一维的悬臂梁模型和二维的悬挂板模型进行物理模型实验,结果表明:该方法提高模态参数的识别梢度,尤其是阻尼比的识别精度,具有较好的工程应用前景. 相似文献
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多核模糊聚类算法的研究 总被引:3,自引:0,他引:3
针对多类样本数据,提出1种多核模糊聚类算法。通过选取子核函数及其参数构造多核函数,使得输入空间的样本经多核函数映射后,增大不同类别样本间的差别,提高核函数的学习能力和泛化能力。聚类实验表明,多核函数模糊聚类对于多类样本数据具有比单核更好的聚类效果。 相似文献
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本文给出了基于L0模求解该问题的非凸模型,借助于稀疏正则化方法来克服问题的不适定性。该模型利用紧小波框架对信号进行稀疏逼近,并利用L0模度量稀疏性。提出了求解该模型的投影迭代硬阈值算法,并证明了算法的全局收敛性。该算法每一步都有闭式解,计算过程简洁高效。数值实验表明,方法在重建信号的视觉质量和量化指标方面均优于所对比的pFISTA方法。 相似文献
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全极化合成孔径雷达(Synthetic Aperture Radar,SAR)数据具有丰富的极化信息,能够提取出大量异构性特征。核学习方法在解决小样本、高维特征分类问题上具有优势,但异构特征对不同核函数具有响应差异。本文利用一种引入先验标签的多核学习方法进行全极化SAR的溢油信息提取,即基于分析结果对特征集进行遴选与组合,分别在每个特征组合中训练得到一个预备层核函数,以新获取的预备层核函数作为新的底层核函数,对全部特征进行学习分类。通过提取与分析溢油和海水的统计特征、物理散射特征和纹理特征,建立溢油全极化SAR特征谱,并利用引入先验标签的多核学习分类器进行溢油提取实验。结果表明,该方法能够利用全极化SAR多维异构特征的互补特性有效提高溢油分类提取精度。 相似文献
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Jianjun Zhang Eric W. Gill 《Oceanic Engineering, IEEE Journal of》2006,31(4):779-796
An algorithm is developed for the inversion of bistatic high-frequency (HF) radar sea echo to give the nondirectional wave spectrum. The bistatic HF radar second-order cross section of patch scattering, consisting of a combination of four Fredholm-type integral equations, contains a nonlinear product of ocean wave directional spectrum factors. The energy inside the first-order cross section is used to normalize this integrand. The unknown ocean wave spectrum is represented by a truncated Fourier series. The integral equation is then converted to a matrix equation and a singular value decomposition (SVD) method is invoked to pseudoinvert the kernel matrix. The new algorithm is verified with simulated radar Doppler spectrum for varying water depths, wind velocities, and radar operating frequencies. To make the simulation more realistic, zero-mean Gaussian noise from external sources is also taken into account 相似文献
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The four-dimensional variational assimilation (4D-Var) has been widely used in meteorological and oceanographic data assimilation. This method is usually implemented in the model space, known as primal approach (P4D-Var). Alternatively, physical space analysis system (4D-PSAS) is proposed to reduce the computation cost, in which the 4D-Var problem is solved in physical space (i.e., observation space). In this study, the conjugate gradient (CG) algorithm, implemented in the 4D-PSAS system is evaluated and it is found that the non-monotonic change of the gradient norm of 4D-PSAS cost function causes artificial oscillations of cost function in the iteration process. The reason of non-monotonic variation of gradient norm in 4D-PSAS is then analyzed. In order to overcome the non-monotonic variation of gradient norm, a new algorithm, Minimum Residual (MINRES) algorithm, is implemented in the process of assimilation iteration in this study. Our experimental results show that the improved 4D-PSAS with the MINRES algorithm guarantees the monotonic reduction of gradient norm of cost function, greatly improves the convergence properties of 4D-PSAS as well, and significantly restrains the numerical noises associated with the traditional 4D-PSAS system. 相似文献
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Combining high precision numerical analysis methods with optimization algorithms to make a systematic exploration of a design space has become an important topic in the modern design methods. During the design process of an underwater glider''s flying-wing structure, a surrogate model is introduced to decrease the computation time for a high precision analysis. By these means, the contradiction between precision and efficiency is solved effectively. Based on the parametric geometry modeling, mesh generation and computational fluid dynamics analysis, a surrogate model is constructed by adopting the design of experiment (DOE) theory to solve the multi-objects design optimization problem of the underwater glider. The procedure of a surrogate model construction is presented, and the Gaussian kernel function is specifically discussed. The Particle Swarm Optimization (PSO) algorithm is applied to hydrodynamic design optimization. The hydrodynamic performance of the optimized flying-wing structure underwater glider increases by 9.1%. 相似文献
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