特征值

Keywords Closed convex cone;gradient projection method;Least-squares solution;Inverse matrix problem;Inverse eigenvalue problem;Matrix completion problem;Optimal approximation

Article From 湖南大学；应用数学博士论文 2005年度闭凸锥；投影梯度法；最小二乘解；矩阵反问题；矩阵逆特征值问题；矩阵完全化；最佳逼近

This paper mainly discusses a novel non probabilistic convex set method used to estimate the eigenvalue bounds of structures with uncertain parameters.

讨论了在不确定参数的影响下估算结构特征值变化界限的一种新型非概率凸集合方法。

The PSE in the curve coordinate systems are solved by the numerical techniques developed efficiently in this paper. A normal transform is introduced, and there are enough much grids in the region between the critical layer and the wall, where the variation of the disturbance is the quickest. The finite-difference of governing equations with fourth-order accuracy in the normal direction is utilized in full regions including points close the wall, and is very important for accurately discreting equations.

对于曲线坐标系下的抛物化稳定性方程，文中发展了求解的高效数值方法：引进法向变换，使得在临界层与壁面之间的扰动量变化最快的区域有更多的法向网格点；导出包含边界邻域在内的完全四阶精度的法向有限差分格式，这对方程精确离散至关重要；采用全局法和局部法相结合的方法及其新的迭代公式，大大加速收敛并得到更精确的特征值。

Car radios - Coaxial aerial connectors - Part 2: Characteristic values, performance requirements and tests; Technical Corrigendum 1

轿车收音机。同轴天线连接器。第2部分：特征值、性能要求和试验。技术勘误1

Via the stochastic averaging method, the four-dimensional system is reduced to a two-dimensional one. Through the logarithmic polar transformation , and then Girsanov theorem and Feynmann-Kac formula, the backword differential operator is then obtained. By expanding the eigenfunctions as a Fourier cosine series, the approximate analytic expansion of the moment Lyapunov exponent is then obtained.

首先在经典二元机翼颤振方程加入随机激励，通过随机平均法，Girsanov定理和Feynmann-Kac公式得到关于矩Lyapunov指数的特征值问题，其次采用Fourier余弦级数对特征函数进行正交展开得到系统矩Lyapunov指数的近似解析式。

The whole algorithm does not need computing covariance matrix and eigen-decomposition, so the complexity is greatly decreased.

整个算法不需要协方差矩阵的计算和特征值的分解，具有较低的计算复杂度。

The new method does not require the formation of the covariance matrix and its eigendecomposition.

不仅使得智能天线的结构尺寸减小了30%，通过多级嵌套维纳滤波器前向递推的方法，子空间的分解和维数确定可同时进行，不需要估计接收信号的协方差矩阵和对其作特征值分解，运算量可以明显降低，收敛速度快。

In the presence of impulsive noise,the two received signals are combinated,so the estimated impulse response of the channel is the eigenvector of its covariation matrix corresponding to the smallest eigenvalue,which can be realized adaptively using generalization o.

该算法在脉冲噪声环境下，组合两个接收信号，使其共变矩阵最小特征值对应的特征向量为信道的估计，并基于广义归一化最小平均p范数方法自适应得到该特征向量，从而获得时延估计。

Submanifold; Homology group; Topological sphere theorem; L~2 harmonic 1-forms; Ends; Eigenvalue; Mean curvature; Second fundamental form

基础科学，数学，几何、拓扑子流形；同调群；拓扑球面定理； L~2调和1-形式；端；特征值；平均曲率；第二基本形式

Principal curvatures and principal directions are obtained by computing in closed form the eigenvalues and eigenvectors of certain 3×3 symmetric matrices defined by integral formulas, and closely related to the matrix representation of the tensor of curvature.

通过计算3×3对称矩阵的特征值和特征向量可以得出主曲率和主方向，而该对称矩阵是由积分公式定义并且与曲率张量的矩阵表达密切相关。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。