特征值

According to the studied results at present, the studied objects are mainly thin plate and beam about sound radiation mode, a method computed sound radiation mode of complex structure is presented in this dissertation, according to the results of the previous two chapter, a theoretical method to solve acoustical radiation mode and acoustical radiation efficiency of complex structure by boundary element method and acoustical radiation theory is posed, the acoustical radiation power is expressed as a Hermitian quadratic form, while the radiation modes is determined by general eigenvalue decomposing, and then the radiation efficiency is computed via the orthodoxy of radiation modes with regard to impedance matrix and average velocity matrix; lastly, the validity of the method is proved by pulsating sphere and radiating cube with analytical results. According to results of the form three chapter, the structure sound radiation sensitivity is studied in detail, the sound radiation power of structure can be expressed as positive Hermitian quadratic form, the sound radiation sensitivity can be expressed as two parts by partial differential with respect to design variable, which are sensitivity of boundary velocity and impedance matrix, combined with the theory of FEM and BEM, the structure sound radiation can be translated to the analysis of structure dynamic sensitivity and impedance matrix sensitivity. The theory posted in this dissertation is tested by the FEM software ANSYS and the software AAS programmed by author.

在前几章的基础上，通过结构声辐射的模态理论对结构的声辐射的机理进行了深入地探讨，针对目前声辐射模态的研究对象主要是简单的板和梁类结构，提出了一种计算复杂结构声辐射模态的方法，利用前两章研究所得的结论，将边界元方法与广义特征值的理论结合起来研究了复杂结构的声辐射模态与声辐射效率，先将结构的声辐射功率表示为一个正定的厄米特二(来源：ABb7C论文0909网www.abclunwen.com)次型，运用广义特征值分解求解了复杂结构的声辐射模态，然后利用声辐射模态关于阻抗矩阵与均方速度耦合矩阵的正交性，求解了复杂结构的声辐射效率，最后用具有解析解的脉动球与辐射立方体验证了该方法的有效性。

The using of the technologies of DOA in the orientation estimating of interference is discussed, then an evolutive ESPRIT algorithm is put forward which avoids the eigendecomposition and is easily achieved. To the MUSIC algorithm, an easy eigendecomposition algorithm for Hermitian matrix is presented. It breaks away form the complex matrix decomposition such as QR algorithm. Basing on the whole matrix, the algorithm makes use of the multiplication operation of matrix and vector, which attains simpleness and is fit for DSP. In the field of DOA estimating of correlation interferences, spatial smoothing algorithm consumes too many array units.

讨论了DOA技术在干扰源方位估计中的应用，提出了一种ESPRIT演变算法，该算法避开了特征值分解，实现简便；在MUSIC算法的实现中提出了一个Hermitian矩阵特征值分解算法，该算法摆脱了复杂矩阵分解，从矩阵整体出发，主要的运算是矩阵与矢量的乘运算，算法简单，非常适合DSP芯片实现；在相关源的DOA估计中，空间平滑技术使阵元的损失非常大，本文提出了一种进一步降低阵元消耗的平滑技术—随机空间增益法，其在运算量上的增加很小，但对于相干源的去相关确是有效的。

We first analyze the relationship between the characteris-tic subspaces of linear transformation A,and its conjuge transformation A*, on then-dimensional complex inner product space Cn, and prove that the characteristicsubspace of an enginvalueλof A is orthogonal to that of enginvalue μ of A* if λ≠μ.

首先，分析n-维复内积空间Cn上的线性变换A与其共轭变换A*的特征子空间之间的关系，证明出只要A的一个特征值λ与A*的一个特征值μ的共轭不同，那么它们对应的特征子空间是正交的。

The eigenvalues of circulant matrices compose of the discrete Fourier transform of the first line, on the contrary, the elements of the first line can recovered from the Fourier inversion formula, all circulant matrices have the same eigenvector that with the same order.

循环矩阵的特征值由其第一行元素的离散傅里叶变换组成，并且第一行元素是特征值的傅里叶变换的逆，而且所有同阶循环矩阵的特征向量相同。

The relationship between minimal model characteristic value of electric power system tie flow Jacobin matrix and voltage steady-state stability is was discussed, and the minimal model eigenvalue is was defined as voltage stability abundant degree. On this foundation, the sensitivity of voltage stability abundant degree to control variables and to PQ point load are was defined in order to seek the factors of impacting voltage stability and explore the voltage weak point, and give out their algorithm simultaneously.

讨论了电力系统潮流雅可比矩阵最小模特征值与系统电压静态稳定性的关系，将最小模特征值定义为电压稳定裕度，在此基础上定义了电压稳定裕度对控制变量的灵敏度和PQ节点负荷灵敏度，用以找出对系统电压稳定性造成影响的因素和寻找系统电压薄弱点，同时给出了它们的算法。

For a given Sturm-Liouville equation with positive leading coefficient function, by use of the monotonicity results of its natural loops, limit of boundary conditions and eigenvalues in the space of self-adjoint boundary conditions, a proof of the equalities among eigenvalues for coupled boundary conditions and those for separated boundary conditions is made.

内蒙古工业大学理学院副教授 2。对于给定的首相系数函数为正的 Sturm-Liouville方程，利用在自伴边界条件空间上自然圈、边界条件的极限和特征值的单调性的几个结果，给出了在偶合边界条件与分离边界条件下的特征值间的一些等式的证明。

This paper surveys a new exact method which uses exact dynamic stiffnesses and therefore results in a nonlinear eigenvalue problem in contrast to the traditional finite element method which reduces the problem into a linear algebraic eigenvalue problem by using approximate shape functions.

与常规有限元方法采用近似形函数将原问题化为线性特征值问题不同，本文的精确方法从杆件精确的形函数出发获得精确的动力刚度，将原问题化为非线性特征值问题。

Firstly, we give a new upper bound of a mixed graph′s largest Laplacian eigenvalue, which is more precise. And also we give a lower bound of a mixed connected graph′s largest Laplacian eigenvalue.

首先给出了混合图的最大Laplace特征值的一个新的上界，并且用实例说明我们的结果与以往结果相比更精确，同时也给出了一个连通混合图的最大Laplace特征值的一个新的下界。

With the aid of theory of normal form, the explicit expression of normal form for the averaged equations associated with a pair of double-zero eigenvalues and a pair of pure imaginary eigenvalues is given by using Maple program.

利用规范形理论和Maple符号程序，获得了一对双零特征值和一对纯虚特征值情况下平均方程的规范形。

Mapping ordered eigenvalue points of sample covariance matrix of the observation data onto Hough parametric space,the number of eigenvalues of noises can be estimated by detecting the peak points on Hough parametric space,and thus the number of signal source is determined.

该方法通过Hough变换将观测数据的采样协方差矩阵的排序特征值点投影到Hough参数空间，通过检测Hough参数空间中积累的峰值来估计噪声特征值的数目，从而确定信源的个数。

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。