查询词典 approximation theorem

To reduce the error between the interpolation function regaining the sampled signal and interpolation function ha by Shannon sampling theorem, this paper suggests that the common linear interpolation is replaced by a second order approximation of the parabolic interpolation.

为减小恢复被采信号所用的内插函数与山农采样定理要求的内插函数ha之间的误差，提出了用抛物线内插--ha的二阶近似代替常规的线性内插。

The main results are as following: A A new demonstration to optical theorem is constructed B The scattering amplitude function for small particles, which is more accurate than that in classical RGB, is gained using electrostatics approximation, C Through a δ transform to the high frequent oscillation function, a concise deduction of the EG-type scattering amplitude function has been achieved.

主要结果如下： A给出了光学定理的一个新证法； B利用静场近似，得到了比经典RGB更精确的小粒子散射振幅函数； C通过一个高频振荡函数的δ变换，给出了一种EG散射振幅表达式的简明推导，并做了小角度散射简化，参照ADT，对EG近似又做了相位修正； D定义了一个新的函数—消光函数，并得到了组合散射体消光函数的平均定理。

A new type of polar decomposition—weighted polar decomposition of matrices is presented and defined. Aim at this new matrix decomposition, we prove its uniqueness theorem and obtain its uniqueness conditions, and also investigate the best approximation property of weighted unitary polar factor.

矩阵的极分解和广义极分解一直是矩阵分析研究的重要内容，本文中我们对其进行了横向扩展，提出并定义了一种新的极分解形式—矩阵的加权极分解。

In order to overcome this problem, in this paper, the surface electric current of the conducting sea surface and the first-order scattering from the conducting plate are obtained by employing Physic Optics method. The backscattering field of the time-dependant sea surface is calculated by using Kirchhoff Approximation. Meanwhile, taking the advantage of a newly developed technique that utilizes the reciprocity theorem, the difficulty in formulating the secondary scattered fields from the composite target is reduced. The dependences of the backscattered field on the parameters, such as the wind speed and the sizes of the plate are discussed.

为了克服这一问题，本文应用物理光学近似求解了导体海面表面电流及导体平板的一阶散射场，应用基尔霍夫近似给出了海面的后向散射场，同时借助互易性定理降低了求解平板和海面之间二次耦合散射场的难度，讨论了平板尺寸、风速等对后向复合散射场的影响。

Based on the above results, the problems of the electromagnetic interaction between a perfect conducting plate and 1-D/2-D conducting slightly random rough surface and the problems of the electromagnetic interaction between a dielectric spherical particle and dielectric slightly random rough surface are investigated. By using the reciprocity theorem, Small Perturbation Method and Physical Optics approximation, the solution for the composite scattering field from the composite target is derived and evaluated, and the numerical results are discussed and analyzed.

在此基础上，用互易性原理分别研究了一维、二维导体微粗糙面与其上方金属导体平板目标的复合电磁散射及介质粗糙面与其上方球形粒子的复合电磁散射，结合互易性原理和粗糙面散射微扰法及物理光学近似导出了复合散射场的计算公式并进行了数值计算，对计算结果进行了讨论和分析。

The equivalent solid sphere have same radius of the original coating shell, using reciprocity theorem, the effective conductivity of composite were obtained, it compare agree with effective medium approximation.

利用倒易定理，其结果与有效介质近似进行比较发现两者基本一

First introduced the lattice-value information systems knowledge, and to partial order for the basis has been a new relationship: advantage, given the reduction and the core, the concept of simplifying the classification of features, it is also given on the approximation, and the approximate reduction of matrix determined theorem and the concept of identification, the final adoption of specific reduction of examples to illustrate this method is effective.

首先介绍了格值信息系统的相关知识，并以偏序关系为基础得到了一种新的关系：优势关系，给出了约简和核心，简化了概念的分类特征，也给出了上近似、下近似及约简的判定定理和辨识矩阵的概念，最后通过具体的例子说明这种约简方法是有效的。

In this paper, the problem of an iterative sequence approximation a common fixed point for nonexpansive non-self mappings is studied in real uniformly convex Banach space, then we obtain a strongly convergence theorem.

在实一致凸Banach空间中，讨论了关于非扩张非自映射序列逼近公共不动点的问题，获得了一个强收敛定理，改进和推广了现有文献的一些相应结果。

In chapter four"The application of generalized sampling theorem to data compression", the qaulity of approximation coefficients is proved and a methodology of discrete cosine transformation combined with ununiform sampling is put forward.

第四章&广义采样定理在数据压缩中的应用&，对广义采样定理一中的展开式系数性质进行了证明，在此基础上提出了一种结合非均匀采样的离散余弦变换方法。

Calculations on the basis of the self-consistent approximation are used to study the effects of slit cracks, elliptical cracks and penny-shaped cracks. The influence of slit cracks on the elastic moduli under all kinds of loading conditions is discussed by Betti's reciprocal theorem and Irwin's relation describing the released energy rate of fracture to the stress intensity factors. The friction between the cracks' surfaces is taken into account for the closed cracks.

采用自恰方法研究了狭长型，椭圆型及硬币型裂纹在荷载作用下对弹性常数的影响；采用Betti的互易定理以及lrwin关于断裂能量释放率与应力强度因子的关系，分析了狭长型裂纹在各种应力状态下对弹性常数的影响；分析研究了裂纹闭合时，由于裂纹面上摩擦力的存在，闭合裂纹时弹性常数的影响。

When this condition occurs, inbound replication with the source partner is stopped on the destination domain controller and event ID 2042 is logged in the Directory Services event log.

计算机密码学是研究计算机信息加密、解密及其变换的科学，是数学和计算机的交义学科，也是一门新兴的学科。

Instructions: click on the thumbnails to see a larger image, then use the left-right arrow keys to scroll through the slideshow.

使用说明：滑鼠点在小图上即可放大观赏。开启后键盘左右键可用来换照片。