特征函数

It is discussed that the methods of discrimination of the stability of the singular point of nonlinear autonomous system by using of eigenvalue,center manifold and Liapunov function .

给出了利用特征根、中心流形和李雅普诺夫函数判断非线性自治系统奇点稳定性的方法。

The fault diagnosis of Fuzzy ANN is realized by the Neural Network Toolbox of MATLAB. The result is proved valid, but also proved easy to be trapped in the local extremum.

这里以BP网络为应用模型，把模糊化后的故障特征参数作为网络的输入样本，对样本数据训练、仿真，应用MATLAB提供的神经网络工具箱函数实现了模糊神经网络对设备故障的诊断，结果证明了该诊断模型的有效性，但也暴露出BP算法易陷入局部极值的弱点。

In the experiment the pre-processings, such as image filtering and Harris operator corner detector, etc. were used to get feature points quickly and realize the mapping transformation of camera parameters. The error estimate function was established to compare the proposed method with Tsai calibration algorithm.

实验过程中，利用图像降噪、改进的Harris算子角点提取等预处理过程快速提取特征点，实现摄像机参数标定的映射变换；建立了误差评价函数评价本文方法与Tsai标定算法。

In the experiment the preprocessings, such as image filtering and Harris operator corner detector, etc., were used to get feature points quickly and realize the mapping transformation of camera parameters. The error estimate function was established to compare the proposed method with Tsai calibration algorithm.

实验过程中，利用图像降噪、改进的Harris算子角点提取等预处理过程快速提取特征点，实现摄像机参数标定的映射变换；建立了误差评价函数评价本文方法与Tsai标定算法。

This approach was based on the NonSubsampled Contourlet Transform. The means and variables of NSCT coefficients matrix in different subbands and various directions were extracted to form the feature vectors which were regarded as indexes of texture images in image database. Two similarity functions were used to compute the similarity between images. A texture retrieval system based on query image was developed.

该方法利用非下采样Contourlet变换对图像进行分解，提取不同子带和不同方向变换系数矩阵的均值和方差为特征向量，作为数据库中纹理图像的索引，并利用两种不同的相似度函数计算图像之间的相似度，建立了一套基于示例查询图像的纹理图像检索系统。

Using a planar target as intermedium, an optimized object function of the position and orientation transformation matrix of the sensor is established; and the matrix, namely registration matrix, is derived from the feature points on the planar target.

采用一个平面靶标作为中介，建立了传感器位姿变换矩阵的优化目标函数，根据靶标上多个特征点求解出该矩阵，即拼接矩阵。

Based on the model of stiffened plates with concentrated added mass, a study of the stochastic vibration was carried out, and system's mean value, mean square value, cross-correlation function, cross-spectral density function were calculated.

从带有附加集中质量加肋板的力学简化模型出发，推导给出了该模型的随机功率谱密度，并分析了系统随机振动响应的其他统计数字特征：均值、均方值、互相关函数和协功率谱密度。

The security verification based on the content authentication is implemented through feature extraction, choosing of the shared encryption key, transformation of the Hash function and generation of the Merkle tree, which is simulated in the environment of NS-2. The result shows that the proposed mechanism has better performance in the efficiency and security.

通过特征提取、选取共享密钥、Hash函数变换和构造Merkle树实现基于内容认证的安全性检验，并在NS-2环境下进行了仿真模拟，结果表明所提出的安全机制具有较好的效率和安全性。

Then using polynomial as digital filter, it gains smooth curve function to depict the metatarsus region edge.

然后，由高次多项式进行数字滤波，再对滤波后的边缘曲线，利用先验知识，依据平均曲率的变化，自适应地选取不同的函数模型，提取出相应特征，自动识别边缘形状。

This project studies the scale-dependent deformation behavior of the metal matrix composite, the void nucleation and void growth mechanisms at the micron/submicron scale. The main results are:(1) In prophase, growth and coalescence of the void embedded in the graded matrix are analyzed in detailed;(2) Based on the infinite solid model containing a micro-void, coupling effects of the void shape and the void size on the void growth are studied carefully, the results show that it seems to exist a critical equivalent void radius, which is associated with the material length. When radius of a microvoid is close to or smaller than the critical void radius, the micro-void growth rate is essentially eliminated;(3) The coupling effects of the particle shape and size on the mesoscopic stress fields within the particle and matrix are also investigated by introducing the conception of inclusion/matrix interfacial energy. The results show that the stress concentration factors within the particle and on the matrix/particle interface are also strongly size-dependent,so the void nucleation mechanism is size-dependent.(4) By employing a specific orthogonal curve coordinate frame and a 'kernel function' conception, a 'unified method'solving the spheriodal and spherical void problems is suggested; by this unified method, size-dependent plastic potentials of the porous materials containing the spheriodal or spherical voids are obtained, which extend the traditional Gurson model for the spherical void and GLD model for the spheriodal voids to the micron scale.(5) Based on the RVE model containing the spheriodal or spherical particles, the influences of the particle shape and size on the size-dependent mechanical behavior of metal matrix composite are studied.

中文摘要：本项目对金属基复合材料在微细观尺度下的尺度相关变形行为、孔洞形核及长大的机理和模型进行了研究，取得了如下主要结果：1）在前期研究中，探讨了基体的梯度分布对孔洞长大和聚合的影响；2）基于含孔洞的无限大体模型，探讨了孔洞形状和孔洞尺寸对其长大的耦合作用，结果表明：可能存在一个与材料特征长度相关的临界孔洞尺寸，当椭球孔洞的等效半径小于临界孔洞半径时，孔洞的长大受到明显抑制；3）通过引入基体/夹杂界面能的概念，分析了夹杂尺寸、夹杂形状对材料细观应力场的耦合影响，结果表明：颗粒内部和界面上的应力集中因子强烈地依赖于夹杂的尺寸和形状，因此，孔洞的形核机理是尺寸相关的；4）采用一种特殊的正交曲线坐标系和引入"核函数"的概念，"统一"地得到了含椭球和球形孔洞的材料的尺寸相关塑性势，它将传统的Gurson球形孔洞模型和GLD椭球孔洞模型推广到微尺度范围；5）基于含椭球和球形夹杂的体胞模型，初步研究了夹杂形状、夹杂尺寸对金属基复合材料尺寸相关力学行为的影响。

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。