不变性

The control objective is achieved by firstly using robust passivity to stabilize the linear subsystem, and then with resort to switching control technique to guarantee the invariance of the specified region in state space simultaneously. Hence, a sufficient condition for the robust invariance switching control of this class of systems is derived.

控制思想是首先通过鲁棒无源性技术来镇定线性子系统，再借助切换控制技术得到系统轨迹对于指定区域的正不变性，从而得到了该类系统鲁棒不变切换控制的充分条件。

In the forth part, we mainly discuss the properties of cosine operators, such as the normcontinuity, locally Lipschitz continuity, which are preserved under the multiplicative perturbation with the-condition.

第四部分讨论了余弦算子在条件下的乘积扰动和扰动下的不变性。如条件下的乘积扰动仍保持范数连续、局部Lipschitz连续不变。

First, the optimal approximating network is presented and the invariance property of the marginal distribution of some variables is studied.

首先解决了在Bayes网络中删除一条弧之后的最优近似网络中的参数赋值问题，并研究了最优近似网络中某些结点子集的边缘分布在近似以后所具有的不变性，给出了边缘分布保持不变的最大结点子集。

No stretching invariance occurs in the Newtonian mechanics which therefore has to be modified.

牛顿力学不具有伸缩不变性，所以必须对其进行修改。

Base on normal invariant moment and wavelet character, construct wavelet moment and eigenvector, which can rotate, zoom and is no change when moved.

基于一般不变矩和小波特征，构造出小波矩及一组具有旋转、缩放和平移不变性的特征量用于特征提取。

In the image denoising algorithms, it is also a hotspot to overcome the lack of shift invariance of discrete orthonormal wavelet transform.

在图像去噪算法中，怎样克服离散正交小波变换的不具备平移不变性的缺点也一直是研究的热点。

This paper presented a new method for ranking the alternatives in AHP, different from the traditional methods, it can directly obtain the importance weight of each alternative by only solving alinear equations, without any given criteria or the paired comparison matrix. Moreover, it keeps the transitivity among the alternatives and the relative importance between arbitrary two neighbouring alternatives in the entire sequence ranked.

针对层次分析方法中传统的层次单排序方法存在的弊端，提出一种新的层次单排序方法，该方法不需判断矩阵和一致性检验，通过解线性方程组直接获得各因素关于上层因素的重要性权值，且保证了因素间重要程度的传递性以及相对重要程度的不变性。

This observation suggests that the relationship between classical and quantum systems is not so clear as it is often portrayed and that the permutation group could also be a part of the same universal symmetry as gauge invariance.

观测表明，这之间的关系经典和量子系统就不那么明确，因为它往往是描述，而置换群也可能是出于同样的普遍的对称性作为规范不变性。

In this chapter, three kinds of target recognition methods are performed, which are:①Target recognition method based on the description of polarization parameter plane. The echo polarization states of target are projected onto the polarization state plane described by the ellipticity ε and the tilt angle τ of the polarization ellipse, the change of parameter following ferquency becomes the chart. According to the changing trait of the chart, the multidimensional polarization feature space of target has been contructed. Furthermore, a series of polarization feature parameters used in designing the structure of target recognition device are extracted, and they are insensible to the posture of target.②Target recognition method based on the description of Poincare polarization sphere. The echo polarization states of target expressed by Stokes vector are projected onto the Poincare polarization sphere. The conception of polarization ferquency stability, which is used in describing the dynamic distribution characteristics of the target echo polarization states on Poincare polarization sphere, has been defined. A group of polarization feature parameters used in designing the structure of target recognition device are extracted, and they are insensible to the posture of target.③Target recognition method based on the description of frequency sensitivity. In accordance with the conception of the polarization state distance defined on Poincare polarization sphere, the frequency sensibility of the physical structure property of target has been investigated, the frequency distribution feature curves in PSD domain are obtained, and targets'features are extracted by means of the curve-fitting method with Least Square Criterion.

这章具体研究了基于三种极化散射特性描述的相应的目标识别方法：①基于极化参数平面描述的目标识别方法，将目标回波极化状态投影到以极化椭圆参数，即椭圆率角ε和倾角τ表征的极化状态平面上，参数随观测频率的变化就形成了图，根据图的变化特点构造了目标的多维极化特征空间，并提取了不敏感目标姿态变化的极化特征参数组来设计目标的识别器结构；②基于Poincare极化球面描述的目标识别方法，采用Stokes矢量表征目标回波的极化状态，并将其投影到描述极化状态的Poincare极化球面上，定义了极化频率稳定度的概念用以刻画目标回波极化状态在Poincare极化球面上的动态分布信息，提取了准方位不变性的目标极化特征，最后设计了目标的识别器结构；③基于频率敏感性描述的目标识别方法，通过在Poincare极化球面上所定义的极化状态距离的概念，研究的是复杂目标物理结构特性对探测信号频率的敏感程度问题，获得了在极化状态距离下的频率分布特性曲线，采用最小二乘估计曲线拟合方法，它既用于极化特征的降维，同时又直接将拟合参数作为目标的分类特征。

Based on the cross-ratio of five coplanar points, a group of projective invariants is derived for recognition planar polygons.

论文利用具有射影不变性的共面五点交比，导出一组用于识别平面多边形的射影不变量，并给出了相应的识别算法。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。