向量的模

The Pinching problems are discussed on the sectional curvature of compact space-like pseudo-umbilical submanifolds M~n with parallel mean curvature vector in De Sitter space S~_p, and the theory of reduction of the codimension is obtained in De Sitter space through evaluating the Laplacian of square of the length.

讨论了De Sitter空间Snp+p中，具有平行平均曲率向量的紧致类空伪脐子流形Mn的截面曲率的拼挤问题，通过估计第二基本形式模长平方的Laplacian，得到了De Sitter空间中的余维数压缩定理。

By the EEOF analysis of subsurface ocean temperature anomaly in the equatorial Pacific Ocean, It is founded that, the first eigenvector is the mode about El Nino and it reflects the entire generation, persistence and diminishment process of El Nino phenomenon, there is good contemporary correlation between the corresponding time coefficient and the Nino3 index.

本文通过对赤道太平洋次表层海温距平场的EEOF分解，发现第一特征向量是关于El Nino的模态，它反映了El Nino的发生持续消亡的整个过程，对应的时间系数与Nino3指数有很好的同时相关。

Also in the 3-D space, we assign the 20 amino acids to 20 vertices of the dodecahedron. By the symmetry of the dodecahedron we obtain 3-D representation of 20 amino acids, and 3-D graphical representation and the corresponding numerical sequence of protein sequences. And similarity and dissimilarity analysis based on the invariants of graphs and characteristics of numerical sequences are given for nine RNA secondary structures of RNA-3 of virus. We construct sequence phylogenetic tree of a group of cytochromes C protein.

在DNA三联体密码子表示的基础上，在半复平面上给出了蛋白质序列的非退化的2-D图形表示，同时利用复向量的主要特征—模和相位，给出了蛋白质序列的一种数值刻划，进一步在3-D空间里，把20种氨基酸分别分配给正12面体的20个顶点，根据正12面体的对称性得到了20种氨基酸的3-D表示，进而得到了蛋白质序列的3-D图形表示和对应的数字序列，并利用图的不变量和数字序列的特征比较了9种动物的神经元

As a foundation, the definition of elementary integral transformation and the method to factorize an integral matrix with elementary integral transformation is proposed firstly. After that, the problem how to find identification vectors in Modular-S-invariants is solved.

文中首先给出初等整数变换的概念，之后借助初等整数变换对整数矩阵进行分解，并在此基础上给出从加模S-不变量中求取不可达见证向量的方法。

The orthogonal expansion method of the stochastic structural analysis leads to an orderexpanded equation whose order is much larger than the actual structures.

针对随机结构正交展开分析方法计算量过大的缺陷，本文首先提出基于Ritz模态向量的扩阶方程动力聚缩算法。

II, Polynomial rings on a general field( on contrast of those over a number field): concepts of ring, ideals, field and several special rings as domains, principal ideal domains and unique factorization domains, the unique factorization theory of polynomial rings.

二、一般域上的多项式理论（是数域上多项式理论的推广）：学习环、域和几类特殊结构的环（整环、主理想环，唯一分解环等）的概念，多项式环的唯一分解定理；三、线性代数：讲述一般数域上的向量空间理论（是数域上向量空间理论的继续和推广），模的概念，主理想环上的模的结构及其线性变换的若当标准型等；四、一元多项式的解及域论：学习域扩张及其相关概念，伽罗瓦理论，用伽罗瓦定理判断根式解的存在性。

The left singular vector of the projection has been tracked by the projection approximation subspace tracking algorithm. Then the modal parameters are obtained by least square method. At last an experiment is made using a cantilever beam to prove the efficiency and stability of the method by changing the frequency band of the exciting signal.

通过子空间跟踪算法，不断跟踪计算投影的左奇异值向量，再利用最小二乘法求出系统的模态参数，最后用悬臂梁作为实验模型，通过不断改变系统激励的频带范围，验证方法的有效性及稳定性。

Based on the decomposition theorem for vector space with module structure and rational canonical form of matrix, a kind of new block diagonal controllably canonical forms are inferred when the time invariant linear multivariable system is completely controllable, which the system matrix is similar to a block diagonal and has an analogy with its rational canonical form. Compare with current controllability canonical forms, this kind is easier to analyse the system constructional characteristic. The process of proof gives an effective solution method.

基于向量空间的模结构分解和矩阵的有理标准形给出了定常多输入线性系统一类新的块对角可控规范型，其中的系统矩阵相似与一个块对角矩阵，该块对角矩阵类似于矩阵的有理标准形，与现在有的可控规范型比较，更容易反映系统的结构特征，证明步骤给出了求解方法。

In chapter Ⅰ, a historial review of structure control is given; In chapter Ⅱ, A discussion of the controllability and observablity of flexible structures is given, Two kinds of controllability and observablity index are defined, and applied to actuator allocation; chapter Ⅲ considers the reduction of high order flexible structure mode; the content of chapter Ⅳ is about the basic problem of distributed parameter control system design. It is proved that a stable controllor in mode space may be unstable in real use in distributed paramater systems, also, by closed loop mode concept, a pole assignment method of flexible structure controllor design is given; chapter Ⅴ is about the low-authority controllor design, it is pointed out by use of high order eigenvalue/eigenvector perturbation, a better controllor can be designed; chapter Ⅳ considers flexible structure reduced order control; chapter Ⅶ disscusses the basic problem of flexible structure computer control, analyses discreate controllablity and observablity and its computing, the sample period and coefficient wordlength; chapter Ⅷ is on the problem of low flexibility compensation; chapter Ⅸ is a design example.

在第一章简要回顾了挠性结构控制的历史，并且指出控制中的一些问题；第二章讨论了挠性结构的能控性与能观性，定义了两类能控性程度和能观性程度指标，还将能控性程度概念应用于执行器位置的确定；第三章论述了高阶模型的降价问题，比较了适于挠性结构模型降阶的方法，指出其适用范围；第四章内容是分布参数系统设计的基本问题，首先证明在模态空间中设计的稳定的控制器在实际分布系统上可能是不稳定的，进而根据闭环模态的概念，获得挠性结构控制器设计的极点配置方法；第五章的内容是关于低权控制器的设计问题，指出利用特征值高价摄动和特征向量的摄动，可以设计出更加完善的低权控制器；第六章讨论挠性结构降阶控制问题；第七章讨论挠性结构计算机控制的基本问题，分析了时间离散化模型的能控性和能观性及其计算问题，讨论了采样周期选择和系数字长问题；第八章讨论低挠性结构的补偿问题；第九章的设计例子用来说明第二章和第四章的结果。

It is a more preferable to simpler frequency criterion, since it takes into account of frequency, vibration mode, damping, s ensor and actuator information. Reduced order model can approximate well the bas i c characteristics of the original system.

该法考虑了可观性向量、模态增益、结构阻尼系数及模态频率，较简单的频率截断法是一个很大的改进，降阶后的模型能很好地近似原系统性能。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。