查询词典 completely continuous operator

Infinite dimensional Hamiltonian operator;semigroups of linear operator;spectrum;residual spectrum;continuous spectrum

中文主题词：无穷维Hamilton算子；线性算子半群；谱；剩余谱；连续谱

We firstly look back thebirth of SD method,and then present the SD scheme presented by Johnson et.al.forlinear problem to explain the basic idea and implementation:At step 1,we change the testfunctionwhere(1,β)t is the streamline or character direction decidedby hyperbolic operator of the continuous problem,therefore the SD method belongs tothe Petrov-Galerkin method;At step 2,we adopt time-space finite element space,whoseelement is only continuous in space variables x but discontinuous in time variable t.

首先回顾了SD方法的产生过程，然后以线性问题为模型，描述了SD方法的基本思想和具体实现：第一步，将标准有限元方法的检验函数ν改成其中(1，β)t是连续问题的双曲算子部分所确定的流线方向。换言之，SD方法是一种Peterov-Galerkin有限元方法；第二步，采用时空有限元空间，其元素关于空间变量x是连续的，但关于时间变量t仅分段连续。

Furthermore, the kernel of a continuous projection ( in fact, a continuous linear operator in general ) is closed.

进一步的，连续投影(事实上，一般的连续线性算子)的核是闭合的。

In processing high sampling data system, discrete time model using delta operator approaches corresponding continuous time model, and the results also tends to the corresponding ones of its continuous counterpart.

在处理高速采样过程时，Delta算子离散模型接近于原来的连续模型，所得结果也趋近于连续模型的相应结果，较好地解决了传统的移位算子方法在高速采样时引起的数值不稳定问题。

Firstly, this paper investigated roundly the basic theory of the ambient vibration method, analyzed systematically the main methods of ambient vibration identification, and discussed their advantages and disadvantages. Then we established the finite element model of structural dynamics and test model and analyzed their mutual relation, improved MUSIC method and correlation function method in the harmonic identification, and gave the subspace method and correlation function method based on continuous model, which is multi-harmonic retrieve technique. And then, this paper also puts forward least-squares method to estimate directly structural physical and modal parameters; this approach replaced the derivative operator in the continuous time model with an equivalent approximation, and estimated the physical parameters of structures by the least-squares method. And then, we discussed the approximation methods of derivative and their convergence. Finally, this paper researched the modal parameters of a frame structure by the simulation and test. The results demonstrated that subspace method, correlation function method and the least-squares method are effective and stable respectively.

全面地研究环境振动识别方法的基本理论，系统地分析环境振动识别方法的主要方法，讨论它们的优点和不足；建立结(来源：6666AB44C论文网www.abclunwen.com)构动力学的有限元模型和试验模型，分析有限元模型与试验模型之间的相互关系；改进谐波识别中的MUSIC识别方法和相关函数识别方法，给出大型结构模态识别的连续型的子空间分解识别方法和相关函数识别方法，这个方法是多元谐波识别方法；提出直接识别结构的物理参数和模态参数的最小二乘方法，这个方法利用导数的近似值代替导数值，并运用最小二乘方法识别结构的物理参数，讨论导数近似值的选择方法，分析算法的收敛性；通过仿真计算和模型实验，研究高层框架结构的模态参数识别，验证子空间分解识别方法、相关函数识别方法和最小二乘识别方法的有效性，算法的稳定性；从理论和试验两个方面分析和研究噪声对识别精度的影响，影响识别精度的因素，以及部分模态成分的模态参数不能够被识别的原因。

Lastly,Using the extension theory of〓-algebras founded and developed by Brown-Douglas-Fillmore in 70s,inparticular,using the homotopy invariance of the extensions and the indexformule of Toeplitz operator matrices,the paper characterized the automorphismgroup of the continuous function symbol Toeplitz 〓-algebra in terms of thetopological degrees of the continuous mappings on the n-dimensional sphere.

最后，本文利用Brown-Douglas-Fillmore在七十年代建立并发展起来的C*-代数扩张理论，尤其是扩张的同伦不变性，以及Toeplitz算子矩阵的指标公式，通过球面上连续映射的拓扑度，刻划了高维球面Hardy空间上连续符号Toeplitz 〓代数的自同构群。

According to [2], we know that if X is a reflexive Banach space and T is a strongly continuous semigroup on X with the infinitesimal generator A, then the adjoint semigroup T~* is also a strongly continuous semigroup on X* and its infinitesimal generator is A~*, the ajoint operator of A.

由文献[2]我们知道，如果X是一自反Banach空间，那么X上强连续半群T的对偶半群T~*也是X~*上的强连续半群，并且其无穷小生成元为半群T的无穷小生成元的对偶。

Digital image process technique is used in pantographic faults monitoring, and a new algorithm named window-edge tracking is proposed in this paper. Based on the binary image of edges which is detected by Canny operator, a window in proper size is set to track the discontinuous edges to estimate the position of the lost edges. With this method continuous edges will be obtained, and continuous and smooth edges will be got after least-squares curve-fitting.

中文摘要：将数字图像处理技术应用于受电弓故障监测，提出一种新型的窗口边缘跟踪算法，在采用Canny算子计算出边缘二值图的基础上，设置适当大小的窗口对初始不连续边缘进行遍历，估计断点处边缘点位置获得连续边缘，并采用最小二乘法拟和出连续平滑的曲线函数。

We establish the equivalent integral equations to these problems, and prove that the defined operator is completely continuous.

建立了与这些问题等价的算子方程，并证明了所定义的算子是全连续的。

2By constructing a completely continuous operator in a functional space and employing the cone compression and expansion fixed point theorems, we obtain some sufficient conditions which guarantee the existence of positive periodic solutions for Eq.

通过在一个函数空间构造一个全连续算子，再利用锥压缩锥拉伸不动点定理，得到了一些保证方程(1)，(2)至少存在一个周期正解的充分条件，所得结论改进了文[1]和[6]中的结果。

"The operators will suffer a temporary decrease in the number of consumers and short message services as people may not like having to provide their ID cards for a phone number," Xu Junqi, vice-dean with the Policy-Making Institute of the Telecommunications Research Centre under MII, said yesterday.

信息产业部下属的通信决策研究院副主任徐俊其昨天说：&实行手机实名制后，人们可能不太情愿用身份证注册手机号，所以通信运营商会暂时面临用户减少和短信用户减少的问题。&

I don't believe in make-believe!

我不相信这些虚构的故事。