查询词典 unbounded operator

We study on the controllability of parabolic systems with a nonlinear term involving the state and the gradient ,the null controllability property of a 1-d parabolic equation involving a fractional power of the Laplace operator ,null controllability of some systems of two parabolic equations with one control force ,and exact controllability of the parabolic system with bilinear control.

我们研究了含有状态和梯度的非线性的项抛物系统的能控性，含有拉普拉斯算子的分数阶的1-d抛物方程的零能控性，带有一个强控制的两个抛物方程的一些系统的零能控性和具有双线性控制抛物系统的精确能控性。

About the retrieval technique of the video, this paper analysed the basic principle and the key technology of Content桞ased Retrieval , have designed one Content桞ased Video Retrieval Systems frame model , and distillde the edge characteristic in static characteristic , expounded one arithmetic that based on modified Laplace operator and obtained a better result.

对于视频检索技术，分析了基于内容检索的基本原理及关键技术，设计了一种基于内容视频检索系统框架模型，并对静态特征中的边缘特征提取，提出一种基于拉普拉斯算子的改进算法，取得了较好的效果。

The second part is the controllability of parabolic equation .We study on the controllability of parabolic systems with a nonlinear term involving the state and the gradient ,the null-controllability property of a 1-d parabolic equation involving a fractional power of the Laplace operator ,null controllability of some systems of two parabolic equations with one control force ,and exact controllability of the parabolic system with bilinear control .

第二部分写的是，抛物方程的能控性，我们研究了含有状态和梯度的非线性的项抛物系统的能控性，含有拉普拉斯算子的分数阶的1-d抛物方程的零能控性，带有一个强控制的两个抛物方程的一些系统的零能控性和具有双线性控制抛物系统的精确能控性。

Stands for the Laplace operator in R~N, u and v represent the densities of two species, a, b, c, d,γare positive constants,α,β, m, n each is more than the positive number 1,γmeasures the saturation level of the species.

充分光滑，△为R~N中Laplace算子，u，v分别表示区域Ω中两种群的密度，参数a、b、c、d、γ均大于0，α、β、m、n均是大于1的正数，γ是测量种群饱和项的水平。

Named for Pierre-Simon Laplace, the equation states that the sum of the second partial derivatives (the Laplace operator, or Laplacian) of an unknown function is zero.

以法国数理学家拉普拉斯命名的这个方程式表述如下：一个未知函数的二级偏微商之和等于零。

Firstly, edge extracting is conducted with a laplace operator for a k frame image of fk and a k-1 frame image of fk-1 collected by a camera; secondly, difference calculus is conducted for images of two frames whose edge is extracted, and a difference image of D is obtained; thirdly, average filtering and binary processing is conducted for the difference image of D, fourthly, the image which is processed of binary is judged, i.e. when the difference of a pixel in the difference image is more than the set threshold value, the pixel is confirmed as a target pixel; otherwise, the pixel is a static background pixel.

首先对摄像头采集的第k帧图像f k和第k-1帧图像f k-1分别采用laplace算子进行边缘提取，然后对经过边缘提取的两帧图像进行差分运算，得到差分图像D，然后对差分图像D进行均值滤波和二值化处理，最后对二值化后的图象进行判断，即认为当差分图像中某一个像素的差大于设定的阈值时，则认为该像素是目标像素，反之则认为是静止不动的背景像素。

A Prove that d/dx is a linear operator on V. b You can put a coordinate system on V by mapping p to p(0, p(1), p(2).(Please imagine that flipped 90 degrees so it is a column.) Find the matrix that represents d/dx in this coordinate system.

1证明d/dx是V上的线性算子；2你可以将p映射到p(0， p(1)， p(2)，从而给V加上坐标系（想象将其翻转90°，形成柱体），找出在此坐标系中代表d/dx的矩阵。

The use of the web to spread fears that flicking the switch on the LHC could create a Black Hole that could swallow up the Earth particularly concerned him, he said.

他说，使用互联网散布恐慌说启动LHC会生成一个可能吞噬地球的黑洞的做法让他感到忧虑。

Not a single word have I written down.

我一个字也没有写下来。