查询词典 operator algebra

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 production moved off-Broadway to New York City, where she won the Joseph E. Calloway award for her performance, and was profiled in American Theater Magazine as one of ten young theater artists to watch.

生产提出过百老汇的新的纽约市，在那里她赢得了约瑟夫calloway奖，她的表现，并于异型在美国的战区杂志之一， 10战区的青年艺术家观赏。

It's a risk tradeoff, and I believe that adding test support code usually wins.

这是一个风险的权衡，我相信添加测试代码通常会占上风。