查询词典 mathematical expectation

Its mathematical foundations were laid in the 17th century with the development of probability theory by Pascal and Fermat .

其数学奠定了基础在17世纪的发展，概率论的帕斯卡和费马。

In this way the"Five Nations Conference on Mathematical Education"was born.

之后，发展为由美国、德国、法国等欧美国家在内的&五国国际会议&。

We have 19 Research Chairs in mathematical and computer sciences, and 12 Faculty are Fellows of the Royal Society of Canada.

我们有19位数学和计算机的加拿大科研主席。我们有12位教授是加拿大皇家学院院士

Solveing to some extent problem to define hidden layer node number of feed forward networks,and makeing successfully it to apply to solve weierstrass theorem of that is polynomial approach continuous function;and establishing dynamic mathematical neural networks of Romberg integration.

从而在一定程度上解决了前向神经网络隐层结点数无法确定的难题，并成功地将其运用于解决用多项式逼近连续函数的魏尔斯特拉斯定理，并建立了龙贝格求定积分的动态数学神经网络模型。

Based on the mathematical model and the Romberg numerical integrating algorithm, an array with 40 sets of data was obtained to describe the aspheric surfaces. By fitting the data with the method of the nonlinear least square, the sag's analytical equations of aspheric surfaces were obtained.

根据基于几何光学原理导出的系统理论模型，采用龙贝格数值积分算法得到40组描述非球面的数据，非线性最小二乘法拟合数据，获得两个非球面矢高解析式。

"It's hard to explain such a huge number from any mathematical postulate or any physical principle," says Greg Landsberg, a theoretical physicist at Brown University in Providence, R.I."It's a bit of an embarrassment for our field, because what it really means is, we don't seem to understand gravity."

&很难解释来自任何数学假设或物理原理的如此庞大的数字，&罗德岛普罗维登斯的布朗大学理论物理学家格雷格·兰茨贝格说：&对我们的领域来说这多少有一点尴尬，因为它真正的意思是，我们似乎并不了解引力。&

This paper reviews and summarizes the progress in this field as follows: the mathematical model and the difficulty of the analytical solutions is introduced; discusses the latest progress of the numerical solutions is discussed; the finite difference method, the Godunov method, the Boltzmann method, and the KFVS method of one-dimensional dam-break problem are introduced; the TVD method, the discontinuous finite element method, the finite volume method and characteristic method of two-dimensional dam-break problem are discussed; the applicability, the advantage and the disadvantage of each method are analyzed; and the progress in the numerical calculations of flow of fluid with free surface are presented.

回顾和总结了国内外对溃坝水流演进问题的研究进展：介绍了溃坝水流的数学模型及解析解法存在的困难，进而讨论了数值解法的最新进展；论述了求解溃坝水流一维问题的有限差分法、近似黎曼解的Godunov格式法、Boltzmann法、KFVS法和二维问题的TVD格式法、间断有限元法、有限体积法、特征线法，并分析了各种方法的适用范围和优缺点，及讨论了限制函数的使用；介绍了利用自由水面追踪方法计算溃坝水流的研究进展，并根据目前存在的不足和实际工程的需要，提出了进一步研究的方向和发展趋势。

Now Choptuik and Frans Pretorius of Princeton University have simulated such collisions, including all the extremely complex mathematical details from general relativity.

现在，肖普提克和普林斯顿大学的弗朗斯·普雷托里斯模拟了这样的对撞，同时利用了广义相对论中全部特别复杂的数学资料。

Now Choptuik and Frans Pretorius of Princeton University have simulated such collisions, including all the extremely complex mathematical details from general relativity.

超普图伊科和比勒陀利乌斯大学的佛朗斯模拟了这种碰撞，并得到了极其复杂的相对论的详细数据。

Based on the research on sensitivity of geomagnetic declination on wind measurement by UAV with Pitot-static tube,mathematical model of wind speed error to effect of geomagnetic declination is set up in virtue of wind measurement theory and error theory.

从无人机(unmanned aerial vehicle，UAV)皮托-静压管测风对磁偏角的敏感性出发，借助无人机皮托-静压管测风原理和误差理论，建立了磁偏角对测风影响的风速误差数学模型；通过仿真，分析了磁偏角对风速测量的影响和误差变化规律，并通过试验数据验证了仿真结论，为磁偏角的校正，提高风速测量精度提供了参考依据。

A carrier gas such as nitrogen is directed through line 20 and valve 22 to connect with line 26 and mix with the gas sample.

如氮气之类的载体通过管线20和阀22引入，与管线26相通，与气体样品混合。

But for the most part, knaves and parasites had the command of his fortune

然而支配他的家产的大多是恶棍和寄生虫。