查询词典 approximation methods in physics

Bridge ; moving load ; identification ; parametric analysis ; simply supported girder ; multi-span continuous girder ; spline approximation method

桥梁；移动荷载；识别；参数分析；简支梁；连续梁；样条函数逼近法

The application of the lattice Boltzmann method in unsteady open channel flows was studied in detail in the paper. An existing lattice BGK model was mended; For the problem of negative local equilibrium and evolutionary distribution, we proposed a lattice Boltzmann model based on cell-population equilibrium, which is a direct non-negative approximation to the continuous Maxwell distribution. The model reduces the transport and collision, two basic evolution steps in the LB model, to transport of the non-equilibrium distribution.

本文系统的研究了格子Boltzmann 方法在明渠非恒定流中的应用问题，改进了一个现有的LB 模型，数值实验表明此改进是有效的；在平衡态分布函数及分布函数的非负性问题上，作者提出了一个基于单元均衡的格子Boltzmann 模型，通过直接对Maxwell 分布函数的离散化实现对速度分布函数的非负离散，这种方法将传统模型演化过程中的碰撞和输运两个步骤直接表现为粒子的输运。

We study the relations among MS, QMDS, RBVS, AMDS, GBVS and NBVS. Finally. we improve some classic results in Fourier analysis such as uniform convergence, L~1 convergence, L~p-integrability, strong approximation of continuous functions et al., by applying this new condition.

我们研究了MS，QMDS，RBVS，AMDS，GBVS和NBVS等不同数列之间的关系，在此基础上，我们给出了NBV条件在研究三角级数的一致收敛性、L~1收敛性、L~p可积性、连续函数的强逼近等Fourier分析经典问题上的应用，对一些经典的结论作了推广。

We consider the cubic Hermite-Pade approximation and give the contour integral representations of coefficient polynomials.

研究了三次Hermite-Pade逼近系数多项式的围道积分表示，利用鞍点法得到了这些多项式的渐近估计。

The concept of controlled λ-exponentially contractive set for the systems is introduced,and relation between the set and that for its Euler approximation discrete-time system is also established.

首先，引入连续时间系统的受控λ-收缩集概念，并建立了与其Euler逼近的离散系统的受控收缩集之间的关系。

In general, stochastic approximation is guaranteed to converge.

在一般的情况下，随机近似方法的收敛效果是受到肯定的。

In view of the tedious and mistakable manual calculation in measuring Gauss projection,coordinate zone transformation and meridian convergence,an itera-tive approximation method is adopted and programmed by BASIC to imple-ment the direct and converse calculation of Gauss projection and computer cal-culation of meridian convergence angle.

针对测量工作中人工进行高斯投影、坐标换带和平面子午线收敛角计算非常麻烦又容易出错的问题，采用迭代法趋近求值，用BASIC语言编制了相应的计算机程序，实现了上述计算。

In the section, the definitions and main properties of the operator have been discussed systematically, the operational rules of one dimensional PGOPO have been strictly established based on the theory of convergence in the mean square, error and convergence analysis of approximation by PGOPO has been discussed.

系统地论述了分段广义正交多项式算子的定义、性质，并为一维PGOPO算子严格地建立一套在均方收敛意义下的代数运算规则，给出了分段广义正交多项式算子作用下的误差及收敛性分析结果。

Properties of measurable functions; approximation by simple functions and by continuous functions; convergence in measure; Egoroff's theorem; Lusin's theorem; Jensen's inequality.

可测函数。可测函数的性质；简单和连续函数逼近；测度收敛；叶果洛夫定理；鲁津定理；詹森不等式

The Pade approximation is combined with 3-D frequency-domain finite difference (3D-FDFD) for the first time. The impact of expansion point and the order of rational function on the accuracy and the convergence radius is discussed in this dissertation.

主要包括以下内容：首次将Pade逼近运用到三维频域有限差分法中，详细讨论了Pade逼近中展开点选取、收敛半径与有理阶数的关系问题。

We have something to do in the new stage.

在这段崭新的时期中，我们有一些要做的。

The difference between tourism decision-making under uncertainty and risky tourism decision-making is indistinctive.

其中不确定性旅游决策和风险旅游决策的界线比较模糊，两者的区分是相对的。