查询词典 finite difference approximation

Numerical dispersion characteristic and impedance relationship of three dimensional perfectly matched layers are analyzed under finite difference approximation in this paper, respectively, which show that numerical dispersion relationship of PML is different from that of the FDTD equations and the impedance of homogeneous PML medium is the same as that of free space.

本文分别分析了有限差分近似下三维理想匹配层的数值色散特性和阻抗关系，分析表明，理想匹配层的数值色散关系有别于时域有限差分方程的数值色散关系；有限差分近似下，均匀理想匹配层媒质的阻抗和自由空间的阻抗相同。

Papers analyzed the management flexibility and value of mining engineering, and set up the model of value of a developed mine,value of an undeveloped mine and value of an exploration project under the conditions of uncertainty with the theory of real option,and worked out the solution of model above-mentioned through three numerical methods,i.e.the Fig Tree,finite difference approximation and Monte Carlo simulation.

论文最后研究了矿业工程中的管理灵活性及其价值，运用实物期权方法分别建立了不确定条件下矿业生产阶段、开发阶段和详查、普查、预查阶段的矿业投资评价模型，并运用二叉树图、有限差分逼近和Monte Carlo模拟三种数值方法对所建模型进行了求解，同时通过实例对论文的研究结果进行了佐证。

The estimation errors, including the finite difference approximation error, the instrumentation channel mismatch error, and the error caused by ambient noise, are studied systematically.

文中基于声信号的空间互谱分析，给出了声强向量阵的定向原理，并系统分析了其定向误差，包括有限差分误差、通道失配误差和环境噪声引起的误差。

On the aspect of error compensation, the system using the geometric average sound pressure instead of the arithmetic average sound pressure to get the sound pressure of the measurement point. This method not only reduces the high frequency error in the sound intensity measurement, which compensates the finite difference approximation error, but also greatly reduces the computation of the sound pressure spectrum.

误差补偿方面，课题采用几何平均声压代替通常的算术平均声压来计算双传声器法的声场声压值，这样不仅可以有效的减少声强测量中的高频误差，对有限差分误差起到了补偿作用，而且还大大减小了声压谱计算中的计算量。

The tether was modeled using finite difference approximation. The balloon was modeled using rigid-body dynamic model including the static derivative, dynamic derivative and added mass.

缆绳采用有限差分法，球体采用经典的六自由度方程，其中气动力导数以静导数、动导数和附加质量表示。

Jacobian, Hessian Matrix Properties, Sensitivity Analysis w.r.t Design Variables, Fixed Parameters and Constraints, Normalization, Finite Difference Approximation, Automatic Differentiation, ANOVA, Adjoint Methods, Examples

Jacobian， Hessian矩阵属性，灵敏度分析w.r.t设计变量，固定参数和约束，归一化，有限差分逼近算法，自动差分算法，ANOVA，伴随矩阵法，举例

We construct an explicit finite difference approximation for the equation by using the equivalence relation between Riemann-Liouville fractional derivative and Grünwald-Letnikovmake fractional derivative.

再利用Riemann-Liouville分数阶导数与Grtinwald-Letnikov分数阶导数之间的等价关系，构造一显式有限差分近似，这一离散格式可以解释为一个随机游走模型，并且收敛于稳定的概率分布。

And we show that random walk model converges to the stable law of Lévy-Feller advection-dispersion equation by use of a properly scaled transition to vanish-ing space and time steps,We propose an explicit finite difference approximation for Lévy-Feller advection-dispersion equation.

第三章讨论描述服从某种稳定分布反常扩散的非对称空间分数阶对流-扩散方程——Lévy-Feller对流-扩散方程，首先利用Fourier变换和Laplace变换给出方程的基本解，然后利用Grünwald-Letnikov分数阶导数移位离散算子离散方程中的Riesz-Feller分数阶导数得到离散格式，证明此格式可以解释为离散随机游走模型，并且证明了当时间和空间步长以一定的比率同时趋于0时，所提出的离散随机游走模型收敛到Lévy-Feller对流-扩散过程的稳定分布。

Af ter applying this result to the conservative gas dy2 namic systems ,the semi2discrete finite difference approximation and the discrete ent ropy couple [Ut , F0j + G1j ] is searched.

关于双曲型守恒方程组ut + f x = 0 ，若存在标量熵对满足熵不等式Ut + Fx ≤0 ，则原方程存在弱解。

This book reviews the many areas of numerical analysis, including the configuration polynomial, finite difference, factorial polynomials, summation, Newton formula, operator and configuration polynomial, Cheung section, close polynomials, TaylM more item type, interpolation, numerical differentiation, numerical integration, and with the series, differential equations, differential equations, least squares polynomial approximation, minimax polynomial approximation, rational function approximation, triangular approximation, non-linear algebra, linear equations, linear programming, boundary value problems, MonteCarIo methods and so on.

本书综述了数值分析领域的诸多内容，包括配置多项式、有限差分、阶乘多项式、求和法、Newton公式、算子与配置多项式、祥条、密切多项式、TaylM多项式、插值、数值微分、数值积分、和与级数、差分方程、微分方程、最小二乘多项式逼近、极小化极大多项式逼近、有理函数逼近、三角逼近、非线性代数、线性方程组、线性规划、边值问题、MonteCarIo方法等内容。本书的特色主要表现在利用例题及大量详细的题解来透彻地阐明所述内容的内涵，同时附有大量的补充题以便读者进一步巩固和深化从书中获得的数值分析知识。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。