查询词典 laplace transform

The nonlinear equation of heat conduction is transformed into a Laplace′s equation by applying the Kirchhoff transformation ,and an analytic approximate solution of the equation is derived.

当介质的导热系数是温度的函数时，热传导方程是非线性偏微分方程，作者采用基尔霍夫变换把它变成拉普拉斯方程，于是可以找到原问题的近似解析解。

We definite and study the very extensive nonlinear random effect models, i. e. exponential family nonlinear models with random effect, then we employ the Laplace methods to deal with these models. Based on this method, the fixed effect parameter estimates and Gauss-Newton formula are obtained. Some asymptotic properties of estimate are proved under some mild assumptions.

首次定义并研究了一类非常广泛的非线性随机效应模型-指数族非线性随机效应模型，并应用Laplace展开方法，给出该模型中固定效应参数的估计以及Gauss Netown选代算法，同时讨论了参数估计的渐近性质。

G = Ω×(0,+∞),F =Ω× 0,+∞, A is the Laplace operator, n is the unit exterior normal vector toΩ.

是边界Ω的单位外法向量。

A 2-D coupled numerical model, which is the combination Boussinesq equations solved by finite difference method with Laplace equation solved by boundary element method, is established.

Boussinesq方程与Laplace方程耦合计算模型：1 建立了外域用有限差分法求解Boussinesq方程、内域用边界元法求解Laplace方程的二维耦合计算模型。

Second order incident boundary condition on fixed incident boundary is derived for numerical simulations, based on the cnoidal or sinusoidal motions of wave maker paddle, which shows that the prediction with second order incident boundary condition is more accurate than the prediction with first order incident boundary condition. 2 The analytical solution for higher-order Boussinesq equations is derived and its applicable range is discussed. 3 A 2-D fully non-linear numerical model using boundary element method is developed to obtain wave forces acting on rectangular obstacle. 4 The three-dimensional fully non-linear waves are studied in a numerical wave tank using finite element method.The studies on the coupled numerical model combined Boussinesq equations with Laplace equation are following.

非耦合非线性波浪计算模型：1 根据造波板做椭圆余弦运动或正弦运动速度，推导出数值模拟波浪水槽时固定入射边界上的二阶波浪入射边界条件，数值计算结果和实验结果的对比表明采用二阶入射边界条件对波面升高的预报比采用一阶入射边界条件对波面升高的预报更为精确；2 推导了波浪水槽造波板做正弦运动所产生波浪的高阶Boussinesq方程摄动展开解析解，讨论了该解析解的适用范围；3 对整个波浪水槽应用边界元方法数值模拟了波浪对物体的非线性作用；4 用有限元法求解三维Laplace方程模拟了三维完全非线性波浪水槽。

An instance was given by means of the numerical solution for the first boundary value inverse problem of Laplace's equation.

将直匀流绕物面作二维无旋不可压缩定常流动时的流函数表达为曲面后，利用流函数曲面控制边界与流曲线的对应关系，采用拉普拉斯方程第一边值逆问题的数值解法，提出了来流为直匀流的流曲线造型方法并给出了实例。

In this paper the direct boundary integral equation of two-dimensional Laplace equation for Dirichlet problem is considered, which is deduced by Green's formula and the fundamental solution, and is a Fredholm integral equation of the first kind.

本文考虑用Green 公式和基本解推导得出直接边界积分方程来求解二维Laplace 方程的Dirichlet 问题，该直接边界积分方程是第一类Fredholm 积分方程。

Methods From the fundamental equation in Laplace domain, using Multiple Reciprocity Method-Boundary Element Method, the integral equations and the boundary integral equations are derived and solved numerically.

方法由 Laplace 变换域中的基本方程出发，利用多重互换边界元方法，得到了积分方程和边界积分方程，并求得数值解。

And the equations are solved coupling iteratively whith PCG method for Laplace equation and Gauss—Seidel method for convective equation.So the distribution of piezometric tube waterhead and saturation can be obtained.And the seepace free surface will be captured automatically according to the distribution of saturation with the concept of VOF.

分别对饱和区的拉普拉斯方程采用预处理共轭梯度法、非饱和区的对流方程采用Gauss—Seidel方法进行耦合迭代求解，得到渗流场的测压管水头分布和饱和度分布，并引入VOF的概念，由饱和度的分布自动扑捉渗流自由面。

Regarding the circular defects such as leakage gnarl in log, this paper designed an improved Laplace's special gradient method to clarify the target image.

针对原木中的漏节等圆形缺陷，本文设计了改进的拉普拉斯算子法增强图像中目标的清晰度。

It was just a normal day of school

那只是上学的普通一天

Which is a very good reference in this issue.

这是一个在这个问题上很好的参考。