查询词典 first approximation

By coupling the moving least squares approximation with a modified functional, the Hybrid Boundary Node Method is a boundary-only, truly meshless method.

中文摘要：杂交边界点方法是一种纯边界类型的无网格方法，它将修正泛函和移动最小二乘近似结合。

LBIE, based on the local boundary equation, adopts the traditional moving least squares approximation which depends on only the values of the nodes in the domain of the problem or along its boundary. The whole process of integration is carried on over a local domain or its local boundary centered at the node in question. The local boundary equation can be rewritten to represent the values of the unknown function at the point of interest, and the essential boundary conditions can be directly and easily enforced by using the Green formula and the characters of the Dirac function.

它以局部边界积分方程为基础，采用移动最小二乘近似函数，从而只需要分布在问题域内及其边界上的节点的信息值，无需划分单元；整个积分是在以节点为中心的局部域及其边界上实现，所以不需要背景积分网格；借助于格林公式及Dirac函数的性质，将局部边界积分方程转化为所考虑点的未知函数的边界积分表达式，便于直接施加本质边界条件。

According to the orthonormality of Legendre polynomials in the function approximation theory, the exact boundary of the ball Bézier surface was optimally squarely approximated in polynomial form.

依据函数逼近论中Legendre多项式的正交性，得到了采用多项式形式表示的球域Bézier曲面的精确边界的最佳平方逼近。

Orthogonal polynomials with weight equaling 1 are used to make least square approximation, so morbidity phenomenon in solving equation is avoided and better results can be obtained. Advantages and disadvantages of Legendre polynomial and Gram-Schmidt polynomial are also discussed.

比较了Legendre多项式和Gram-Schmidt正交化构造的多项式在处理时间漂移方面的优缺点，并介绍了通过随机误差的平稳性来检验处理结果优劣。

The derivative of f with respect to x, which is the slope of the linear approximation to f.

f对x的微分，是对於函数f的线性近似。

To reduce the complexity of the proposed model, a simple linear approximation for Schottky diode is introduced.

采用线性近似的肖特基二极管模型进行建模，降低了数学模型的复杂性。

Based on a linear approximation and some reasonable propositions,a powerful expression for the SNR was derived.

通过对采样数据的一级近似以及合理的假设，推导出了信噪比的数学表达式。

The theories of matrix approximation and linear space decomposition are used to derive the solution and properties of TLS.

采用矩阵逼近和线性空间的分解理论推导了全最小二乘法的解及性质。

However, the performance of these algorithms that are based on linear approximation degrades considerably in highly nonlinear situation.

作者在文中重点讨论了用于多传感器目标跟踪系统的多项式最小二乘平滑、滤波和外推技术。

To solve this problem, we employ a linear approximation of the Almost Ideal Demand System Deaton and Muellbauer, 1980

要解决这个问题，我们聘用了线性近似几乎理想需求系统（ deaton和穆鲍尔， 1980年

"Second Life is remarkably easy to work with, and is very popular,"

"第二次生命是显着容易的工作，并且很受欢迎，"

For example, we usually assume that materials are homogeneous and isotropic and free of internal defects or flaws.

为了得到适合有限元分析的模型，我们必须经过如图2所示的简化步骤。