查询词典 initial approximation

In this thesis, we use the Min-Max criterion and Parks-McClellan algorithm to design this optimal approximation error of spectrum. Moreover, we give constraint of this optimal spectrum to get the positive spectrum. Then the positive spectrum can be factored by Spectrum Factorization Theorem and can be realized by FIR system.

我们利用最小化最大误差指标，及Parks-McClellan演算法，设计出具有最佳误差的频谱，并对此频谱做限制式上的处理，来得到正数列频谱，并将所得到之正数列频谱利用分解理论做分解，并以FIR系统实现之。

By using slowly-varying envelope approximation, a family of solutions of the paraxial wave equation are found in theory, which represents a new family of ultrashort pulsed beams called ultrashort pulsed complex argument Sinc-Gaussian beams.

杨振峰 河北科技大学经济管理学院，石家庄 050018杨振军河北师范大学物理学院，石家庄 050016胡巍华南师范大学传输光学实验室，广州 510631利用理论解析推导的方法，在傍轴近似条件下，给出了一组新的超短脉冲光束的解析解，称为超短脉冲复宗量辛格高斯光束。

We establish mathematical models of optimal operation schema, and to solve them by feasible direction method and linear approximation.

在管网布局的基础上，以管网投资净现值为目标，建立了管网结构参数优化模型，并充分考虑了输气量、管径、输气压力、管长、增压比、压缩机数目之间的关系，采用混合变量优化方法进行求解。

This thesis is concerned with metric Diophantine approximation for formal Laurent series over a finite base field.

我们将在本论文中探讨有限体下正规Laurent级数上的Diophantine逼近。

The absorbing performance of one dimensional PML is theoretically analyzed and numerically simulated in view of the error caused by finite difference approximation, respectively, whose results show that this theoretical analysis can exactly indicate practical circumstances.

在计及有限差分近似造成的误差下，理论分析和数值模拟了一维理想匹配层的吸收性能，结果表明这种理论分析能完全反映实际情况。

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。

This model used the finite—difference approximation to the advection— dispersion equation. The spatial derivatives in the flow equation are approximated by central difference written about grid—block boundaries and time derivatives are approximated by a fully implicit backward scheme.

水流方程的空间导数采用中心差分格式离散，时间导数采用隐式差分格式离散，建立了土壤水分和污染物在各种饱和度的条件下迁移转化方程耦合求解的二维数值计算模型。

Many will continue to choose to live in duality and in conflict.

许多人将继续选择活在二元对立性和冲突中。

I find that students of the University of Physical Education all wear sportswear at first sight.

我发现：体育大学的学生乍一看，都是穿运动衣，大家都一样