查询词典 method of approximation

Two kind of function approximator are involved, the state aggregation method and the linear construction approximation method.

因此本文的第二部分对平均报酬准则值函数近似问题进行了研究。

It takes less time to get the model approximation than rectangular automata method and flow pipe method.

相比于基于矩形自动机和流管道方法的模型近似，计算时间显著减小。

The error analysis of asymptotic approximation of finite series expansion is also given. Our method avoids choosing the integral length of the reentrant comer, and can be used to calculate the charge on the conductor conveniently and efficiently. Numerical examples are presented to demonstrate the efficiency of the method.

本文算法克服了邓肯矫正需要选择角点积分区域的不足，有效地校正了导体角点奇异性引起的电容参数提取的计算误差，最后给出了算法的数值实验与分析结果。

In MA models, the likelihood function is so complicated that we just search a better estimate value in a range. Another method introduced is autoregression approximation method.

在滑动平均模型中，由于似然函数形式很复杂，这里采用逐一搜索的方法，本文介绍的另一种估计方法是自回归逼近方法。

The procedure of designing a FIR filter with the proximate best uniform approximation method is given.The example shows that the filter designed by this method is of good performance in both pass band ...

给出了用近似最佳一致逼近方法设计FIR滤波器的具体过程，然后通过实例表明该方法设计的滤波器在通带和阻带内具有较好的特性，且计算简单、计算量小，有较好的应用前景。

The numerical result demonstrates the Born Approximation can be effectively used for 3D imaging for borehole-ground electrical method. It also demonstrates that the method can be used as the basis for fast 3D inversion in reservoir monitoring application and in water injection exploration.

数值计算的结果表明Born近似是一种有效的井地电法三维快速反演方法，同时也说明井地电法监测油水前驱和储层边界预测的观测数据可以用该方法进行快速三维反演成像。

The traditional method of design is given by the design requirements of the selected approximation method, the manual calculation of the order of N filter or check the design of the corresponding chart (for example, Chebyshev design chart) determine the order of N; search function transfer table ( Butterworth transfer function, such as tables, Chebyshev transfer function table) to determine the transfer function.

传统的设计方法是由给定的设计要求选用相应的逼近方法，手动计算滤波器的阶数N或查相应的设计图表确定阶数N；查转移函数表（如巴特沃思转移函数表，切比雪夫转移函数表）来确定转移函数。

Numerical results for the original stochastic Duffing-van der Pol system obtained separately by the Mento-Carlo method and the Chebyshev polynomial approximation are compared to show the effectiveness and efficiency of the latter method in solving the nonlinear dynamical problems of system with bounded random parameters.

数值模拟结果显示，Chebyshev正交多项式逼近法是研究含有界随机参数的耦合非线性动力学系统的一种有效方法。

Spectral element methods for partial differencial equation is introduced in this study from viewpoint of the collocation approximation of Chebyshev polynomial. Wave Equation and its space discretization are deduced. Two time integral methods, central difference method and implicit Newmark method, are introduced, and their stability and applicability are also discussed in some details. The significance of absorbing boundary conditions in spectral element methods for Aeroacoustics is explained, and Clayton-Engquist-Majda absorbing boundary conditions is emphasized and introduced, then the discrete scheme of this boundary conditions is deduced and applied to spectral element methods for wave equation.

本文从Chebyshev多项式逼近理论出发，详细介绍了谱元方法求解偏微分方程的过程；推导了流体中的声波动方程并在空间上对其进行了谱元离散；详细讨论了两种时间积分方法──中心差分法和Newmark方法，分析了它们的稳定性条件，并从理论上对比了两种方法的优缺点和适用范围；将吸收边界条件推广应用于谱元方法求解气动声学问题中，重点介绍了Clayton-Engquist-Majda吸收边界条件的原理和公式，推导了该吸收边界条件的变分形式，并将其引入波动方程的离散形式中。

The phase of optical wave can be recovered by the intensity transport equation under the paraxial approximation For the optical system with diffraction limit, it is difficult to get the boundary radical slope of phase and sample in the circular domain boundary when using the intensity transport equation to recover the phase, consequently, we reviewed an algorithm mentioned in the reference ［4］, namely, the equation, computation domain and boundary condition are changed, then the phase is reconstructed by the multigrid method and corrected at last Moreover, the experiment system is set to testify the algorithm, and the recovered phase from the intensity data detected by CCD is compared with the result from phase retrieval algorithm, it is found that the phase reconstruction error can reach 017 λ in the case of non-uniform intensity distribution, as a result, the method is suitable for the phase recovery with low wavefront sensing accuracy.

在傍轴近似条件下，可以利用光强传播方程对畸变波前进行相位恢复。对于衍射受限的光学系统，很难获得相位的边界径向斜率值作为边界条件，此外，要获得精确的圆域边界采样值也并非易事。为了克服上述困难，进一步研究了相位恢复改进方法，即改变了方程的表示形式、计算区域和边界条件，并用多重网格法进行求解获得重构相位，最后再将其修正。为了验证算法的精确性，搭建了实验系统对算法进行实验验证，将由CCD探测的光强分布进行计算得到的相位分布与相位恢复算法的结果进行比较，证明在光强分布非均匀的情况下，该方法恢复的相位均方根误差能够达到017 λ，可以适用于波前传感精度要求不是很高的相位恢复。标签自适应光学相位恢复相位修正光强传播方程 adaptive optics phase retrieval phase correction intensity transport equation

Among which is the mindset, perceptions and moralities of those who accept mini- military tasks for economic gains.

其中最重要的是心态，观念和道德的人谁接受小型军事任务的经济收益。

In time course imaging, activity peaked 2 days after coronary ligation.

在时程成像检测，活性峰值在冠脉结扎后2天。