查询词典 approximation methods in physics

Using the change of variable and fixed point method andmethod of approximation, we obtain some interesting and new results on the existenceand uniqueness of bounded solutions and almost periodic solutions of these equations.

利用变量替换和不动点方法及逼近法，我们得到了此类方程有界解和概周期解的存在性及唯一性的一些有趣的新结果。

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。

The surface electromagnetic is expanded in a polynomial function via the Chebyshev approximation , then the electromagnetic distribution can be obtained at any frequency within the given frequency range , which is used to compute the scattered fields and the wideband radar cross section .

论文摘要：将切比雪夫逼近理论应用于目标宽带电磁散射特性分析中，通过求解给定频带的切比雪夫节点并用高阶有限元方法求得各节点处的目标表面场值，实现整个频带内任一频率点目标表面场值的快速预测，使得目标电磁散射特性得到快速分析。

While Chebyshev's Inequality gives an upper bound on P, there is no guarantee that the upper bound is a good approximation.

因为切尔雪夫不等式给出的是每个象素灰度的上限，而又没法保证其上限是一个很好的估计。

Based on this thought, in this thesis, the alternation theorem is first extended to the Chebyshev approximation problems with inequality constraints, and then two algorithms are devised for designing linear phase FIR filters with inequality constraints in Chebyshev sense according to the extended theorem.

L.J.Karam和McClellan在文献[20]中把交错点组定理扩展到复数域，并提出了求解复系数FIR滤波器的复Remez算法，但由于此扩展定理只是一个充分条件，所以此算法不能保证得到最优解。在文献[23]中，他们对复Remez算法进行了完善，使其收敛到最优解。

Both the numerical results of these two chapters show that the Chebyshev polynomial approximation is an effective method in the study of system with random parameter.

数值结果表明Chebyshev正交多项式逼近法对于分析谐和激励和脉冲激励共同作用下的含有界随机参数系统的分岔现象也是有效的。

The Chebyshev polynomial approximation is used to investigate the stochastic bifurcation of van der Pol system with two-sided barriers.

利用随机光滑动力系统的Chebyshev正交多项式逼近方法，研究了双边约束条件下随机van der Pol系统的分岔现象。

Numerical simulations show that similar to their counterpart in deterministic nonlinear system some symmetry-breaking bifurcation may occur in the stochastic Duffing-Van der pol system, and Chebyshev polynomial approximation is an effective approach in solving dynamical problems of nonlinear system with random parameter.

数值模拟显示随机Duffing-Van der pol系统与确定性均值参数系统有着类似的对称破裂分岔行为，文中的主要数值结果表明Chebyshev多项式逼近法是研究非线性随机参数系统动力学问题的一种有效方法。

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。

The stochastic Bonhoeffer-Van der Pol system is first transformed into an equivalent deterministic system using the Chebyshev polynomial approximation, so that the problem of controlling stochastic chaos is reduced to the problem of controlling deterministic chaos in the equivalent system.

首先运用Chebyshev多项式逼近的方法，将随机Bonhoeffer-Van der Pol系统转化为等价的确定性系统，使原系统的随机混沌控制问题转换为等价的确定性系统的确定性混沌控制问题，继而可用Lyapunov指数指标来研究等价确定性系统的确定性混沌现象和控制问题。数值结果表明，随机Bonhoeffer-Van der Pol系统的随机混沌现象与相应的确定性Bonhoeffer-Van der Pol系统极为相似。

The studies on the developing of new media are very important to the increasing of the area density of HDD and to the implementation of hybrid recoding technology.

光磁混合记录方法，是一种可以突破超顺磁极限的限制，并进一步提高硬盘记录密度和读写速率的一种新型超高密度信息存储方式。

In io, mTOR inhibition promotes T cell anergy under conditions that would normally induce priming.

体内研究中，在正常可激发免疫反应的条件下，抑制mTOR可促使T细胞无能。