查询词典 approximation method

It is proved that if the RungeKutta method and the linear multistep method are of order p, then the numerical Hopf bifurcation value is an approximation to the Hopf bifurcation value of the equation itself of the same order p.

证明了如果Runge-Kutta方法和线性多步法是p阶的，那么数值Hopf分支值以相同的阶数p逼近于方程本身的Hopf分支值。

The given estimated values of variables in Newton method is a crucial problem for the final solutions, the solutions of the first order approximation of the Fourier series to land surface temperature were used to the input initial given values of the Newton numerical method.

在牛顿迭代解法中，很关键也很困难的一个问题是初始值的给定，本模型中牛顿迭代的初始值是傅立叶级数对地表温度一次逼近得到的结果。

Secondly, the effectiveness and limitation of the classical perturbation, such as the method of multiple scales and the Poincare-Lindstedt method, are discussed in detail through a Duffing oscillator with delayed velocity feedback. It is shown that the two perturbation methods are effective only in solving the approximate solution of the first two orders. An ambiguity or paradox will be encountered when they are used to seeking for the third or higher order approximation of solution.

其次，以一具有时滞速度反馈的Duffing系统为例，研究了经典摄动法如多尺度法，Poincaré-Lindstedt法等在求解时滞微分方程级数解时的适用性和局限性问题，指出利用这些方法只能有效求得系统的前两阶近似解，而在求系统的三次以上近似解时会出现矛盾或二义性。

The full parallax CGHs are generated by the point source method and the wave-oriented method without paraxial approximation.

这种全视差计算全息图是由点基元方法和平面波导向法生成并且没有经过旁轴近似。

On the basis of the generalized phase integral approximation and the beam displacement ray mode theory, which are both developed by Chinese acousticians, a fast method for normal modes analyzing including the leaky modes is presented. The application of this method in the coupled mode parabolic equation theory gives an efficient algorithm for both the range dependent problems (CMPE2D) and the three dimensional problems (CMPE3D).

在我国独创的广义相积分理论和波束位移射线简正波理论的基础上，提出了一种可以快速而精确地求解简正波本征值的算法，并将该算法应用于简正波-抛物方程理论，从而实现了二维(CMPE2D)和三维(CMPE3D)声场的快速预报。

Basing on the variation principle of solid-fluid coupled problem,on the situation of the tank being full filled,the essential method and principle have been found by using the numerical approximation of finite element method.

在罐车满载的情况下，根据固液耦合问题的广义变分原理，使用有限元的近似数值计算方法，找到解决满载罐车液固耦合振动问题的基本方法和原理，建立铁路罐车的固液耦合问题的动力学控制方程，并通过算例验证液体对罐车耦合振动的影响，得到在工程上所需要的分析结果。

If the method is combined with the subdivision method of curve,the rational spline curve with higher-order continuity is presented which is the approximation of offset curve.

该方法与离散算法相结合，可得到等距曲线的高阶连续的有理样条逼近曲线，最后，通过数值实例与已有方法作了比较。

The left singular vector of the projection has been tracked by the projection approximation subspace tracking algorithm. Then the modal parameters are obtained by least square method. At last an experiment is made using a cantilever beam to prove the efficiency and stability of the method by changing the frequency band of the exciting signal.

通过子空间跟踪算法，不断跟踪计算投影的左奇异值向量，再利用最小二乘法求出系统的模态参数，最后用悬臂梁作为实验模型，通过不断改变系统激励的频带范围，验证方法的有效性及稳定性。

The error estimates for moving least-square approximation, which is the method for obtaining the shape function in element-free Galerkin method, are presented in Sobolev space W k , p for high dimensional problems.

在高维情况下，首先研究了无单元Galerkin方法的形函数构造方法——移动最小二乘法在Sobolev空间 W k ， p中的误差估计。

In order to resolve the problem of the coordinates transformation between the WGS 84 and local geodetic system, in this paper, four parameter method with plane constraint and the method based on polynomial approximation are discussed.

GPS定位技术在各个领域中已得到了广泛的应用，而GPS定位成果属于WGS-84地心大地坐标系，致使将GPS地心坐标转换成本地坐标的方法愈来愈得到广大工程技术人员的关注。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。