查询词典 truncation

The truncation error of CSCD is derived and compared with some symmetric finite difference methods having the same order of accuracy,which shows that CSCD has the smallest coefficients in error terms.

从定性角度，得出同阶中心差分格式中，CSCD格式的截断误差系数最小的结论。

In order to reduce error of Nu number at large Ra number and thermal diffusivity, we analyze truncation error of corresponding heat-transfer equation and introduce an adjusting parameter in the equilibrium distribution function.

针对一二阶精度模型在Ra数极高或热传导系数极大时，Nu数的计算与经验值相比出现较大偏差，分析LBM对应宏观热传导方程的截断误差后，在平衡分布函数中引进一个调节因子。

This paper measures the fault vibration signal of the sun-gear in planetary gear box. Bring forward a new arithmetic of time-field average which settle the problem of cycle truncation error affect the result of averaging in substance.

但这些信号又往往被伴随产生的噪声干扰，在噪声较强时，不但信号的时间历程显示不出规律性，而且在频谱图上这些周期分量很可能被淹没在噪声背景中。

Based on the concept of antenna near-field measurement and the theory of plane wave spectrum, the theory of plane near-field measurement and error analysis are introduced, two errors of plane radiation near-field measurement are discussed in detail: the probe positioning error and the truncation error of finite scanning.

本文从天线近场测量的基本概念出发，以平面波谱理论为基础，介绍了平面近场测量理论及其误差分析方法。

In the PFD, both the differentials and non-differential terms in the differential equation are discretized, and the coefficients of the power series are determined by means of eliminating the truncation error of the corresponding modified scheme, then the high accurate difference scheme is obtained.

摄动有限差分方法在微分方程的差分近似中，离散微商项的同时，也离散非微商项，把非微商项摄动展开成网格步长△x的幂级数，并通过提高差分格式相应修正微分方程误差阶的方法求出摄动幂级数系数，从而获得高精度差分格式。

Based on Crank-Nicoson's technique, and a new approach for the numerical simulation of the model is raised. The truncation error of the one step difference method reaches O (△t^2+△x^2) and of quite good stability condition.

基于Coriolis加速度和Lagrangian应力公式，利用Newton第二定律导出轴向加速度运动弦线横向振动的动力学模型；通过线性变换将方程化为一阶无量纲的非线性微分方程组；并利用Crank-Nicoson的中点离散技巧，给出运动方程的单步二阶差分方法；算法把对运动方程和本构方程分别离散，使之可以用于不同本构的运动弦线的数值仿真。

Both upper bound formula and lower bound formula of the global truncation error of Euler method have been derived theoretically.After making certain approximat e processing,the derived upper formula changes into current upper bound formula.

从理论上推导出了欧拉方法的整体截断误差的上限公式和下限公式，作一定的近似后，得到的整体截断误差上限公式就变为现用的整体截断误差上限公式。

In this paper the effects of scanning truncation error, scanning position error, random amplitude and phase error, and multiple-reflection error in near-field antenna measurement are analyzed; error equations and the uncertainty of measurement are obtained through computer simulation; compensated techniques for reducing the effects of measurement errors in near-field antenna measurement are presented and the formula and arithmetic of phaseless near-field techniques are derived.

本文从解析法和数值仿真两个角度深入分析口面天线近场测量中扫描面截断误差、扫描面位置误差、随机幅相误差、多次反射误差等误差源对天线远场特性测量精度的影响，一方面从理论上给出相应的误差方程，另一方面建立误差分析模型，通过计算机模拟，得到不同误差条件下测量结果的不确定度，并介绍了减小这些误差的修正方法，推导无相位近场测量的公式和算法。

The computation implies that the influence of truncation error of up/downwards continuation is about 0.001 m2·s-2, the maximum error is only 0.11 m2·s-2, which can be ignored in CHAMP gravity field recovery. The influence of the reference gravity field error of up/downwards continuation is less than 0.1 m2·s-2 in general, but the maximum error can reach 1.3 m2·s-2. To reduce this error, a high-precision gravity field model should be used in the up/downwards continuation.

计算表明：延拓误差中的截断误差部分影响量级约0.001 m2·s-2，最大误差仅为0.11 m2·s-2，可完全忽略；延拓误差中的参考重力场模型误差影响随参考场选取的不同而有所差异，整体而言小于0.1 m2·s-2，但最大误差可达1.3 m2·s-2，采用高精度的参考重力场模型能大大减小延拓误差影响。

A variable-step modified Euler time integration method is proposed and analyzed. Four major factors that affect the efficiency of the variable-step modified Euler time integration method are discussed. These include stability and accuracy analysis for the damped fix-step modified Euler integration formula, adjustment method of the fix-step basic integration formula to accommodate step-size changes, suitable range of the step-size selection strategy based on truncation error concept and development of the step-size selection strategy based on apparent frequency concept to satisfied the specified error bound and stability condition.

提出了变步长修正Euler时间积分法，详细讨论了影响变步长修正Euler时间积分算法效率的四个主要因素，它们包括：有阻尼问题的修正Euler法的稳定性和精度分析，调整固定步长的基本积分公式使之容纳步长大小变化的研究，基于截断误差概念的步长大小选择策略适用范围的讨论，同时满足规定误差界和稳定性条件的、基于表观频率概念的步长大小选择策略的建立。

I am sure after a few weeks of adaptation and familiarization I will have no difficulty in functioning on a daily basis in an English speaking society or in participating fully in graduate studies.

在大学的三年的学习生活不仅给予我自身的充实，更重要的是磨练和培养了我较强的自觉能力和严谨，踏实的作风以及不怕困难的精神，对未来充满了信心！

As the first volcanoes erupted, one of the gases that bellowed out was steam.

在第一批火山喷发时，喷出的气体之一就是水蒸汽。