截断误差

Gear法用于二阶线性微分方程组时的稳定性与局部截断误差分析

The Stability and Local Truncation Error in Applying Gear 's Method to Second-Order Differential Equations

一种降低DDS相位截断误差的方法

A Method for Eliminating the Phase Truncation Error of the DDS

这些函数要么在返回值和参数上缺乏一致性，要么隐含着所谓的“截断误差”（truncationerrors）错误，要么无法提供足够强大的功能。

The current functions have inconsistent return values and parameters , truncation errors , and lack advanced functionality .

基于DSP技术和整周期自适应采样算法实现了信号的倍频采样，有效地提高了计算速度，避免了谱泄漏和截断误差。

Based on DSP and full period sampling method the sampling of double frequency is realized , and calculating precision is improved effectively .

首先，本文利用相位抖动技术来抑制DDS相位截断误差。

First , we employ phase-dithering method .

DDS频率合成器相位截断误差频谱特性仿真分析

Emulational analysis of the spectrum characteristic caused by the phase truncation in direct digital frequency synthesizer

具极小化局部截断误差的Runge-Kutta方法

Runge-Kutta methods with minimizing the local truncation error

基于分段式变步长截断误差LMS算法的心率信号提取

The Abstraction of the Heart Rate Signals Based on Clipped-error LMS Algorithm with Variable Step Size of Segmenting Type

具有截断误差校正的广角反射NMO方法

NMO method of wide angle reflection with truncation error correction

此计算方法基于Newmark方法假定，具有四阶的截断误差，精度高；

With Newmark presumption , this method has high accuracy of the fourth order truncation error .

时域参数识别法无需将测试信号在时域与频域之间变化，避免了由FFT变换引起的截断误差，如能量泄漏等。

Parameters identification in time domain is accomplished in the paper with no truncation errors of FFT Transform such as the error of energy leakage .

本文在分析相位截断误差的基础上，分析、比较了几种抑制相位截断杂散信号的方法并给出了仿真结果，从而为软件实现DDS提供了理论基础。

This paper analyses the spurious signal generating by phase truncation in DDS , compares several methods of spur-reducing and provides results of computer simulations .

验证了DDS因为全数字结构带来的杂散来源，包括相位截断误差、幅度量化误差和DAC非线性误差等。

Sources of spurious signals for entirely digital structure of DDS include phase truncation error , amplitude quantization error and non-linear characteristics of DAC .

在采样密度大于Nyquist率2.135倍的条件下，截断误差的上界随着样点个数的增加呈指数衰减；

Furthermore , if the density of sampling points is more than 2.135 times of Nyquist rate , the upper limit of truncation error decreases exponentially .

以全方向推进器计算为例，对FLUENT中网格划分，截断误差积累，加速收敛，求解稳定性问题进行了单独讨论。

Take variable vector propeller as an example , talk about some important problems in FLUENT software , such as mesh division , error accumulation , accelerated convergence and the stability in the solution procedure .

考虑观测误差、截断误差和数值天气预报的需要，本文给出了决定最优相邻测站之间距离d、最优垂直网格距Δp和最优观测时间间隔Δt的公式。

In consideration of the observational error , the truncation error and the requirements of numerical weather prediction , three formulas for determining the distance between two neighboring stations d , the vertical increment Δ p and the observational time interval At in optimum sense , have been derived .

第三章，分析了微分方程的解法，包括Euler法的基本概念、截断误差估计、收敛性问题、稳定性问题；Runge&Kutta法的构造、绝对稳定性；

In chapter 3 , the basic concept , the estimate of truncation error , convergence , stability of Euler method , indicated the conformation and absolute stability of Runge-Kutta method were put forward .

由Hurty〔1〕创始的、后经Craig〔2〕发展的固定界面模态综合法属于具有模态截断误差的常规（近似）固定界面法。

Synthesis of fixed-interface component modes , which is developed by Hurly and improved by Craig , is an approximate substructural coupling method that has modal truncated error .

理论模型与实际资料试算结果表明，具有截断误差校正的广角反射NMO校正方法可以改善同相轴质量，提高叠加效果。

According to the theoretical model and factual data calculation result , this method reforms the quality for phase axis , and improve the stacking effect .

介绍了一种基于DDS的DTMF软件合成器之工作原理及其实现，分析了时钟相位噪声、杂散噪声、相位截断误差对输出波形的影响。

This paper introduces a DTMF software synthesizer based on DDS and its implementation and analyzes the effect of phase noise , spurious noise and phase truncation error on output wave form .

从Taner的反射波时距曲线方程入手，提出了具有截断误差校正的广角NMO校正方法。

Start with Taner reflection time curve equation , present the wide angle NMO correction method on truncation error correction .

在图像处理中，L~2（R）上的小波基因截断误差会在边界处产生失真，为了消除这种边界效应人们需要对其进行改进，这就产生了区间小波的理论。

In image processing , the wavelet of L2 ( R ) will cause distortion on the boundary by truncation error . In order to exterminate this phenomenon , one must modify the wavelet on the boundary . This gives rise to the wavelet on the interval .

本文对Schrodinger方程构造了一个高精度绝对稳定的隐式差分格式，其截断误差阶为O（τ~2+h~4）。

An absolutely stable high-order difference scheme with high accuracy for solving Schrodinger equation is established in this paper . Its order of local truncation is O (τ 2 + h4 ) .

介绍了锁相环（PLL）技术和直接数字式频率合成（DDS）技术的基本工作原理，给出了一种提高DDS输出频率精度及减小其相位截断误差的方法。

This paper introduces the theory of the phase-locked loop ( PLL ) and the direct digital synthesis ( DDS ) , a method to improve the precision of DDS and reduce its phase truncation error is also given .

适当选取参数时，可得到一个高精度恒稳格式，其截断误差达到O[（△t）2+（△x）8]，数值例子表明该格式是有效的。

When parameters are properly chosen , we obtain an absolutely stable implicit difference scheme of high accuracy . Its truncation error reach ( O [ (△ t ) ~ 2 + (△ x ) ~ 8 ] . ) A numerical example shows that the scheme is effectives .

通过对DDS实际频谱曲线的分析，发现产生了在理论分析中相位截断误差及幅度量化误差产生的杂散之外的其它杂散来源，特别是时钟泄露与输出信号及它的谐波的差拍产生的杂散。

Based on the spectrum analysis , except for some spurious sources because of phase truncation and amplitude truncation in theoretical analysis , spurs come from the DDS , and the beat frequency of the output signal , its harmonics and clock leakage .

简要评述了SADI方法和样条方法在每一坐标方向的分步计算方法、截断误差和稳定性。

SADI method and a spline method of fractional steps in each coordinate direction as well as truncation errors and its stability are briefly reviewed .

具有这样性质的Walter抽样定理（1992）在对多分辨空间的信号进行D/A转换时，除了计算机的有限字长误差外，没有任何截断误差。

Walter 's wavelet sampling theorem ( 1992 ) corresponding to the scaling function has the compactly supported interplant . Therefore , the signals in multiresolution subspaces can be reconstructed exactly and quickly without any truncated errors except finite field length errors .

本文针对一类非刚性问题，讨论了多步Runge－Kutta方法的收敛性与稳定性，并且给出了该方法的整体截断误差的一个先验界。

In this paper , for a class of non-stiff problems , the convergence and stability of multistep Runge-Kutta methods are discussed and a prior bound of the global truncated error for this methods is presented .

运用巧妙细致的分析方法，对这一类极值函数进行了截断误差估计，这些估计结果对于研究带有Sobolev-Hardy临界指标的椭圆方程具有重要意义。

By delicate analytic methods , the cutting-off error estimates are obtained , which play important role in the study of elliptic problems with the critical Sobolev-Hardy exponents .