周期性误差

Local discontinuous Galerkin method for convection-dominated diffusion problems with periodic boundary conditions is constructed. To deal with the derivative of second order, an auxiliary variable is introduced. The stability and error estimations are presented simultaneously.

针对具有周期性边界条件对流占优的扩散问题中的二阶导数，引入辅助变量，构造了局部间断Galerkin方法，并给出了方法的稳定性结果和误差估计式。

With the nearest interpolation algorithm, the results could be acquired at any location, any time within research areas after eliminating periodic variation and boundary interception error. This method could be applied in the marine environment field.

该方法在高维空间中使用最邻近插值算法，消除了周期性变化以及边界截断误差的影响，实现了对研究区域任意时间，任意地点的插值，在海洋环境领域有着一定的应用前景。

There are many ways to calculate GPS satellite azimuth and elevation, but the precision is low. A new method to decide GPS satellite position using the broadcast ephemeris is presented, the way to checkup the precision is also given, and some research are made to analysis the error feature of the position which is calculated by the broadcast ephemeris as well, the results show the error is periodic.

GPS卫星高度角、方位角计算方法众多，但精度低；针对这点，提出了一种利用广播星历计算卫星高度角、方位角的方法，对该方法能够达到的精度提出了鉴定的途径，并分析了利用广播星历计算卫星高度角以及方位角的误差特点，结果表明利用广播星历计算的卫星高度角、方位角呈现出周期性变化的规律。

A new method to decide GPS satellite position using the broadcast ephemeris is presented, the way to checkup the precision is also given, and some research are made to analysis the error feature of the position which is calculated hy the broadcast ephemeris as well, the results show the error is periodic.

GPS卫星高度角、方位角计算方法众多，但精度低；针对这点，提出了一种利用广播星历计算卫星高度角、方位角的方法，对该方法能够达到的精度提出了鉴定的途径，并分析了利用广播星历计算卫星高度角以及方位角的误差特点，结果表明利用广播星历计算的卫星高度角、方位角呈现出周期性变化的规律。

In order to reduce the periodic current tracking error of the deadbeat control when compensating abruptly changing nonlinear load current, a repetitive controller is plugged into the deadbeat controller. Also, the repetitive controller can alleviate the parametric dependency of the deadbeat control and eliminate the effects on compensation performance caused by the uncertainties in the system.

另外，为了降低无差拍控制对系统参数的依赖型和系统中存在的不确定性对补偿性能的影响以及减小在补偿电流变化剧烈的非线性负载电流过程中存在的周期性的局部跟踪误差，本文在无差拍控制器的基础上，又提出了基于无差拍和重复控制的复合电流控制器。

The error spectra obtained from the results of the data processing by different operators based on rectangular formula, trapezoid formula and their compensation forms are discussed, through which some error features of these operators are obtained.

文中在总体上讨论了诸如矩形公式、梯形公式以及它们的补偿形式等数据处理方法的误差谱，讨论了它们的一系列性质，例如对称性、周期性。

In order to overcome the shortcoming of PI controller in harmonics control, the repetitive control and PI control are combined and used in the closed-loop control of TSMC; The problem of conventional repetitive controller is pointed out and a modified repetitive control method is proposed: To avoid the influence of no-periodical disturbance on the control action of repetitive controller, the error caused by no-periodical disturbance is identified and discarded.

针对PI控制器对谐波控制的不足，将重复控制技术与PI控制相结合，应用于TSMC逆变级的闭环控制中；在此基础上提出了重复控制器的改进方案：对由非周期性扰动引起的误差不进行记忆，以避免其对重复控制器的控制动作产生干扰。

This paper systematically researched this sort of nonuniformly sampled signals'digital spectrum structure, signal-to-noise ratio , the response of D/A converter with nonuniformly sampled signals, the algorithm for estimating timing offsets, the relationship between the discrete time expression of the total energy and the continuous time expression, the estimation of the average power, the algorithm of recovery and application in designing and analyzing the digital waveform synthesizer.

本文全面系统地研究了这类周期性非均匀采样信号的数字谱结构，信噪比表达式，数模转换器对非均匀采样信号输入的响应，误差校正算法，时域与频域的能量对应关系，对功率测量的影响，内插恢复算法，以及在设计和分析数字波形合成器中的应用。

This gleam of the sexual relationships existence, adds step-by-step electric motor characteristics such as only having the cyclicity error but there being no accumulative error.

这一线性关系的存在，加上步进电机只有周期性的误差而无累积误差等特点。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了