采样误差

The phase of optical wave can be recovered by the intensity transport equation under the paraxial approximation For the optical system with diffraction limit, it is difficult to get the boundary radical slope of phase and sample in the circular domain boundary when using the intensity transport equation to recover the phase, consequently, we reviewed an algorithm mentioned in the reference ［4］, namely, the equation, computation domain and boundary condition are changed, then the phase is reconstructed by the multigrid method and corrected at last Moreover, the experiment system is set to testify the algorithm, and the recovered phase from the intensity data detected by CCD is compared with the result from phase retrieval algorithm, it is found that the phase reconstruction error can reach 017 λ in the case of non-uniform intensity distribution, as a result, the method is suitable for the phase recovery with low wavefront sensing accuracy.

在傍轴近似条件下，可以利用光强传播方程对畸变波前进行相位恢复。对于衍射受限的光学系统，很难获得相位的边界径向斜率值作为边界条件，此外，要获得精确的圆域边界采样值也并非易事。为了克服上述困难，进一步研究了相位恢复改进方法，即改变了方程的表示形式、计算区域和边界条件，并用多重网格法进行求解获得重构相位，最后再将其修正。为了验证算法的精确性，搭建了实验系统对算法进行实验验证，将由CCD探测的光强分布进行计算得到的相位分布与相位恢复算法的结果进行比较，证明在光强分布非均匀的情况下，该方法恢复的相位均方根误差能够达到017 λ，可以适用于波前传感精度要求不是很高的相位恢复。标签自适应光学相位恢复相位修正光强传播方程 adaptive optics phase retrieval phase correction intensity transport equation

The paper discusses the theory of speed controlling after interpolating and how do the factor that mostly include cutting speed,time constant of speed controlling and vector angle of conterminous CNC segment affects arriving precision.

文章论述了后加减速的原理及进给速度、加减速时间常数、上下程序段之间的矢量夹角对轮廓误差的影响，给出了数据采样插补应用后加减速时依据矢量夹角控制轮廓误差的一种方法，并对矢量夹角的计算给出了详细解析。

The estimating expression of theory error based on the hardware synchronous sampling measurement is advanced, and the system measuring error is analyzed.

提出了硬件同步采样算法的理论误差估计公式，并对系统测量误差进行了分析。

With the knowledge of linear algebra, general formula for arbitrary order Taylor finite difference has been derived. In this paper, the analysis of spectral property and computational error of arbitrary order TFD is presented in detail. Then it is applied into the numerical solution of Maxwell's equations. Stability condition and numerical dispersion relation are derived.

本文借助于采样定理，详细分析了不同阶Taylor中心差分格式的谱特性以及计算误差，并将任意阶Taylor中心差分格式用于数值求解麦克斯韦方程中，严格导出了稳定性条件和数值色散关系的表达式，引入了新的误差定义来衡量算法的好坏。

A Special Maximum Likelihood method for building mathematical models in dynamic calibration is proposed, which is a kind of maximum likelihood method with a special noise model.

提出了误差估计表达式以及在带宽有限测量假设条件下，辨识离散时间模型时，采样频率的选择与模型辨识误差的关系。

The noninformative prior of the standard deviation of error terms was introduced for Bayesian analysis. Then, given the prior density of the random coefficients in the degradation path model, the Markov Chain Monte Carlo method was adopted to generate samples of joint posterior distribution of random coefficients and unknown standard deviation.

为了处理未知的误差项方差，引入相应的标准差的无信息先验分布，并进一步结合退化轨道模型中随性参数的先验分布，利用马尔可夫链蒙特卡罗方法得到随机参数及误差项标准差的联合后验分布的采样值，进而实时预测产品在未来一段时间内的可靠度。

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 experiment takes Badaling watershed in Yanqing Beijing as an example,based on 1:10 000 the large geographical scale,adopting statistical analytical methods,the authors compared the errors of the slope,aspect,average cross section curvatures and average surface coarsens curvatures while the DEM grids varies.Besides,the authors analyzed the qualitative relation between variety of grids size and the slope,aspect,average cross section curvatures and average surface coarsens curvatures with the results of calculation.

以北京市延庆县八达岭小流域为例，不考虑DEM采样点上高程误差，采用1∶10 000大比例尺，运用统计分析方法，比较当DEM网格尺寸变化时，对坡度，坡向，剖面曲率和平面曲率计算结果的误差，分析网格尺寸的变化与坡度，坡向，剖面曲率和平面曲率计算结果之间定性定量关系。

Survey gain through this project, analysed use double base the RTK measurement technique of station double sampling, the system that can eliminate error of fiducial station coordinate effectively to nod planar coordinate to sampling is affected, disappear weak troposphere changes to be affected to what RTK tall Cheng measures randomly, make RTK planar coordinate measures the need that one class lead measures contented city thereby, make RTK tall Cheng is measured be close to or achieve the 4 precision that wait for leveling.

通过该项目测量成果，分析了采用双基站双采样的RTK测量方法，可有效消除基准站坐标误差对采样点平面坐标的系统影响，消弱对流层随机变化对RTK高程测量的影响，从而使RTK平面坐标测量满足城市一级导线测量的需要，使RTK高程测量接近或达到四等水准测量的精度。

Exibility for point sampling. Secondly, by combining the splat-ting algorithm with Layered Depth Buffers, we implement an algorithm fordetermining the points'visibilities and re?ectance properties, which is more accuratethan pervious methods.

其改进之处包括两点：一方面，根据灭点的性质，设计出等间隔索引表的结构来组织采样图像中物体的轮廓边，有效地提高了点采样的效率；另一方面，通过将splatting绘制算法和层次深度缓存的数据结构相结合，提出了一种高精度的点云可见性判断算法，从而克服了已有方法存在可见性判断误差的缺点。

By the time of its fall, most of the prisoners were writers who had written against the corruptions of the government.

到它被攻陷的时候，里面多数的犯人是写了反对政府贪污文章的作家。

The most obvious variation to ovum morphological character was that the color was changed from light green to sepiaceous in embryonic development, and all the ovums were almost hatched after 96h.

在胚胎发育过程中卵的形态特征最明显的变化是颜色从淡绿到深褐色，卵在发育96h后卵基本全部孵化。