计算误差

Finishing calculation of mean value, standard deviation, skewness, kurtosis of Beta distribution.(2) Fitting parameters of many kinds of typical distribution and using residual deviation to evaluate fitting precision.(3) Using Beta distribution as an agreed indication distribution applied to many kinds of practical photoelectric measurement distributions.(4) Deriving theory formula of Bayes point estimation about Beta distribution parameters and mean value and standard deviation on the condition of mean square error loss function and supposed the prior distribution is uniform distribution.(5) Generating MCMC sample from post distribution by the method of Gibbs sample algorithm. Calculating bayes point estimation from sample on the condition of mean square error loss function. Calculating confidence interval by an approximate method to complete interval estimation.

本文的主要工作有：(1)解决了Beta分布参数a和b的精确计算以及均值、标准差、偏度、峰度的计算问题；(2)拟合出10余种典型分布的Beta分布的两个参数，并且采用剩余标准差评价该Beta分布的拟合精度；(3)对多种典型的光学与光电测量系统的测量分布进行了Beta分布统示表示；(4)在假设先验分布为均匀分布前提下，得到参数a和b以及均值μ和标准差σ在均方误差损失函数下的贝叶斯点估计理论计算公式；(5)利用直接抽样的Gibbs抽样算法，从后验分布中产生MCMC样本，从样本直接计算均方误差损失函数下的贝叶斯点估计，并使用一种近似方法计算其置信区间，完成区间估计。

The coordinate transformation and numerical integration was executed on the discretized tetrahedral elements based on which the 3-D MT vector-finite element method was implemented. A whole computation framework for 3-D vector-finite element method with unstructured mesh was given. Based on this some typical models were tested which has demonstrated that our algorithm could distinctively avoid problems caused by the fake solution and both the accuracy and efficiency were enhanced which made our algorithm has a bright future for further application.3. According to theory of Sobolev vector space and the discretization of Helmholtz space, the error estimate which was suitable for 3-D MT vector-finite element modeling was deduced by which the procedure of adaptive technique was guaranteed.4. Based on the fully unstructured tetrahedralization and optical strategy, the 3-D magnetotelluric h-adaptive vector-finite element method was presented through combining the error estimate. With this work, the accuracy and creditableness for 3-D MT complicatedly modeling was guaranteed.5. The 3-D magnetotelluric h-adaptive vector-finite element algorithm with unstructured mesh was implemented.

针对非结构化的四面体单元，采用坐标变换和数值积分方法，实现了MT三维矢量有限单元分析，建立起基于非结构化网格的三维MT矢量有限元计算流程，并对典型模型和国际标准电磁模型进行了数值模拟，结果对比和分析表明，基于非结构化网格的三维MT矢量有限元不仅消除了节点型有限元的伪解，而且具有很高的计算精度和速度，有广阔的应用前景。3、根据Sobolev函数的向量空间和Hemlholtz空间的分解，推导出基于残差的三维大地电磁矢量有限元后验误差估计公式，为三维大地电磁自适应矢量有限元数值模拟的实现奠定了基础。4、在完全非结构化四面体单元剖分及优化基础上，结合三维大地电磁矢量有限元后验误差估计公式，提出了基于非结构化网格的三维大地电磁h-型自适应矢量有限元计算策略，保证了对复杂大地电磁模型数值计算的精度和可靠性。5、实现了基于非结构化网格的三维大地电磁h-型自适应矢量有限元计算流程，对典型模型和国际标准电磁模型进行了数值模拟。

On the aspect of error compensation, the system using the geometric average sound pressure instead of the arithmetic average sound pressure to get the sound pressure of the measurement point. This method not only reduces the high frequency error in the sound intensity measurement, which compensates the finite difference approximation error, but also greatly reduces the computation of the sound pressure spectrum.

误差补偿方面，课题采用几何平均声压代替通常的算术平均声压来计算双传声器法的声场声压值，这样不仅可以有效的减少声强测量中的高频误差，对有限差分误差起到了补偿作用，而且还大大减小了声压谱计算中的计算量。

On the basis of the study on the mathematical model of the closed-loop location control, the analysis of contour error in the process motion control and error calculation model, according to the lack of using normal contour error model not to calculate contour error of curve in real-time, combining real-time contour error compensation control strategy and fuzzy logic theory, the fuzzy logic and real-time contour error calculation based self-discipline control strategy is proposed.

2在研究闭环位置控制数学模型、加工轮廓运动控制中的误差分析和轮廓误差计算模型的基础上，针对利用一般运动轮廓误差计算模型不能实时计算出曲线轮廓误差的不足，结合实时轮廓误差补偿控制策略和模糊逻辑理论，研究了基于模糊逻辑理论和实时误差计算的轮廓自律控制策略。

The horizontal and vertical first derivatives of magnetic anomalies of an infinite cylinder are calculated by the cosine transform method, in which the maximum errors are -0.28 nT/m and 0.47nT/m, respectively and the percent errors are generally within -3.57%~3.27% and -1.94%~1.88%, respectively except several data of the boundary and part are bigger because of remains of Gibbus effect. The calculating curve and theoretical curve are approximately coincident, and there is no influence by effective magnetic dip angle in computing. But the errors with the Fourier transform method are -10.62nT/m and 14.42nT/m, there is large departure between the calculating curve and theoretical curve and evident influence by effective magnetic dip angle in computing.

利用余弦变换法计算的无限长水平圆柱体磁异常水平和垂向一阶导数的最大误差分别为-0.28nT/m、0.47nT/m；水平一阶导数的误差一般在-3.57%~3.27%之间，垂向一阶导数的误差一般在-1.94%~1.88%之间；计算的磁异常一阶导数值与理论值大致重合，而且不受有效磁化倾角的影响而Fourier变换法计算的水平和垂向一阶导数最大误差分别为-10.62nT/m、14.42nT/m，计算曲线与理论曲线偏离大，受磁化倾角的影响也较大。

In this paper, the effects of the rigid body motions and low frequency surface errors on the image quality were analyzed. Quadratic equations were used to build the mathematical model of the Wolter type I and II X-ray telescopes and reduce the computational complexity of ray tracing. With the help of a self-developed optical surface analysis code, the effects of the perturbations of the mirrors on the image quality was analyzed and the growth of the image spot formed by deformed telescopes was calculated, this is important for giving the reasonable fabrication tolerance.

在本篇文章中，详细分析了刚体运动误差和低频表面误差对成像质量的影响；使用空间解析几何学的二次曲面方程建立Wolter I、II型X射线掠入射望远镜镜片的数学模型，降低光线追踪的计算复杂度；借助自主开发的光学仿真软件分析了国内研制的X射线成像望远镜的刚体运动误差和低频表面误差对成像质量的影响，计算出像点艾里斑半径均方根值随误差变化的增长率，对工程上提出合理的制造公差的误差容限有重要的指导意义。

Based on the conservation law, applying appropriate rezone methods for meshes we modify the 9-point method to reduce computation error due to poor regularity of the meshes and low precision due to the approximation to vertices values by an average of neighboring cell values. The nonlinear system obtained is a different system from the 9-point scheme.

该方法从守恒方程出发，将九点差分格式应用于按某种合适的方式进行重分之后的网格上，减少由于网格正则性差以及网格节点上的物理量采用周围网格量的加权平均等原因所引起的计算误差，得到一个新的但其解仍然逼近原来网格上的物理量的方程组。

The RANS governing equation and RNG κ-ε turbulence model were used, and the flow fields at different relative positions between blade and volute tongue in a centrifugal pump were simulated by using finite volume method, under the hypothesis of steady flow.

本文选择RANS方程和RNGk-ε湍流模型，采用有限体积法，在假定流动定常的前提下对离心泵中叶片与蜗舌不同相对位置时的流场进行数值模拟，总结分析了各性能参数的计算误差在不同的相对位置时的变化规律。

In the course of testing, the laser was used as light source with twin-light path, dispelled the error of light-intensity variation of traditional detection devices, the measurement result only relates to the relative change of optical intensity .

测量以激光为光源，采用双光路法，消除了通用检测仪由于光源光强不稳定产生的误差，使得测量结果只与光强的相对变化量有关；光波出入波导均采用棱镜耦合，减少了普通测试方法因样品质量及面形误差和端面洁净情况不同或输出透镜不能很好汇聚光波而产生的误差；利用常规仪器设备实现了数字化检测显示，避免了人为主观读数产生的误差；利用AD538实时模拟计算芯片，提高了计算精度和运算速度。

The key technologies of Grid Method including grid divided in basin, impact radius of rainfall and number of reference rainfall stations have been discussed with example. The parameters of Grid Method have been selected through trial and error. Using simple random sampling to simulate the failure to collect rainfall, the relation between surface rainfall calculation error and station density, station distribution, uneven spatial distribution of rainfall has been sought.

论文探讨了流域网格剖分、降雨影响半径、搜索半径范围和参证站数量等关键技术，研究了网格法参数的优选，并采用简单随机抽样模拟降雨缺测情况，给出了面雨量计算误差与流域站网密度、均匀度、降雨分布不均匀性指标的关系。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。