查询词典 error estimation

When the random error is not subject to normal distribution, the least absolute deviation estimation is superior to the least squares estimation. In addition, the robustness of the least absolute deviation estimation is also better than that of the least squares estimation.

在随机误差不服从正态分布的问题中，最小一乘估计的统计性能优于最小二乘枯计；另外，最小一乘估计的稳健性更强。

As a differential detection is used between the intercarrier, the proposed algorithm overcome the high sensitivity to timing error of conventional algorithm and is robust to multi-path. The effect of sample frequency offset can't be ignored in a continuous OFDM system of a large number of subcarriers. The estimation precision of the conventional algorithm is low and the realization is complex. A joint estimation of sample frequency offset and fine frequency offset based on difference operation is proposed. As averaging use a large number of samples in a maximum likelihood algorithm, the estimation precision is very high. The use of difference operation cancel the effect of carrier frequency offset, and the proposed sampling frequency estimation algorithm is robust to carrier frequency offset.

最后，本文对连续系统中的采样频率和载波频率精同步技术进行较为深入的研究，由于子载波数目大的连续OFDM传输系统中，采样频率偏差不可忽视，以往的采样频率估计方法精度低、实现复杂，因此本文提出了一种基于差分处理的采样频率偏差和精载波频率偏差联合估计算法，利用了最大似然算法进行采样频率偏差的估计，由于采用了差分处理方法，消除了载波频率偏差对采样频率偏差估计的影响，采用的最大似然算法对大量样点进行平均化处理，所以，相对以往算法，提出的联合算法估计精度高，而且采样频率偏差估计对载波频率偏差具有鲁棒性。

The adaptive program is calculated by T-B stress recovery scheme and z-z error estimation, the error is estimated by energy norm of difference of recovery stress and meshless stress. If the local relative error exceeds the limit relative error, then new nodes will be generated at the high error area.

本研究的自适应方法采用TB应力平滑技术和Z-Z误差估计，利用平滑应力和无网格法所得应力解差值的能量范数来估算误差，如果局部相对误差超过了允许误差，则在高误差域插入新的离散点进行加密。

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。

Error Analysis of UGPS Error sources of UGPS include GPS observation error, attitude error, baseline network strength, sound velocity error, time measuring error.

系统的误差分析实现水下的精密定位，需要分析影响系统定位的各种因素。

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 evaluation method and algorithm of shape error (roundness, plane straightness, space straightness, cylindricity) were discussed. A new kind of algorithm, namely mesh searching method, which can be used to evaluate the roundness error, plane straightness error, space straightness error and cylindricity error, were put forward. With this algorithm, the shape error can be obtained by transferring the distance formula repeatedly and simple judgment without linearzing the distance formula (from point to point or point to line) and choosing optimal direction and step length.

对形状误差(圆度、平面直线度、空间直线度、圆柱度)的评定方法及算法进行了讨论，提出了一种评价圆度误差、平面直线度误差、空间直线度误差及圆柱度误差的新算法——网格搜索法，该算法不需要对距离公式线性化，也不需要选定优化方向和优化步长，只需重复调用距离公式和简单的判断即可得到符合定义的形状误差。

In the paper, a generalized error model for the robots is set up by using DH coordinates. Moreover, a new analytical technique called"analysis on the error prominency factors for the robot pose error"is proposed. Numerically, the error prominency factor can express the extent of influence on the pose error of the end effector resulted form every DH parameter error within the whole working space of the robot.

在这一研究过程中，除了建立了用DH坐标描述的机器人末端位姿误差和轨迹误差的通用模型之外，还提出了一种新的机器人位姿误差分析技术——机器人位姿误差的显著性分析法。

Based on the discussion about fitting normal error's definition, constitution and properties, it was suggested that fitting normal error represented the error of fitting plane linear in old highway. The accuracy index of fitting plane linear in old highway based on fitting normal error was set up. The algorithm of swinging approach on compressible size step that could be used to calculate the fitting normal error was put forward. The method and basic norm of decision about fitting normal error's symbolic were discussed.

在论述拟合法线偏差定义、构成及性质的基础上，提出以拟合法线偏差表征旧路平面线形拟合偏差；建立了基于法线偏差的旧路平面线形拟合精度指标；提出了采用步长压缩摆动趋近法计算拟合法线偏差的算法，并就拟合法线偏差的符号判定准则及方法进行了讨论。

On a grating type gear integrated error measuring equipm ent, this technique employs the three-point method error separation technique fo r separation of the systematic error of the measuring chain of equipment spindle system including measuring worm error, grating transducer error, bearing rota ry error etc.

在一台光栅式齿轮整体误差测量仪上，它用三点法误差分离技术能分离开仪器轴系测量链的系统误差(包括测量蜗杆误差、光栅传感器误差、轴承回转误差等)和被测齿轮的全谐波误差。

The dissecting of samples in group2 were difficult. The root of pulmonary artery and ascending aorta failed to be unfolded because fibrous tissue was tough, right and left fibrous trigone were too firm to be solved by hand. Cardiac muscle fibers couldn't be stripped along myofibrillar trajectory since they were prone to break because of their friability.

组2的心脏解剖困难，表现为纤维组织坚韧，游离肺动脉非常困难；徒手无法松解左、右纤维三角，肺动脉和主动脉根部的游离非常困难；心肌纤维坚硬、质脆，解剖时容易断离成碎块，无法沿纤维走行方向剥离。

We have battled against the odds in a province that has become increasingly violent.

我们对在一个争夺日益激烈省的可能性。