计算误差

The optimal pH of xylanases was calculated based on the model and the results was shown as below: there were only two xylanses with the deviation between the calculated pHs the optimum pHs larger than 0.6, while there 6 xylanases with the deviation less than 0.1 the mean absolute percent error was 5.91%, the mean absolute error were 0.26 pH unit, respectively. It was superior when compared with the reported stepwise regression model based on dipeptide composition.

利用该方程，计算各木聚糖酶的pH值，结果表明，仅有2个木聚糖酶的最适合pH计算值与实测值相差大于0.6，而有6个木聚糖酶最适pH计算值与测定值相差小于0.1，平均绝对百分比误差为5.91%，平均绝对误差为0.26个pH单位，所得结果优于用二肽进行逐步回归所得模型的结果。

Then , aiming at characteristic of MCG data , we design the object of error analysis and make concrete analysis by error theory . We draw the conclusions that MCG signals measured by SQUID include obvious random errors and no system errors and crassitude errors .

本文根据心磁信号的测量过程，分析了测量过程中可能产生的误差，针对心磁数据的特点设计了误差分析对象，应用误差理论进行分析计算，得出了通过SQUID测得的心磁信号包含明显的随机误差，无根据怀疑存在系统误差和粗大误差的结论。

Phase velocity error caused by position error of microtremor observation array is computed under different conditions such as two different dispersive phase velocity models of Rayleigh wave, three kinds of radius, 19 kinds of observation position mode and 6 types of position error.

为研究地脉动观测台阵中观测点之间的定位误差带来的影响，计算了在两种瑞利波频散模型、3种不同的圆周半径以及19种观测位置等多种情况下由6种定位误差引起的瑞利波相速度相对误差，结果表明：由于圆周上观测点数目有限，在不存在定位误差时，相速度误差也是存在的，随观测点位置的不同，相速度相对误差存在差异，其最大值约为最小值的3倍。

First, in the horizontal positioning accuracy aspect of total-station instrument, point out the importance of direction, distance to correct calculation and coordinates to convert, give coordinates calculated formula of single intersection point of non-symmetry type of horizontal curve, deduce to square–error's calculated formula of horizontal coordinates and point space by polar coordinates positioning methods, and analyze the main influence factor of square–error.

首先，在全站仪的平面定位精度方面，指出方向、距离归化计算和坐标转换的重要性，给出单交点非对称型平曲线坐标的计算公式，导出极坐标定位法平面坐标和点位中误差的计算公式，并分析中误差的主要影响因素。

Direct difference is sensitive to noisy data, so a threshold limitation is given, which can not only filter the result from noisy data but also pick edge points up according men's desire. On the other hand, artificial intelligence is used for segmentation in reverse engineering. Because the essence of segmentation is clustering similar characteristics and self-organizing feature mapping is one function of neural network, SOFM network is used for segmentation in the thesis, coordinates and normal of data points is took as the characteristics vector.

第二种方法，基于双向角度微分的边点提取法，针对三维正交模型采用基于截面线的方式组织数据，此方法比基于曲率半径方法更简洁，不用进行曲面拟合，大大提高了计算速度；计算过程中由数据点的直接差分逼近微分，但直接差分对数据误差敏感，为此，本文提出了阈值过滤的方法，一方面过滤了数据误差在计算结果中引起的噪音，另一方面可以按照设计意图控制边点的提取；来决定是否提取光滑交接的边点。

According to the definition of axis straightness error ,a mathematical model was developed to evaluate axis straightness error by way of least square method in the rectangular coordinates.

根据轴线直线度误差的定义，建立了在直角坐标采样时该项误差的最小二乘评定法数学模型，该模型的采样数据不需要等角度间隔采样；并用计算机进行仿真分析·结果表明，所建立的数学模型编程简单，计算出的轴线直线度误差值与真实情况的误差小于 10 -6μm·因此由本模型引入的误差可忽略不计·所建立的数学模型为研制形位误差虚拟测量系统提供了理论基础

In model experiments, we find that the deviation of the first derivative calculated by Fourier transform is very large to comparing with the theoretical derivative, but the fitting effect of the derivative of anomalies calculated by cosine transform is very good. The calculation accuracy of data are all very high except that errors of several data on the boundary are large because of the residual Gibbus effect induced by finite truncation of gravity anomalies. Errors are -009%～5%.

模型实验中发现，用Fourier变换计算的一阶导数与理论导数偏差很大，而余弦变换计算的导数与理论异常导数拟合效果非常好，除边界几个数据因重力异常的有限截断产生的吉布斯效应残留使误差较大外，数据的计算精度均很高，误差为-009%～5%。

Results In static phantom studies, the percent error of mean activity obtained by Carson's method was reduced to about 9 %, and it is less than that of image-derived method using maximum likelihood expectation maximization (about 14 %). In simulated dynamic phantom studies, the vessel component could be extracted using ICA in image and sinogram domain. In sinogram domain, the six components extracted by ICA could be obtained quickly.

在静态物理假体实验结果来看，使用Carson's method计算出感兴趣区域活性的百分比误差( 9%)比直接从影像取得活性的百分比误差( 14%)来得小；从数位模拟动态假体实验结果来看，独立成份分析法运用在影像空间或是弦波图空间上，都可以将血管分离出来，但从弦波图空间上得到各个独立成份相对於影像空间就快得多；imageICA和sinogramICA计算出的输入函数的标准化均方根误差分别是0.57和0.28。

It is pointed that the parabola method is straightforward, but the results are relatively coarse, and the catenaries method is relatively complicated, but the results are precise, which takes into account all-around factors.

结果发现：抛物线法比较简单，但计算结果比较粗略；分段悬链线法考虑因素比较全面，计算相对复杂，但结果比较精确；对于空缆线形竖向坐标值两种方法的误差为0 739%，无应力索长计算两种方法的误差仅为0 31%。

The tooth profile error and longitudinal form error are calculated,and the change rule with setting angle of them is got.

针对花键的齿形误差和齿向误差，按照误差计算原理，得出了计算结果及其随安装角改变的变化规律。

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％。