In this paper the topological structure of multi - body system and their low - order body arrays , and basic concepts of characteristic matrixes and their composing methods are presented , basic rules of having - error kinematics of multi - body system are analyzed , 891e gear measurement center taken as an example , volumetric geometirc errors of gear measurement center based on characteristic matrixes are researched , it provides a kind of ideal method of model building for the precision analysis and geometric errors of gear measurement center 摘要本文阐述了多体系统的拓扑结构和低序体阵列，其特征矩阵的基本概念和构建方法，分析了多体系统误差运动的基本规律，结合891e型齿轮测量中心研究了根据特征矩阵得到其空间几何误差的算法，为齿轮测量中心精度分析和几何误差提供了一种理想的建模方法。
With an introduction of the influences of the final quality of rail aluminothermic welding , such as : the quality of welding kits ( esp . the portion ) , the result of pre - heating , the welding operation and the level of operators etc . , this paper analyzes some problems when rail welding under special conditions 摘要介绍了焊接材料质量、预热效果、操作人员水平等因素对钢轨铝热焊接接头质量的影响，以及几何误差不同、轨头宽度不等、寒冷气候等特殊条件下进行铝热焊接应注意的问题。
( 4 ) it is important to program the geometric error compensation software in order to put this technology into use . the program is written with vc + + 6 . 0 under windows platform . after the design of compensation software of sk - 21 nc machine tool is completed , precision nc instruction is resolved automatically by error compensation software ( 4 )运用面向对象的程序设计方法,开发几何误差补偿软件,在windowsxp平台上以vc + + 6 . 0编写,结合生产中的设计、装配和加工需要,进一步分析实际的影响因素,完善相关的数学处理运算,实现软件的实用化。
21 pajarola r , sainz m , lario r . extreme splatting : external memory multiresolution point visualization . department of computer science , university of california irvine , 2004 , uci - ics - 04 - 14 . 22 airey j m , rohlf j h , brooks f p jr . towards image realism with interactive update rates in complex virtual building environments 二是考察各个层次结点的几何误差情况，并为每种几何误差记录序列中最先满足该误差要求的层次片段，以便成象时能很快剔除太粗糙的点数据，这对于模型的近距离成象是非常有用的。
