The class acquisition of expression mode semantics , projection relationship semantics and dimension constraint semantics , and integration acquisition technology of tangency combined relationship , interpenetrate combined relationship and intersected combined relationship are emphatically introduced , which lay the foundation for further primitive recognition 重点介绍了表达方式语义、投影关系语义和尺寸约束语义的分类获取技术，以及相切组合关系、相贯组合关系、截交组合关系语义的整合获取技术，为后续基元体信息的识别、理解和获取奠定基础。
The stress and local stability constraints are transformed into movable lower bounds of sizes . an inverse variable xt = ? is inducted , and the objective function is expanded as second order taylor approximation while the displacement constriction is expanded as first order taylor approximation . the lemke algorithm is used to get the final design result 把复杂的应力约束和局部稳定约束转化为动态尺寸约束，引入倒变量x _ i 1 / a _ i将目标函数展开为二阶近似，将位移约束用莫尔积分化为一阶近似，用对偶规划方法将原问题化为等价的二次规划问题，调用lemke算法，求得最优设计结果。
The system depends on the features of rapidness , simplicity , driving by parameter and fitting for designers ’ habits and blends the size parameter into data structure and by using the driving technology realizes the drawing of single and double track lines of inter - station and the plane arrangement maps of station contact net 该系统依赖参数化方法所具备的快速、简洁、参数驱动、符合设计者习惯等特性，将尺寸参数融入到数据结构中，利用尺寸驱动技术实现尺寸约束，实现区间单、复线和站场接触网平面布置图的绘制。
In chapter 2 , we analyze shop drawings hierarchically such as projection relation , expression mode and dimension restriction , etc ; conclude the main difference between mechanical and architectural drawings , based on it , strategies of knowledge - based engineering drawing computer understanding aim at shop drawings are introduced 论文第二章面向图形理解对施工图语义从表达方式、投影关系、尺寸约束等不同层次进行了分析，归纳出建筑图样和机械图样视图表达方式的主要区别，针对现有的三维重建策略在建筑图样图形理解中的局限性，提出了针对建筑图样的基于知识的建筑图理解策略。
According to the model , in respect of the content of engineering drawing the semantics is divided into the projection relation semantics , the expression mode semantics and the dimension constraint semantics . in respect of the deepness of information , the semantics is classified into the lower semantics , the middle semantics and the upper semantics 该模型从类别化的角度分为投影关系语义、尺寸约束语义和表达方式语义，从层次化的角度分为底层语义、中间层次语义和高层语义，从网络化的角度得到各个类别、各个层次之间的语义。
In this paper , based on analyzing the forming regularity , geometric characteristic and dimensioning factor of primitive and combined entity , the notion of explicitly feature position of geometric shape of primitive is introduced , the classification is dicussed . the notion of explicitly feature position constraint of geometric shape of combined entity is introduced . the classification , the explicitly reductive property for location dimension , the constraint of the explicitly feature position constraint of geometric shape of combined entity degree are systematically analyzed 本文通过对基元体和组合体的形成规律、几何特性及尺寸要素分析的基础上，引入了基元体和组合体的隐式几何形状特征位的概念，系统地分析了隐式几何形状特征位约束的分类、及其约束度等概念；提出了定位尺寸预先加入的策略及隐式几何形状特征位约束对定位尺寸的隐含性缩减的性能，并建立了求解组合体的尺寸约束解的推理求解公式；通过引入基元体的隐式几何形状特征位和组合体的隐式几何形状特征位约束等概念，把尺寸约束解的求解转化为对基元体的隐式几何形状特征位相互之间的位置关系。
In the following , based on that theories analysis and the 3d space of primitive and combined entity is existed , a new strategy appending the location dimension beforehand is applied , and the formula to solving the constraint dimensions is established . the algorithms to testing the feature position constraint among the primitive are brought forward 进而，在以上理论分析和三维形体所处的空间基础上，提出了定位尺寸预先虚拟加入的策略，给出求组合体尺寸约束解的推理求解公式，通过此公式西安建筑科技大学硕士论文可求解出组合体的尺寸约束解。
By analyzing all sorts of data involved in the drawing of plane arrangement of the contact net , the paper then presents and realizes the sub - systems of drawing data management , which includes setting up the data structure , programming and managing of the data and provides the drawing data for the whole system used for the later drawing , finally by introducing the concerned theories of the parameterized design explains the similarities and differences and their applied scope of all kinds of parameterized technologies , and by associating with the features of the plane arrangement maps of the railway contact net analyzing size restraint of contact net 它是针对铁路接触网平面布置图的特点来完成选择区间或站场绘制、图纸设定、图型设定、字符高度、图型坐标点、绘图基点和图型数据文件保存路径的设置以及布置图的标注栏和明细表尺寸设置；紧接着通过对接触网平面布置图的绘图中所涉及的各种类型数据进行分析，提出并实现绘图数据管理子系统，它包括建立绘图系统的数据结构，对数据进行编辑管理，向整个系统提供绘图数据，供其后的图形绘制使用；最后通过对参数化设计的相关理论进行介绍，阐述了各种参数化技术的异同点和适用范围，并结合铁路接触网平面布置图的特点具体分析了接触网线路的尺寸约束。
Finally , the constraint dimensions of combined entity can be get with that formula . to prove correctness of this approach , the development system is based on autocad system , we introduced object - oriented technology including objectarx and visual c + + in the prototype system , the system achived the aim of solution the constraint dimensions of combined entity 井以obectarx和msualch为开发工具，利用面向对象的技术、基于auocad为实现平台，完成组合体的尺寸约束解的推理求解的实现，以对本文提出的尺寸约束解的推理求解的方法予以验证，论证了本方法的正确性。
Intelligentization and automation of dimensioning is an important part of cad / capp / cam , but due to the multiplicity of entity and flexibility of allocating dimensions , the problem of constraint dimensions has not been solved perfectly . constraint dimensions can give a numerical standard for testing completeness of 2d engineer graphics dimensioning 尺寸标注的智能化和自动化一直是cad capp cam领域研究的重要课题，但由于形体表达的多样性和尺寸标注的灵活性，形体的尺寸约束解的获得一直都未得到很好的解决。
