Each program consists of the following three modules : the first one is the program of managing and driving the dialog box , which can adjust the input parameters of the dialog box ; the second one is the calculating program , which can calculate the coordinates of the points in the unfolding drawing . the parameters used in the second module are obtained from the first module . the third module is drawing module 每一段绘图程序都由三个模块构成，第一模块为对话框管理和驱动程序并对对话框输入的参数进行回调；第二模块为计算程序，利用上面回调所得到的参数，再根据上面得出的计算公式，计算展开图上各点坐标；第三模块为绘图模块。
The software of analysis method of multi - armed caliper log imaging has been developed , and the on - site applied results show that the software can get the casing maximum drift diameter and effective drift diameter and simultaneously give the caliper hoop extension graph and cross section graph in arbitrary depth which can diagnose the sort and degree of casing deformation 摘要研制了多臂井径成像测井解释方法软件，现场应用结果表明：运行该软件可以解释得到套管最大通径、有效通径；同时给出任意深度井径周向展开图、横截面图，进而可判断套变的种类和程度。
The sheet metal work pieces are first divided into several groups such as cylinder , cone and so on . then , under considering the intersection of two cylinders or a cone and a plane , the mathematical models have been developed , and the corresponding unfolding methods have been determined . on the platform of autocad , the system has been redeveloped by means of autolisp and activex object , and the unfolding cad system has been designed , which can realize the parametric drawing of the extension of sheet metal 结合工程实际对曲面构件进行了分类，并通过分析建立了包括圆柱、圆锥、圆柱与圆柱相贯、圆锥与平面相贯等曲面构件的数学模型，确定了适当的展开方法，以autocad2000为平台，以autolisp结合activex对象为工具，进行二次开发，设计了曲面展开cad系统，从而实现钣金件展开图的参数化绘图。
Engineering drawing has always been labeled as a practical subject . a combination of geometrical , building . mechanical and electrical drawing , it relates between theory and the picture of reality . engineering drawing will provide an accurate and complete ptcture for every object tn terms of shapes and sizes . usually , it is taught using the face - to - face teaching mode even in an odl environment . due to its nature , some students may find difficulty in imagining and interpreting the drawings . however , the availability of sophisticated technology provides the opportunity for the learning of engineering drawing to be enhanced via online . a web - based system for teaching and learning engineering drawing was developed based on a constructivism model . the web - based system is tailored for several topics of engineering drawing such as orthographic projection , sectional view , isometric and oblique drawing at the secondary level . the learning strategy consists of multiple phases beginning with introduction , concept learning , engineering drawing method , application and exercises . during introduction , students will be exposed to an overview of the topic followed by learning of specific concepts . the system provides a learning environment that allows engineering students to view objects from different angles , such as third angle projection and first angle projection as well as views of plans , side and front elevations . after learning about the concepts , students wilt be guided through the various steps in drawing methods for each topic via animations and simulations . learners are able to view any section repeatedly . examples of real application of engineering drawings were also given using graphic , animations and video . to evaluate students understanding , exercises were given at the end of each session 工程制图一直被认为是一门实践性学科,其整合了几何学、建筑、力学、电子制图等,从而将理论与现实图像联系起来,工程制图能为每个不同形状、尺寸的物体提供精确的、完整的图像.通常,即使在开放与远程教育环境中,工程制图的教学也是通过面对面的教学模式来进行的.由于其特殊性,一些学习者可能难以想象并解释这些图像.然而,尖端的技术使得可以通过在线的方式加强工程制图的学习.研究者基于建构主义模式开发了一个面向工程制图教学和学习的网络系统.该系统适用于几种工程制图,例如展开图、刻面图、等角图和斜角图.学习过程包括导论、概念学习、工程制图方法,以及应用与练习等阶段.在导论阶段,系统为学习者提供了专题简介,然后是概念学习阶段.系统所提供的学习环境允许工程专业的学生从三维透视、一维透视、平面图、侧立面、正立面等不同角度来观察物体.经过概念学习阶段后,系统将引导学生通过动画和模拟学习每个专题中制图方法的不同步骤,学习者也能重复观察任何剖面.另外,还通过图像、动画和视频等方式展示真实的工程制图应用案例.最后,为了评价学生的理解能力,在每部分内容后面都附有相关的练习
