geometrical concept
1.With the inspiration of the basic design philosophy of the nearest feature line (NFL) classi-(fier),the geometrical concept of line is generalized to plane and space.
2.In this paper, the concept of parameter describing of geometrical elements, include real meas ured elements and logical elements, is proposed, is proposed,all olgical operations between elements are classified into sever al types, and equations are given for the solving of the parameters of the new logical element created by each of these operations,This work settles a foundation for the extension geometrical software of CMMs
3.The cable-strut tensile structures are the self-stress equilibrium systems composed by tensional cables and struts.In this paper,the basic concept of the structures was described.The analysis methods of the structural characteristics(statically and kinematically determinate or indeterminate) and the geometrical stability were presented.It is indicated that the cable-strut tensile structures are in stable equilibrium with first-order infinitesimal mechanisms.The ranks of equilibrium matrix were calculated by employing the singular value decomposition,and the independent modes of inextensional mechanisms and the states of self-stress were also obtained in the same way.This paper contains some typical examples which illustrate all of the main points of the work.
4.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.收藏指正
