实体建模（曲面）——表示整个对象的体积 特点：信息最完整，复杂的实体形较网格对象容 易构造。灵活方便但占用资源多，建筑建模 能采用Pline 就不用实体。 实体建模分三种方法：构造基本实体形、组合基 本实体成复杂实体、对实体作圆角、倒角和 其他编辑处理

一. 室内给排水工程的内容 室内给排水工程主要介绍室内给水、排水和热水供应工程的设计原理及方法，同时还要 介绍一些施工及管理方面的基本知识和技术。这是一门专业技术课程，是给排水专业的必修 课

第6章基本输入/输出接口技术 本章主要教学内容 一、输入输出接口技术的概念和功能 二、CPU与IO接口之间传递的信息类型及IO端口的编址方式 三、CPU与外部设备之间数据传送方式的原理、特点及应用

一、SQLServer的身份验证 二、创建和管理用户登录的方法 三、固定服务器角色和服务器角色 四、管理数据库权限的方法

1 Model problem 1.1 Poisson Equation in 1D Boundary Value Problem(BVP) (x)=∫(x) (0,1),u(0)=(1)=0,f Describes many simple physical phenomena(e.g) Deformation of an elastic bar Deformation of a string under tension Temperature distribution in a bar The Poisson equation in one dimension is in fact an ordinary differ tion. When dealing with ordinary differential equations we Poisson equation will be used here to illastrate numerical techniques for elliptic PDE's in multi-dimensions. Other techniques specialized for ordinary differen tial equations could be used if we were only interested in the one dimension

Course Outline Overview of pdes(1) o Finite differences methods(6) Finite volume methods(3) Finite element methods(7) Boundary integral methods(6)

Despite its apparent simplicity this equation appears in a wide range of dis m heat 7 to financial er we will make extensive use of this equation, and several of the limiting cases contained therein, to illustrate the numerical techniques that will be presented

Background Developed over the last 25 years- Brandt (1973) published first paper with practical results Offers the possibility of solving a problem with work and storage proportional to the number of unknowns Well developed for linear elliptic problems application to other equations is still an active area of research

1 First Order ave Equation SLIDE 1 The simplest first order partial differential equation in two variables(a, t)is the linear wave equation. Recall that all first order PDE's are of hyperbolic type INITIAL BOUNDARY VALUE PROBLEM (IBVP) 0,x∈(0,1)

Motivation Consider a standard second order finite difference discretization