Modelling Natural Branching Structures

This paper describes the work done in creating a computer program capable of modelling rooted trees and in particular the branching structures of botanical and bronchial trees. Simplicity of design and flexibility of use was achieved by generalising the program to handle any rooted branching structure with the particular form being dictated by various controlling parameters which can be modified via a direct manipulation interface. The program provides a graphical display of the resultant tree and leaf distribution. The open skeletal design allows the user to tailor the program to a particular model and to easily access data derived by the model.     

Dynamics Modelling of Hexaslides using the Decoupled Natural Orthogonal Complement Matrices

In this paper, dynamic model of a class of parallel systems, namely, the hexaslides, is proposed. The model developed is based on the concept the decoupled natural orthogonal complement (DeNOC) matrices, introduced elsewhere. The dynamic model of hexslides, though complex due to the existence of multi-loop kinematic chains, is required for actuator power estimation, computed-torque control, optimum tool trajectory generation, etc. The use of DeNOC offers many physical interpretations, recursive algorithms, and parallel computations. Using the proposed dynamic model, a parallel inverse dynamics algorithm has been presented to compute the actuator forces. This is useful to choose suitable motors for an application. An illustration is provided using an existing machine tool based on hexaslides, namely, the HexaM, while it is carrying out a circular contouring. Secondly, the effect of leg and slider inertias is also studied, which clearly suggests that neither of these can be neglected while finding the actuator forces.     

发动机冷却系统的建模与仿真

该文在基于MATLAB/SIMULINK的环境中建立了某重型汽车柴油发动机冷却系统模型。该系统主要由发动机、节温器、散热器、水泵以及空气冷却系统组成。模型着重考虑了节温器的迟滞和热惯性等非线性特点，并建立了风扇的风速控制逻辑。在不同运行状况下仿真结果与相应的发动机实测数据基本一致，表明所建立的模型具有较好的温度预测能力。     

Optimal Motion Synthesis – Dynamic Modelling and Numerical Solving Aspects

A general approach for generating optimal movements of actuatedmulti-jointed systems is presented. The method is based on theimplementation of the Pontryagin Maximum Principle (PMP) used as amathematical optimization tool. It applies to mechanical systems withkinematic tree-like topology such as serial robots, walking machines,and articulated biosystems. Emphasis is put on the choice of anappropriate dynamic model of the multibody system, together with thechoice of relevant performance criteria to be minimized for generatingthe optimal motion. It is shown that the Hamiltonian formalism isperfectly suitable to deal with the optimization problem using the PMP.On the other hand, prominence is given to performance criteria ensuringsoft and efficient functioning of the articulated systems. Two computingtechniques for solving the optimization problem are presented. Threenumerical simulations demonstrate the applicability of the method.     

基于总和时间常数法的送引风控制系统仿真

该文对电厂锅炉燃烧送引风控制系统进行了讨论,对该系统从多变量角度进行了分析,引入总和时间常数法对解耦后的等效对象进行了校正、整定和计算机仿真,给出了仿真曲线。结果表明,总和时间常数法整定系统简便易行,控制质量好,能够满足工程要求,有推广价值。     

The Little Towers of Antwerpen problem

The Little Towers of Antwerpen problem is a simple variant of the Towers of Hanoi problem requiring the interchanging of two stacks (black, white) of N rings using the third tower as a spare, subject to the usual rules governing ring movement. An optimal algorithm for the problem is presented and its performance is analyzed.     

The Towers Fall and War Begins

The implications of the tragic attack on 11 September will continue to shape the world we live in for years to come. The loss of life and the consequent declaration of a global war against terrorism will fundamentally change business in many ways. Physical security and the protection of far flung global business operations obviously merit attention.     

输电塔架参数化三维建模方法研究与实现

快速建立输电塔架三维仿真模型对电网安全运行与信息管理有重要作用。根据输电塔架的结构特点及结构相似性进行模块化划分,并用参数化方法为相同结构型式的模块建立原始三维模型;在此基础上根据塔架型号与呼高,对各模块进行选择与组装,赋值参数驱动各模块的原始模型,实现各种塔型与呼高的塔架三维快速建模。以某酒杯型直线塔为例,输入塔架型号与呼高即实现其三维模型快速建立,验证了该参数化三维建模方法的正确性与实用性。     

用VB设计汉诺塔动画游戏

汉诺塔问题是程序设计教学中关于递归调用的经典案例。该文介绍了用VB设计汉诺塔动画游戏程序的基本过程,其中重点介绍了用VB的自定义数据类型和图形处理技术设计游戏步点状态记录和动画效果的方法。     

The associativity of equivalence and the Towers of Hanoi problem

Dijkstra and Scholten have argued that greater use should be made of the associativity of equivalence. This note shows how the property is used in specifying the rotation of the disks in the well-known Towers of Hanoi problem.     

An iterative algorithm for the cyclic Towers of Hanoi problem

In the cyclic Towers of Hanoi problem, the discs may only move in a clockwise direction from a source peg to a specified peg subject to the usual restrictions of the standard problem. An iterative solution to the modified problem is presented. A number of observations that lead to the construction of an iterative algorithm is also discussed.     

广义Hanoi塔问题的动态规划算法

基于动态规划算法思想，深入分析了广义Hanoi塔问题动态规划分割点的特征，给出动态规划分割点的简单计算公式，使得动态规划算法转化为一个非常简单的递归算法，由此可以迅速产生广义Hanoi塔问题的最优移动序列，从而彻底解决了广义Hanoi塔问题的最优移动序列问题．     

一种基于自适应颜色压缩的织物图案提取方法

文章介绍了一种新的基于主成分分析网络PCA与自组织特征映射网络SOFM的颜色自适应压缩技术,并首先将该技术应用到了纹理状织物图案的提取研究中。研究表明:提取主颜色系对消除图像中的噪声污染成分非常有效,能够减少原图像上因噪声干扰引起的纹理分割误差。通过竞争学习的分类识别引入了像素间的空间位置关系,使得经神经网络分类出的图像与原图像最接近,并提高了在图案提取分割中的计算效率。该研究结果在获取织物图案设计与仿制中可减少人机交互量,提高识别效率,在工程应用上具有相当的实用价值。     

在演示文稿课件中嵌入FLASH的技巧

目的:在演示文稿中插入FLASH动画。方法:可使用ActiveX控件、插入对象、超链接这三种方法。结果:可成功将FLASH动画插入到演示文稿中。结论:在演示文稿中使用FLASH动画具有良好的教学效果。     

在演示文稿课件中嵌入FLASH的技巧

目的：在演示文稿中插入FLASH动画。方法：可使用ActiveX控件、插入对象、超链接这三种方法。结果：可成功将FLASH动画插入到演示文稿中。结论：在演示文稿中使用FLASH动画具有良好的教学效果。