期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
一类飞行器载荷设计的三分段方法研究与应用 被引量:2
1
作者 商霖 张海瑞 +1 位作者 李璞 马友林 《国防科技大学学报》 EI CAS CSCD 北大核心 2019年第2期63-68,共6页
为有效解决传统载荷设计方法中存在的诸多不足,提出一种适用于一类飞行器载荷设计的三分段法,即分段刚度、分段质量和分段气动。该方法能够很好地逼近飞行器的真实质量分布和气动载荷分布。针对简化飞行器,分别利用三分段法、理论计算... 为有效解决传统载荷设计方法中存在的诸多不足,提出一种适用于一类飞行器载荷设计的三分段法,即分段刚度、分段质量和分段气动。该方法能够很好地逼近飞行器的真实质量分布和气动载荷分布。针对简化飞行器,分别利用三分段法、理论计算法和质量分站法计算其模态参数和截面载荷。结果表明,三分段法和理论计算法在模型参数、计算原理上是一致的,基本可以认为是一种方法,因而它们的模态参数和截面载荷完全吻合;质量分站法所得左、右截面载荷不一致,且相差很大,还不符合真实载荷情况。总之,采用三分段法能够得到较为真实、合理的飞行器截面载荷分布,且工程应用简便,方法合理、可信,同时还可以在很大程度上降低飞行器载荷设计和结构设计的难度。 展开更多
关键词 飞行器 载荷设计 三分段法 质量分站法 理论计算法
下载PDF
大江大河河流分段方法探讨 被引量:5
2
作者 董耀华 汪秀丽 《人民长江》 北大核心 2015年第4期10-15,共6页
河流分段方法研究属于河流动力学与河流地貌学的交叉研究领域,其研究成果是流域规划、河流管理与河道治理等的重要基础与依据。基于Schumm河流分区理论,总结了"三河段分段法";基于地貌临界条件,提出了"控制节点分段法&qu... 河流分段方法研究属于河流动力学与河流地貌学的交叉研究领域,其研究成果是流域规划、河流管理与河道治理等的重要基础与依据。基于Schumm河流分区理论,总结了"三河段分段法";基于地貌临界条件,提出了"控制节点分段法";综合提出并推荐了"最大五河段分段法"。根据十大江河河流分段实践,检验了"最大五河段分段法"的适用性与有效性。分析结果表明,该方法与十大江河的分段实践吻合一致,值得推荐。 展开更多
关键词 最大五河段分段法 控制节点分段法 河段分段法 Schumm河流分区理论 地貌临界条件
下载PDF
3D Multiphase Piecewise Constant Level Set Method Based on Graph Cut Minimization 被引量:2
3
作者 Tiril P Gurholt Xuecheng Tai 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE 2009年第4期403-420,共18页
Segmentation of three-dimensional(3D) complicated structures is of great importance for many real applications.In this work we combine graph cut minimization method with a variant of the level set idea for 3D segmenta... Segmentation of three-dimensional(3D) complicated structures is of great importance for many real applications.In this work we combine graph cut minimization method with a variant of the level set idea for 3D segmentation based on the Mumford-Shah model.Compared with the traditional approach for solving the Euler-Lagrange equation we do not need to solve any partial differential equations.Instead,the minimum cut on a special designed graph need to be computed.The method is tested on data with complicated structures.It is rather stable with respect to initial value and the algorithm is nearly parameter free.Experiments show that it can solve large problems much faster than traditional approaches. 展开更多
关键词 Piecewise constant level set method energy minimization graph cut SEGMENTATION three-dimensional.
下载PDF
A Novel 360°3D Profilometry
4
作者 SONG Yuanhe,ZHAO Hong,FAN Hua,CHEN Wenyi,TAN Yushan (Research Institute for Laser & Infrared Applications, Xi’an Jiaotong University,Xi’an 710049,CHN) 《Semiconductor Photonics and Technology》 CAS 1998年第1期45-49,共5页
A new method of 360° turning 3D shape measurement in which light sectioning and phase shifting techniques are both used is presented in this paper.A sine light field is applied in the projected light stripe,meanw... A new method of 360° turning 3D shape measurement in which light sectioning and phase shifting techniques are both used is presented in this paper.A sine light field is applied in the projected light stripe,meanwhile phase shifting technique is used to calculate phase of the light slit.Thereafter wrapped phase distribution of the slit is formed and the unwrapping process will be made by means of the height information based on the light sectioning method.Therefore phase measuring results with better precision can be obtained.At last the target 3D shape data can be produced according to geometric relationships between phases and the object heights.The principles of this method are discussed in detail and experimental results are shown in this paper. 展开更多
关键词 Light Sectioning Phase Shifting Phase Unwrapping Algorithm 3D Shape Measurement
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部