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A new method of mesh simplification for 3-Dimension terrain using Laplace operator 被引量:1
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作者 Zuo Wenpin Che Xiangjiu 《Computer Aided Drafting,Design and Manufacturing》 2012年第1期44-48,共5页
This paper proposes a new method to simplify mesh in 3D terrain. The 3D terrain is presented by digital elevation model. First, Laplace operator is introduced to calculate sharp degree of mesh point, which indicates t... This paper proposes a new method to simplify mesh in 3D terrain. The 3D terrain is presented by digital elevation model. First, Laplace operator is introduced to calculate sharp degree of mesh point, which indicates the variation trend of the terrain. Through setting a critical value of sharp degree, feature points are selected. Second, critical mesh points are extracted by an recursive process, and constitute the simplified mesh. Third, the algorithm of linear-square interpolation is employed to restore the characteris- tics of the terrain. Last, the terrain is rendered with color and texture. The experimental results demonstrate that this method can compress data by 16% and the error is lower than 10%. 展开更多
关键词 3-dimension terrain critical mesh point simplified mesh Laplace operator
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NUMERICAL MODELLING OF THREE-DIMENSION CHARACTERISTICS OF WIND-DRIVEN CURRENT IN THE BOHAI SEA 被引量:5
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作者 赵进平 侍茂崇 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 1993年第1期70-79,共10页
Three- dimension (3-D) wind-driven currents in the Bohai Sea in both winter and summer are calculated by using a 3- D barotropic steady model, and the results are consistent with observed flow char -acteristics. Based... Three- dimension (3-D) wind-driven currents in the Bohai Sea in both winter and summer are calculated by using a 3- D barotropic steady model, and the results are consistent with observed flow char -acteristics. Based on the results, 3- D characteristics of flow, currents at different depths, compensated flow in the lower layer , long and narrow alongshore current, the area of upwelling and downwelling, main circulation in vertical profile, and the current in Bohai Strait are discussed. 展开更多
关键词 the Bohai Sea- 3-dimension model NUMERICAL study WIND-DRIVEN CURRENT
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3-dimensional slope stability analyses using non-associative stress-strain relationships 被引量:4
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作者 CHEN ZuYu SUN Ping +1 位作者 WANG YuJie ZHANG HongTao 《Science China(Technological Sciences)》 SCIE EI CAS 2009年第9期2517-2527,共11页
The research work presented in this paper refers to a new slope stability analysis method used for landslide risk evaluations. It is an extension of the 3-dimensional upper-bound slope stability analysis method propos... The research work presented in this paper refers to a new slope stability analysis method used for landslide risk evaluations. It is an extension of the 3-dimensional upper-bound slope stability analysis method proposed by Chen et al. in 2001,which employs the Mohr-Coulomb's associative flow rule. It has been found that in a 3-dimensional area,a prism may not be able to move at friction angles to all its surrounding interfaces,as required by this associative rule,and convergence problems may occasionally arise. The new method establishes two velocity fields:(i) The plastic one that represents a non-associative and the best representative dilation behavior,and (ii) the virtual one that permits the solution for factor of safety in the work and energy balance equation. The new method can then allow any input value of dilation angle and thus solve the convergence problem. A practical application to a concrete dam foundation is illustrated. 展开更多
关键词 non-associative flow RULE SLOPE stability limit analysis 3-dimension
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基于编码结构光和外极线约束的自由曲面三维轮廓术 被引量:4
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作者 程俊廷 赵灿 莫健华 《计算机测量与控制》 CSCD 2007年第1期120-121,131,共3页
提出了一种新的基于编码结构光和外极线约束的自由曲面立体视觉测量方法,这种方法有效解决了立体视觉中的图像匹配问题;外极线约束将可能的候选点限制在直线分布,引入编码光用来确定光栅条纹的级次;这种方法极大地减小了图像匹配的运算... 提出了一种新的基于编码结构光和外极线约束的自由曲面立体视觉测量方法,这种方法有效解决了立体视觉中的图像匹配问题;外极线约束将可能的候选点限制在直线分布,引入编码光用来确定光栅条纹的级次;这种方法极大地减小了图像匹配的运算量,同时减小了错误匹配的概率;实验表明,采用编码光栅投影视觉测量能够高效准确地测量自由曲面的三维轮廓。 展开更多
关键词 三维轮廓术 立体视觉 编码结构光 外极线约束
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基于立体视觉的砌体房屋模型振动试验研究 被引量:1
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作者 单宝华 申宇 《地震工程与工程振动》 CSCD 北大核心 2013年第3期103-109,共7页
针对结构动态响应监测三维变形的需求,研究立体视觉三维测量算法,建立基于结构测面的世界坐标系,得到结构振动响应三维位移公式。研究圆形标识点边缘检测、中心拟合及匹配约束算法,编译基于MATLAB平台的立体视觉结构振动测试分析软件。... 针对结构动态响应监测三维变形的需求,研究立体视觉三维测量算法,建立基于结构测面的世界坐标系,得到结构振动响应三维位移公式。研究圆形标识点边缘检测、中心拟合及匹配约束算法,编译基于MATLAB平台的立体视觉结构振动测试分析软件。使用本文集成的立体视觉测量系统完成不同加速度峰值Taft波及El Centro波作用下砌体房屋模型振动台试验,同时测得结构三维位移时程曲线。面内位移时程曲线表明立体视觉方法与位移计数据吻合非常好,证实立体视觉测量方法的有效性。离面位移时程曲线表明砌体房屋模型在地震动作用下发生扭转,且随地震动加速度峰值增大,扭转反应加剧,充分验证立体视觉方法用于监测结构三维振动响应的可靠性及实用性。 展开更多
关键词 立体视觉 振动测量 三维 标识点 砌体房屋模型
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新的超声立体视觉数据增强技术
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作者 刘宛予 唐志健 +5 位作者 朱跃敏 刘文辉 胡珊 张延丽 王丽会 I.E.Magnin 《光学精密工程》 EI CAS CSCD 北大核心 2008年第9期1759-1766,共8页
针对超声成像噪声大、数据质量严重退化的特点,提出了一种新颖的非稳定度度量算法,该算法通过加强图像变化较大的部分来实现超声数据的增强。给出了输入信号信噪比不同情况下非稳定度算子与Deriche算子的输出仿真结果;通过兔子肝脏和12... 针对超声成像噪声大、数据质量严重退化的特点,提出了一种新颖的非稳定度度量算法,该算法通过加强图像变化较大的部分来实现超声数据的增强。给出了输入信号信噪比不同情况下非稳定度算子与Deriche算子的输出仿真结果;通过兔子肝脏和12周胎儿的实际数据计算,得到了二者经非稳定度算子处理前后的超声立体视觉图像。研究结果表明,非稳定度数据增强技术对噪声不敏感,通过对比处理前后的图像可清晰地看出非稳定度算子能够有效地改善超声立体视觉成像的质量。 展开更多
关键词 三维立体视觉 超声成像技术 立体视觉图像 数据增强 非稳定度
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基于结构光和序列图像的三维重建方法 被引量:4
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作者 滕世明 王森 许志闻 《吉林大学学报(信息科学版)》 CAS 2009年第4期400-406,共7页
为解决在基于图像三维重建物体表面的过程中,对不同图像进行立体匹配的难题,提出了基于特征的立体匹配算法,建立了利用序列图像重建物体表面的系统。系统采用投影结构光给物体表面加上主动特征的方法,以快速精确地重建物体表面,并对Cann... 为解决在基于图像三维重建物体表面的过程中,对不同图像进行立体匹配的难题,提出了基于特征的立体匹配算法,建立了利用序列图像重建物体表面的系统。系统采用投影结构光给物体表面加上主动特征的方法,以快速精确地重建物体表面,并对Canny算法进行了改进,用于轮廓提取、细化和修正等操作,从而准确获取图像主动线索特征。该方法能快速获取物体表面的三维点云数据,并达到了较高的精度。 展开更多
关键词 三维重建 三维建模 双目立体视觉 三角测量原理
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立体视觉中基于球坐标的发散式像素化分析方法
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作者 贾东 雷勇 《电脑开发与应用》 2007年第9期24-27,共4页
在机器人立体视觉场景恢复中,采用球坐标发散分割方法及相关操作,实现模型库均匀分割与场景发散分割很好地变换,为模型在置入场景空间中产生与真实场景相近的2.5维轮廓图像,利用该方法可为移动机器人视觉系统建立起直观的模型操作和对... 在机器人立体视觉场景恢复中,采用球坐标发散分割方法及相关操作,实现模型库均匀分割与场景发散分割很好地变换,为模型在置入场景空间中产生与真实场景相近的2.5维轮廓图像,利用该方法可为移动机器人视觉系统建立起直观的模型操作和对象匹配平台,仿真演示了采用该方法的直观视觉效果。 展开更多
关键词 立体视觉 3D轮廓 球坐标 像素化 发散式分割 2.5维图像
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THE DIVERGENCE-CONVERGENCE EFFECT OF SURFACE CURRENT AND ITS ACTION ON THE BOHAI SEA
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作者 赵进平 侍茂崇 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 1993年第2期135-142,共8页
The action of the wind field and the influence of topography can cause divergence or convergence of surface current. The existence of the divergence-convergence effect is proved and the dynamical significance of the d... The action of the wind field and the influence of topography can cause divergence or convergence of surface current. The existence of the divergence-convergence effect is proved and the dynamical significance of the divergent or convergent state and its link with many marine phenomena are pointed out. Divergence fields of surface current in the Bohai Sea in winter and summer are obtained by numerical modelling describing the divergence-convergence character of seasonally wind-driven current. The relation between the effect and seasonal marine phenomena is discussed. Study on the divergence-convergence effect of surface current (DCESC)can be an indirect method for testing the calculated results. 展开更多
关键词 DIVERGENCE divergence-convergence effect SURFACE CURRENT the Bohai SEA 3-dimension model
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Controlling Unstable Discrete Chaos and Hyperchaos Systems
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作者 Xin Li Suping Qian 《Applied Mathematics》 2013年第11期1-6,共6页
A method is introduced to stabilize unstable discrete systems, which does not require any adjustable control parameters of the system. 2-dimension discrete Fold system and 3-dimension discrete hyperchaotic system are ... A method is introduced to stabilize unstable discrete systems, which does not require any adjustable control parameters of the system. 2-dimension discrete Fold system and 3-dimension discrete hyperchaotic system are stabilized to fixed points respectively. Numerical simulations are then provided to show the effectiveness and feasibility of the proposed chaos and hyperchaos controlling scheme. 展开更多
关键词 2-dimension DISCRETE FOLD SYSTEM 3-dimension DISCRETE HYPERCHAOTIC SYSTEM LYAPUNOV Stability Theory Controlling Chaos
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Discussion on design for alkaline cleaning system of continual annealing line
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作者 HE Daohong,YI Fan and LU Zhiyi Baosteel Engineering & Technology Group Co.,Ltd.,Shanghai 201900 《Baosteel Technical Research》 CAS 2010年第S1期117-,共1页
Conventional process flow and main work mechanism of alkaline cleaning process of Continual Annealing Line are generally reviewed in the paper,and the work flow of design is analysed including the lye,rinse water circ... Conventional process flow and main work mechanism of alkaline cleaning process of Continual Annealing Line are generally reviewed in the paper,and the work flow of design is analysed including the lye,rinse water circuit,conductivity detection circuit,utility media supply circuit and other main working circuits.Meanwhile,the heat demand of the alkaline cleaning system,rinse water system and dryer device are also analysed.Lumped parameter method in the heat-transfer theory is adopted to calculate the heating time of unsteady heat transfer for strips in the on-line tank.And the reasons why brush roller is of inverse brush and rinsing nozzles are equipped at the inlet side are found.Types and working principles of iron removal and degreasing devices for alkaline cleaning system,which adopt new magnetic filtration and ultra filtration processes,are described.Besides,the bypass filtering method is used to calculate the processing capacity of magnetic filtration and ultra filtration devices.Finally,the related features of 3-Dimension software "PlantSpace" for designing a CAL in Baosteel are totally introduced,such as specification for piping,co-designing,pipe code and 3-Dimension design process. 展开更多
关键词 alkaline cleaning heating time magnetic filtration ultra filtration 3-dimension design
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A Study of Transform Encoding Using Frequency Spectrum Selection in 3D-DCT for Sequence Image 被引量:1
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作者 WANGShi-gang CHENHe-xin 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2001年第3期34-38,共5页
This paper puts forward the concept of laminar e ncoding based on frequency spectrum selection in 3D-DCT of sequence image. And the pattern of laminar encoding is suitable for the demands of the development of current... This paper puts forward the concept of laminar e ncoding based on frequency spectrum selection in 3D-DCT of sequence image. And the pattern of laminar encoding is suitable for the demands of the development of current communication. So this method is very useful in video communication and has wide prospect. 展开更多
关键词 image encode 3-dimensioned Discrete Cosine Transform (3D-DCT) transform encoding frequency spectrum selection
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