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二维复杂型面数字化比较技术的应用 被引量:1
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作者 高中亚 李振平 +1 位作者 方海滨 顾梦龙 《工具技术》 北大核心 2015年第5期60-62,共3页
以动压空气轴承弹性箔片为代表的具有二维复杂异性结构的精密零部件对型面具有很高的精度要求,加工此类产品的质量控制已成为批量生产的一个难题。传统的比较方法费时、费力,并且不便于交流。本文针对该类型产品的型面比较提出了一套完... 以动压空气轴承弹性箔片为代表的具有二维复杂异性结构的精密零部件对型面具有很高的精度要求,加工此类产品的质量控制已成为批量生产的一个难题。传统的比较方法费时、费力,并且不便于交流。本文针对该类型产品的型面比较提出了一套完整的解决方案,详细论述了实现方法和关键技术,并采用C#编写了程序,实现了对检测结果的快速比较,目前,该方案已经在产品的首件鉴定和批量检测中得到验证。 展开更多
关键词 二维型面 数字化比较 批量检测
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FACE RECOGNITION FROM FRONT-VIEW FACE
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作者 Wu Lifang Shen Lansun (Signal & Information Processing Laboratory, Beijing Polytechnic University, Beijing 100022) 《Journal of Electronics(China)》 2003年第1期45-50,共6页
This letter presents a face normalization algorithm based on 2-D face model to recognize faces with variant postures from front-view face. A 2-D face mesh model can be extracted from faces with rotation to left or rig... This letter presents a face normalization algorithm based on 2-D face model to recognize faces with variant postures from front-view face. A 2-D face mesh model can be extracted from faces with rotation to left or right and the corresponding front-view mesh model can be estimated according to the facial symmetry. Then based on the inner relationship between the two mesh models, the normalized front-view face is formed by gray level mapping. Finally, the face recognition will be finished based on Principal Component Analysis (PCA). Experiments show that better face recognition performance is achieved in this way. 展开更多
关键词 Face Normalization 2-D face model Geometric relation in face
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Analytical solution of vacuum preloading technology combined with electroosmosis coupling considering impacts of distribution of soil’s electrical potential 被引量:2
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作者 FENG Jian-ting SHEN Yang +1 位作者 XU Jun-hong SHI Wen 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第8期2544-2555,共12页
Combining vacuum preloading technology and electroosmosis can improve the treatment effect of soft soil foundation by utilizing the advantages of both methods.Many studies indicate that the soil electrical potential i... Combining vacuum preloading technology and electroosmosis can improve the treatment effect of soft soil foundation by utilizing the advantages of both methods.Many studies indicate that the soil electrical potential is non-linearly distributed in the treatment process by the combined method.However,in the previous theoretical study,the non-linear-distribution impacts of soil’s electrical potential on soft soil foundation treatment have not been considered.It is always assumed to be linear distribution,which is different from the experimental results.In this paper,the coupling consolidation model of this technology under the two-dimensional plane strain condition is initially established;and the well resistance effect,the vacuum load decreasing along the soil depth and the non-linear variation of electrical potential in the soil are considered.Then,the analytical solutions of the average excess pore water pressure and soil’s consolidation degree in the anode affected area are acquired based on the soil’s electrical potential distribution.Finally,the rationality of the analytical solution is testified by conducting an experimental model test,which proves the scientificity of the analytical solution.The analytical solution is adopted to better predict the dissipation of excess pore water pressure and soil consolidation degree when using the combined technology.This study can provide a reference with more accuracy for the engineering practices of this combined technology in the future. 展开更多
关键词 vacuum preloading-electroosmosis non-linear distribution 2D plane strain coupling consolidation model pore water pressure
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Developing a 2D vertical flow and sediment transport model for open channels using the Youngs-VOF method
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作者 赵东淼 唐军 +3 位作者 吴修广 林昌宁 刘丽君 陈剑 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2017年第2期444-451,共8页
A 2D vertical (2DV) numerical model, without o-coordinate transformation in the vertical direction, is developed for the simulation of flow and sediment transport in open channels. In the model, time-averaged Reynol... A 2D vertical (2DV) numerical model, without o-coordinate transformation in the vertical direction, is developed for the simulation of flow and sediment transport in open channels. In the model, time-averaged Reynolds equations are closed by the k-e nonlinear turbulence model. The modified Youngs- VOF method is introduced to capture free surface dynamics, and the free surface slope is simulated using the ELVIRA method. Based on the power-law scheme, the k-e model and the suspended-load transport model are solved numerically with an implicit scheme applied in the vertical plane and an explicit scheme applied in the horizontal plane. Bedload transport is modeled using the Euler-WENO scheme, and the grid-closing skill is adopted to deal with the moving channel bed boundary. Verification of the model using laboratory data shows that the model is able to adequately simulate flow and sediment transport in open channels, and is a good starting point for the study of sediment transport dynamics in strong nonlinear flow scenarios. 展开更多
关键词 sediment transport 2D vertical model Youngs-VOF Euler-WENO bed evolution
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A two-dimensional numerical model coupled with multiple hillslope hydrodynamic processes and its application to subsurface flow simulation 被引量:6
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作者 LAN Min HU HongChang +1 位作者 TIAN FuQiang HU HePing 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第10期2491-2500,共10页
A numerical hillslope hydrodynamic model is of great importance in facilitating the understanding of rainfall-runoff mechanism.However,most of the currently existing models do not consider the effect of coupled hydrod... A numerical hillslope hydrodynamic model is of great importance in facilitating the understanding of rainfall-runoff mechanism.However,most of the currently existing models do not consider the effect of coupled hydrodynamic processes as runoff,subsurface flow or groundwater flow.In this study,the Tsinghua Hillslope Runoff Model based on multiple hydrodynamic process,THRM model,is developed,which couples with Saint Venant equation for surface runoff and Richards equation for variably saturated soil water movement(including subsurface flow and groundwater flow).A finite difference scheme with improved boundary conditions is adopted in this research.It is revealed from the simulation that the THRM model has a high computational efficiency and stability in simulating subsurface flow of the experimental hillslope,which is valuable in assessing the hillslope runoff generation mechanism.A model based sensitivity analysis is also carried out.The impact of boundary condition,grid size and initial soil moisture on simulation result and model stability are revealed,which provides insightful references to understand the mechanism of subsurface flow. 展开更多
关键词 hillslope hydrological process subsurface flow Richards equation seepage face boundary numerical stability
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