For fully understanding the hydrological dynamics of an infinite terraced slope, the infiltration process was studied by employing the Green and Ampt infiltration model. The limit equilibrium method and the Mohr-Coulo...For fully understanding the hydrological dynamics of an infinite terraced slope, the infiltration process was studied by employing the Green and Ampt infiltration model. The limit equilibrium method and the Mohr-Coulomb failure criterion were adopted to derive a stability model for the infinite terraced slope subjected to an intense rainfall. Numerical simulation was performed for verifying its applicability. The results of numerical simulation indicate that a set of stepped wetting fronts are found during infiltration, and the infiltration of terraced slope covered by coarse-textured soils can be approximated as one-dimensional infiltration. The potential sliding surfaces from the numerical method are all parallel to the slope line, and the proposed model and framework can provide an approximate method of estimating how the infiltration affects the stability of an infinite terraced slope.展开更多
This paper presents a region-based method for extraction of consistent surfaces from raw point clouds. The method uses a new robust estimation method of constructing seed regions and a new method of orientating region...This paper presents a region-based method for extraction of consistent surfaces from raw point clouds. The method uses a new robust estimation method of constructing seed regions and a new method of orientating regions or surfaces. The robust estima- tion method selects good seed regions from candidate regions generated randomly in a structured neighborhood. The orienta- tion method uses transition vectors from which include angles of adjacent normal vectors are not greater than 90~ and thus can be orientated correctly crossing sharp features or close-by opposite surfaces. The region-based method consists of two levels of segmentation： planar segmentation and quadric segmentation, both of which produce consistent surfaces. The quadric segmen- tation fits general quadrics by 3 L fitting algorithm in its region growing process and can take consistent planar surfaces as ini- tials. Experimental results show that the robust estimation method has higher probability of success than the traditional one and the orientation method works well. Experimental results also demonstrate the applicability of our method to various data.展开更多
The motion of micro-particles with different mass flow rate in the planer turbulent jet flow has been simulated, using LES method to obtain the flow vorticity evolution and Lagrangian method to track micro-particles. ...The motion of micro-particles with different mass flow rate in the planer turbulent jet flow has been simulated, using LES method to obtain the flow vorticity evolution and Lagrangian method to track micro-particles. The re- suits showed that when the flow rate is small, the particles more likely to present in the vortex periphery, the dis- tribution pattern is similar to the flow pattern. When the flow rate is high, some particles will escape from the mo- tion region to the original static region, so that in the jet region, particles are relatively evenly distributed. When the flow field is full developed, the particles average concentration in the y direction affected by the mass flow rate relative slightly, the normalized mean particles concentrations at different flow rate were similar to Gaussian shape.展开更多
基金Project(51178423)supported by the National Natural Science Foundation of China
文摘For fully understanding the hydrological dynamics of an infinite terraced slope, the infiltration process was studied by employing the Green and Ampt infiltration model. The limit equilibrium method and the Mohr-Coulomb failure criterion were adopted to derive a stability model for the infinite terraced slope subjected to an intense rainfall. Numerical simulation was performed for verifying its applicability. The results of numerical simulation indicate that a set of stepped wetting fronts are found during infiltration, and the infiltration of terraced slope covered by coarse-textured soils can be approximated as one-dimensional infiltration. The potential sliding surfaces from the numerical method are all parallel to the slope line, and the proposed model and framework can provide an approximate method of estimating how the infiltration affects the stability of an infinite terraced slope.
基金supported by the National Natural Science Foundation of China(Grant No.51205332)the SRF for the Returned Overseas Chinese Scholars
文摘This paper presents a region-based method for extraction of consistent surfaces from raw point clouds. The method uses a new robust estimation method of constructing seed regions and a new method of orientating regions or surfaces. The robust estima- tion method selects good seed regions from candidate regions generated randomly in a structured neighborhood. The orienta- tion method uses transition vectors from which include angles of adjacent normal vectors are not greater than 90~ and thus can be orientated correctly crossing sharp features or close-by opposite surfaces. The region-based method consists of two levels of segmentation： planar segmentation and quadric segmentation, both of which produce consistent surfaces. The quadric segmen- tation fits general quadrics by 3 L fitting algorithm in its region growing process and can take consistent planar surfaces as ini- tials. Experimental results show that the robust estimation method has higher probability of success than the traditional one and the orientation method works well. Experimental results also demonstrate the applicability of our method to various data.
基金supported by National Natural Science Foundation of China (Grant No. 50976107 and 51206149)National Key Technology R&D Program of China (Grant No. 2009BAF39B01)Zhejiang Science Technology Project (Grant No. 2011C11073)
文摘The motion of micro-particles with different mass flow rate in the planer turbulent jet flow has been simulated, using LES method to obtain the flow vorticity evolution and Lagrangian method to track micro-particles. The re- suits showed that when the flow rate is small, the particles more likely to present in the vortex periphery, the dis- tribution pattern is similar to the flow pattern. When the flow rate is high, some particles will escape from the mo- tion region to the original static region, so that in the jet region, particles are relatively evenly distributed. When the flow field is full developed, the particles average concentration in the y direction affected by the mass flow rate relative slightly, the normalized mean particles concentrations at different flow rate were similar to Gaussian shape.
