Now the researches concerning integral bus mainly focused on design and analysis of overall mechanical property of bus body, and paid little attention to characteristic of local structures, such as joint, plug welding...Now the researches concerning integral bus mainly focused on design and analysis of overall mechanical property of bus body, and paid little attention to characteristic of local structures, such as joint, plug welding hole, and bolt connection point, etc. So there is much blindness on the design of local connecting structure. Since integral bus body structure cancels large section longitudinal beam, and uses framework made by welding small section bars together as principal part to bear the whole load when the vehicle works, there are many joints receiving high load in the body structure, and local stress concentration can not be avoided. Under such circumstances, by adopting beam-shell mixed model based on super element technique, and selecting a joint commonly used by bus sidewall, the rule of the effect of bar joint’s welding seam spacing on joint’s local mechanical property is investigated in this paper, and the investigating results show that joints have minimum stress concentration with welding seam spacing of 8 mm. To learn whether the above rule is affected by relative bar wall thickness, many groups of bars with different relative bar wall thicknesses are studied experimentally, and the experimental results show that the joints local stress levels vary with different relative bar wall thicknesses, but the rule of the effect of bar joint’s welding seam spacing on joint’s local stress level remains the same. The research is significant for local structure design of bus joint in the future.展开更多
Depth discontinuity edge affects the visual quality of synthesized images in 3D image warping.However,it suffers from accuracy degradation when up-sampled from low-resolution depth maps,especially at large scaling fac...Depth discontinuity edge affects the visual quality of synthesized images in 3D image warping.However,it suffers from accuracy degradation when up-sampled from low-resolution depth maps,especially at large scaling factors.To preserve the accuracy of depth discontinuity,a novel joint bilateral depth super-resolution with intensity guidance method is proposed.Particularly,the fast local intensity classification is exploited to estimate depth coefficients in joint bilateral up-sampling for depth maps,so as to eliminate depth discontinuity edge misalignment.Additionally,the proposed method is accelerated on graphic processing units(GPUs)to meet the requirement of realtime application.Experiments demonstrate that our method can preserve the accuracy of depth discontinuity edges after super resolution,leveraging the visual quality of synthesized image in 3D image warping.展开更多
文摘针对车载雷达多参数联合超分辨计算复杂度高、无法快速实现参数估计的问题,提出了基于频域波束降维的多参数联合超分辨算法。所提算法通过快速傅里叶变换(fast Fourier transform,FFT)将空时多参数域联合数据变换到频域,处理感兴趣区域的多维频域数据,完成空时波束空间降维和基于频域数据的多参数联合超分辨,实现目标信息的快速联合估计。推导了频域子空间正交性及频域波束降维超分辨算法理论。仿真研究了算法的分辨率和估计性能与信噪比的关系。仿真结果表明,所提算法的精度和分辨率远超传统FFT算法,相对于传统多重信号分类(multiple signal classification,MUSIC)算法,所提算法计算量大幅降低。
基金supported by National Hi-tech Research and Development Program of China (863 Program, Grant No. 2006AA110104)
文摘Now the researches concerning integral bus mainly focused on design and analysis of overall mechanical property of bus body, and paid little attention to characteristic of local structures, such as joint, plug welding hole, and bolt connection point, etc. So there is much blindness on the design of local connecting structure. Since integral bus body structure cancels large section longitudinal beam, and uses framework made by welding small section bars together as principal part to bear the whole load when the vehicle works, there are many joints receiving high load in the body structure, and local stress concentration can not be avoided. Under such circumstances, by adopting beam-shell mixed model based on super element technique, and selecting a joint commonly used by bus sidewall, the rule of the effect of bar joint’s welding seam spacing on joint’s local mechanical property is investigated in this paper, and the investigating results show that joints have minimum stress concentration with welding seam spacing of 8 mm. To learn whether the above rule is affected by relative bar wall thickness, many groups of bars with different relative bar wall thicknesses are studied experimentally, and the experimental results show that the joints local stress levels vary with different relative bar wall thicknesses, but the rule of the effect of bar joint’s welding seam spacing on joint’s local stress level remains the same. The research is significant for local structure design of bus joint in the future.
基金Supported by the National Natural Science Foundation of China(61572058)
文摘Depth discontinuity edge affects the visual quality of synthesized images in 3D image warping.However,it suffers from accuracy degradation when up-sampled from low-resolution depth maps,especially at large scaling factors.To preserve the accuracy of depth discontinuity,a novel joint bilateral depth super-resolution with intensity guidance method is proposed.Particularly,the fast local intensity classification is exploited to estimate depth coefficients in joint bilateral up-sampling for depth maps,so as to eliminate depth discontinuity edge misalignment.Additionally,the proposed method is accelerated on graphic processing units(GPUs)to meet the requirement of realtime application.Experiments demonstrate that our method can preserve the accuracy of depth discontinuity edges after super resolution,leveraging the visual quality of synthesized image in 3D image warping.
