针对现有双目场景流计算方法在大位移、运动遮挡及光照变化等复杂场景下场景流估计的准确性与鲁棒性问题,提出一种基于金字塔块匹配的双目场景流计算方法.首先对双目图像序列进行超像素分割和视差估计,得到图像初始分割结果和视差信息,...针对现有双目场景流计算方法在大位移、运动遮挡及光照变化等复杂场景下场景流估计的准确性与鲁棒性问题,提出一种基于金字塔块匹配的双目场景流计算方法.首先对双目图像序列进行超像素分割和视差估计,得到图像初始分割结果和视差信息,然后建立基于金字塔块匹配的运动模型并采用Ransac随机一致性算法拟合刚性运动模型和最小化重投影算法估计对象运动参数.最后,本文将金字塔块匹配结果作为约束项,联合对象运动参数和超像素平面参数构建基于金字塔块匹配的双目场景流估计能量函数模型,通过最小化能量函数得到最终场景流.实验分别采用KITTI2015(Karlsruhe Institute of Technology and Toyota technological Institute 2015)和MPI-Sintel(Max-Planck Institute and Sintel)数据集测试图像对本文方法和具有代表性场景流算法进行综合对比分析,结果表明本文方法相对于其他对比方法有效提高大位移、运动遮挡以及光照变化情况下场景流估计精度和鲁棒性.展开更多
In recent years the application of friction-based passive energy dissipation devices have been proven very effective in reducing structural response to earthquake excitations and also implemented for a large number of...In recent years the application of friction-based passive energy dissipation devices have been proven very effective in reducing structural response to earthquake excitations and also implemented for a large number of buildings. Their design heavily relies on numerical simulations to model the influence of the energy dissipation devices. The modeling of friction forces must be accurate for realistic simulation of the influence of these devices. In state-of-the-practice, the hysteretic behavior of friction devices has been typically modeled with Coulomb friction having a constant coefficient of friction. However, the basic laws for typical sliding materials and experimental investigations show non-linear relationship between friction and sliding velocity, which includes stiction and Stribeck effect. The influence of stiction and Stribeck effect may be significant and can not be ignored in simulating the dynamic responses of structures with friction-based energy dissipation devices. In this paper the optimal performance of dry friction device in shear-frame buildings when subjected to earthquake ground motions has been investigated. The focus of this paper is on the optimal minimization of response of the shear-frame building. Since buildings with friction devices behave in a highly nonlinear manner, nonlinear response-history analysis considering comprehensive sliding friction models has been carried out. The performance has also been evaluated using the various response measures： the maximum absolute acceleration, the maximum base shear, and the maximum inter-story drift. Different performance indices have been used to quantify the influence of the device properties.展开更多
文摘针对现有双目场景流计算方法在大位移、运动遮挡及光照变化等复杂场景下场景流估计的准确性与鲁棒性问题,提出一种基于金字塔块匹配的双目场景流计算方法.首先对双目图像序列进行超像素分割和视差估计,得到图像初始分割结果和视差信息,然后建立基于金字塔块匹配的运动模型并采用Ransac随机一致性算法拟合刚性运动模型和最小化重投影算法估计对象运动参数.最后,本文将金字塔块匹配结果作为约束项,联合对象运动参数和超像素平面参数构建基于金字塔块匹配的双目场景流估计能量函数模型,通过最小化能量函数得到最终场景流.实验分别采用KITTI2015(Karlsruhe Institute of Technology and Toyota technological Institute 2015)和MPI-Sintel(Max-Planck Institute and Sintel)数据集测试图像对本文方法和具有代表性场景流算法进行综合对比分析,结果表明本文方法相对于其他对比方法有效提高大位移、运动遮挡以及光照变化情况下场景流估计精度和鲁棒性.
文摘In recent years the application of friction-based passive energy dissipation devices have been proven very effective in reducing structural response to earthquake excitations and also implemented for a large number of buildings. Their design heavily relies on numerical simulations to model the influence of the energy dissipation devices. The modeling of friction forces must be accurate for realistic simulation of the influence of these devices. In state-of-the-practice, the hysteretic behavior of friction devices has been typically modeled with Coulomb friction having a constant coefficient of friction. However, the basic laws for typical sliding materials and experimental investigations show non-linear relationship between friction and sliding velocity, which includes stiction and Stribeck effect. The influence of stiction and Stribeck effect may be significant and can not be ignored in simulating the dynamic responses of structures with friction-based energy dissipation devices. In this paper the optimal performance of dry friction device in shear-frame buildings when subjected to earthquake ground motions has been investigated. The focus of this paper is on the optimal minimization of response of the shear-frame building. Since buildings with friction devices behave in a highly nonlinear manner, nonlinear response-history analysis considering comprehensive sliding friction models has been carried out. The performance has also been evaluated using the various response measures： the maximum absolute acceleration, the maximum base shear, and the maximum inter-story drift. Different performance indices have been used to quantify the influence of the device properties.
