我国高速铁路桥梁设计以行车平顺性作为首要目标,体现为基于刚度的设计,导致桥梁抗震性能和震致破坏特征不明确.基于此,建立了5跨32 m简支梁桥模型,模型包括桥墩、支座、梁体、轨道结构、钢轨等,同时考虑了桥下群桩基础的桩土相互作用和活动支座摩擦力受竖向力变化的影响.以此模型为基础,研究了近断层地震下多跨简支梁桥震致响应,参考构件破坏限值,分析了结构震致破坏特征,指出了高铁简支梁桥在近断层地震动下的破坏部位集中于梁缝处和滑动层,桥墩破坏并不严重,明确在高铁桥梁设计和评估中应关注上部轨道结构等功能部件的抗震性能及破坏特征,轨道结构的破坏可能会导致高铁桥梁功能中断和严重经济损失.

针对于采矿过程中以电机为研究对象的碳排放来源的复杂性以及其影响因素的多样性所引起的碳排放短期预测精度不高的问题,结合灰色理论提出一种基于改进高斯过程回归模型的铅锌矿采矿过程碳排放预测方法。对碳排放来源及其影响因素进行分析,用灰色理论进行聚类分析以归并同类因素;根据灰色关联性分析得到主要影响因素;因传统高斯过程回归模型直接选定协方差函数的方式易导致与研究对象的物理过程拟合度不够高的问题,因而提出了一种依据先验知识的协方差函数选择方式,将四种常用协方差函数建模的训练结果作为反馈,结合极大似然估计法、最小二乘法和蒙特卡洛法参数估计的对比结果得到与研究对象拟合度最高即预测误差最小的协方差函数,进而得到预测效果最好的改进模型。经实验证明,基于该种方法选择协方差函数的模型相较于其他常规预测模型能更精确地预测铅锌矿采矿过程的碳排放量,其预测误差更小。

To solve the small area occlusion problems in gait recognition,a method based on weighted block sparse representation was proposed which was combined with the characteristics that the contribution of different parts of the bodies to identification is different.Video image was processed to get gait energy image (GEI) and GEI was divided into several blocks.Block sparse representation was introduced to classify various blocks of GEI respectively and an original weighting scheme was proposed to generate the weight value.On the basis of these processing,a sparse representation weighted model was constructed to complete the gait recognition tasks.The proposed method was tested and evaluated on CASIA database (Datasct _ B).Experimental results suggest that the proposed method shows robustness to the small area occlusion problems and outperforms the state of art method in several cases.

提出了一种基于上下文和稀疏编码框架的无监督异常行为识别方法.首先对图像进行稠密采样,获得稠密轨迹,并提取轨迹中心周围图像块的形状特征、R–HOG、HOF特征作为特征描述符,加强了对运动信息的描述.其次,将人体行为区域和上下文区域分割开来建立2个独立字典.再将它们组成联合字典最大化字典信息,避免了单独识别人体异常行为而忽略上下文信息所导致的漏报.最后,利用稀疏重构的方法进行异常检测,分别计算测试样本中上下文区域和行为区域的重构误差,相对重构误差为负表示为正常行为,否则判断为异常行为.在KTH行为数据集上进行对比实验,实验结果表明本文算法在不同背景下均能有效识别异常行为.

By use of the analysis method of vertical vibration of train and ballastless track system with the lateral finite strip and slab segment element,the dynamic responses of vertical vibration of urban rail transit train-floating slab track system with one or several failed fasteners were investigated.The results show that when a train passes the failed fasteners the interaction between wheel and rail increases,the vertical displacement and vertical acceleration of rails increase obviously,and the more fasteners fail the increase is more obvious;the vertical displacement and vertical acceleration of the rails which are adjacent to the failed fastener will also remarkably increase,and speeds up the track deterioration and even does harm to driving safety.

According to structural characteristics of floating slab tracks,a track segment element was taken between two adjacent fasteners.For each element,rails were regarded as Euler beams supported by discrete viscoelastic supports.The fasteners and rubber supports were replaced by a linear spring and damp.So the vibration model of the floating slab track was established.In constructing vibration model of a metro train,each car of the metro train with two suspensions was modeled as a multi-rigid body system,in which rigid bodies were connected with each other by a linear spring and damp.Combining the potential energy of vertical vibration of the track with that of the metro train,the total potential energy of vertical vibration of the train and track was obtained.And then,the matrix equation of vertical vibration of the system was established using the principle of total potential energy with stationary value in elastic system dynamics and the set-in-right-position rule for formulating system matrices.The vibration responses of the system can be obtained by solving the matrix equation with the direct time integration such as Wilson-θ method.The results show that by using the floating slab track vibration model,the vertical rail displacement is 4.18 mm and the vertical floating slab displacement is 0.69 mm,which is consistent with the existing results.When the metro train runs on the floating slab track at 60 km/h,the waveforms of vertical vibration of the system accord with the physic concepts and the vibration response values reflect the general vibration magnitudes of the system.