针对点云配准过程中,下采样时容易丢失关键点、影响配准精度的问题,本文提出一种基于特征融合和网络采样的配准方法,提高了配准的精度和速度。在PointNet分类网络基础上,引入小型注意力机制,设计一种基于深度学习网络的关键点提取方法,...针对点云配准过程中,下采样时容易丢失关键点、影响配准精度的问题,本文提出一种基于特征融合和网络采样的配准方法,提高了配准的精度和速度。在PointNet分类网络基础上,引入小型注意力机制,设计一种基于深度学习网络的关键点提取方法,将局部特征和全局特征融合,得到混合特征的特征矩阵。通过深度学习实现对应矩阵求解中相关参数的自动优化,最后利用加权奇异值分解(singular value decomposition,SVD)得到变换矩阵,完成配准。在ModelNet40数据集上的实验表明,和最远点采样相比,所提算法耗时减少45.36%;而配准结果和基于特征学习的鲁棒点匹配(robust point matching using learned features,RPM-Net)相比,平移矩阵均方误差降低5.67%,旋转矩阵均方误差降低13.1%。在自制点云数据上的实验,证实了算法在真实物体上配准的有效性。展开更多
在图结构数据上开展推理计算是一项重大的任务,该任务的主要挑战是如何表示图结构知识使机器可以快速理解并利用图数据。对比现有表示学习模型发现,基于随机游走方法的表示学习模型容易忽略属性对节点关联关系的特殊作用,因此提出一种...在图结构数据上开展推理计算是一项重大的任务,该任务的主要挑战是如何表示图结构知识使机器可以快速理解并利用图数据。对比现有表示学习模型发现,基于随机游走方法的表示学习模型容易忽略属性对节点关联关系的特殊作用,因此提出一种基于节点邻接关系与属性关联关系的混合随机游走方法。首先通过邻接节点间的共同属性分布计算属性权重,并获取节点到每个属性的采样概率;然后分别从邻接节点与含有共有属性的非邻接节点中提取网络信息;最后构建基于节点−属性二部图的网络表示学习模型,并通过上述采样序列学习得到节点向量表达。在Flickr、BlogCatalog、Cora公开数据集上,用所提模型得到的节点向量表达进行节点分类的Micro-F1平均准确率为89.38%,比GraphRNA(Graph Recurrent Networks with Attributed random walks)高出了2.02个百分点,比经典工作DeepWalk高出了21.12个百分点;同时,对比不同随机游走方法发现,提高对节点关联有促进作用的属性的采样概率可以增加采样序列所含信息。展开更多
The problem of guaranteed cost control for the networked control systems(NCSs) with time-varying delays, time-varying sampling intervals and signals quantization was investigated, wherein the physical plant was contin...The problem of guaranteed cost control for the networked control systems(NCSs) with time-varying delays, time-varying sampling intervals and signals quantization was investigated, wherein the physical plant was continuous-time one, and the control input was discrete-time one. By using an input delay approach and a sector bound method, the network induced delays, quantization parameter and sampling intervals were presented in one framework in the case of the state and the control input by quantized in a logarithmic form. A novel Lyapunov function with discontinuity, which took full advantages of the NCS characteristic information, was exploited. In addition, it was shown that Lyapunov function decreased at the jump instants. Furthermore, the Leibniz-Newton formula and free-weighting matrix methods were used to obtain the guaranteed cost controller design conditions which were dependent on the NCS characteristic information. A numerical example was used to illustrate the effectiveness of the proposed methods.展开更多
文摘针对点云配准过程中,下采样时容易丢失关键点、影响配准精度的问题,本文提出一种基于特征融合和网络采样的配准方法,提高了配准的精度和速度。在PointNet分类网络基础上,引入小型注意力机制,设计一种基于深度学习网络的关键点提取方法,将局部特征和全局特征融合,得到混合特征的特征矩阵。通过深度学习实现对应矩阵求解中相关参数的自动优化,最后利用加权奇异值分解(singular value decomposition,SVD)得到变换矩阵,完成配准。在ModelNet40数据集上的实验表明,和最远点采样相比,所提算法耗时减少45.36%;而配准结果和基于特征学习的鲁棒点匹配(robust point matching using learned features,RPM-Net)相比,平移矩阵均方误差降低5.67%,旋转矩阵均方误差降低13.1%。在自制点云数据上的实验,证实了算法在真实物体上配准的有效性。
文摘在图结构数据上开展推理计算是一项重大的任务,该任务的主要挑战是如何表示图结构知识使机器可以快速理解并利用图数据。对比现有表示学习模型发现,基于随机游走方法的表示学习模型容易忽略属性对节点关联关系的特殊作用,因此提出一种基于节点邻接关系与属性关联关系的混合随机游走方法。首先通过邻接节点间的共同属性分布计算属性权重,并获取节点到每个属性的采样概率;然后分别从邻接节点与含有共有属性的非邻接节点中提取网络信息;最后构建基于节点−属性二部图的网络表示学习模型,并通过上述采样序列学习得到节点向量表达。在Flickr、BlogCatalog、Cora公开数据集上,用所提模型得到的节点向量表达进行节点分类的Micro-F1平均准确率为89.38%,比GraphRNA(Graph Recurrent Networks with Attributed random walks)高出了2.02个百分点,比经典工作DeepWalk高出了21.12个百分点;同时,对比不同随机游走方法发现,提高对节点关联有促进作用的属性的采样概率可以增加采样序列所含信息。
基金Project(61104106) supported by the National Natural Science Foundation of ChinaProject(201202156) supported by the Natural Science Foundation of Liaoning Province,ChinaProject(LJQ2012100) supported by Program for Liaoning Excellent Talents in University(LNET)
文摘The problem of guaranteed cost control for the networked control systems(NCSs) with time-varying delays, time-varying sampling intervals and signals quantization was investigated, wherein the physical plant was continuous-time one, and the control input was discrete-time one. By using an input delay approach and a sector bound method, the network induced delays, quantization parameter and sampling intervals were presented in one framework in the case of the state and the control input by quantized in a logarithmic form. A novel Lyapunov function with discontinuity, which took full advantages of the NCS characteristic information, was exploited. In addition, it was shown that Lyapunov function decreased at the jump instants. Furthermore, the Leibniz-Newton formula and free-weighting matrix methods were used to obtain the guaranteed cost controller design conditions which were dependent on the NCS characteristic information. A numerical example was used to illustrate the effectiveness of the proposed methods.
