从单张RGB图像中实现双手的3D交互式网格重建是一项极具挑战性的任务。由于双手之间的相互遮挡以及局部外观相似性较高,导致部分特征提取不够准确,从而丢失了双手之间的交互信息并使重建的手部网格与输入图像出现不对齐等问题。为了解...从单张RGB图像中实现双手的3D交互式网格重建是一项极具挑战性的任务。由于双手之间的相互遮挡以及局部外观相似性较高,导致部分特征提取不够准确,从而丢失了双手之间的交互信息并使重建的手部网格与输入图像出现不对齐等问题。为了解决上述问题,本文首先提出一种包含两个部分的特征交互适应模块,第一部分特征交互在保留左右手分离特征的同时生成两种新的特征表示,并通过交互注意力模块捕获双手的交互特征;第二部分特征适应则是将此交互特征利用交互注意力模块适应到每只手,为左右手特征注入全局上下文信息。其次,引入三层图卷积细化网络结构用于精确回归双手网格顶点,并通过基于注意力机制的特征对齐模块增强顶点特征和图像特征的对齐,从而增强重建的手部网格和输入图像的对齐。同时提出一种新的多层感知机结构,通过下采样和上采样操作学习多尺度特征信息。最后,设计相对偏移损失函数约束双手的空间关系。在InterHand2.6M数据集上的定量和定性实验表明,与现有的优秀方法相比,所提出的方法显著提升了模型性能,其中平均每关节位置误差(Mean Per Joint Position Error,MPJPE)和平均每顶点位置误差(Mean Per Vertex Position Error,MPVPE)分别降低至7.19 mm和7.33 mm。此外,在RGB2Hands和EgoHands数据集上进行泛化性实验,定性实验结果表明所提出的方法具有良好的泛化能力,能够适应不同环境背景下的手部网格重建。展开更多
The past two decades have seen formative assessment claim legitimacy in policy discourse and engender immense tensions within the testing-dominated assessment regimes of multiple educational settings.These tensions,al...The past two decades have seen formative assessment claim legitimacy in policy discourse and engender immense tensions within the testing-dominated assessment regimes of multiple educational settings.These tensions,along with the top-down approach of the policy process,have made the inroads of formative assessment in local contexts very complex.This study seeks to unveil the localized appropriation and actualization of a formative assessment initiative in the College English area at a Chinese local university.The focus is on how the key actors at the institutional and classroom levels appropriate and negotiate the policy meaning within their local community of practice.Analysis of an individual interview with the dean and a focus-group interview with six 1 teachers has revealed a“two-hand”approach to the national policy and a nested mediation from local constraints,“cultural tools for thinking”and,more importantly,power in the policymaking process at the institutional level.The classroom level,on the other hand,witnesses capable teachers exercising their agency within a limited space.As a result,we would caution that power and agency could be solid mediators in the policy process and need to be exercised with care to ensure a more coherent implementation of assessment innovations.展开更多
文摘从单张RGB图像中实现双手的3D交互式网格重建是一项极具挑战性的任务。由于双手之间的相互遮挡以及局部外观相似性较高,导致部分特征提取不够准确,从而丢失了双手之间的交互信息并使重建的手部网格与输入图像出现不对齐等问题。为了解决上述问题,本文首先提出一种包含两个部分的特征交互适应模块,第一部分特征交互在保留左右手分离特征的同时生成两种新的特征表示,并通过交互注意力模块捕获双手的交互特征;第二部分特征适应则是将此交互特征利用交互注意力模块适应到每只手,为左右手特征注入全局上下文信息。其次,引入三层图卷积细化网络结构用于精确回归双手网格顶点,并通过基于注意力机制的特征对齐模块增强顶点特征和图像特征的对齐,从而增强重建的手部网格和输入图像的对齐。同时提出一种新的多层感知机结构,通过下采样和上采样操作学习多尺度特征信息。最后,设计相对偏移损失函数约束双手的空间关系。在InterHand2.6M数据集上的定量和定性实验表明,与现有的优秀方法相比,所提出的方法显著提升了模型性能,其中平均每关节位置误差(Mean Per Joint Position Error,MPJPE)和平均每顶点位置误差(Mean Per Vertex Position Error,MPVPE)分别降低至7.19 mm和7.33 mm。此外,在RGB2Hands和EgoHands数据集上进行泛化性实验,定性实验结果表明所提出的方法具有良好的泛化能力,能够适应不同环境背景下的手部网格重建。
基金based on research projects sponsored by the National Social Science Fund of China(NSSFC)(No.17BYY100)the China Association of Higher Education—Foreign Language Teaching and Research Association[21WYJYYB24]。
文摘The past two decades have seen formative assessment claim legitimacy in policy discourse and engender immense tensions within the testing-dominated assessment regimes of multiple educational settings.These tensions,along with the top-down approach of the policy process,have made the inroads of formative assessment in local contexts very complex.This study seeks to unveil the localized appropriation and actualization of a formative assessment initiative in the College English area at a Chinese local university.The focus is on how the key actors at the institutional and classroom levels appropriate and negotiate the policy meaning within their local community of practice.Analysis of an individual interview with the dean and a focus-group interview with six 1 teachers has revealed a“two-hand”approach to the national policy and a nested mediation from local constraints,“cultural tools for thinking”and,more importantly,power in the policymaking process at the institutional level.The classroom level,on the other hand,witnesses capable teachers exercising their agency within a limited space.As a result,we would caution that power and agency could be solid mediators in the policy process and need to be exercised with care to ensure a more coherent implementation of assessment innovations.
