初始图像对选取是增量式从运动中恢复结构的一个关键环节,但传统方法中存在计算效率低、对特殊场景不鲁棒的问题。因此,提出基于多任务学习的初始图像对选取网络以提高该过程的效率,并针对某些特殊场景容易出现初始图像对位于场景边缘...初始图像对选取是增量式从运动中恢复结构的一个关键环节,但传统方法中存在计算效率低、对特殊场景不鲁棒的问题。因此,提出基于多任务学习的初始图像对选取网络以提高该过程的效率,并针对某些特殊场景容易出现初始图像对位于场景边缘的问题,提出结合场景连接图的初始对选取策略。该策略首先构建图像间的拓扑结构,通过图像间连接的疏密程度判断初始图像对是否处于场景中心,从而避免初始图像对处于场景边缘导致重建不完整的问题。对比传统SfM(structure from motion)中的初始图像对选取方法,结果表明:所提出的方法在多种不同场景中的选取速度提升5倍以上;同时,提出的结合场景图的选取策略可使得特殊场景中重建的空间点数量增加10倍,且重投影误差下降0.05 px,显著提升了在特殊场景中初始图像对选取的鲁棒性,证明了所提方法的有效性,在提高了效率的同时,能够很好地保证特殊场景重建的完整性和稳定性。展开更多
The dorsal area of the anterior cingulate cortex (ACC) constructs the salience network associated with the anterior insular cortex. Conventional brain imaging studies, such as functional magnetic resonance imaging (fM...The dorsal area of the anterior cingulate cortex (ACC) constructs the salience network associated with the anterior insular cortex. Conventional brain imaging studies, such as functional magnetic resonance imaging (fMRI), have demonstrated that relational memory formation occurs in the ACC. However, how such memory is encoded and retrieved remains unknown due to limited time resolution of conventional fMRI. This study aimed to investigate temporal dynamics of the dorsal ACC (dACC) during word-pair tasks based on a newly developed event-related deep brain activity (ER-DBA) method using occipital electroencephalogram (EEG) signal powers. The method assesses dACC activity at a temporal resolution of approximately 0.3 s beyond the conventional resolution limit. We found that transient deactivation of dACC during the presentation of the second word of each pair was essential for encoding success regardless of whether the words were related or unrelated. We also found that memory accuracy was not affected by the intervention of inter-trials until the recall trial. Taken together, these findings suggest that dACC deactivation for encoding success is accompanied with short-term potentiation essential for durability of memory. We further found that false memory formation associated with the presentation of word pairs was occasionally committed. In such cases, dACC exhibited a similar transient deactivation although false memory commission was independent of related or unrelated conditions. Our findings suggest that encoding and retrieval of associates are paralleled and that simultaneous production of associates seems to be an essential strategy for successful relational memory formation. The study was limited to the assessment of dACC activity and did not account for other regional brain activities or receptor regulation related to short-term potentiation. We detected fast behavior of dACC during relational memory formation using the novel ER-DBA method. Such temporal dynamics will be important for eliciting underlying mechanisms of memory dysfunctions.展开更多
文摘初始图像对选取是增量式从运动中恢复结构的一个关键环节,但传统方法中存在计算效率低、对特殊场景不鲁棒的问题。因此,提出基于多任务学习的初始图像对选取网络以提高该过程的效率,并针对某些特殊场景容易出现初始图像对位于场景边缘的问题,提出结合场景连接图的初始对选取策略。该策略首先构建图像间的拓扑结构,通过图像间连接的疏密程度判断初始图像对是否处于场景中心,从而避免初始图像对处于场景边缘导致重建不完整的问题。对比传统SfM(structure from motion)中的初始图像对选取方法,结果表明:所提出的方法在多种不同场景中的选取速度提升5倍以上;同时,提出的结合场景图的选取策略可使得特殊场景中重建的空间点数量增加10倍,且重投影误差下降0.05 px,显著提升了在特殊场景中初始图像对选取的鲁棒性,证明了所提方法的有效性,在提高了效率的同时,能够很好地保证特殊场景重建的完整性和稳定性。
文摘The dorsal area of the anterior cingulate cortex (ACC) constructs the salience network associated with the anterior insular cortex. Conventional brain imaging studies, such as functional magnetic resonance imaging (fMRI), have demonstrated that relational memory formation occurs in the ACC. However, how such memory is encoded and retrieved remains unknown due to limited time resolution of conventional fMRI. This study aimed to investigate temporal dynamics of the dorsal ACC (dACC) during word-pair tasks based on a newly developed event-related deep brain activity (ER-DBA) method using occipital electroencephalogram (EEG) signal powers. The method assesses dACC activity at a temporal resolution of approximately 0.3 s beyond the conventional resolution limit. We found that transient deactivation of dACC during the presentation of the second word of each pair was essential for encoding success regardless of whether the words were related or unrelated. We also found that memory accuracy was not affected by the intervention of inter-trials until the recall trial. Taken together, these findings suggest that dACC deactivation for encoding success is accompanied with short-term potentiation essential for durability of memory. We further found that false memory formation associated with the presentation of word pairs was occasionally committed. In such cases, dACC exhibited a similar transient deactivation although false memory commission was independent of related or unrelated conditions. Our findings suggest that encoding and retrieval of associates are paralleled and that simultaneous production of associates seems to be an essential strategy for successful relational memory formation. The study was limited to the assessment of dACC activity and did not account for other regional brain activities or receptor regulation related to short-term potentiation. We detected fast behavior of dACC during relational memory formation using the novel ER-DBA method. Such temporal dynamics will be important for eliciting underlying mechanisms of memory dysfunctions.
