针对传统ORB(Oriented FAST and Rotated BRIEF)算法提取图像特征时存在的特征点数量不足且分布不均匀问题,提出了一种基于四叉树的ORB特征阶梯分布算法。通过四叉树算法分割出特征点疏密不同的区域,对每个区域采用逐步降低阈值的方法,...针对传统ORB(Oriented FAST and Rotated BRIEF)算法提取图像特征时存在的特征点数量不足且分布不均匀问题,提出了一种基于四叉树的ORB特征阶梯分布算法。通过四叉树算法分割出特征点疏密不同的区域,对每个区域采用逐步降低阈值的方法,实现FAST(Features from Accelerated Segment Test)角点自适应提取;同时依据分割区域设置逐次递减的分割深度和特征点提取比例,以减少运算时间和特征冗余,使特征点分布更均匀。采用覆盖均匀度对特征点的均匀性进行量化。试验结果表明,该算法比传统ORB算法单幅图片的特征点提取数量平均多10.45%,覆盖均匀度平均低20%,运行时间比Mur-Artal算法平均减少20.54%,有效地提高了提取特征点的数量和均匀性,提升了运算效率。展开更多
The genus distribution of a graph is a polynomial whose coefficients are the partition of the number of embeddings with respect to the genera. In this paper, the genus distribution of Mobius ladders is provided which ...The genus distribution of a graph is a polynomial whose coefficients are the partition of the number of embeddings with respect to the genera. In this paper, the genus distribution of Mobius ladders is provided which is an infinite class of 3-connected simple graphs.展开更多
目的观察硫芥对大鼠脾脏淋巴细胞线粒体的损伤作用。方法用密度梯度离心法分离大鼠脾淋巴细胞,与硫芥共同进行体外培养。用琼脂糖DNA凝胶电泳观察细胞凋亡的发生;用W estern b lot观察Cyt-c释放。用MTT法检测线粒体功能状态,以罗丹明12...目的观察硫芥对大鼠脾脏淋巴细胞线粒体的损伤作用。方法用密度梯度离心法分离大鼠脾淋巴细胞,与硫芥共同进行体外培养。用琼脂糖DNA凝胶电泳观察细胞凋亡的发生;用W estern b lot观察Cyt-c释放。用MTT法检测线粒体功能状态,以罗丹明123标记的荧光探针检测线粒体跨膜电位。结果100μmol/L硫芥作用4 h线粒体功能就有降低,线粒体跨膜电位降低,二者间呈直线相关。硫芥中毒早期即可引起淋巴细胞线粒体细胞色素C释放和细胞凋亡(DNA ladder)。结论硫芥可引起大鼠脾淋巴细胞线粒体明显损伤,线粒体参与了硫芥的细胞毒性作用过程。展开更多
In Riemann’s prime distribution formula, there is a key Riemann ladder function. This is the basis for Riemann to study the distribution of prime numbers. But the calculation of Riemann’s ladder function is very com...In Riemann’s prime distribution formula, there is a key Riemann ladder function. This is the basis for Riemann to study the distribution of prime numbers. But the calculation of Riemann’s ladder function is very complicated. According to the definition of Riemannian ladder function, we greatly improve the Riemannian ladder function, obtain new ladder function and improved Riemannian prime distribution formula, and prove the improved Riemannian prime distribution formula. We use the improved Riemannian prime distribution formula and merdens theorem to obtain a strong prime theorem.展开更多
文摘针对传统ORB(Oriented FAST and Rotated BRIEF)算法提取图像特征时存在的特征点数量不足且分布不均匀问题,提出了一种基于四叉树的ORB特征阶梯分布算法。通过四叉树算法分割出特征点疏密不同的区域,对每个区域采用逐步降低阈值的方法,实现FAST(Features from Accelerated Segment Test)角点自适应提取;同时依据分割区域设置逐次递减的分割深度和特征点提取比例,以减少运算时间和特征冗余,使特征点分布更均匀。采用覆盖均匀度对特征点的均匀性进行量化。试验结果表明,该算法比传统ORB算法单幅图片的特征点提取数量平均多10.45%,覆盖均匀度平均低20%,运行时间比Mur-Artal算法平均减少20.54%,有效地提高了提取特征点的数量和均匀性,提升了运算效率。
基金The NSF (10201022) of China NSF (1012003) of Beijing City.
文摘The genus distribution of a graph is a polynomial whose coefficients are the partition of the number of embeddings with respect to the genera. In this paper, the genus distribution of Mobius ladders is provided which is an infinite class of 3-connected simple graphs.
文摘In Riemann’s prime distribution formula, there is a key Riemann ladder function. This is the basis for Riemann to study the distribution of prime numbers. But the calculation of Riemann’s ladder function is very complicated. According to the definition of Riemannian ladder function, we greatly improve the Riemannian ladder function, obtain new ladder function and improved Riemannian prime distribution formula, and prove the improved Riemannian prime distribution formula. We use the improved Riemannian prime distribution formula and merdens theorem to obtain a strong prime theorem.
