在自动驾驶应用场景下,将YOLOv5应用于目标检测中,性能较之前版本有明显的提升,但在高运行速度情况下检测精度仍不够高,本文提出一种基于改进YOLOv5的车辆端目标检测方法.为解决训练不同数据集时需手动设计初始锚框大小,引入自适应锚框...在自动驾驶应用场景下,将YOLOv5应用于目标检测中,性能较之前版本有明显的提升,但在高运行速度情况下检测精度仍不够高,本文提出一种基于改进YOLOv5的车辆端目标检测方法.为解决训练不同数据集时需手动设计初始锚框大小,引入自适应锚框计算.在主干网络(backbone)添加压缩与激励模块(squeeze and excitation,SE),筛选针对通道的特征信息,提升特征表达能力.为了提升检测不同大小物体时的精度,将注意力机制与检测网络融合,把卷积注意力模块(convolutional block attention module,CBAM)与Neck部分融合,使模型在检测不同大小的物体时能关注重要的特征,提升特征提取能力.在主干网络中使用空间金字塔池化SPP模块,使得模型输入可以输入任意图像高宽比和大小.在激活函数方面,进行卷积操作后使用Hardswish激活函数,应用于整个网络模型.在损失函数方面,使用CIoU作为检测框回归的损失函数,改善定位精度低和训练过程中目标检测框回归速度慢的问题.实验结果表明,改进后的检测模型在KITTI 2D数据集上测试,目标检测的精确率(precision)提高了2.5%,召回率(recall)提高了5.1%,平均精度均值(mean average precision,mAP)提高了2.3%.展开更多
A new kind of non-Gaussian quantum catalyzed state is proposed via multiphoton measurements and two-mode squeezing as an input of thermal state.The characteristics of the generated multiphoton catalysis output state d...A new kind of non-Gaussian quantum catalyzed state is proposed via multiphoton measurements and two-mode squeezing as an input of thermal state.The characteristics of the generated multiphoton catalysis output state depends on the thermal parameter,catalyzed photon number and squeezing parameter.We then analyze the nonclassical properties by examining the photon number distribution,photocount distribution and partial negativity of the Wigner function.Our findings indicate that nonclassicality can be achieved through the implementation of multiphoton catalysis operations and modulated by the thermal parameter,catalyzed photon number and squeezing parameter.展开更多
By applying the bosonic creation operator to squeezed vacuum states, this paper introduces a new kind of quantum states： photon-added squeezed vacuum states. It also presents an experimental approach to prepare these...By applying the bosonic creation operator to squeezed vacuum states, this paper introduces a new kind of quantum states： photon-added squeezed vacuum states. It also presents an experimental approach to prepare these states, and investigates their quantum statistical properties by the numerical method. The results indicate that these states reveal some interesting non-classical properties, such as anti-bunching effects, squeezing effects and negativities of the relevant Wigner functions.展开更多
We show that if a bounded domain Ω is exhausted by a bounded strictly pseudoconvex domain D with C^2 boundary, then Ω is holomorphically equivalent to D or the unit ball, and show that a bounded domain has to be hol...We show that if a bounded domain Ω is exhausted by a bounded strictly pseudoconvex domain D with C^2 boundary, then Ω is holomorphically equivalent to D or the unit ball, and show that a bounded domain has to be holomorphically equivalent to the unit ball if its Fridman's invariant has certain growth condition near the boundary.展开更多
This survey paper consists of two folds. First of all, we recall the concept of intrinsic derivative which was introduced by Lu(1979) and the related works due to Lu in his last ten years, including the holomorphicall...This survey paper consists of two folds. First of all, we recall the concept of intrinsic derivative which was introduced by Lu(1979) and the related works due to Lu in his last ten years, including the holomorphically isometric embedding into the infinite dimensional Grassmann manifold and the Bergman curvature estimates for bounded domains in C^n. Inspired by Lu's idea, we give the lower and upper bounds estimates for the Bergman curvatures in terms of the squeezing function—one concept originally introduced by Deng et al.(2012).Finally, we survey some recent progress on the asymptotic behaviors for Bergman curvatures near the strictly pseudoconvex boundary points and present some open problems on the squeezing functions of bounded domains in C^n.展开更多
文摘在自动驾驶应用场景下,将YOLOv5应用于目标检测中,性能较之前版本有明显的提升,但在高运行速度情况下检测精度仍不够高,本文提出一种基于改进YOLOv5的车辆端目标检测方法.为解决训练不同数据集时需手动设计初始锚框大小,引入自适应锚框计算.在主干网络(backbone)添加压缩与激励模块(squeeze and excitation,SE),筛选针对通道的特征信息,提升特征表达能力.为了提升检测不同大小物体时的精度,将注意力机制与检测网络融合,把卷积注意力模块(convolutional block attention module,CBAM)与Neck部分融合,使模型在检测不同大小的物体时能关注重要的特征,提升特征提取能力.在主干网络中使用空间金字塔池化SPP模块,使得模型输入可以输入任意图像高宽比和大小.在激活函数方面,进行卷积操作后使用Hardswish激活函数,应用于整个网络模型.在损失函数方面,使用CIoU作为检测框回归的损失函数,改善定位精度低和训练过程中目标检测框回归速度慢的问题.实验结果表明,改进后的检测模型在KITTI 2D数据集上测试,目标检测的精确率(precision)提高了2.5%,召回率(recall)提高了5.1%,平均精度均值(mean average precision,mAP)提高了2.3%.
基金supported by the National Natural Science Foundation of China (Grant No.11347026)the Natural Science Foundation of Shandong Province,China (Grant Nos.ZR2020MA085 and ZR2020MF113)。
文摘A new kind of non-Gaussian quantum catalyzed state is proposed via multiphoton measurements and two-mode squeezing as an input of thermal state.The characteristics of the generated multiphoton catalysis output state depends on the thermal parameter,catalyzed photon number and squeezing parameter.We then analyze the nonclassical properties by examining the photon number distribution,photocount distribution and partial negativity of the Wigner function.Our findings indicate that nonclassicality can be achieved through the implementation of multiphoton catalysis operations and modulated by the thermal parameter,catalyzed photon number and squeezing parameter.
基金Project supported by the National Natural Science Foundation of China (Grant No.10874142)
文摘By applying the bosonic creation operator to squeezed vacuum states, this paper introduces a new kind of quantum states： photon-added squeezed vacuum states. It also presents an experimental approach to prepare these states, and investigates their quantum statistical properties by the numerical method. The results indicate that these states reveal some interesting non-classical properties, such as anti-bunching effects, squeezing effects and negativities of the relevant Wigner functions.
基金Supported by NSFC(Grants Nos.11371025 and 11871451)the University of Chinese Academy of Sciences
文摘We show that if a bounded domain Ω is exhausted by a bounded strictly pseudoconvex domain D with C^2 boundary, then Ω is holomorphically equivalent to D or the unit ball, and show that a bounded domain has to be holomorphically equivalent to the unit ball if its Fridman's invariant has certain growth condition near the boundary.
基金supported by National Natural Science Foundation of China(Grant Nos.11371025 and 11671270)
文摘This survey paper consists of two folds. First of all, we recall the concept of intrinsic derivative which was introduced by Lu(1979) and the related works due to Lu in his last ten years, including the holomorphically isometric embedding into the infinite dimensional Grassmann manifold and the Bergman curvature estimates for bounded domains in C^n. Inspired by Lu's idea, we give the lower and upper bounds estimates for the Bergman curvatures in terms of the squeezing function—one concept originally introduced by Deng et al.(2012).Finally, we survey some recent progress on the asymptotic behaviors for Bergman curvatures near the strictly pseudoconvex boundary points and present some open problems on the squeezing functions of bounded domains in C^n.
