1 宁夏大学, a.物理与电子电气工程学院
2 b.沙漠信息智能感知重点实验室, 银川 750000
针对光学遥感图像飞机目标背景复杂、检测精度与检测速度不平衡、易漏检等问题, 提出一种融合不同网络模块的SPSSD模型。首先, 采用Resnet50替换SSD300算法中的特征提取网络, 并加入可操控的空洞卷积模块, 扩大特征感受野获取更多有利检测目标的特征信息;其次, 加入FPN和SPP网络, 得到浅层特征信息, 并将感受野二次放大后的特征与深层特征信息进行融合;然后, 送入ECANet网络中获取更加完整且更具有判断力的特征信息;最后, 采用NWPU-RESISC45数据集3400张高分辨率飞机遥感图像输入至SPSSD模型中迭代训练, 最终改进算法模型mAP值达到92.68%, 较改进前的算法模型提升了5.18个百分点, 检测速度达到25.1 帧/s。实验结果表明, 该方法可以有效兼顾飞机目标的检测精度与检测速度, 一定程度上降低了目标漏检率。
遥感图像 目标检测 注意力机制 特征融合 remote sensing image target detection attention mechanism feature fusion
利用COMSOL仿真软件建立了铜片双温模型, 通过控制变量, 数值研究了光斑半径和激光能量对电子与晶格温度的影响, 并预测了烧蚀形貌。结果表明, 单脉冲激光光斑半径越大, 铜片的烧蚀深度越小, 烧蚀面积越大; 激光能量越高, 铜片的烧蚀深度越大, 烧蚀面积越大。实验结果进一步证实了仿真的可靠性。
激光技术 激光加工 COMSOL仿真 双温模型 温度场 激光与光电子学进展
2018, 55(10): 101402
Author Affiliations
Abstract
1 College of Information Engineering, Zhejiang University of Technology, Hangzhou 310032
2 State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130022
3 Department of Mechanical Engineering, Changchun Institute of Technology, Changchun 130020
A theoretical method based on the diffractive theory is used for predicting three-dimensional (3D) focusing performances of the compound X-rays refractive lenses (CRLs). However, the derivation of the 3D intensity distribution near focus for the X-ray refractive lenses is quite complicated. In this paper, we introduce a simple theoretical method that is based on the first and second moments in the theory of probability. As an example, the 3D focusing performance of a CRL with Si material is predicted. Moreover, the results are compared with those obtained by the diffractive theory. It is shown that the method introduced in this paper is accurate enough.
340.0340 X-ray optics 260.1960 diffraction theory 110.0110 imaging systems Chinese Optics Letters
2005, 3(10): 10618
