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基于改进Double-Head RCNN的无人机航拍图像小目标检测算法 被引量:1
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作者 王殿伟 胡里晨 +1 位作者 房杰 许志杰 《北京航空航天大学学报》 EI CAS CSCD 北大核心 2024年第7期2141-2149,共9页
为解决无人机航拍图像中小目标特征信息少且容易被噪声干扰导致现有算法漏检率和误检率高的问题,提出一种改进Double-Head Region-卷积神经网络(RCNN)的无人机航拍图像小目标检测算法。在骨干网络ResNet-50上引入Transformer和可变形卷... 为解决无人机航拍图像中小目标特征信息少且容易被噪声干扰导致现有算法漏检率和误检率高的问题,提出一种改进Double-Head Region-卷积神经网络(RCNN)的无人机航拍图像小目标检测算法。在骨干网络ResNet-50上引入Transformer和可变形卷积(DCN)模块,更有效提取小目标特征信息和语义信息;提出一种基于内容感知特征重组(CARAFE)的特征金字塔网络(FPN)结构模块,解决特征融合过程中小目标被背景噪声干扰而丢失特征信息的问题;在区域建议网络中针对小目标尺度分布特点重新设置Anchor生成尺度,进一步提升小目标检测性能。在VisDrone-DET2021数据集上的实验结果表明:所提算法能提取更具有表征能力的小目标特征信息和语义信息,对比Double-Head RCNN算法,所提算法的参数量增加了9.73×10^(6),FPS损失了0.6,但是AP、AP50和AP75分别提升了2.6%、6.2%和2.1%,APs提升了3.1%。 展开更多
关键词 小目标检测 无人机航拍图像 double-head RCNN TRANSFORMER 内容感知特征重组
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The amino acid sequence of a double-headed trypsin inhibitor from the seeds of Momordica charantia Linn.Cucurbitaceae
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作者 ZENG Fu-Yue QIAN Rui-Qing WANG Yu Shanghai Institute of Organic Chemistry,Academia Sinica.Shanghai 《Acta Chimica Sinica English Edition》 SCIE CAS CSCD 1989年第1期79-85,共9页
A double-headed trypsin inhibitor(MCI-1)was isolated and purified from the seeds of Momordica charantia Linn.Cucurbitaceae,by using the trypsin-sepharose-4B affinity chroma- tography and CM-Sephadex-C50 ion exchange c... A double-headed trypsin inhibitor(MCI-1)was isolated and purified from the seeds of Momordica charantia Linn.Cucurbitaceae,by using the trypsin-sepharose-4B affinity chroma- tography and CM-Sephadex-C50 ion exchange chromatography.It is composed of 77 amino acid residues:Asp_8 Thr_1 Ser_4 Glu_8 Pro_2 Gly_6 Ala_4 Cys_(14) Val_2 Met_4 Ile_8 Leu_1 Phe_1 His_3 Lys_ Arg_7. The amino acid sequence of MCI-1 was determined by sequencing the cyanogen bromide,tryptic and staphylococcus aureus V8 proteolytic peptides,then aligned by overlapped sequences.The result shows that MCI-1 contains 7 pairs of disulfide bonds,its sequence showed the high homology with those of “Bowman-Birk”inhibitors.About 50% trypsin inhibitory activity still remained after MCI-1 was cleavaged with cyanogen bromide. 展开更多
关键词 MCI The amino acid sequence of a double-headed trypsin inhibitor from the seeds of Momordica charantia Linn.Cucurbitaceae ACID
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基于特征共享双头Cascade R-CNN的混凝土细观损伤特征检测 被引量:2
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作者 赵亮 高升伦 +1 位作者 陈俊英 李佳佳 《控制与决策》 EI CSCD 北大核心 2022年第7期1745-1751,共7页
混凝土内部损伤破坏形态具有明显的离散性和随机性,内部损伤特征检测是混凝土细观研究的重要内容.针对已有混凝土结构内部损伤特征检测模型精度低的问题,提出一种特征共享双头Cascade R-CNN模型对混凝土CT图像的损伤特征进行检测.首先,... 混凝土内部损伤破坏形态具有明显的离散性和随机性,内部损伤特征检测是混凝土细观研究的重要内容.针对已有混凝土结构内部损伤特征检测模型精度低的问题,提出一种特征共享双头Cascade R-CNN模型对混凝土CT图像的损伤特征进行检测.首先,为了有效识别损伤特征的空间信息,构建具有空间敏感性的fc-head(fully connected head)与空间相关性的conv-head(convolution head)相结合的Cascade R-CNN网络模型;其次,通过特征共享的方法将检测网络各层级分类信息进行融合,提升低IOU(intersection over union)阈值(0.5~0.7) ROI (regions of interest)检测任务的精度.实验结果表明,所提方法在检测混凝土CT图像的损伤特征中平均精度达到91.31%,比原始的Cascade R-CNN提高3.04%,低IOU阈值(0.5~0.7) ROI平均精度提高1.49%,该模型可以较好地从混凝土CT图像中检测出细观损伤部分,具有精度高、运算简单、易于工程实现等特点. 展开更多
关键词 深度学习 目标检测 混凝土CT图像 Cascade R-CNN double-head ROI
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Comparison of the clinical efficacy of different fixation systems for the treatment of transverse patellar fractures 被引量:4
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作者 Zhi-Biao Bai Shi-Chang Gao +2 位作者 Hai-Bo Zhou Chao Zhang Chun Chen 《Chinese Journal of Traumatology》 CAS CSCD 2021年第3期169-173,共5页
Purpose:This study was designed to compare the clinical efficacy of"8"and"0"wire fixation systems combined with double-head cannulated compression screws or Kirschner wires for the treatment of tra... Purpose:This study was designed to compare the clinical efficacy of"8"and"0"wire fixation systems combined with double-head cannulated compression screws or Kirschner wires for the treatment of transverse patellar fractures.Methods:From September 2011 to September 2018,patients with closed transverse patellar fractures treated with a double-head compression screw or Kirschner wire were included and analyzed retrospectively.Patients with patellar fractures combined with distal femoral fractures,tibial plateau fracture or preoperative lower limb dysfunction were excluded.The patients treated with the"8"tension band wire fixation system and Kirschner wire were taken as Group A;those treated with the"0"fixation system and Kirschner wire were taken as Group B;those treated with the"8"fixation system and double-head cannulated compression screw were taken as group C;and those treated with the"0"fixation system and double-head cannulated compression screw were taken as group D.Six weeks and one year after the operation and every month from the third month after the operation until the fractures healed,an X-ray examination was performed to identify fracture healing.The time of fracture healing and postoperative complications of the four groups were compared.One year after the operation,knee function was evaluated by Bostman’s score.Results:During the study period,168 patients with patellar fractures were treated by operations,and 88 patients were excluded because the fracture type did not meet the requirements or because there were combined fractures of the distal femur or tibial plateau.As a result,80 patients were included in this study,20 in each group.All the patients were followed up for an average period of 12.2 months.Compared with Group A,patients in Group D presented less postoperative discomfort in the prepatellar region,quicker fracture healing,less fixation failure and better postoperative knee function scores(all p<0.05).The incidence of internal fixation failure in Group(B+D)was lower than that in Group(A+C)(p>0.05).Conclusion:The"0"wire fixation system combined with a double-head cannulated compression screw seems to be more beneficial than the other three fixation systems for the treatment of transverse patellar fractures. 展开更多
关键词 Transverse patellar fractures "0"fixation system double-head cannulated compression screw
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