结合Swin Transformer的多尺度遥感图像变化检测研究

由于地物信息的复杂性及变化检测数据的多元性,遥感图像特征提取的充分性和有效性难以得到保证,导致变化检测方法获取的检测结果可靠性较低。虽然卷积神经网络(CNN)凭借有效提取语义特征的优势,被广泛应用于遥感领域的变化检测之中,但卷积操作固有的局部性导致感受野受限,无法捕获时空上的全局信息以至于特征空间对中远距离依赖关系的建模受限。为捕获远距离的语义依赖,提取深层全局语义特征,设计了一种基于Swin Transformer的多尺度特征融合网络SwinChangeNet。首先,SwinChangeNet采用孪生的多级Swin Transformer特征编码器进行远距离上下文建模;其次,编码器中引入特征差异提取模块,计算不同尺度下变化前后的多级特征差异,再通过自适应融合层将多尺度特征图进行融合;最后,引入残差连接和通道注意力机制对融合后的特征信息进行解码,从而生成完整准确的变化图。在CDD和CD_Data_GZ 2个公开数据集上分别与7种经典和前沿变化检测方法进行比较,CDD数据集中本文模型的性能最优,相比于性能第二的模型,F1分数提高了1.11%,精确率提高了2.38%。CD_Data_GZ数据集中本文模型的性能最优,相比于性能第二的模型,F1分数、精确率和召回率分别提高了4.78%,4.32%,4.09%,提升幅度较大。对比实验结果证明了该模型具有更好的检测效果。在消融实验中也证实了模型中各个改进模块的稳定性和有效性。本文模型针对遥感图像变化检测任务,引入了Swin Transformer结构,使网络可以对遥感图像的局部特征和全局特征进行更有效地编码,让检测结果更加准确,同时保证网络在地物要素种类繁多的数据集上容易收敛。

Effect of acupuncture on the daytime function in patients with post-stroke sleep-wake disturbance:A randomized controlled trial

Objective:To explore the improvements in sleep duration,drowsiness and daytime fatigue in patients with sleep-wake disturbance after ischemic stroke treated by needling at Baihui(百会GV20)and Sishencong(四神聪EX-HN1).Methods:A total of 81 patients with post-stroke sleep-wake disturbance were randomly divided into 2 groups,i.e.a control group(39 cases)and a treatment group(42 cases).In the control group,the basic treatment for ischemic stroke was administered.In the treatment group,on the base of the treatment as the control group,acupuncture was applied to GV20 and EX-HN1.The treatment was given once a day,30 min each time,totally for 4 weeks.The daytime sleep duration,sleep need,Epworth Sleepiness Score(ESS)and Fatigue Severity Scale(FSS)score were observed in the patients of two groups before and after treatment.The therapeutic effects were observed.Results:After treatment,the daytime sleep duration and sleep need were all reduced to different extents in the patients of two groups.The daytime sleep duration and sleep need in the treatment group were lower than those in the control group(all P<0.05).After treatment,ESS of two groups were reduced significantly to be(11.21±3.33)points and(6.40±2.11)points,respectively(both P<0.05)and the FSS scores reduced significantly to be(33.62±9.17)points and(21.45±8.17)points,respectively(both P<0.05).Conclusion:Acupuncture at GV20 and EX-HN1 effectively reduces daytime sleep duration,relieves drowsiness and daytime fatigue and improves daytime function of the patients with post-stroke sleepwake disturbance.