随着人工智能的发展,人脸识别在生活中的应用越来越广泛,但当前识别的多是高分辨率下的人脸图像,低分辨率图像的识别还需进一步提升。基于此,本文提出一种CNN和Transformer的融合网络(Combining CNN and Transformer Dual Network,CCTDN...随着人工智能的发展,人脸识别在生活中的应用越来越广泛,但当前识别的多是高分辨率下的人脸图像,低分辨率图像的识别还需进一步提升。基于此,本文提出一种CNN和Transformer的融合网络(Combining CNN and Transformer Dual Network,CCTDN)低分辨率人脸识别(Low-Resolution Face Recognition,LRFR)方法,融合了卷积神经网络(Convolutional Neural Network,CNN)和Transformer双网结合的优点,并运用损失函数,在LFW数据集上取得了优异效果,提高了准确率。随着人工智能技术的快速发展,人脸识别因其非接触性、便捷性和唯一性[1]广受欢迎,然而,人脸识别在实际应用中面临更多挑战,尤其是在监控视频中,由于图像分辨率低、信息量少、噪声大,识别难度显著增加[2]。展开更多
Numerical simulation and experimental research on Linear Friction Welding(LFW) for GH4169 superalloy were carried out. Based on the joint microstructure and mechanical properties,a suitable welding process was determi...Numerical simulation and experimental research on Linear Friction Welding(LFW) for GH4169 superalloy were carried out. Based on the joint microstructure and mechanical properties,a suitable welding process was determined, which provided an important theoretical basis for the manufacture and repair of aeroengine components such as the superalloy blisk. The results show that the joint strain rate gradually increases with the increase of welding frequency, and the deformation resistance of the thermoplastic metal increases in the welding process, resulting in the interface thermoplastic metal not being extruded in time to form a flash, so the joint shortening amount gradually decreases. The thermoplastic metal in the center of the welding surface is kept at high welding temperature for a long time, resulting in the decrease of the joint strength. The microhardness of the joint shows a “W” distribution perpendicular to the weld, and most of the joints break in the Thermo-Mechanically Affected Zone(TMAZ) with high tensile strength and low elongation.When the welding area is increased without changing the aspect ratio of the welding surface, the interface peak temperature increases gradually, and the joint shortening amount decreases with the increase of the welding interface size.展开更多
Linear Friction Welding(LFW)technology was used to realize the welding of GH4169 superalloy,and the effect of welding parameters on the microstructure,mechanical properties and corrosion behavior of the joint was anal...Linear Friction Welding(LFW)technology was used to realize the welding of GH4169 superalloy,and the effect of welding parameters on the microstructure,mechanical properties and corrosion behavior of the joint was analyzed.The results show that there is a positive correlation between the weld hardness and the tensile strength.With the gradual increase of heat input and welding pressure,the joint quality is gradually improved,but the heat affected zone is not significantly increased.The smaller the grain size of the weld,the higher the strength and plasticity of the joint.With the increase of the joint shortening amount,the corrosion resistance of the weld first gradually increases.However,when the shortening reaches a certain level,the corrosion resistance of the joint becomes little changed.With the increase of solution temperature,the corrosion current density increases and the polarization impedance decreases.The higher the corrosion temperature,the worse the corrosion resistance of the joint.There is no significant correlation between the joint strength and the corrosion resistance.The corrosion resistance of the joint can be enhanced without changing the joint mechanical properties by reducing the welding frequency and amplitude or increasing the welding pressure.展开更多
The effects of oceanic forcing on the atmospheric low-frequency wave (LFW for short) in the tropics are analyzed, where ocean and atmosphere are taken as an independent system, respectively. Here oceanic effects are p...The effects of oceanic forcing on the atmospheric low-frequency wave (LFW for short) in the tropics are analyzed, where ocean and atmosphere are taken as an independent system, respectively. Here oceanic effects are parameterized as evaporation-wind feedback (EWF for short) and forcing of SST. Under the modulation of EWF, forcing of SST plays a different role from that without EWF, So LFWs are diabatic waves, forced by the interactions of multiple factors, in the tropics. Key words Atmospheric LFW - Oceanic forcing - EWF - Radiative cooling - SST This paper was supported by “ First Institute of Oceanic Sciences, State Oceanic Administration, State Key Laboratory of Geophysical Fluid Dynamics and Numerical Modeling”.展开更多
文摘随着人工智能的发展,人脸识别在生活中的应用越来越广泛,但当前识别的多是高分辨率下的人脸图像,低分辨率图像的识别还需进一步提升。基于此,本文提出一种CNN和Transformer的融合网络(Combining CNN and Transformer Dual Network,CCTDN)低分辨率人脸识别(Low-Resolution Face Recognition,LRFR)方法,融合了卷积神经网络(Convolutional Neural Network,CNN)和Transformer双网结合的优点,并运用损失函数,在LFW数据集上取得了优异效果,提高了准确率。随着人工智能技术的快速发展,人脸识别因其非接触性、便捷性和唯一性[1]广受欢迎,然而,人脸识别在实际应用中面临更多挑战,尤其是在监控视频中,由于图像分辨率低、信息量少、噪声大,识别难度显著增加[2]。
基金supported by the National Natural Science Foundation of China (Nos. 52305420, 52074228 and 51875470)the China Postdoctoral Science Foundation (No. 2023M742830)the Xi’an Beilin District Science and Technology Planning Project, China (No. GX2349)。
文摘Numerical simulation and experimental research on Linear Friction Welding(LFW) for GH4169 superalloy were carried out. Based on the joint microstructure and mechanical properties,a suitable welding process was determined, which provided an important theoretical basis for the manufacture and repair of aeroengine components such as the superalloy blisk. The results show that the joint strain rate gradually increases with the increase of welding frequency, and the deformation resistance of the thermoplastic metal increases in the welding process, resulting in the interface thermoplastic metal not being extruded in time to form a flash, so the joint shortening amount gradually decreases. The thermoplastic metal in the center of the welding surface is kept at high welding temperature for a long time, resulting in the decrease of the joint strength. The microhardness of the joint shows a “W” distribution perpendicular to the weld, and most of the joints break in the Thermo-Mechanically Affected Zone(TMAZ) with high tensile strength and low elongation.When the welding area is increased without changing the aspect ratio of the welding surface, the interface peak temperature increases gradually, and the joint shortening amount decreases with the increase of the welding interface size.
基金supported by the research fund of the National Natural Science Foundation of China(Nos.52305420,52074228,51875470)the China Postdoctoral Science Foundation(No.2023M742830)the Xi’an Beilin District Science and Technology Planning Project,China(No.GX2349).
文摘Linear Friction Welding(LFW)technology was used to realize the welding of GH4169 superalloy,and the effect of welding parameters on the microstructure,mechanical properties and corrosion behavior of the joint was analyzed.The results show that there is a positive correlation between the weld hardness and the tensile strength.With the gradual increase of heat input and welding pressure,the joint quality is gradually improved,but the heat affected zone is not significantly increased.The smaller the grain size of the weld,the higher the strength and plasticity of the joint.With the increase of the joint shortening amount,the corrosion resistance of the weld first gradually increases.However,when the shortening reaches a certain level,the corrosion resistance of the joint becomes little changed.With the increase of solution temperature,the corrosion current density increases and the polarization impedance decreases.The higher the corrosion temperature,the worse the corrosion resistance of the joint.There is no significant correlation between the joint strength and the corrosion resistance.The corrosion resistance of the joint can be enhanced without changing the joint mechanical properties by reducing the welding frequency and amplitude or increasing the welding pressure.
基金This paper was supported by" First Institute of Oceanic Sciences, State Oceanic Administration, StateKey Laboratory of Geophys
文摘The effects of oceanic forcing on the atmospheric low-frequency wave (LFW for short) in the tropics are analyzed, where ocean and atmosphere are taken as an independent system, respectively. Here oceanic effects are parameterized as evaporation-wind feedback (EWF for short) and forcing of SST. Under the modulation of EWF, forcing of SST plays a different role from that without EWF, So LFWs are diabatic waves, forced by the interactions of multiple factors, in the tropics. Key words Atmospheric LFW - Oceanic forcing - EWF - Radiative cooling - SST This paper was supported by “ First Institute of Oceanic Sciences, State Oceanic Administration, State Key Laboratory of Geophysical Fluid Dynamics and Numerical Modeling”.
