基于重建的工业图像异常检测通常假设模型能很好重建正常区域,而不能很好重建异常区域。但由于深度神经网络存在过度泛化问题,使得异常区域也能被较好重建,导致异常区域漏检。为解决上述问题,提出一种基于多记忆增强模块及图像轮廓重建...基于重建的工业图像异常检测通常假设模型能很好重建正常区域,而不能很好重建异常区域。但由于深度神经网络存在过度泛化问题,使得异常区域也能被较好重建,导致异常区域漏检。为解决上述问题,提出一种基于多记忆增强模块及图像轮廓重建的工业表面异常检测网络(industrial surface anomaly detection based on recon-struction with multiple memory enhancement modules and image edge,MMAERec)。具体来说,在带有跳跃连接的U-Net类型去噪自编码器上引入多记忆增强模块和图像轮廓提取模块。多记忆增强模块得到的记忆特征有利于很好地重建正常区域;而提取到的图像轮廓特征则有利于很好重建图像轮廓。将这两种不同特征的融合经注意力机制处理并用于重建能很好地提高重建图像质量。所提方法可以强制网络学习正常的低频和高频信息,防止模型直接复制异常区域,有效缓解过度泛化问题。在MVTec AD和BTAD两个工业数据集上的实验结果也展现了所提方法良好的检测和定位性能。展开更多
Reverse-sheared Alfv6n eigenmodes （RSAEs） have been observed by using an interferometer and ECE diagnostics in NBI heated ELMy H-mode plasma on EAST tokamak. A typical feature of these modes is a fast frequency swee...Reverse-sheared Alfv6n eigenmodes （RSAEs） have been observed by using an interferometer and ECE diagnostics in NBI heated ELMy H-mode plasma on EAST tokamak. A typical feature of these modes is a fast frequency sweeping upward from -80 kHz to -110 kHz in hundred milliseconds during which the plasma temperature, density and rotation keeps no change. Only core channels of the interferometer can observe these modes, implying a core localized mode. The ECE measurement further showed that these modes located at about ρ = 0.37-0.46, just around the position of qmin with ρ -0.4. These core localized modes are very weak in the magnetic fluctuations measured by mirnov probes mounted at the machine vacuum vessel. A multiple frequency fluctuation component, seemingly the so-called ＇grand cascades＇, was also clearly observed on the ECE signal at ρ = 0.46. During the phase, a transient internal transport barrier （ITB） in ion temperature and toroidal rotation was observed and the ITB foot was just close to the position of qmin. A modulation of RSAE frequency by ELM event was observed and this modulation could be attributed to rotation decrease or qmin increase due to ELM. Further study of these modes in EAST can provide valuable constraints for the q profile measurement and will be important for the long pulse operation.展开更多
Abstract EAST has demonstrated its capability of long pulse operation using RF heating （LHCD and ICRF） in past experiments. One key issue to realize the long pulse H-mode expert- meats is to sustain the plasma curre...Abstract EAST has demonstrated its capability of long pulse operation using RF heating （LHCD and ICRF） in past experiments. One key issue to realize the long pulse H-mode expert- meats is to sustain the plasma current for steady state operation. Based on the calculations of the transport code ONETWO and its coupled RF code GENRAY, two scenarios have been proposed to achieve the 10 s H-mode plasma with Ip=400 kA, 〈 ne 〉=4.5×1019 m-a, βN=2, and the 100 s H-mode plasma with Ip=280 kA, 〈 ne 〉=3.5×1019 m-a, βN=1.8 recently. The current drive of lower hybrid wave is an important issue in the two scenarios. An experimental result on lower hybrid current drive in H-mode plasmas on EAST is also presented.展开更多
Pedestal plasma turbulence was experimentally studied by microwave reflectometry on EAST tokamak. The characteristics of edge pedestal turbulence during dithering L-H transition, ELM-free H-mode phase and inter-ELM ph...Pedestal plasma turbulence was experimentally studied by microwave reflectometry on EAST tokamak. The characteristics of edge pedestal turbulence during dithering L-H transition, ELM-free H-mode phase and inter-ELM phase have recently been studied on EAST. An edge spatial structure of density fluctuation and its dithering temporal evolution is observed for the first time on the EAST tokamak during the L-H transition phase. A coherent mode usually appears during the ELM-free phase prior to the first ELM on EAST tokamak. The mode frequency gradually decreases as the pedestal evolves. Analysis shows that the coherent mode is in the pedestal region inside the separatrix. In plasma with type-III ELMs, a precursor mode before ELM is usually observed. The frequency of the precursor was initially about 150 kHz and gradually decreased till the next ELM. The mode amplitude increases or shows saturation before ELM. In the plasma with compound ELMs composed of high and low frequency ELMs, the precursor was also observed before the high frequency ELM while the harmonic oscillations with frequencies of 20 kHz, 40 kHz and 60 kHz appear before the low frequency ELM.展开更多
文摘基于重建的工业图像异常检测通常假设模型能很好重建正常区域,而不能很好重建异常区域。但由于深度神经网络存在过度泛化问题,使得异常区域也能被较好重建,导致异常区域漏检。为解决上述问题,提出一种基于多记忆增强模块及图像轮廓重建的工业表面异常检测网络(industrial surface anomaly detection based on recon-struction with multiple memory enhancement modules and image edge,MMAERec)。具体来说,在带有跳跃连接的U-Net类型去噪自编码器上引入多记忆增强模块和图像轮廓提取模块。多记忆增强模块得到的记忆特征有利于很好地重建正常区域;而提取到的图像轮廓特征则有利于很好重建图像轮廓。将这两种不同特征的融合经注意力机制处理并用于重建能很好地提高重建图像质量。所提方法可以强制网络学习正常的低频和高频信息,防止模型直接复制异常区域,有效缓解过度泛化问题。在MVTec AD和BTAD两个工业数据集上的实验结果也展现了所提方法良好的检测和定位性能。
基金supported by the National Key R&D Program of China (No. 2014GB106004)National Natural Science Foundation of China (Nos. 11605235, 11675211, 11505221)Scientific Research Grant of Hefei Science Center of CAS (No. 2015SRG-HSC010)
文摘Reverse-sheared Alfv6n eigenmodes （RSAEs） have been observed by using an interferometer and ECE diagnostics in NBI heated ELMy H-mode plasma on EAST tokamak. A typical feature of these modes is a fast frequency sweeping upward from -80 kHz to -110 kHz in hundred milliseconds during which the plasma temperature, density and rotation keeps no change. Only core channels of the interferometer can observe these modes, implying a core localized mode. The ECE measurement further showed that these modes located at about ρ = 0.37-0.46, just around the position of qmin with ρ -0.4. These core localized modes are very weak in the magnetic fluctuations measured by mirnov probes mounted at the machine vacuum vessel. A multiple frequency fluctuation component, seemingly the so-called ＇grand cascades＇, was also clearly observed on the ECE signal at ρ = 0.46. During the phase, a transient internal transport barrier （ITB） in ion temperature and toroidal rotation was observed and the ITB foot was just close to the position of qmin. A modulation of RSAE frequency by ELM event was observed and this modulation could be attributed to rotation decrease or qmin increase due to ELM. Further study of these modes in EAST can provide valuable constraints for the q profile measurement and will be important for the long pulse operation.
基金supported by the National Magnetic Confinement Fusion Program of China(Nos.2014GB106000,2014GB106001,and2014GB106003)National Natural Science Foundation of China(Nos.11275234,11321092,11305215,11305208,11405214)CAS Hefei Center for Scientific Research Program of China(No.2015SRG-HSC010)
文摘Abstract EAST has demonstrated its capability of long pulse operation using RF heating （LHCD and ICRF） in past experiments. One key issue to realize the long pulse H-mode expert- meats is to sustain the plasma current for steady state operation. Based on the calculations of the transport code ONETWO and its coupled RF code GENRAY, two scenarios have been proposed to achieve the 10 s H-mode plasma with Ip=400 kA, 〈 ne 〉=4.5×1019 m-a, βN=2, and the 100 s H-mode plasma with Ip=280 kA, 〈 ne 〉=3.5×1019 m-a, βN=1.8 recently. The current drive of lower hybrid wave is an important issue in the two scenarios. An experimental result on lower hybrid current drive in H-mode plasmas on EAST is also presented.
基金supported by the National Magnetic Confinement Fusion Program of China(Nos.2010GB106000,2010GB106001)National Natural Science Foundation of China(Nos.11021565,11275234)
文摘Pedestal plasma turbulence was experimentally studied by microwave reflectometry on EAST tokamak. The characteristics of edge pedestal turbulence during dithering L-H transition, ELM-free H-mode phase and inter-ELM phase have recently been studied on EAST. An edge spatial structure of density fluctuation and its dithering temporal evolution is observed for the first time on the EAST tokamak during the L-H transition phase. A coherent mode usually appears during the ELM-free phase prior to the first ELM on EAST tokamak. The mode frequency gradually decreases as the pedestal evolves. Analysis shows that the coherent mode is in the pedestal region inside the separatrix. In plasma with type-III ELMs, a precursor mode before ELM is usually observed. The frequency of the precursor was initially about 150 kHz and gradually decreased till the next ELM. The mode amplitude increases or shows saturation before ELM. In the plasma with compound ELMs composed of high and low frequency ELMs, the precursor was also observed before the high frequency ELM while the harmonic oscillations with frequencies of 20 kHz, 40 kHz and 60 kHz appear before the low frequency ELM.
