针对光路对接准直目标识别算法对双目标粘连状态无法判别的问题,提出了基于二进制大对象(Binary Large Object,BLOB)区域和边缘特征分析的准直图像双光学目标识别方法。首先,对二值化图像进行数字形态学处理,计算全图各BLOB区域的面积...针对光路对接准直目标识别算法对双目标粘连状态无法判别的问题,提出了基于二进制大对象(Binary Large Object,BLOB)区域和边缘特征分析的准直图像双光学目标识别方法。首先,对二值化图像进行数字形态学处理,计算全图各BLOB区域的面积、中心、轴长、区域、有效BLOB区域个数等信息。其次,对有效BLOB区域个数大于1的完全分离双目标准直图像,统计各BLOB区域中心分别为位于两个面积最大的BLOB区域内的BLOB数量,数量小的候选BLOB区域为主激光目标,数量大的候选BLOB区域为模拟光目标。然后,对于有效BLOB区域个数等于1的待识别图像,从左、右、上、下4个方向分别提取模板边缘图像的有效坐标序列和待识别边缘图像坐标序列,搜索有效坐标序列和待识别边缘图像坐标序列的最大相关系数对应的有效坐标序列。当4个方向的相关系数全部大于0.95时,待识别图像为模拟光目标;当4个方向的相关系数都小于0.95时,待识别图像为主激光目标;否则待识别图像为粘连图像。实验结果表明:提出的双光学目标识别算法,不仅能够识别完全分离的模拟光目标和主激光目标,误差小于3个像素,处理时间小于1 s,而且能够判别处于粘连状态的光学目标和单个独立的光学目标,满足光路对接准直图像识别算法对于自适应性、精度和效率的要求。展开更多
The impact of resonant magnetic perturbation(RMP)on blob motion and structure in the SOL of the HL-2A tokamak is studied using a gas puff imaging diagnostic.Ellipse fitting is applied to study the structure and motion...The impact of resonant magnetic perturbation(RMP)on blob motion and structure in the SOL of the HL-2A tokamak is studied using a gas puff imaging diagnostic.Ellipse fitting is applied to study the structure and motion of blobs quantitatively.The radial locations,amplitudes and scale sizes of blobs are obtained based on the fitted ellipse.Furthermore,based on the measurement of blob location,the radial and poloidal velocities of blobs are calculated.With the application of RMP,the edge poloidal shear flow is significantly weakened and the wave number spectrum changes from quasisymmetric to significantly up-down asymmetric.The application of RMP also causes the detected blob location to be much further into the far scrape-off layer(SOL)and increases the blob amplitude.Blob poloidal velocity in the SOL is slowed.Larger-size and longer-lifetime blobs are observed with RMP.With the application of RMP,stronger-amplitude and larger-size blobs are detected in the far SOL and they may cause a more serious erosion problem to the first wall.展开更多
The blob properties in I-mode and ELM-free H-mode plasmas compared to L-mode have been investigated on the EAST tokamak,including the blob detection rate Nb,sizeδb,lifetimeτb and radial velocity vr,b.The blob proper...The blob properties in I-mode and ELM-free H-mode plasmas compared to L-mode have been investigated on the EAST tokamak,including the blob detection rate Nb,sizeδb,lifetimeτb and radial velocity vr,b.The blob properties in L-mode and I-mode are similar,and those in ELM-free H-mode are different to them.The blob Nbis smaller whileτbis larger in H-mode.The experimental blob sizeδband velocity scalings vr,b-δb show a good agreement with the theoretical models.The variation in blob properties during the L-I and H-L transitions,and their relations to the scrape-off layer(SOL)density,edge and SOL turbulence,and SOL collisionality are discussed.The suppression of the edge(inside the last closed flux surface)turbulence is not reflected in the blob behavior,while the blob detection rate shows a correlation with the SOL density and its low-frequency(3–50 kH z)fluctuations.In addition,the blob detection rate is found to increase with the divertor collisionalityΛdiv,indicating a dependence of blob behavior onΛdiv.The differences in blob detection rates among the three operating regimes might be due to their different SOL densities and collisionalities.The investigation contributes to understanding the influences of edge and SOL plasma parameters on the blob behavior.展开更多
Space-based plasma(i.e.,a highly ionized gas or the fourth state of matter)blobs are isolated pockets of this highly ionized gas made up of charged particles.These blobs are believed to have a substantial impact on th...Space-based plasma(i.e.,a highly ionized gas or the fourth state of matter)blobs are isolated pockets of this highly ionized gas made up of charged particles.These blobs are believed to have a substantial impact on the structure and dynamics of the cosmos and can be seen in a variety of astronomical objects,including stars,galaxies,and the intergalactic medium.Some plasma blobs are connected to intense phenomena like magnetic reconnection,shock waves,and supernovae,while others may be the result of more passive processes like cooling and gravitational collapse.In both astrophysics and plasma physics,there is ongoing research on the characteristics and behavior of plasma blobs.This phenomenon has a very adverse effect on tokamak-based MCF(magnetic confinement fusion),which is the subject of this short review paper.展开更多
文摘针对光路对接准直目标识别算法对双目标粘连状态无法判别的问题,提出了基于二进制大对象(Binary Large Object,BLOB)区域和边缘特征分析的准直图像双光学目标识别方法。首先,对二值化图像进行数字形态学处理,计算全图各BLOB区域的面积、中心、轴长、区域、有效BLOB区域个数等信息。其次,对有效BLOB区域个数大于1的完全分离双目标准直图像,统计各BLOB区域中心分别为位于两个面积最大的BLOB区域内的BLOB数量,数量小的候选BLOB区域为主激光目标,数量大的候选BLOB区域为模拟光目标。然后,对于有效BLOB区域个数等于1的待识别图像,从左、右、上、下4个方向分别提取模板边缘图像的有效坐标序列和待识别边缘图像坐标序列,搜索有效坐标序列和待识别边缘图像坐标序列的最大相关系数对应的有效坐标序列。当4个方向的相关系数全部大于0.95时,待识别图像为模拟光目标;当4个方向的相关系数都小于0.95时,待识别图像为主激光目标;否则待识别图像为粘连图像。实验结果表明:提出的双光学目标识别算法,不仅能够识别完全分离的模拟光目标和主激光目标,误差小于3个像素,处理时间小于1 s,而且能够判别处于粘连状态的光学目标和单个独立的光学目标,满足光路对接准直图像识别算法对于自适应性、精度和效率的要求。
基金supported by the National Key Research and Development Program of China(Nos.2022YFE03100002,2022YFE03010004 and 2019YFE03060002)National Natural Science Foundation of China(Nos.U1867222,U1967206 and 51821005)the Sichuan Natural Science Foundation(Nos.2022NSFSC1791 and 2020JDTD0030).
文摘The impact of resonant magnetic perturbation(RMP)on blob motion and structure in the SOL of the HL-2A tokamak is studied using a gas puff imaging diagnostic.Ellipse fitting is applied to study the structure and motion of blobs quantitatively.The radial locations,amplitudes and scale sizes of blobs are obtained based on the fitted ellipse.Furthermore,based on the measurement of blob location,the radial and poloidal velocities of blobs are calculated.With the application of RMP,the edge poloidal shear flow is significantly weakened and the wave number spectrum changes from quasisymmetric to significantly up-down asymmetric.The application of RMP also causes the detected blob location to be much further into the far scrape-off layer(SOL)and increases the blob amplitude.Blob poloidal velocity in the SOL is slowed.Larger-size and longer-lifetime blobs are observed with RMP.With the application of RMP,stronger-amplitude and larger-size blobs are detected in the far SOL and they may cause a more serious erosion problem to the first wall.
基金supported by the National Key R&D Program of China(Nos.2022YFE03020004,2017YFE0301300,2018YFE0303104 and 2019YFE03030000)the Major Science and Technology Infrastructure Maintenance and Reconstruction Projects of the Chinese Academy of Sciences+3 种基金National Natural Science Foundation of China(Nos.12275313,11922513,12005004 and U19A20113)the Institute of Energy,Hefei Comprehensive National Science Center(No.GXXT-2020-004)the Anhui Provincial Natural Science Foundation(No.2008085QA38)the Users with Excellence Program of Hefei Science Center,Chinese Academy of Sciences(No.2020HSC-UE009)。
文摘The blob properties in I-mode and ELM-free H-mode plasmas compared to L-mode have been investigated on the EAST tokamak,including the blob detection rate Nb,sizeδb,lifetimeτb and radial velocity vr,b.The blob properties in L-mode and I-mode are similar,and those in ELM-free H-mode are different to them.The blob Nbis smaller whileτbis larger in H-mode.The experimental blob sizeδband velocity scalings vr,b-δb show a good agreement with the theoretical models.The variation in blob properties during the L-I and H-L transitions,and their relations to the scrape-off layer(SOL)density,edge and SOL turbulence,and SOL collisionality are discussed.The suppression of the edge(inside the last closed flux surface)turbulence is not reflected in the blob behavior,while the blob detection rate shows a correlation with the SOL density and its low-frequency(3–50 kH z)fluctuations.In addition,the blob detection rate is found to increase with the divertor collisionalityΛdiv,indicating a dependence of blob behavior onΛdiv.The differences in blob detection rates among the three operating regimes might be due to their different SOL densities and collisionalities.The investigation contributes to understanding the influences of edge and SOL plasma parameters on the blob behavior.
文摘Space-based plasma(i.e.,a highly ionized gas or the fourth state of matter)blobs are isolated pockets of this highly ionized gas made up of charged particles.These blobs are believed to have a substantial impact on the structure and dynamics of the cosmos and can be seen in a variety of astronomical objects,including stars,galaxies,and the intergalactic medium.Some plasma blobs are connected to intense phenomena like magnetic reconnection,shock waves,and supernovae,while others may be the result of more passive processes like cooling and gravitational collapse.In both astrophysics and plasma physics,there is ongoing research on the characteristics and behavior of plasma blobs.This phenomenon has a very adverse effect on tokamak-based MCF(magnetic confinement fusion),which is the subject of this short review paper.
