为进一步提高红外与可见光融合图像的细节信息和整体对比度,降低伪影和噪声,考虑了红外与可见光图像的相关性,提出了一种基于联合低秩稀疏分解的红外与可见光图像融合方法。首先,利用联合低秩稀疏分解方法将红外和可见光源图像分别分解...为进一步提高红外与可见光融合图像的细节信息和整体对比度,降低伪影和噪声,考虑了红外与可见光图像的相关性,提出了一种基于联合低秩稀疏分解的红外与可见光图像融合方法。首先,利用联合低秩稀疏分解方法将红外和可见光源图像分别分解成共同低秩分量、特有低秩分量和特有稀疏分量;其次,利用非下采样Shearlet变换方法对特有低秩分量进行融合;然后,采用区域能量融合策略实现特有稀疏分量融合;最后,共有低秩分量与融合后的特有低秩分量和特有稀疏分量相加得到最终融合图像。在Nato-camp、Bristol Eden Project和TNO公共测试数据集上进行的实验测试了所提算法性能。实验结果表明,与其他9种融合方法相比,所提方法能够有效地提取红外图像中的目标信息和保留可见光图像的背景信息,熵、互信息、标准差、视觉信息保真度、差异相关系数之和和Q Y客观评价指标明显优于对比方法。展开更多
The gearbox of a wind turbine （WT） has dominant failure rates and highest downtime loss among all WT subsystems. Thus, gearbox health assessment for maintenance cost reduction is of paramount importance. The concurr...The gearbox of a wind turbine （WT） has dominant failure rates and highest downtime loss among all WT subsystems. Thus, gearbox health assessment for maintenance cost reduction is of paramount importance. The concurrence of multiple faults in gearbox components is a common phenomenon due to fault induction mechanism. This problem should be considered before planning to replace the components of the WT gearbox. Therefore, the key fault patterns should be reliably identified from noisy observation data for the development of an effective maintenance strategy. However, most of the existing studies focusing on multiple fault diagnosis always suffer from inappropriate division of fault information in order to satisfy various rigorous decomposition principles or statistical assumptions, such as the smooth envelope principle of ensemble empirical mode decomposition and the mutual independence assumption of independent component analysis. Thus, this paper presents a joint subspace learning-based multiple fault detection （JSLMFD） technique to construct different subspaces adaptively for different fault pattems. Its main advantage is its capability to learn multiple fault subspaces directly from the observation signal itself. It can also sparsely concentrate the feature information into a few dominant subspace coefficients. Furthermore, it can eliminate noise by simply performing coefficient shrinkage operations. Consequently, multiple fault patterns are reliably identified by utilizing the maximum fault information criterion. The superiority of JSL-MFD in multiple fault separation and detection is comprehensively investigated and verified by the analysis of a data set of a 750 kW WT gearbox. Results show that JSL-MFD is superior to a state-of-the-art technique in detecting hidden fault patterns and enhancing detection accuracy.展开更多
Model recognition of second-hand mobile phones has been considered as an essential process to improve the efficiency of phone recycling. However, due to the diversity of mobile phone appearances, it is difficult to re...Model recognition of second-hand mobile phones has been considered as an essential process to improve the efficiency of phone recycling. However, due to the diversity of mobile phone appearances, it is difficult to realize accurate recognition. To solve this problem, a mobile phone recognition method based on bilinear-convolutional neural network(B-CNN) is proposed in this paper.First, a feature extraction model, based on B-CNN, is designed to adaptively extract local features from the images of secondhand mobile phones. Second, a joint loss function, constructed by center distance and softmax, is developed to reduce the interclass feature distance during the training process. Third, a parameter downscaling method, derived from the kernel discriminant analysis algorithm, is introduced to eliminate redundant features in B-CNN. Finally, the experimental results demonstrate that the B-CNN method can achieve higher accuracy than some existing methods.展开更多
文摘为进一步提高红外与可见光融合图像的细节信息和整体对比度,降低伪影和噪声,考虑了红外与可见光图像的相关性,提出了一种基于联合低秩稀疏分解的红外与可见光图像融合方法。首先,利用联合低秩稀疏分解方法将红外和可见光源图像分别分解成共同低秩分量、特有低秩分量和特有稀疏分量;其次,利用非下采样Shearlet变换方法对特有低秩分量进行融合;然后,采用区域能量融合策略实现特有稀疏分量融合;最后,共有低秩分量与融合后的特有低秩分量和特有稀疏分量相加得到最终融合图像。在Nato-camp、Bristol Eden Project和TNO公共测试数据集上进行的实验测试了所提算法性能。实验结果表明,与其他9种融合方法相比,所提方法能够有效地提取红外图像中的目标信息和保留可见光图像的背景信息,熵、互信息、标准差、视觉信息保真度、差异相关系数之和和Q Y客观评价指标明显优于对比方法。
基金This work was supported by the National Natural Science Foundation of China （Grant Nos. 51505364 and 51335006）, the National Key Basic Research Program of China （Grant No. 2015CB057400）, and the Program for Changjiang Scholars. The authors thank NREL for supporting this work and providing the vibration data used for the validation of the JSL-MFD technique.
文摘The gearbox of a wind turbine （WT） has dominant failure rates and highest downtime loss among all WT subsystems. Thus, gearbox health assessment for maintenance cost reduction is of paramount importance. The concurrence of multiple faults in gearbox components is a common phenomenon due to fault induction mechanism. This problem should be considered before planning to replace the components of the WT gearbox. Therefore, the key fault patterns should be reliably identified from noisy observation data for the development of an effective maintenance strategy. However, most of the existing studies focusing on multiple fault diagnosis always suffer from inappropriate division of fault information in order to satisfy various rigorous decomposition principles or statistical assumptions, such as the smooth envelope principle of ensemble empirical mode decomposition and the mutual independence assumption of independent component analysis. Thus, this paper presents a joint subspace learning-based multiple fault detection （JSLMFD） technique to construct different subspaces adaptively for different fault pattems. Its main advantage is its capability to learn multiple fault subspaces directly from the observation signal itself. It can also sparsely concentrate the feature information into a few dominant subspace coefficients. Furthermore, it can eliminate noise by simply performing coefficient shrinkage operations. Consequently, multiple fault patterns are reliably identified by utilizing the maximum fault information criterion. The superiority of JSL-MFD in multiple fault separation and detection is comprehensively investigated and verified by the analysis of a data set of a 750 kW WT gearbox. Results show that JSL-MFD is superior to a state-of-the-art technique in detecting hidden fault patterns and enhancing detection accuracy.
基金supported by the National Key Program of China(Grant No.2018YFC1900800-5)the National Natural Science Foundation of China(Grant Nos.61890930-5 and 61622301)the Beijing University Outstanding Young Scientist Program(Grant No.BJJWZYJH0120191000-5020)。
文摘Model recognition of second-hand mobile phones has been considered as an essential process to improve the efficiency of phone recycling. However, due to the diversity of mobile phone appearances, it is difficult to realize accurate recognition. To solve this problem, a mobile phone recognition method based on bilinear-convolutional neural network(B-CNN) is proposed in this paper.First, a feature extraction model, based on B-CNN, is designed to adaptively extract local features from the images of secondhand mobile phones. Second, a joint loss function, constructed by center distance and softmax, is developed to reduce the interclass feature distance during the training process. Third, a parameter downscaling method, derived from the kernel discriminant analysis algorithm, is introduced to eliminate redundant features in B-CNN. Finally, the experimental results demonstrate that the B-CNN method can achieve higher accuracy than some existing methods.
