Person re-identification (Re-ID) is a challenging research topic which aims to retrieve the pedestrian images of the same person that captured by non-overlapping cameras. Existing methods either assume the body parts of the same person are well-aligned, or use attention selection mechanisms to constrain the effective region of feature learning. But these methods concentrate only on coarse feature representation and cannot model complex real scenes effectively. We propose a novel Local Attention Guided Network (LAG-Net) to not only exploit the most salient area among different people, but also extract important local detail through a Local Attention System (LAS). LAS is an attention selection unit that could extract approximate semantic local features of human body parts without extra supervision. To learn discriminative attention feature representation, we explore an attention feature regularization scheme to enhance the relevance of body part features that belong to same personal identity. Considering the effectiveness of feature augmentation in the Re-ID task and the defect of the existing methods, we propose a Batch Attention DropBlock (BA-DropBlock) to further improve DropBlock by combining the attention selection mechanism. Results on mainstream datasets demonstrate the superiority of our model over the state-of-the-art. Especially, our approach exceeds the current best method by a large margin of 4.6 ${\%}$ on the most challenging dataset CUHK03.

In clinical medicine, the contrast-enhanced ultrasound (CEUS) has been a commonly used imaging modality for diagnosis of breast tumor. However, most researchers in computer vision field only focus on B-mode ultrasound image which does not get good results. To improve the accuracy of classification, first, we propose a novel method, i.e., a Temporal Sequence Dual-Branch Network (TSDBN) which, for the first time, can use B-mode ultrasound data and CEUS data simultaneously. Second, we designed a new Gram matrix to model the temporal sequence, and then proposed a Temporal Sequence Regression Mechanism (TSRM), which is a novel method to extract the enhancement features from CEUS video based on the matrix. For B-mode ultrasound branch, we use the traditional ResNeXt network for feature extraction. While CEUS branch uses ResNeXt + R(2 + 1) D network as the backbone network. We propose a TSRM to learning temporal sequence relationship among frames, and design a Shuffle Temporal Sequence Mechanism (STSM) to shuffle temporal sequences, the purpose of which is to further enhance temporal information among frames. Experimental results show that the proposed TSRM could use temporal information effectively and the accuracy of TSDBN is higher than that of state-of-art approaches in breast cancer classification by nearly 4%.

In recent years, a more robust facial feature can be learned by convolutional neural networks once introducing margins into loss functions. Those methods set a margin for each class manually to squeeze the intra‐class variations within each class equally. However, the internal feature distributions of different persons in the real world are highly unbalanced, and the distance between different identities is not uniform either. As a result, applying the same margin on all classes might not lead to higher inter‐class differences. To address this problem, this paper proposes an adaptive margin based on feature distribution to squeeze the feature interior spaces of different classes. Simultaneously, because the inter‐class margin can adequately represent the distribution of different classes in the feature space, this paper proposes a novel diversity regularization method. The regularization weights of each class are dynamically set depending on their margins. This method proposed in this paper is intuitively interpretable and can be easily applied to other classification scenarios. Experiments on current existing benchmarks have demonstrated the superiority of our method over state‐of‐the‐art competitors.