WeiKai He

Muhao Xu, Xueying Zhou, Xizhan Gao et al.

Unsupervised representation learning has been extensively employed in anomaly detection, achieving impressive performance. Extracting valuable feature vectors that can remarkably improve the performance of anomaly detection are essential in unsupervised representation learning. To this end, we propose a novel discriminative feature learning framework with gradient preference for anomaly detection. Specifically, we firstly design a gradient preference based selector to store powerful feature points in space and then construct a feature repository, which alleviate the interference of redundant feature vectors and improve inference efficiency. To overcome the looseness of feature vectors, secondly, we present a discriminative feature learning with center constrain to map the feature repository to a compact subspace, so that the anomalous samples are more distinguishable from the normal ones. Moreover, our method can be easily extended to anomaly localization. Extensive experiments on popular industrial and medical anomaly detection datasets demonstrate our proposed framework can achieve competitive results in both anomaly detection and localization. More important, our method outperforms the state-of-the-art in few shot anomaly detection.

Sen Zhang, Xin Ma, Hongwang Lu et al.

Echolocating bats locate the targets by echolocation. Many theoretical frameworks have been suggested the abilities of bats are related to the shapes of bats ears, but few artificial bat-like ears have been made to mimic the abilities, the difficulty of which lies in the determination of the elevation angle of the target. In this study, we present a device with artificial bat pinnae modeling by the ears of brown long-eared bat (Plecotus auritus) which can accurately estimate the elevation angle of the aerial target by virtue of active sonar. An artificial neural-network with the labeled data obtained from echoes as the trained and tested data is used and optimized by a tenfold cross-validation technique. A decision method we named sliding window averaging algorithm is designed for getting the estimation results of elevation. At last, a right-angle pinnae construction is designed for determining direction of the target. The results show a higher accuracy for the direction determination of the single target. The results also demonstrate that for the Plecotus auritus bat, not only the binaural shapes, but the binaural relative orientations also play important roles in the target localization.