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Comput Intell Neurosci ; 2021: 1955116, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34621305


Video abnormal event detection is a challenging problem in pattern recognition field. Existing methods usually design the two steps of video feature extraction and anomaly detection model establishment independently, which leads to the failure to achieve the optimal result. As a remedy, a method based on one-class neural network (ONN) is designed for video anomaly detection. The proposed method combines the layer-by-layer data representation capabilities of the autoencoder and good classification capabilities of ONN. The features of the hidden layer are constructed for the specific task of anomaly detection, thereby obtaining a hyperplane to separate all normal samples from abnormal ones. Experimental results show that the proposed method achieves 94.9% frame-level AUC and 94.5% frame-level AUC on the PED1 subset and PED2 subset from the USCD dataset, respectively. In addition, it achieves 80 correct event detections on the Subway dataset. The results confirm the wide applicability and good performance of the proposed method in industrial and urban environments.

Algoritmos , Redes Neurais de Computação
Chemosphere ; 141: 80-6, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26141554


Bisphenol A (BPA) is a ubiquitous environmental contaminant with endocrine disruption potential. This study explored the efficiency, kinetics, and mechanism of BPA removal from weakly acidic solutions by using NaBiO3 as a source of singlet oxygen. It was observed that the use of NaBiO3 (1gL(-1)) could eliminate almost all (more than 97%) of the added BPA (0.1mmolL(-1)) in solutions at pH 5.0 in 60min. The degradation of BPA followed pseudo-first-order kinetics over the pH range from 3 to 9, and the pseudo-first-order rate constant (k) was dependent on pH, NaBiO3 concentration and the coexisting compounds. As solution pH was decreased from 9 to 3 or NaBiO3 concentration was increased from 0.5 to 2gL(-1), the k value was increased logarithmically. Humic acid and Fe(3+) showed little effect on the BPA removal, but Mn(2+) exhibited exceptionally enhancing effect on the degradation of BPA. The involved reactive species were identified as singlet oxygen by using radical scavenger probes and ESR measurement, and the generated singlet oxygen was confirmed to be generated from the decomposition of NaBiO3 mediated by H(+) ions.

Compostos Benzidrílicos/análise , Bismuto/química , Disruptores Endócrinos/análise , Fenóis/análise , Oxigênio Singlete/química , Sódio/química , Compostos Benzidrílicos/química , Disruptores Endócrinos/química , Substâncias Húmicas/análise , Cinética , Luz , Compostos de Manganês/química , Oxirredução , Fenóis/química , Soluções