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Detection of subsurface hydrodynamic anomalies plays a significant role in groundwater resource management and environmental monitoring. In this paper, based on data from the groundwater level, atmospheric pressure, and precipitation in the Chengdu area of China, a method for detecting outliers considering the factors affecting groundwater levels is proposed. By analyzing the factors affecting groundwater levels in the monitoring site and eliminating them, simplified groundwater data is obtained. Applying sl-Pauta (self-learning-based Pauta), iForest (Isolated Forest), OCSVM (One-Class SVM), and KNN to synthetic data with known outliers, testing and evaluating the effectiveness of 4 technologies. Finally, the four methods are applied to the detection of outliers in simplified groundwater levels. The results show that in the detection of outliers in synthesized data, the OCSVM method has the best detection performance, with a precision rate of 88.89%, a recall rate of 91.43%, an F1 score of 90.14%, and an AUC value of 95.66%. In the detection of outliers in simplified groundwater levels, a qualitative analysis of the displacement data within the field of view indicates that the outlier detection performance of iForest and OCSVM is better than that of KNN. The proposed method for considering the factors affecting groundwater levels can improve the efficiency and accuracy of detecting outliers in groundwater level data. [ABSTRACT FROM AUTHOR]

Due to the explosive growth of data in the Internet, more and more applications are being deployed on Big Data platforms. However, as the scale of data continues to increase, the probability of anomalies in the platform is also increasing. However, traditional anomaly detection techniques cannot effectively handle the massive amount of historical data and can hardly meet the security requirements of big data platforms. In order to solve the above problems, this paper proposes a security anomaly detection method for big data platforms based on quantum optimization clustering. Firstly, a framework of big data platform anomaly detection system is designed based on distributed software architecture through Hadoop and Spark big data open source technology. The system achieves effective detection of network anomalies by collecting and analyzing big data platform server log data. Secondly, an offline anomaly detection algorithm based on quantum ant colony optimized affinity propagation clustering is designed for various anomalies mined from historical data. The bias parameters of the affinity propagation clustering are treated as individual ants to construct an ant colony, and the clustering accuracy is set as fitness. Finally, in order to improve the accuracy of the optimal path search of the ant colony, quantum bit encoding is applied to the ant colony position to refine the granularity of the individual ant colony position update. The experimental results show that the proposed method can effectively complete the anomaly clustering detection of massive data. With a reasonable threshold, the quantum ant colony–based affinity propagation clustering has high detection accuracy. [ABSTRACT FROM AUTHOR]