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Anomaly detection is crucial in the petroleum industry for monitoring critical machinery. [20] Martí et al. used a novel segmentation algorithm to analyze sensor data for real-time anomaly detection. [20] This approach helps promptly identify and address any irregularities in sensor readings, ensuring the reliability and safety of petroleum ...
In statistical analysis, change detection or change point detection tries to identify times when the probability distribution of a stochastic process or time series changes. In general the problem concerns both detecting whether or not a change has occurred, or whether several changes might have occurred, and identifying the times of any such ...
Isolation Forest is an algorithm for data anomaly detection using binary trees.It was developed by Fei Tony Liu in 2008. [1] It has a linear time complexity and a low memory use, which works well for high-volume data.
The following example shows 20 observations of a process with a mean of 0 and a standard deviation of 0.5. From the Z {\displaystyle Z} column, it can be seen that X {\displaystyle X} never deviates by 3 standard deviations ( 3 σ {\displaystyle 3\sigma } ), so simply alerting on a high deviation will not detect a failure, whereas CUSUM shows ...
Version 0.2 (July 2009) added functionality for time series analysis, in particular distance functions for time series. [ 13 ] Version 0.3 (March 2010) extended the choice of anomaly detection algorithms and visualization modules.
In anomaly detection, the local outlier factor (LOF) is an algorithm proposed by Markus M. Breunig, Hans-Peter Kriegel, Raymond T. Ng and Jörg Sander in 2000 for finding anomalous data points by measuring the local deviation of a given data point with respect to its neighbours.
For example, time series are usually decomposed into: , the trend component at time t, which reflects the long-term progression of the series (secular variation). A trend exists when there is a persistent increasing or decreasing direction in the data. The trend component does not have to be linear. [1]
Another method is to define what normal usage of the system comprises using a strict mathematical model, and flag any deviation from this as an attack. This is known as strict anomaly detection. [3] Other techniques used to detect anomalies include data mining methods, grammar based methods, and Artificial Immune System. [2]