Towards Efficient Data Sampling for Temporal Anomaly Detection in Sensor Networks
Rayane El Sibai, Yousra Chabchoub, Chady Abou Jaoude, Jacques Demerjian, Maurras Ulbricht Togbe · 2019
Data streams sampling is intended to build a sample on which the future data analysis tasks will be performed. Several parameters affect the effectiveness of the built sample: the used sampling algorithm, chosen sampling rate, and window size if the sliding window model is adopted. Thus, given a stream of items, the most challenging task is to select the most relevant sampling technique to apply and the right parameters to employ to sample the data. In this paper, we address the impact of data sampling on the anomaly detection results. First, we develop a new version of the Weighted Random Sampling (WRS) algorithm that samples the data based on their values with respect to the values of their neighbors in the current sliding window. Thereafter, we study the impact of the sampling process on the anomalies detection using the Exponential Weighted Moving Average (EWMA) algorithm. In this context, the comparison of the sampling algorithms is based on their response time in case of anomaly and the relevance of the detected anomalies.