“…To overcome the anomaly-based IDS weaknesses, various artificial and computational intelligence algorithms either integrating with meta-heuristic optimization approaches or without them are investigated, such as fuzzy logic Karami & Guerrero-Zapata (2015b); Feizollah et al (2013), Support Vector Machine (SVM) Kabir et al (2017); Bao & Wang (2016), Radial Basis Function (RBF) Karami & Guerrero-Zapata (2015c); Bi et al (2009), Artificial Neural Network (ANN) Subba et al (2016); Hodo et al (2016), Self-Organizing Map (SOM) la Hoz et al 2015; Karami & Guerrero-Zapata (2014); dong Wang et al (2007), Adaptive Neuro-Fuzzy Inference System (ANFIS) Devi et al (2017); Karami & Guerrero-Zapata (2015a), and Principle Component Analysis (PCA) An & Weber (2017); Khalid et al (2015). Nevertheless, the major drawbacks of anomaly-based IDSs exist in terms of the lower detection precision and the higher false positive rate in presence of low-frequent patterns called outliers, resulting in weaker detection stability Karami & Guerrero-Zapata (2015b); Jabez & Muthukumar (2015); Luo & Xia (2014).…”