“…The highest recognition rate is calculated for the five types of hierarchical entropies under multi-feature extraction, as shown in Table 7, where (1,5) indicates the combination of nodes with the highest recognition rate for two features are node 1 and node 5, (1,5,6) indicates the combination of nodes with the highest recognition rate for three features are node 1, node 5 and node 6, and so on. Table 7 shows that no matter how many features are extracted, the recognition rate of these ten types of bearing signals using WSO-HSlopEn is higher than that of other hierarchical entropies; additionally, the more features we select, the better the recognition effect we obtain; in the circumstances of multi-features, the recognition rates of WSO-HSlopEn are all higher than 97.5%, yet the highest recognition rates of other hierarchical entropies are all significantly below 97.5%; for WSO-HSlopEn, when five nodes are selected, that is, choosing nodes (1,5,6,7,11), the highest recognition rate of these ten types of bearing signals reaches 100%; however, the highest recognition rate of other entropies is, respectively, 3.80%, 10.53%, 16.73%, and 4.13% lower than that of WSO-HSlopEn. Through the above comparison, we can clearly find the significant advantages of the proposed method based on WSO-HSlopEn, and the recognition results applied to diagnose faults of rolling bearings are higher than those of classic methods.…”