“…In topic clustering, based on previous experience, the number of design stages in this design process is usually between five and nine, so the cluster number was selected from 5 to 9. Another parameter, the fusion coefficient parameter was selected from 0.2 to 0.9 [40]. To determine optimal K and , three measures evaluation metrics: silhouette-score (S score), Calinski-Harabaz score (CH score), and Davies-Bouldin score (DBI score) [45], are utilised.…”