“…In the past decades, researchers have developed many extensions built on the above formulation, and they have been successfully applied to deal with various problems as well as various kinds of text data, e.g., topic correlations [5,23,27,30], dynamic topics varying over time [4,51], and sparse topics within short texts [9,16,31,44], etc. Commonly, the popular model inference methods include variational inference often with mean-field approximations [6,24], Gibbs sampling [18], and hybrid methods [29,38].…”