Text Mining NLP ML (Hierarchical)Topic Modeling Yueshen Xu (lecturer) ysxu@xidian.edu.cn xuyueshen@163.com Data and Knowledge Engineering Research Center Xidian University(Hierarchical) Topic Modeling Yueshen Xu (lecturer) ysxu@xidian.edu.cn / xuyueshen@163.com Data and Knowledge Engineering Research Center Xidian University Text Mining & NLP & ML