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Dependent Hierarchical Normalized Random Measures for Dynamic Topic Modeling Changyou Chen, Nan Ding and Wray Buntine ICML 2012. Presented by: Mingyuan Zhou Duke University, ECE October 24, 2012. Introduction. NRM: normalized random measures with independent increments
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Dependent Hierarchical Normalized Random Measures for Dynamic Topic ModelingChangyou Chen, Nan Ding and Wray BuntineICML 2012 Presented by: Mingyuan Zhou Duke University, ECE October 24, 2012
Introduction • NRM: normalized random measures with independent increments • Superposition, subsampling and point transition of NRM • Dependent hierarchical NRM • Dynamic topic modeling
Normalized Random Measures • Poisson process • Completely random measures (CRM)
Normalized Random Measures • Completely random measures (CRM)
Normalized Random Measures • Slice sampling NRMs Ref: Griffin, J.E. and Walker, S.G. Posterior simulation of normalized random measure mixtures. J. Comput. Graph. Stat., 2011.
Normalized Random Measures • Normalized generalized gamma process
Dynamic topic modeling with dependent hierarchical NRMs • Ideas: • Inherit topics from the previous time frame through three dependency operators: • Superposition • Subsampling • Point transition • Generate new topics
Dynamic topic modeling with dependent hierarchical NRMs • Properties of the dependence operators
Dynamic topic modeling with dependent hierarchical NRMs • Reformulated model
Dynamic topic modeling with dependent hierarchical NRMs • Original and reformulated model
Sampling • Sampling under the Chinese restaurant metaphor
Sampling • Sampling under the Chinese restaurant metaphor
Experiments • Power-law in the NGG