As mentioned above, the current topic trend θ t,k is drawn from the following Dirichlet distribution with the previous trendθ t−1,k where θ t,k,v represents the probability that word v is chosen in topic k at time t. Here our proposed Twitter-TTM adapts the above TTM assumptions to the improved model.
we extend the improved model whereby user interest ϕ t,u and topic trend θ t,k depend on previous states.