papers: Estimation of Dirichlet Distribution Parameters

Recently, I am interested in apply Pachinko Allocation topic models to the object recognition problems. Mixtures of Hierarchical Topics with Pachinko Allocation, ICML 2007 mentioned several methods in training the hPAM model, and here are the related papers: 

• Gibbs EM: 
• An introduction to MCMC for machine learning, Machine Learning 2003
• implementations of the Monte Carlo EM Algorithm, 2001
  
• fixed point iteration method for estimating the Dirichlet parameters: 
• Estimating a Dirichlet distribution, Minka 2000, and code
• Maximum Likelihood Estimation of Dirichlet Distribution Parameters by Jonathan Huang