PARAMETER-ESTIMATION OF DEPENDENCE TREE MODELS USING THE EM ALGORITHM

被引:41
作者
RONEN, O [1 ]
ROHLICEK, JR [1 ]
OSTENDORF, M [1 ]
机构
[1] BBN HARK SYST CORP,CAMBRIDGE,MA 02138
关键词
D O I
10.1109/97.404132
中图分类号
TM [电工技术]; TN [电子技术、通信技术];
学科分类号
0808 ; 0809 ;
摘要
A dependence tree is a model for the joint probability distribution of an n-dimensional random vector, which requires a relatively small number of free parameters by making Markov-like assumptions on the tree. In this letter, we address the problem of maximum likelihood estimation of dependence tree models with missing observations, using the expectation-maximization algorithm. The solution involves computing observation probabilities with an iterative ''upward-downward'' algorithm, which is similar to an algorithm proposed for belief propagation in causal trees, a special case of Bayesian networks.
引用
收藏
页码:157 / 159
页数:3
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