One note of the Baum-Welch algothrim on FSNLP chapter 9

Posted on October 21, 2008 by yongsun

On chapter 9 of "Foundations of Statistical Natural Language Processing", section 9.3.3, for a state-emission HMM, we need to use the following equation to re-estimate the b'_ik

$\hat{b}_{ik} = \frac{\sum_{\{ o_t=k, t\in[1,T]\}}\gamma_i(t)}{\sum_{t=1}^T\gamma_i(t)}$

So that, b'_{cp,cola} = 0.88/(1.0+0.3+0.88) = 0.4037

2 thoughts on “One note of the Baum-Welch algothrim on FSNLP chapter 9”

Jean-Claude Vandonghen on October 21, 2008 at 11:44 am said:

sho nuff, thanks for the tip
all the best
Yong Sun on October 21, 2008 at 8:22 pm said:

The new CodeCogs equation editor (previously aka as izyba editor) is so great, powerful and better than sitmo's.

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