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Posted to commits@mahout.apache.org by is...@apache.org on 2013/11/21 12:58:47 UTC
svn commit: r1544145 -
/mahout/site/mahout_cms/trunk/content/users/stuff/hidden-markov-models.mdtext
Author: isabel
Date: Thu Nov 21 11:58:47 2013
New Revision: 1544145
URL: http://svn.apache.org/r1544145
Log:
MAHOUT-1245 - formatting
Modified:
mahout/site/mahout_cms/trunk/content/users/stuff/hidden-markov-models.mdtext
Modified: mahout/site/mahout_cms/trunk/content/users/stuff/hidden-markov-models.mdtext
URL: http://svn.apache.org/viewvc/mahout/site/mahout_cms/trunk/content/users/stuff/hidden-markov-models.mdtext?rev=1544145&r1=1544144&r2=1544145&view=diff
==============================================================================
--- mahout/site/mahout_cms/trunk/content/users/stuff/hidden-markov-models.mdtext (original)
+++ mahout/site/mahout_cms/trunk/content/users/stuff/hidden-markov-models.mdtext Thu Nov 21 11:58:47 2013
@@ -1,13 +1,16 @@
Title: Hidden Markov Models
+
+# Hidden Markov Models
+
<a name="HiddenMarkovModels-IntroductionandUsage"></a>
-### Introduction and Usage
+## Introduction and Usage
Hidden Markov Models are used in multiple areas of Machine Learning, such
as speech recognition, handwritten letter recognition or natural language
processing.
<a name="HiddenMarkovModels-FormalDefinition"></a>
-### Formal Definition
+## Formal Definition
A Hidden Markov Model (HMM) is a statistical model of a process consisting
of two (in our case discrete) random variables O and Y, which change their
@@ -28,26 +31,26 @@ containing the observation probabilities
P(O=o_i|Y=y_j).
<a name="HiddenMarkovModels-Problems"></a>
-### Problems
+## Problems
Rabiner \[1\](1\.html)
defined three main problems for HMM models:
- 1. Evaluation: Given a sequence O of observations and a model M, what is
+1. Evaluation: Given a sequence O of observations and a model M, what is
the probability P(O|M) that sequence O was generated by model M. The
Evaluation problem can be efficiently solved using the Forward algorithm
- 2. Decoding: Given a sequence O of observations and a model M, what is
+2. Decoding: Given a sequence O of observations and a model M, what is
the most likely sequence Y*=argmax(Y) P(O|M,Y) of hidden variables to
generate this sequence. The Decoding problem can be efficiently solved
using the Viterbi algorithm.
- 3. Learning: Given a sequence O of observations, what is the most likely
+3. Learning: Given a sequence O of observations, what is the most likely
model M*=argmax(M)P(O|M) to generate this sequence. The Learning problem
can be efficiently solved using the Baum-Welch algorithm.
<a name="HiddenMarkovModels-Resources"></a>
-### Resources
+## Resources
-\[1\](1\.html)
+\[1\]
Lawrence R. Rabiner (February 1989). "A tutorial on Hidden Markov Models
and selected applications in speech recognition". Proceedings of the IEEE
77 (2): 257-286. doi:10.1109/5.18626.