Forward–backward algorithm

The forward–backward algorithm is an inference algorithm for hidden Markov models which computes the posterior marginals of all hidden state variables given a sequence of observations/emissions , i.e. it computes, for all hidden state variables , the distribution . This inference task is usually called smoothing. The algorithm makes use of the principle of dynamic programming to efficiently compute the values that are required to obtain the posterior marginal distributions in two passes. The first pass goes forward in time while the second goes backward in time; hence the name forward–backward algorithm.

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enThe forward–backward algorithm is an inference algorithm for hidden Markov models which computes the posterior marginals of all hidden state variables given a sequence of observations/emissions , i.e. it computes, for all hidden state variables , the distribution . This inference task is usually called smoothing. The algorithm makes use of the principle of dynamic programming to efficiently compute the values that are required to obtain the posterior marginal distributions in two passes. The first pass goes forward in time while the second goes backward in time; hence the name forward–backward algorithm.
Has abstract
enThe forward–backward algorithm is an inference algorithm for hidden Markov models which computes the posterior marginals of all hidden state variables given a sequence of observations/emissions , i.e. it computes, for all hidden state variables , the distribution . This inference task is usually called smoothing. The algorithm makes use of the principle of dynamic programming to efficiently compute the values that are required to obtain the posterior marginal distributions in two passes. The first pass goes forward in time while the second goes backward in time; hence the name forward–backward algorithm. The term forward–backward algorithm is also used to refer to any algorithm belonging to the general class of algorithms that operate on sequence models in a forward–backward manner. In this sense, the descriptions in the remainder of this article refer but to one specific instance of this class.
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Forward–backward algorithm
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enForward–backward algorithm
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www.cs.jhu.edu/~jason/papers/%23eisner-2002-tnlp
dx.doi.org/10.1109/5.18626
www.cs.brown.edu/research/ai/dynamics/tutorial/Documents/HiddenMarkovModels.html
code.google.com/p/aima-java/
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Algorithm
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Category:Dynamic programming
Category:Error detection and correction
Category:Machine learning algorithms
Category:Markov models
Conditional independence
Dynamic programming
Hidden Markov model
IEEE
Ill-conditioned
Island algorithm
Lawrence Rabiner
Marginal probability
Posterior probability
Python programming language
Statistical inference
Time complexity
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Algorithme forward-backward
Algoritmo de avance-retroceso
Algoritmo forward-backward
m.0283cbn
Q4909
Алгоритм прямого-обратного хода
الگوریتم پس‌رو-پیش‌رو
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Category:Dynamic programming
Category:Error detection and correction
Category:Machine learning algorithms
Category:Markov models
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