Learning
The parameter learning task in HMMs is to find, given an output sequence or a set of such sequences, the best set of state transition and output probabilities. The task is usually to derive the maximum likelihood estimate of the parameters of the HMM given the set of output sequences. No tractable algorithm is known for solving this problem exactly, but a local maximum likelihood can be derived efficiently using the Baum–Welch algorithm or the Baldi–Chauvin algorithm. The Baum–Welch algorithm is a special case of the expectation-maximization algorithm.
Read more about this topic: Hidden Markov Model
Famous quotes containing the word learning:
“The first man to discover Chinook salmon in the Columbia, caught 264 in a day and carried them across the river by walking on the backs of other fish. His greatest feat, however, was learning the Chinook jargon in 15 minutes from listening to salmon talk.”
—State of Oregon, U.S. public relief program (1935-1943)
“Isn’t it odd that networks accept billions of dollars from advertisers to teach people to use products and then proclaim that children aren’t learning about violence from their steady diet of it on television!”
—Toni Liebman (20th century)
“Men and boys are learning all kinds of trades but how to make men of themselves. They learn to make houses; but they are not so well housed, they are not so contented in their houses, as the woodchucks in their holes.”
—Henry David Thoreau (1817–1862)