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Activity Number:
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20
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Type:
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Topic Contributed
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Date/Time:
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Sunday, July 29, 2007 : 2:00 PM to 3:50 PM
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Sponsor:
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Section on Bayesian Statistical Science
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| Abstract - #308910 |
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Title:
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Bayesian Classification of Sleep States in Mice (Student Paper Competition)
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Author(s):
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Chaitra Nagaraja*+ and Shane T. Jensen and Abraham Wyner
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Companies:
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University of Pennsylvania and University of Pennsylvania and University of Pennsylvania
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Address:
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2400 Chestnut St, Wharton School, Philadelphia, PA, 19103,
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Keywords:
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Bayesian ; classification ; hidden Markov model ; Viterbi
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Abstract:
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We examine the problem of inferring sleep states (awake, non-REM sleep, and REM sleep) in mice based on video data. Observed measures of velocity, size, and aspect ratio of a mouse were taken from video images over extended time periods. Data from one mouse was used to fit a hidden Markov model with the sleep states for each observation as latent variables. Mixture modeling in the emission densities was needed to account for multi-modality in the observed variables. We compare the accuracy of predictions based on the optimal path of sleep states generated from a Viterbi algorithm with predictions generated directly with the posterior state probabilities for each observation. The proposed Bayesian procedure provides more accurate classifications.
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