hal-00328181, version 1
Bayesian hidden Markov Model for DNA segmentation : A prior sensitivity analysis
Computational Statistics & Data Analysis (2009) 9999
Résumé : The focus of this paper is on the sensitivity to the specification of the prior in a hidden Markov model describing homogeneous segments of DNA sequences. An intron from the chimpanzee α-fetoprotein gene, which plays an im- portant role in embryonic development in mammals is analysed. Three main aims are considered : (i) to assess the sensitivity to prior specification in Bayesian hidden Markov models for DNA sequence segmentation; (ii) to examine the impact of replacing the standard Dirichlet prior with a mixture Dirichlet prior; and (iii) to propose and illus- trate a more comprehensive approach to sensitivity analysis, using importance sampling. It is obtained that (i) the posterior estimates obtained under a Bayesian hidden Markov model are indeed sensitive to the specification of the prior distributions; (ii) compared with the standard Dirichlet prior, the mixture Dirichlet prior is more flexible, less sensitive to the choice of hyperparameters and less constraining in the analysis, thus improving posterior estimates; and (iii) importance sampling was computationally feasible, fast and effective in allowing a richer sensitivity analysis.
- 1 :
- University of Newcastle
- 2 :
- ARC center of excellence for complex dunamic systems and control
- 3 :
- CNRS : UMR7534 – Université Paris IX - Paris Dauphine
- 4 :
- INSEE – École Nationale de la Statistique et de l'Administration Économique
- 5 :
- Queensland University of Technology
- Collaboration : Darfiana Nur,David Allingham, Judith Rousseau , Kerrie L. Mengersen, Ross McVinishd
- Domaine : Mathématiques/Statistiques
Statistiques/Théorie - Mots-clés : DNA sequence – hidden Markov model – Bayesian model – sensitivity analysis – α-fetoprotein – Markov chain Monte Carlo – importance sampling.
- hal-00328181, version 1
- http://hal.archives-ouvertes.fr/hal-00328181
- oai:hal.archives-ouvertes.fr:hal-00328181
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- Soumis le : Vendredi 10 Octobre 2008, 22:10:25
- Dernière modification le : Samedi 14 Février 2009, 17:00:07




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