Journal article
Infinite hidden conditional random fields for human behavior analysis
Imperial Coll. London, London, UK
Inst. for Creative Technol., Univ. of Southern California, Playa Vista, CA, USA
Hidden conditional random fields (HCRFs) are discriminative latent variable models that have been shown to successfully learn the hidden structure of a given classification problem (provided an appropriate validation of the number of hidden states). In this brief, we present the infinite HCRF (iHCRF), which is a nonparametric model based on hierarchical Dirichlet processes and is capable of automatically learning the optimal number of hidden states for a classification task.
We show how we learn the model hyperparameters with an effective Markov-chain Monte Carlo sampling technique, and we explain the process that underlines our iHCRF model with the Restaurant Franchise Rating Agencies analogy. We show that the iHCRF is able to converge to a correct number of represented hidden states, and outperforms the best finite HCRFs--chosen via cross-validation--for the difficult tasks of recognizing instances of agreement, disagreement, and pain.
Moreover, the iHCRF manages to achieve this performance in significantly less total training, validation, and testing time.
Language: | English |
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Publisher: | IEEE |
Year: | 2013 |
Pages: | 170-177 |
ISSN: | 21622388 and 2162237x |
Types: | Journal article |
DOI: | 10.1109/TNNLS.2012.2224882 |
Algorithms Artificial Intelligence Behavior Computer Simulation Discriminative models Hidden Markov models Humans Learning systems Markov Chains Mathematical model Monte Carlo Method Pain Pattern Recognition, Automated Training Trajectory Vectors hidden conditional random fields nonparametric Bayesian learning