1 / 7

Markov Networks

Markov Networks. Markov Networks. Smoking. Cancer. Undirected graphical models. Asthma. Cough. Potential functions defined over cliques. Markov Networks. Smoking. Cancer. Undirected graphical models. Asthma. Cough. Log-linear model:. Weight of Feature i. Feature i.

usoa
Télécharger la présentation

Markov Networks

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Markov Networks

  2. Markov Networks Smoking Cancer • Undirected graphical models Asthma Cough • Potential functions defined over cliques

  3. Markov Networks Smoking Cancer • Undirected graphical models Asthma Cough • Log-linear model: Weight of Feature i Feature i

  4. Hammersley-Clifford Theorem If Distribution is strictly positive (P(x) > 0) And Graph encodes conditional independences Then Distribution is product of potentials over cliques of graph Inverse is also true. (“Markov network = Gibbs distribution”)

  5. Markov Nets vs. Bayes Nets

  6. Moralization To convert a Bayesian network into a Markov network: • For each variable:Add arcs between its parents(“marry” them) • Remove arrows

  7. Examples • Statistical physics • Vision / Image processing • Social networks • Web page classification • Etc.

More Related