1 / 11

Dynamic Bayesian Networks

Representation. Probabilistic Graphical Models. Template Models. Dynamic Bayesian Networks. Template Transition Model. Weather. Weather’. Velocity. Velocity’. Location. Location’. Failure. Failure’. Obs’. Time slice t. Time slice t+1. Initial State Distribution. Weather 0.

reegan
Télécharger la présentation

Dynamic Bayesian 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. Representation Probabilistic Graphical Models Template Models DynamicBayesianNetworks

  2. Template Transition Model Weather Weather’ Velocity Velocity’ Location Location’ Failure Failure’ Obs’ Time slice t Time slice t+1

  3. Initial State Distribution Weather0 Velocity0 Location0 Failure0 Obs0 Time slice 0

  4. Ground Bayesian Network Weather0 Weather1 Weather2 Velocity0 Velocity1 Velocity2 Location0 Location1 Location2 Failure0 Failure1 Failure2 Obs0 Obs1 Obs2 Time slice 2 Time slice 0 Time slice 1

  5. Tim Huang, Dieter Koller, JitendraMalik, Gary Ogasawara, Bobby Rao, Stuart Russell, J. Weber

  6. Dynamic Bayesian Network • A transition model over X1,…,Xn is specified via • A dynamic Bayesian network is specified via

  7. Ground Network

  8. Hidden Markov Models S S’ S0 S1 S2 S3 O’ O1 O2 O3 0.3 0.1 0.5 0.7 0.4 0.5 s1 s2 s3 s4 0.6 0.9

  9. Hidden Markov Models S S’ S0 S1 S2 S3 O’ O1 O2 O3 0.3 0.1 0.5 0.7 0.4 0.5 s1 s2 s3 s4 0.6 0.9

  10. Consider a smoke detection tracking application, where we have 3 rooms connected in a row. Each room has a true smoke level (X) and a smoke level (Y) measured by a smoke detector situated in the middle of the room. Which of the following is the best DBN structure for this problem? X1 X1 X1 X1 X’1 X’1 X’1 X’1 Y’1 Y’1 Y’1 Y’1 X2 X2 X2 X2 X’2 X’2 X’2 X’2 Y’2 Y’2 Y’2 Y’2 X3 X3 X3 X3 X’3 X’3 X’3 X’3 Y’3 Y’3 Y’3 Y’3

  11. Summary • DBNS are a compact representation for encoding structured distributions over arbitrarily long temporal trajectories • They make assumptions that may require appropriate model (re)design: • Markov assumption • Time invariance

More Related