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SUMMARY:Calibration of an individual based HIV computer model using emulat
 ion and history matching - Ioannis Andrianakis\, London School of Hygiene 
 and Tropical Medicine
DTSTART:20131129T153000Z
DTEND:20131129T163000Z
UID:TALK48823@talks.cam.ac.uk
CONTACT:Prof. Julia Gog
DESCRIPTION:\nAdvances in scientific computing have allowed the developmen
 t of complex models that are being routinely applied to problems in physic
 s\, engineering\, biology and other disciplines. The utility of these mode
 ls depends on how well they are calibrated to empirical data. Their calibr
 ation is hindered however\, both by large numbers of input and output para
 meters and by run times that increase with the model's complexity. In this
  talk we present a calibration method called History Matching\, which is i
 terative and scales well with the dimensionality of the problem. History m
 atching is based on the concept of an emulator\, which is a Bayesian repre
 sentation of our beliefs about the model\, given the runs that are availab
 le to us. Capitalising on the efficiency of the emulator\, History Matchin
 g iteratively discards regions of the input space that are unlikely to pro
 vide a good match to the empirical data\, and is based on successive runs 
 of the computer model in narrowing areas of the input space\, which are kn
 own as waves. This calibration technique can be embedded in a comprehensiv
 e error modelling framework\, that takes into account various sources of u
 ncertainty\, due to the parameters\, the model itself\, the observations e
 tc. A calibration example of a high dimensional HIV model will be used to 
 illustrate the method. \n\n
LOCATION:MR15\,  Centre for Mathematical Sciences\, Wilberforce Road\, Cam
 bridge
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