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crowdfightcovid19 / req-550-Syria

Repository to host the code of request 550 coming from the Pax Syriana Foundation
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Update of total population size #5

Closed apascualgarcia closed 4 years ago

apascualgarcia commented 4 years ago

Clarify if N should be reduced with deaths and removal of population from the camps

ecam85 commented 4 years ago

I am trying to find a good reference to double check this, but I believe that N should remain constant.

From the technical point of view, the derivation of the model requieres N constant. In the simplest model, one has (S/N)' = - \beta (I/N)(S/N), representing that contacts are independent and \beta is the infection probability in a given contact. This equation becomes S' = - \beta/N I S iff N is constant.

From the practical point of view, if the reduction in N is significant, the effective population in the camp is small and the SEIR type model is no longer be a good approximation.