ie a SIR infection model upgrade
Professor Petty said, in reply: “I remember well wrestling with the three differential equations governing thermally stimulated currents. Much fun, but one equation would have been preferable.” I remember that there were umpteen equations in Nicollian & Goetzberger*, but the novelty was to match the wide curves with (numerous) surface potential variation (area)s across the MOS device interface.
He continued “But, I don’t think you can reduce the number of unknowns.” And my feeling is that the little areas, though never really calculated, except statistically, give you the multiple unknowns needed to solve the problem.
Nowadays the modelling is simpler with computers but the real problem lies elsewhere. And in the current scenario it’s appreciation of the R0 (Reproduction value). Two points:
Average R0
Statistics understanding It was nice to see Boris give us an online video on the reproductive number. And thereafter the BBC chap explain that we are talking about average R.
Effective R0 (ie after the this testing…. via healthknowledge.org.uk)
For example, if R0 for influenza is 12 in a population where half of the population is immune, the effective reproductive number for influenza is 12 x 0.5 = 6. Under these circumstances, a single case of influenza would produce an average of 6 new secondary cases.
Interestingly the above last two paras are currently pending approval on the Times website
- The si-sio, interface — electrical properties as determined by the metal-insulator-silicon conductance technique. Nicollian & Goetzberger 1967
