Wednesday, December 11, 2013

Functions for life span distribution. GG91

page 43, two parameter Gompertz model

page 44, Gompertz-Makeham model

Quadratic form of Gompertz-Makeham model, El Shaarawi et al 1974
  u(t) = M + R exp( at + bt^2)

Logistic equations like the Perks equation, which can be derived from GG91's avalanche-like aging model.

 Weibull model (1951): u(t) = B * t^c

page 46, GG91's generalized bionomial mortality model:
  u(t) = A + (b + c t)^n
GG91 argues that when b >>c, bionomial model lead to R=b^n, G=nc/b
When b<<c,  it is the Weibull model.





No comments:

Post a Comment