K値論文

Indicator K to analyze the transition of
COVID-19 spread In this study,

we introduce a new indicator called the
K value defined by K(d) = 1−N(d − 7)/N(d), where d is the number
of days from the reference date,
and N (d) and N (d − 7) are the
total number of infected people
on days d and (d − 7), respectively.
Since N (d) is greater than N (d − 7)
during the period from the initiation
of spread to convergence,
K takes a value between 0 and 1.
( infected people 感染者)


k = 1 + 2.88K′ (Fig. S1).
この公式を図へあてはめたのか、
図から帰納的に公式を導いたのか、
特に2.88の由来はなんだろう？？