Solution
= Solution
With frequency-dependent transmission parameter $\beta$, the nonlinear SEIR equations are
$$
\dot S=-\beta\frac{SI}{N},
\qquad
\dot E=\beta\frac{SI}{N}-q_{EI}E,
\qquad
\dot I=q_{EI}E-q_{IR}I,
\qquad
\dot R=q_{IR}I.
$$
= Solution
With frequency-dependent transmission parameter $\beta$, the nonlinear SEIR equations are
$$
\dot S=-\beta\frac{SI}{N},
\qquad
\dot E=\beta\frac{SI}{N}-q_{EI}E,
\qquad
\dot I=q_{EI}E-q_{IR}I,
\qquad
\dot R=q_{IR}I.
$$