Dynamic Behaviors of an SEIR Epidemic Model in a Periodic Environment with Impulse Vaccination

Figure 4

Dynamical behavior of system (2) with 𝛽(𝑡)=0.005(sin𝑡+2), 𝜆(𝑡)=10, 𝛼(𝑡)=0.01, 𝜇(𝑡)=0.1, 𝛾(𝑡)=0.1, 𝜀(𝑡)=0.8, 𝜔=2𝑇=2𝜋, and 𝜃₁=𝜃₂=0.01. (a) Time series of 𝑆(𝑡). (b) Time series of 𝐼(𝑡).

(a)

(b)