How Do You Solve the SIS Disease Model Equation?

  • Thread starter Thread starter tactical
  • Start date Start date
  • Tags Tags
    Disease Model
tactical
Messages
6
Reaction score
0
The following problem is an SIS disease problem:

Calling: I(t) = number of infectives at time t
N = the total population (assumed constant)
b = infection rate (here, a positive constant)
v = recovery rate (also, a positive constant)

a model for this disease is given bu the following:

dI/dt = bI(N-I) - vI

And since the population is assumed constant, we can just take S(t) to be N -I(t). Derive a condition for when the number of infectives goes to zero.

Is there anyone out there than can help me, even if it's just a little bit?
 
Physics news on Phys.org
The equation is separable. Just integrate
dx=dI \frac{1}{I(bN-v-bI)}
 
it's a Bernoulli equation...I have to solve the same as you...did u solve it?
 
Last edited:
Thread 'Direction Fields and Isoclines'
I sketched the isoclines for $$ m=-1,0,1,2 $$. Since both $$ \frac{dy}{dx} $$ and $$ D_{y} \frac{dy}{dx} $$ are continuous on the square region R defined by $$ -4\leq x \leq 4, -4 \leq y \leq 4 $$ the existence and uniqueness theorem guarantees that if we pick a point in the interior that lies on an isocline there will be a unique differentiable function (solution) passing through that point. I understand that a solution exists but I unsure how to actually sketch it. For example, consider a...
Back
Top