1、Preventing Smallpox Epidemics Using a Computational Model,By Chintan Hossain and Hiren Patel,Facts About Smallpox,Symptoms occur in stages Highly contagious (causes epidemics) Fatal in 30% cases There is a vaccine- Death may occur,GOAL (Objective),Prevent smallpox epidemics via. vaccination. Vaccina
2、te as few as possible because:1. Minimize reactions2. Reduce cost,HYPOTHESIS: Vaccinating certain percentage of the population may be sufficient to prevent a smallpox epidemic.,Stages of Smallpox,Normal (Susceptible) Immune (or vaccinated) Incubation First Stage Early Symptoms Late Symptoms Death,Ou
3、r Model: Social Networks,Cliques Represent:FamiliesWorkplacesSchool,Our Society Generator Algorithm,Use random numbers to pick a family size. Generate a clique of that size. Repeat to create more families. Use a similar technique to generate schools and workplaces. Schools and workplaces connect exi
4、sting vertices, not new vertices.,Our Model Comes Alive!,MARKOV GRAPH + SOCIETY NETWORKSIMULATION Advance time 1 day Spread Disease Advance Stages Death,Normal (Susceptible),Infected Stage,Vaccinated / Immune,Death,FIRST,EARLY,LATE,Procedure,Run the society generator Vaccinate k% of people with most
5、 friends (vertices with the greatest degree) Control: k = 0% Variable: Vary percent, k, vaccinated Randomly, infect one person. Run simulation, and observe results (percent infect and length of epidemic),OUR PROGRAM,Results,Epidemics intensify, reach a peak, and then vanish Vaccination reduces inten
6、sity and speed.,Results (cont),Vaccinating more people decreases the % infected The % infected becomes small if over 50% are vaccinated.,Conclusion,Vaccinating 50% of the population effectively prevents epidemics. Vaccinating less than 50% may not prevent an epidemic, but it reduces the severity and speed of the epidemic.,This model can be used for other diseases by changing the Markov Graph.,
