1. Presentation Topic : Modeling Human Vaccinating Behaviors On a Disease Diffusion Network PhD Student : Shang XIA Supervisor : Prof. Jiming LIU Department of Computer Science August 31, 2009 10th Postgraduate Research Symposium

2. Content: 1 2 Research Motivation & Objectives Disease Diffusion Dynamics 3 Individual Behaviors and Interactions 4 AOC Modeling for Local-Global Relationship Page 1/15 5 Conclusions

3.  In recent years, the emergence of vital epidemic which spreads all over the world have greatly endangered the public health and cause great social impacts. Swine Flu Spreading Map Research Background  SARS, 2002.11 ~ 2003.07 8,096 known infected cases and 774 deaths worldwide  Bird Flu, (H5N1) Recent Years 65 outbreaks in 2006; 55 in 2007; 11 in 2008.  Swine Flu, (H1N1) 2009.04 ~ Now 177,699 infected cases and 1,126 deaths ( Aug. 6 th ) Page 2/15

4. Swine Flu World Wide Spreading 04/24/200905/04/200905/26/2009 06/16/200907/06/200907/30/2009 Data Source: [1] WHO, ECDC, CPC, HPA (UK), governments [2] BBC Website: http://news.bbc.co.uk/2/hi/uk_news/8083179.stm Page 3/15

5. Research Motivation  Disease Diffusion on Human Social Contact Network. Human is the host of many severe infectious disease. Human’s traveling and interaction spread infection worldwide.  Disease Diffusion changes human’s behavioral pattern. Decision making for vaccination or not. Individual changes its social interactions.  Human’s contact pattern and demography features characterize disease diffusion dynamics. Human social contact is the medium of disease diffusion. Human demographical characteristics influence disease infection. Page 4/15

6. Research Objectives Local Individual Reaction Pattern Relationship ? Global Disease Diffusion Dynamics Human Interaction Network  Human Interaction Network Disease Infection Model  Disease Infection Model Human Behavioral Mechanism  Human Behavioral Mechanism Disease Diffusion Dynamics  Disease Diffusion Dynamics  Local-Global Relationship Problem Page 5/15 Complex Social Disease Diffusion System

7. Disease Infection Model SIV Percolation Model  Individual States in Network Susceptible Individual Infected Individual Vaccinated Individual  Epidemic Transmission in Network  Individual States Transition Neighbor Infections. Infected individuals die or recover. Vaccination escape potential infection. Random Selection for a neighbor susceptible. Selection Probability in terms of contact patterns. Page 6/15

8. Short Range Routine Mobile Long Range Chance Traveling Trajectory from home to workplace; Regular shopping in nearby supermarket; Visiting familiar friends or customers. Enjoying vacations abroad; Business trip to other regions; Social Contact Network Human Mobility Dynamics Human Social Contact Network (1) Scale Free Network Page 7/15

9. Human Social Contact Network (2)  Heterogeneity in demography difference  Heterogeneity in community structure Disease - Independent host parameters Ages, Gender, Occupation and so on. Community structure by contact pattern. Community structure by demography characteristics Disease - Dependent host parameters Current health status, Susceptibility, Disease transmission rate, etc.  Heterogeneity in contact pattern Degree Distribution : Neighbor Contacts Edge Weight : Contact Frequency Page 8/15

10. Individual Behavioral Mechanism (1)  Individual Vaccination Dilemma Herd Immunity Dilemma: T he individual incentive to vaccinate disappears at high coverage levels. So the individual incline to persuade other instead of itself to adopt the vaccination. Self-Interest Decision Page 9/15 Risk of Vaccination Risk of Infection Self-Trust Experience Group Psychology Irrational Predictions

11. Individual Behavioral Mechanism (2)  Individual Decision Making Dynamics Perceived Payoff for Vaccination or not  Perceived Payoff for Vaccination or not Records of History Decision Making  Records of History Decision Making Environment Estimation  Environment Estimation Individuals’ Biased Preference  Individuals’ Biased Preference Decision Making Mechanism Page 10/15

12. Local - Global Relationship Modeling Autonomy Oriented Computing “ AOC emphasize the modeling of autonomy in the entities of a complex system and the self-organization of them in achieving a specific goal ” -- By Liu (2005) AOC Modeling Framework Natural System Identification Artificial System Construction Performance Measurement Page 11/15

13. AOC Modeling  Natural System Identification  Artificial System Construction  Performance Measurement Disease Infection Model Individual Contact Network Individual Interaction Patterns Individual Behaviors Mechanism Vaccination Patterns Disease Diffusion Dynamics Multi-Agent System Autonomous Entities & Self-Organization Local-Global Relationship Page 12/15

14. Result Evaluation Criteria  Social Vaccination Dynamics  Disease Diffusion Dynamics The proportion of vaccinated individuals. The Efficacy of Vaccination. The proportion of vaccinated individuals which are infected by its infectious neighbors. The proportion of non-vaccinated individuals which are also infected. The proportion of infected individuals in the whole population. Page 13/15 The mass outbreak in a certain community.

15. Conclusion  Social Contact Network  Entities Infection Model  Decision Making  Vaccination Dynamics  Disease Diffusion Dynamics Local Behaviors Global Dynamics Page 14/15

16. Q & A Thank You Very Much!