Plenary Lecture
The Statistical Behavior of the Spread of Infection by the Contact Systems

Professor Jun Wang
College of Science
Beijing Jiaotong University
Beijing 100044, P. R. CHINA
E-mail: wangjun@bjtu.edu.cn
Abstract: We consider a contact system
that describes the behavior of a process which has been used to model the
spread of a disease or a biological population. The collection of
individuals that may be infected at any given time is taken to be the set of
vertices of a connected, undirected graph . For such a graph, the degree of
a vertex is the number of vertices that are connected to by an edge. In the
present paper, we consider the contact model on the dimensional integer
lattice (in which the degree of each vertex is ). In -dimensional space, one
point is stood by one individual. The virus infects one proximate individual
at a rate equal to , where is an intensity of the contact model. And the
individual infected recovers at rate one. Speaking concretely, contact model
is a continuous time Markov process in the configuration . At some random
time, one individual at the point is deemed to be infected when and the
infected individual recovers at rate one; if , the individual at the point
is healthy and will be infected at a rate equal to times the number of the
infected neighbors. In this paper, applying the theory of the contact
system, one kind of spread of infection model (which defined from the
contact model) is analyzed and estimated by the theory of stochastic
analysis, including the stopping time method. Further, we show the
asymptotic behavior of probability distributions which describe the
fluctuations for the spread of infection.
Brief Biography of the Speaker:
Professor and Dr. Jun Wang is a full professor at College of Science in
Beijing Jiaotong University, P.R. China. He is also the Director of
Institute of Financial Mathematics and Financial Engineering. Professor Wang
received his Ph.D. from the Kobe University of Japan, and continued his
research work in Kobe University as a researcher supported by Japan Society
for the Promotion of Science. Recently, his research work is supported in
part by the National Natural Science Foundation of China Grant No. 70471001
and No. 70771006, Ministry of Education of China Grant No. 406 (2003), BJTU
Foundation No. 2006XM044.
Professor Wang has wide research interests, which include: Large Scale
Interacting Systems, Stochastic Systems, Dynamical Systems, Statistical
Physics Systems (Ising Dynamical Systems, Percolation Theory, Voter Systems
and Contact Systems, Widom-Rowlinson Model, etc.), Non-linear Systems,
Stochastic Control, Artificial Intelligence, Modeling and Computer
Simulation, Ergodic Theory, Probability Theory and Statistics, Financial
Mathematics and Financial Engineering (Risk Management and Risk Analysis,
Marketing, Stock Fluctuations Analysis, Option, Contingent Claims, Valuation
and Hedging, etc.).