Note. The text below is part 4 of the paper titled "Epidemiological Modeling of Computer Virus Propagation." This is now Chapter II - Epidemiological Modelling.
Growth and decay are two subjects that can be mathematically modeled. These two are natural phenomena that occur in both the living and the non-living things. Examples of living things are human population and those biological diseases like HIV and malaria. Meanwhile, examples of non-living things where these occur are the spread of rumors and the simple but not so obvious subject of waiting-in-line10. The computer virus propagation is viewed to have growth and decay periods. As such, this paper adopted the aforementioned growth and decay phenomena in modeling this propagation.
The paper patterned the model for computer virus propagation with the spread of biological a disease. The widespread infection of people from a biological disease is often called an epidemic. Being an epidemic, the model used to describe the spread of a biological disease is often called epidemiological model.
The spread of a computer virus (although non-biological) is typically viewed as similar to a biological one (the justification on this is discussed in the next section). Hence in the spread of a computer virus, epidemiological modeling is conventionally applied.-----------------
10Daniel P. Maki, Mathematical Models and Applications (New Jersey: Prentice Hall, 1973), 356.