Leslie's model is a discrete, age-structured model of population growth.
Cao and Zhou [16] formulated and studied a discrete age-structured SEIT epidemic model, and as an application, discussed the tuberculosis transmission in China.
Babad et al. [15] employed a discrete age-specific mathematical model to predict the impact of measles vaccination in England and Wales.
So, we propose a discrete age-structured SIR model on the basis of age has great influence on the spread of infectious disease.
When reproduction is continuous, as it is in C. elegans populations, the continua of time t and age x can be divided into discrete intervals of arbitrary length, thus approximating a continuous-time model to any desired degree of accuracy by a discrete age-class model ([ 31]: p. 14).
The population of infectives is divided into a number of discrete "age" classes.
The physiologic changes, as a result of aging, occur along a continuum rather than in discrete age groups, and life expectancies continually change as medical advances are made.
We previously assumed that a single discrete age-range of RBCs was susceptible to infection [14]; some variations include continuously variable or even bimodal susceptibility of RBCs to infection as a function of age, or differences in the fecundity of infected RBCs with age.
We used a discrete, multiple age cohort, compartmental model 8 to model a population of individuals with active tuberculosis.
Design Economic evaluation using a discrete, multiple age cohort, compartmental model of treated and untreated cases of active tuberculosis.
The Leslie model combines births and deaths in a single model and it is based on these hypotheses: (i) The age x is a variable starting from 0 and subdivided into n discrete age classes of size h.
