Table 1.

Definitions of some symbols used in the proposed co-evolution model

Symbol	Definition
N	Total number of individuals in the proposed co-evolution model
A	Adjacency matrix of the network in the information dissemination layer
B	Adjacency matrix of the network in the epidemic spreading layer
$a_{\mathit{ij}}$	Elements of the adjacency matrix A
$b_{\mathit{ij}}$	Elements of the adjacency matrix B
m	Probability of an individual with state US receiving epidemic-relevant information through mass media
$\eta$	Probability of an individual with state US taking highly effective self-protective actions due to mass media
$\kappa$	Probability of an individual with state $V^{N}S$ changing his view on epidemic prevention due to mass media
${\lambda }_P$	Probability of an individual with state US receiving positive information from one of his neighbors with state $V^{P}S$ or $V^{P}I$
${\lambda }_N$	Probability of an individual with state US receiving negative information from one of his neighbors with state $V^{N}S$
$\xi$	Probability of an individual with state $V^{N}S$ changing his view on epidemic prevention due to one of his neighbors with state $V^{P}S$ or $V^{P}I$
${\delta }_P$	Forgetting rate of positive information
${\delta }_N$	Forgetting rate of negative information
$\beta$	Epidemic infection rate
${\mathrm{\Gamma }}_P$	Attenuation factor of $\beta$ in case of taking highly effective self-protective actions
${\mathrm{\Gamma }}_N$	Attenuation factor of $\beta$ in case of taking self-protective actions with poor effect
${\beta }_U$	Probability of an individual with sate US being infected by one of his neighbors with state $V^{P}I$, ${\beta }_U=\beta$
${\beta }_P$	Probability of an individual with sate $V^{P}S$ being infected by one of his neighbors with state $V^{P}I$, ${\beta }_P={\mathrm{\Gamma }}_P\beta$
${\beta }_N$	Probability of an individual with sate $V^{N}S$ being infected by one of his neighbors with state $V^{P}I$, ${\beta }_N={\mathrm{\Gamma }}_N\beta$
$\mu$	Recovery rate of infected individuals
$\omega$	Preference of individuals with state US for negative information, $0\le \omega \le 1$