简介:ThispaperconsidersanSIRSepidemicmodelthatincorporatesconstantimmigrationrate,ageneralpopulation-sizedependentcontactrateandproportionaltransferratefromtheinfectiveclasstosusceptibleclass.Athresholdparameteraisidentified.Ifσ≤1,thedisease-freeequilibriumisgloballystable.Ifσ>1,auniqueendemicequilibriumislocallyasymptoticallystable.Fortwoimportantspecialcasesofmassactionincidenceandstandardincidence,globalstabilityoftheendemicequilibriumisprovedprovidedthethresholdislargerthanunity.Somepreviousresultsareextendedandimproved.
简介:ThepaperestablishestwostochasticSIRSmodelswithjumpstodescribethespreadofnetworkvirusbycyberwar,terrorismandothers.First,addingrandomperturbationsproportionallytoeachvariable,wegetthedynamicpropertiesaroundthepositiveequilibriumofthedeterministicmodelandtheconditionsforpersistenceandextinction.Second,givingarandomdisturbancetoendemicequilibrium,wegetastochasticsystemwithjumps.BymodifyingtheexistingLyapunovfunction,weprovethepositivesolutionofthesystemisstochasticallystable.