the efficiency of harvested factor; lotka-volterra predator-prey model

scientists are interested in find out “how to use living resources without damaging the ecosystem at the same time?” from nineteen century because the living resources are limited. thus, the harvested rate is used as the control parameters. moreover, the study of harvested population dynamics is more realistic.    in the present paper, some predator-prey models in which two ecologically interacting species are harvested independently with constant or variable rates have been considered. also, the behavior of their solutions in the global and local stability aspect have been investigated. the main aim is to present a mathematical analysis for the above model.