This research presents a study of dynamical system which models natural resources. Using fishes and water resources as the case study. In this work model equation was used to determine density We also introduced second stage Runge Kutta method, obtain result for harvesting terms from 10% 50% producing population life in pond after each harvesting.
 work, solution dynamic that can using Run...

the object of this study was evaluation of a walking tractor drawn peanut harvester at different conditions of soil moisture content and forward speed and comparing it with manual harvesting. the evaluation factors for peanut harvester were two levels of soil moisture content and three levels of forward speed. the results revealed that the effect of soil moisture content was only significant on...

In this paper, we investigate the dynamics of a discrete-time stage-structured population model where juveniles and adults may be subject to threshold harvesting. This management policy allows harvesting target only if its size exceeds predetermined threshold. It is commonly used for maintaining biomass, obtaining higher yield, preventing collapse. We focus on response structured populations st...

In this paper, we investigate the stability of equilibrium in stage-structured and density-dependent predator–prey system with Beddington–DeAngelis functional response. First, by checking sign real part for eigenvalue, local origin boundary are studied. Second, explore positive τ=0 τ≠0 (time delay τ is time taken from immaturity to maturity predator), which shows that dependent on parameter τ. ...