чисельне моделювання

This paper aims to prezent mathematical model for Viral infection which incorporates both the cell-free and cell-to-cell transmission.  The model includes four compartments, namely, the susceptible, the infected ones, the viral load and the humoral immune response, which is activated in the host to attack the virus.  Firstly, we establish the well-posedness of our mathematical model in terms of proving the existence, positivity and boundedness of solutions.  Moreover, we determine the different equilibrium of the problem.  Also, we will study the global stability of each equilibrium.  Final

This study proposes and explores a prey–predator model that presents a functional response to group behavior of prey–predator harvesting.  We study a non-linear model of prey–predator growths in two species.  The proposed model is supported by theoretical and numerical results.  Some numerical descriptions are provided to help our analytical and theoretical conclusions.  For all possible parameter values occurring in a prey–predator system, we solved it by using both VIM (variational iteration method) and HPM (homotopy perturbation method).  We also used MATLAB coding to compare our approxi

In this paper, we investigate the population dynamics of phytoplankton–zooplankton–nanoparticle model with diffusion and density dependent death rate of predator.  The functional response of predator in this model is considered as Beddington–DeAngelis type.  The stability analysis of the equilibrium points is observed by applying the Routh–Hurwitz criterion.  Numerical simulations are given to illustrate the theoretical results.

The article presents a theoretical analysis of existing concepts to evaluate the non-failure of RC structures in operation. To perform the analysis, the authors considered a number of scientific works of both Ukrainian and foreign researchers. The main focus was on works in which the model of the stochastic nature of the RC structure operation included random parameters of acting loads, as well as the reserve of its bearing capacity and serviceability (geometric dimensions of cross sections of constructive members, strength and deformation characteristics of materials, etc.).

The phenomenon of mixed convection heat transfer in a homogeneous mixture is deliberated thoroughly in this study for cooper-water nanofluids flowing inside a lid-driven square cavity.  By adopting the Oberbeck-Boussinesq approximation and using the single-phase nanofluid model, the governing partial differential equations modeling the present flow are stated mathematically based on the Navier--Stokes and thermal balance formulations, where the important features of the scrutinized medium are presumed to remain constant at the cold temperature.  Note here that the density quantity in the bu

Vehicle routing problems are widely available in real world application.  In this paper, we tackle the resolution of a specific variant of the problem called in the literature vehicle routing problem with flexible time windows (VRPFlexTW), when the solution has to obey several other constraints, such as the consideration of travel, service, and waiting time together with time-window restrictions.  There are proposed two modified versions of the Multi-objective Adaptive Large Neighbourhood Search (MOALNS).  The MOALNS approach and its different components are described.