mathematical modeling

An Influence of the Time and Spatial Harmonics on an Electromagnetic Torque of a Symmetrical Six-Phase Induction Machine With a Six-Step Inverter Supply Under Open Phase Circuit Fault

Six-phase induction machines offer several advantages over traditional three-phase machines, including higher levels of electromechanical compatibility with loads, energy efficiency, and fault tolerance.

This article presents an analysis of the impact of harmonics in the winding distribution function in the stator slots and the harmonics of the machine’s supply on its electromechanical compatibility with the load during a single-phase failure.

Energy-efficient Control of Electric Vehicle Heating, Ventilation, and Air Conditioning System – Performance Optimization and Energy Consumption Reduction

The article addresses the challenge of improving the energy efficiency of the heating, ventilation, and air conditioning (HVAC) system in electric vehicles. Due to the absence of an internal combustion engine in electric vehicles, there is no additional heat source, meaning that HVAC systems consume a significant portion of the battery energy, thereby reducing the vehicle’s range. The aim of this study is to develop an energy-efficient control algorithm for the HVAC system that minimizes energy consumption while maintaining adequate comfort levels for passengers.

Mathematical modeling of solid municipal waste landfill surface settlement with regard to organic component biodegradation

Landfilling of municipal solid waste generates a number of problems.  This article focuses on one of them – the settling of the landfill surface due to organic residue biodegradation.

Mathematical modeling of impurity diffusion process under given statistics of a point mass sources system. II

Modeling of the impurity diffusion process in a layer under the action of a system of random point sources is carried out.  Mass sources of different power are uniformly distributed in a certain internal interval, that may also coincide with the entire region of the layer.  The statistics of random sources is given.  The solution of the initial-boundary value problem is found as the sum of the homogeneous problem solution and the convolution of the Green's function with the system of the random point sources.  Averaging of the solution is performed on the internal subinterval and in the ent

Algorithm for determining inclusion parameters in solving inverse problems of geoelectrical exploration using the profiling method

The paper aims to develop an algorithm for recognizing the physical and geometric parameters of inclusion, using indirect methods of boundary, near-boundary, and partially-boundary elements based on the data of the potential field. Methodology. The direct and inverse two-dimensional problems of the potential theory concerning geophysics were solved when modeling the earth's crust with a piecewise-homogeneous half-plane composed of a containing medium and inclusion that are an ideal contact.

Spatiotemporal dynamics of RNA viruses in the presence of immunity and treatment: case of SARS-CoV-2

In this paper, we develop a mathematical model using partial differential equations to investigate the behavior of RNA viruses in the presence of antiviral treatment.  The developed model includes both cell-to-cell and virus-to-cell modes of transmission.  Initially, we establish the well-posedness of the model by demonstrating the existence and uniqueness of solutions, as well as their positivity and boundedness.  Additionally, we identify and analyze the stable equilibrium states, their global stability depending on specific threshold parameters, using Lyapunov functi

Mathematical modeling of impurity diffusion process under given statistics of a point mass sources system. I

The model of the impurity diffusion process in the layer where a system of random point mass sources acts, is proposed.  Mass sources of various power are uniformly distributed in a certain internal interval of the body.  Statistics of random sources are given.  The solution of the initial-boundary value problem is constructed as a sum of the homogeneous problem solution and the convolution of the Green's function and the system of the random point mass sources.  The solution is averaged over both certain internal subinterval and the entire body region.  Simulation unit

The impact of rumors on the success of Covid-19 vaccination programs in a Coronavirus-infected environment: optimal control approach

In this paper, we propose a mathematical model that describes the effect of rumors on the success of vaccination programs against Covid-19 in an environment infected by the coronavirus.  The aim of this study is to highlight the role of addressing the spread of rumors regarding vaccination risks and booster doses in the success of vaccination programs and in achieving herd immunity.  Additionally, we formulate an optimal control problem by proposing several strategies, including awareness and anti-rumor programs, to assist country officials in achieving successful vacci

Dynamics of an ecological prey–predator model based on the generalized Hattaf fractional derivative

In this paper, we propose and analyze a fractional prey–predator  model with generalized Hattaf fractional (GHF) derivative.  We prove that our proposed model is ecologically and mathematically well-posed.  Furthermore, we show that our model has three equilibrium points.  Finally, we establish the stability of these equilibria.

Формування захисних зображень на основі фрактальної геометрії

Розглянуто застосування фрактальної геометрії для захисту зображень. Рекоменду- ється метод, який призначений для побудови зображення за допомогою кривої Гільберта та інших фракталів. На основі цього методу розроблено відповідне програмне забезпечення.

We consider the application of fractal geometry to protect the images. We advise the method that is for constructing images using Hilbert curve and other fractals. Basing on this methods, there was developed appropriate software.