stability

Analysis and optimal control problem for a fractional mathematical model of tuberculosis with smoking consideration

This article studies a mathematical model of the fractional order of tuberculosis (TB).  It describes the dynamics of the spread of tuberculosis among smokers.  The purpose of this research is to protect vulnerable people against the virus.  According to the survey results, the required model has an equilibrium point: the disease-free equilibrium point $E_f$.  We also analyze the local stability of this equilibrium point of the model, using the basic reproduction number $\mathcal{R}_{0}$ calculated according to the new generation method.  In our model, we include three

A generalized diffusive IS-LM business cycle model with delays in gross product and capital stock

In this paper, we suggest a diffusive and delayed IS-LM business cycle model with interest rate, general investment and money supply under homogeneous Neumann boundary conditions.  The time delays are respectively incorporated into capital stock and gross product.  We first demonstrate the model's sound mathematical and economic posing.  By examining the corresponding characteristic equation, the local stability of the economic equilibrium and the existence of Hopf bifurcation are proved.

Dynamics of a fishery with nonlinear harvesting: control, price variation, and MSY

In this paper, we construct and analyse a new fishing mathematical model, which describes the time evolution of a fish stock, which is harvested by a fishing fleet, described by its fishing effort.  We consider that the price, which is given by the difference between supply and demand, is varying with respect to time.  For the harvesting function, we use the Holling II function.  On the other hand, we consider two different time scales: a fast one for the price variation and a slow one for fish stock and fishing effort variations.  We use an "aggregation of variables" m

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.

Поєднання алгоритму RSA і побітових операцій при шифруванні-дешифруванні зображень

Стосовно зображень розроблено модифікації алгоритму RSA такі, що зберігається криптографічна стійкість і забезпечується повна зашумленість зображення, з метою унеможливити використання методів візуальної обробки зображень.

For images modified RSA algorithm is developed such that stored cryptographic and secured full noisy image in order to prevent the use of methods of visual imaging.

Застосування алгоритму RSA у шифруванні і дешифруванні елементів локально-скінченного топологічного покриття зображення як компакту

Запропоновано застосування алгоритму RSA шифрування і дешифрування елементів локально скінченного топологічного покриття зображення, яке має чітко виділені внутрішні контури.

An application of RSA algorithm encryption and decryption of locally finite topological elements cover image that is clearly marked internal contours.

Effect of a nonlinear demand function on the dynamics of a fishery

In this work, we present and analyze a fishery model with a price variation.  We take into account the evolution in time of the fish biomass and the harvesting effort, while the price of fish is dependent on supply and demand.  Assuming that the price variation occurs at a fast time scale.  We assume that the stock and the effort evolution follow a slow time scale.

Basicity and Nucleophilicity Effect in Charge Transfer of AlH3-Base Adducts: Theoretical Approach

This study permits to explore the interactions involved in Lewis acid $\left(\mathrm{AlH}_3\right)$ and Lewis bases: $\mathrm{CO} ; \mathrm{H}_2\mathrm{O} ; \mathrm{NH}_3 ; \mathrm{PH}_3 ; \mathrm{PCl}_3 ; \mathrm{H}_2 \mathrm{S} ; \mathrm{CN}^{-} ; \mathrm{OH}^{-} ; \mathrm{O}_2^{-2} ; \mathrm{F}^{-} ; \mathrm{N}\left(\mathrm{CH}_3\right)_3 ; \mathrm{N}_2 ; \mathrm{N}_2 \mathrm{H}_4 ; \mathrm{N}_2 \mathrm{H}_2 ; \mathrm{C}_5 \mathrm{H}_5 \mathrm{N} ; \mathrm{C}_6 \mathrm{H}_{5^{-}}\mathrm{N}\mathrm{H}_2$.

Stability analysis and Hopf bifurcation of a delayed prey–predator model with Hattaf–Yousfi functional response and Allee effect

The Allee effect is an important phenomena in the context of ecology characterized by a correlation between population density and the mean individual fitness of a population.  In this work, we examine the influences of Allee effect on the dynamics of a delayed prey–predator model with Hattaf–Yousfi functional response.  We first prove that the proposed model with Allee effect is mathematically and ecologically well-posed.  Moreover, we study the stability of equilibriums and discuss the local existence of Hopf bifurcation.