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Along with the developing technology, obesity and diabetes are increasing rapidly among people. The identification of diabetes diseases, modeling, predicting their behavior, conducting simulations, studying control and treatment methods using mathematical methods has become of great importance. In this paper, we have obtained numerical solutions by considering the glucose-insulin fractional model. This model consists of three compartments: the blood glucose concentration (G), the blood insulin concentration (I) and the ready-to-absorb glucose concentration (D) in the small intestine. The fractional derivative is used in the sense of Caputo. By performing mathematical analyzes for the Glucose-Insulin fractional mathematical model, numerical results were obtained with the help of the Euler method and graphs were drawn. [ABSTRACT FROM AUTHOR]

Today, the socio-cultural lack of some countries with increased urbanization has led to the unconscious breeding of stray dogs. The failure to care for the offspring of possessive dogs or ignoring the responsibility to find a suitable family for the offspring increased the dog population on the streets and in the shelters. In this study, our main target is to analyze the habitat of stray dogs and the strategy of how to control the population without damaging the ecosystem of the species. For this aim, we establish a fractional-order differential equation system to investigate the fractal dimension with long-term memory that invovles two compartments; the non-sterilized dog population (x(t)) and the sterilized one (y(t)). Firstly, we analyze the stability of the equilibrium points using the Routh-Hurwitz criteria to discuss cases that should not affect the ecosystem of the dog population, but control the stray dog population in the habitat. Since the intervention to the stray dog population occurs at discrete time impulses, we use the Euler method's discretization process to analyse the local and global stability around the equilibrium points. Besides this, we show that the solutions of the system represent semi-cycle behaviors. At the end of the study, we use accurate data to demonstrate the sterilization rate of stray dogs in their habitat. [ABSTRACT FROM AUTHOR]

In this article, the fractional derivatives in the sense of modified Riemann–Liouville and the exp-function method are used to construct exact solutions for some nonlinear partial fractional differential equations via the nonlinear fractional Liouville equation and nonlinear fractional Zoomeron equation. These nonlinear fractional equations can be turned into another nonlinear ordinary differential equation by complex transform method. This method is efficient and powerful in solving wide classes of nonlinear fractional order equations. The exp-function method appears to be easier and more convenient by means of a symbolic computation system.

Psychological diseases and their treatment are problems related to public health. According to data from the World Health Organization, about a billion people have either mental illness or substance use disorder problems in 2017. Mental, neurological diseases and substance use disorders account for 30 percent of the global non-fatal disease burden and 10 percent of the global disease burden. It is noted that in the world Dec 2005 and 2015, the incidence of mental health diseases increased by about 16 percent. In this study, we have created a fractional-order mathematical modeling of the population of individuals suffering from psychological diseases in a society. In this model, the total population was divided into three compartments: individuals who did not receive psychological treatment (S), individuals who received psychological support (P) and individuals who recovered after completing psychological treatment (R). As a fractional derivative, we used the Caputo derivative definitions. Numerical solutions were obtained with the help of the Euler method by performing stability analysis related to the fractional SPR model created for the mathematical model of psychological patients. Thus, it was interpreted by creating dynamics for the number of individuals with psychological problems in a population. [ABSTRACT FROM AUTHOR]

Throughout history, infectious diseases have been the cause of outbreaks and the deaths of people. It is crucial for endemic disease management to be able to forecast the number of infections at a given moment and the frequency of new infections so that the appropriate precautions can be taken. The COVID-19 pandemic has highlighted the value of mathematical modeling of pandemics. The susceptible–infected–quarantined–recovered–vaccinated (SIQRV) epidemic model was used in this work. Symmetrical aspects of the proposed dynamic model, disease-free equilibrium, and stability were analyzed. The symmetry of the population size over time allows the model to find stable equilibrium points for any parameter value and initial conditions. The assumption of the strong symmetry of the initial conditions and parameter values plays a key role in the analysis of the fractional SIQRV model. In order to combat the pandemic nature of the disease, control the disease in the population, and increase the possibility of eradicating the disease, effective control measures include quarantine and immunization. Fractional derivatives are used in the Caputo sense. In the model, vaccination and quarantine are two important applications for managing the spread of the pandemic. Although some of the individuals who were vaccinated with the same type and equal dose of vaccine gained strong immunity thanks to the vaccine, the vaccine could not give sufficient immunity to the other part of the population. This is thought to be related the structural characteristics of individuals. Thus, although some of the individuals vaccinated with the same strategy are protected against the virus for a long time, others may become infected soon after vaccination. Appropriate parameters were used in the model to reflect this situation. In order to validate the model, the model was run by taking the COVID-19 data of Türkiye about a year ago, and the official data on the date of this study were successfully obtained. In addition to the stability analysis of the model, numerical solutions were obtained using the fractional Euler method. [ABSTRACT FROM AUTHOR]

In this study, the Stokes flow problem in an S-shaped double lid-driven cavity filled with fluid was analyzed. Side edges of the cavity were considered as immovable walls. The flow region was divided into two sub-regions, and the streamfunction in each sub-region was considered as an extension of Papkovich–Faddle eigenfunctions. Parameters in the analytical solution were obtained using biorthogonality conditions. The Newton iteration method was used to obtain the eigenvalues of the problem, and integrals were calculated with the Gaussian quadrature method. It was ensured that solutions made separately for the two sub-regions converge on the interface, which is the intersection of these sub-regions. The two parameters controlling the flow structure were determined as the speed ratio of movable lids (S) and the aspect ratio of the cavity (A). The effects of these parameters on flow structures were shown. New eddy formation mechanisms and bifurcations were observed in the cavity by keeping the speed ratio of the lids constant and slowly changing the aspect ratio. [ABSTRACT FROM AUTHOR]

Smoking is one of the most common habits in the world. Due to the harmful substances contained in it cigarette disturb people's health and causes their death. Every year, many people lose their health from smoking or by direct exposure to cigarettes. In this study, we conducted a new application and stability analysis related to a fractional model of cigarette use. This model consists of three compartments: potential smokers (P), smokers (S) and definitely quitters of smoking (Qp). The fractional derivative is used in the sense of Caputo. In this article, we develop a fractional mathematical model to illustrate the consequences of smoking habit in Turkey by the Caputo fractional-order derivative. In addition to stability analysis, numerical solutions are obtained by using Euler method for different values of fractional order. [ABSTRACT FROM AUTHOR]

Grey System Theory predicts the behaviour of unknown systems using a small amount of data. Grey System Theory is an interdisciplinary science field and has been successfully applied to many fields. In this study, the Grey System Theory is used to estimate Turkey's education expenditures. Turkey's education expenditure data were taken from the Turkish Statistical Institute for the years of 2011-2020. It has been estimated for the years of 2021-2030 using Standard Grey Model (GM (1,1)) and Exponential Grey Model (EXGM (1,1)). The percentage relative error (RPE) between the actual and the predicted values. Also, the mean absolute percentage error (MAPE) were determined using the actual and the predicted data from 2011-2020. Consequently, the MAPE values were calculated as 3,32 % and 3,09 % for GM (1,1) and EXGM (1,1) models, respectively. R² value which shows the correlation between the actual and predicted values was determined as 0,9845 and 0,9846 for GM (1,1) and EXGM (1,1), respectively. It has been determined that the estimation precision of the EXGM (1,1) method is higher according to calculated errors and R² values. Accordingly, education expenditures were estimated for the years 2021-2030. Hereby, it is predicted that our country's education expenditures will increase exponentially in the next 10 years. [ABSTRACT FROM AUTHOR]

Abstract\nHighlightsIn this study, we established a system of differential equations with piecewise constant arguments to explain the impact of epidemiological transmission between different locations. Our main goal is to look into the need for vaccines as well as the necessity of the lockdown period. We proved that keeping social distance was necessary during the pandemic spread to stop transmissions between different locations and that re-vaccinations, including screening tests, were crucial to avoid reinfections. Using the Routh-Hurwitz Criterion, we examined the model’s local stability and demonstrated that the system could experience Stationary and Neimark-Sacker bifurcations depending on certain circumstances.Modeling a SEIVRS dynamic behavior with transportation-related transmissionEstablishing a system of two urban as differential equations with piecewise constant argumentsStability analysis of disease-free and co-existing equilibrium pointsAnalyzing bifurcation types around the disease-free and co-existing equilibrium points.Illustrating numerical scenarios that were applied during the pandemic event [ABSTRACT FROM AUTHOR]

In this paper, we obtain the 1-soliton solutions of the variable-coefficient modified Kawahara equation (VCMKE). The dark optical as well as bright optical soliton solutions were found related to the model considered in this study. The solitary wave ansatz method is used to carry out the integration. [ABSTRACT FROM AUTHOR]