Arshyn Altybay^1,2,*, Niyaz Tokmagambetov^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.2, pp. 1867-1881, 2024, DOI:10.32604/cmes.2024.054892 - 27 September 2024

Abstract In this paper, we consider the numerical implementation of the 2D wave equation in isotropic-heterogeneous media. The stability analysis of the scheme using the von Neumann stability method has been studied. We conducted a study on modeling the propagation of acoustic waves in a heterogeneous medium and performed numerical simulations in various heterogeneous media at different time steps. Developed parallel code using Compute Unified Device Architecture (CUDA) technology and tested on domains of various sizes. Performance analysis showed that our parallel approach showed significant speedup compared to sequential code on the Central Processing Unit (CPU). More >

Muhammad Altaf Khan^1,*, Mahmoud H. DarAssi², Irfan Ahmad³, Noha Mohammad Seyam⁴, Ebraheem Alzahrani⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.2, pp. 1365-1394, 2024, DOI:10.32604/cmes.2024.053681 - 27 September 2024

Abstract A mathematical model is designed to investigate Tuberculosis (TB) disease under the vaccination, treatment, and environmental impact with real cases. First, we introduce the model formulation in non-integer order derivative and then, extend the model into fractional order derivative. The fractional system’s existence, uniqueness, and other relevant properties are shown. Then, we study the stability analysis of the equilibrium points. The disease-free equilibrium (DFE) is locally asymptotically stable (LAS) when . Further, we show the global asymptotical stability (GAS) of the endemic equilibrium (EE) for and for . The existence of bifurcation analysis in the More >

Shamitha Shetty^1,2, Asha Crasta¹, Sher Afghan Khan^3,*, Abdul Aabid⁴, Muneer Baig⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.10, pp. 2353-2376, 2024, DOI:10.32604/fdmp.2024.051059 - 23 September 2024

Abstract The purpose of this work is to shed light on the effect of the pivot position on the surface pressure distribution over a 3D wing in different flight conditions. The study is intended to support the design and development of aerospace vehicles where stability analysis, performance optimization, and aircraft design are of primary importance. The following parameters are considered: Mach numbers (M) of 1.3, 1.8, 2.3, 2.8, 3.3, and 3.8, angle of incidence (θ) in the range from 5° to 25°, pivot position from h = 0.2 to 1. The results of the CFD numerical More >

Umar Shafique^1,*, Mohamed Mahyoub Al-Shamiri², Ali Raza³, Emad Fadhal^4,*, Muhammad Rafiq^5,6, Nauman Ahmed^5,7

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.1, pp. 311-329, 2024, DOI:10.32604/cmes.2024.052383 - 20 August 2024

Abstract Based on the World Health Organization (WHO), Meningitis is a severe infection of the meninges, the membranes covering the brain and spinal cord. It is a devastating disease and remains a significant public health challenge. This study investigates a bacterial meningitis model through deterministic and stochastic versions. Four-compartment population dynamics explain the concept, particularly the susceptible population, carrier, infected, and recovered. The model predicts the nonnegative equilibrium points and reproduction number, i.e., the Meningitis-Free Equilibrium (MFE), and Meningitis-Existing Equilibrium (MEE). For the stochastic version of the existing deterministic model, the two methodologies studied are transition… More >

Wei Chen, Nan Qiu^*, Xusheng Yang

Energy Engineering, Vol.121, No.4, pp. 987-1005, 2024, DOI:10.32604/ee.2023.045475 - 26 March 2024

Abstract During the operation of a DC microgrid, the nonlinearity and low damping characteristics of the DC bus make it prone to oscillatory instability. In this paper, we first establish a discrete nonlinear system dynamic model of a DC microgrid, study the effects of the converter sag coefficient, input voltage, and load resistance on the microgrid stability, and reveal the oscillation mechanism of a DC microgrid caused by a single source. Then, a DC microgrid stability analysis method based on the combination of bifurcation and strobe is used to analyze how the aforementioned parameters influence the More >

Muhammad Shoaib Arif^1,2,*, Kamaleldin Abodayeh¹, Yasir Nawaz²

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.3, pp. 3417-3434, 2024, DOI:10.32604/cmes.2024.046944 - 11 March 2024

Abstract This study focuses on the urgent requirement for improved accuracy in disease modeling by introducing a new computational framework called the Hybrid SIR-Fuzzy Model. By integrating the traditional Susceptible-Infectious-Recovered (SIR) model with fuzzy logic, our method effectively addresses the complex nature of epidemic dynamics by accurately accounting for uncertainties and imprecisions in both data and model parameters. The main aim of this research is to provide a model for disease transmission using fuzzy theory, which can successfully address uncertainty in mathematical modeling. Our main emphasis is on the imprecise transmission rate parameter, utilizing a three-part… More >

Muhammad Tariq Ali¹, Dumitru Baleanu^2,3,4, Muhammad Rafiq⁵, Jan Awrejcewicz⁶, Nauman Ahmed⁷, Ali Raza^8,*, Muhammad Sajid Iqbal⁹, Muhammad Ozair Ahmad⁷

Intelligent Automation & Soft Computing, Vol.36, No.2, pp. 1479-1496, 2023, DOI:10.32604/iasc.2023.033157 - 05 January 2023

Abstract The human immunodeficiency viruses are two species of Lentivirus that infect humans. Over time, they cause acquired immunodeficiency syndrome, a condition in which progressive immune system failure allows life-threatening opportunistic infections and cancers to thrive. Human immunodeficiency virus infection came from a type of chimpanzee in Central Africa. Studies show that immunodeficiency viruses may have jumped from chimpanzees to humans as far back as the late 1800s. Over decades, human immunodeficiency viruses slowly spread across Africa and later into other parts of the world. The Susceptible-Infected-Recovered (SIR) models are significant in studying disease dynamics. In… More >

Zhijie Zheng¹, Song Zhang¹, Xiaolei Zhang², Bo Yang¹, Fang Yan³, Xiaoning Ge^3,*

Energy Engineering, Vol.120, No.3, pp. 633-647, 2023, DOI:10.32604/ee.2022.024081 - 03 January 2023

Abstract The DC distribution network system equipped with a large number of power electronic equipment exhibits weak damping characteristics and is prone to low-frequency and high-frequency unstable oscillations. The current interpretation of the oscillation mechanism has not been unified. Firstly, this paper established the complete state-space model of the distribution system consisting of a large number of electric vehicles, characteristic equation of the distribution network system is derived by establishing a state-space model, and simplified reduced-order equations describing the low-frequency oscillation and the high-frequency oscillation are obtained. Secondly, based on eigenvalue analysis, the oscillation modes and More >

Yufang Zhang¹, Yingfa Lu^2,*, Yao Zhong², Jian Li¹, Dongze Liu²

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.1, pp. 357-381, 2023, DOI:10.32604/cmes.2022.020874 - 24 August 2022

Abstract An analytical method for determining the stresses and deformations of landfills contained by retaining walls is proposed in this paper. In the proposed method, the sliding resisting normal and tangential stresses of the retaining wall and the stress field of the sliding body are obtained considering the differential stress equilibrium equations, boundary conditions, and macroscopic forces and moments applied to the system, assuming continuous stresses at the interface between the sliding body and the retaining wall. The solutions to determine stresses and deformations of landfills contained by retaining walls are obtained using the Duncan-Chang and More >

Arooj Nasir^1,2, Dumitru Baleanu^3,4,5, Ali Raza^6,*, Pervez Anwar⁷, Nauman Ahmed⁸, Muhammad Rafiq⁹, Tahir Nawaz Cheema¹⁰

CMC-Computers, Materials & Continua, Vol.73, No.3, pp. 5717-5734, 2022, DOI:10.32604/cmc.2022.031879 - 28 July 2022

Abstract In 2020, the reported cases were 0.12 million in the six regions to the official report of the World Health Organization (WHO). For most children infected with leprosy, 0.008629 million cases were detected under fifteen. The total infected ratio of the children population is approximately 4.4 million. Due to the COVID-19 pandemic, the awareness programs implementation has been disturbed. Leprosy disease still has a threat and puts people in danger. Nonlinear delayed modeling is critical in various allied sciences, including computational biology, computational chemistry, computational physics, and computational economics, to name a few. The time… More >