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 >

Dongmei Huang¹, Dang Hong², Wei Li^1,*, Guidong Yang¹, Vesna Rajic³

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.1, pp. 509-524, 2024, DOI:10.32604/cmes.2023.029215 - 22 September 2023

Abstract In this paper, the bifurcation properties of the vibro-impact systems with an uncertain parameter under the impulse and harmonic excitations are investigated. Firstly, by means of the orthogonal polynomial approximation (OPA) method, the nonlinear damping and stiffness are expanded into the linear combination of the state variable. The condition for the appearance of the vibro-impact phenomenon is to be transformed based on the calculation of the mean value. Afterwards, the stochastic vibro-impact system can be turned into an equivalent high-dimensional deterministic non-smooth system. Two different Poincaré sections are chosen to analyze the bifurcation properties and… More >

Yang Liu^1,*, Luis Dorfmann²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.4, pp. 1-1, 2023, DOI:10.32604/icces.2023.09499

Abstract In this talk, we present some analytical results concerning localized instabilities in stretched soft cylinders with residual-stress effect. Within the framework of finite elasticity, a bifurcation analysis is carried out based on the incremental theory. It is found that with the residual stress effect taken into consideration additional singularities of the incremental equations appear. To overcome this difficulty we apply the Stroh formulism and an expansion methodology and derive a bifurcation condition. Then we consider three loading scenarios and perform a detailed analysis of the bifurcation behaviors. It turns out that the zero mode, giving More >

Mohamad Afendee Mohamed¹, Talal Bonny², Aceng Sambas³, Sundarapandian Vaidyanathan⁴, Wafaa Al Nassan², Sen Zhang⁵, Khaled Obaideen², Mustafa Mamat¹, Mohd Kamal Mohd Nawawi^6,*

CMC-Computers, Materials & Continua, Vol.75, No.3, pp. 5987-6006, 2023, DOI:10.32604/cmc.2023.035668 - 29 April 2023

Abstract In recent years, there are numerous studies on chaotic systems with special equilibrium curves having various shapes such as circle, butterfly, heart and apple. This paper describes a new 3-D chaotic dynamical system with a capsule-shaped equilibrium curve. The proposed chaotic system has two quadratic, two cubic and two quartic nonlinear terms. It is noted that the proposed chaotic system has a hidden attractor since it has an infinite number of equilibrium points. It is also established that the proposed chaotic system exhibits multi-stability with two coexisting chaotic attractors for the same parameter values but… More >

Fahad Sameer Alshammari¹, Md Fazlul Hoque², Harun-Or-Roshid², Muhammad Nadeem^3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.3, pp. 2197-2217, 2023, DOI:10.32604/cmes.2023.022301 - 23 November 2022

Abstract We investigate the bounded travelling wave solutions of the Biswas-Arshed model (BAM) including the low group velocity dispersion and excluding the self-phase modulation. We integrate the nonlinear structure of the model to obtain bounded optical solitons which pass through the optical fibers in the non-Kerr media. The bifurcation technique of the dynamical system is used to achieve the parameter bifurcation sets and split the parameter space into various areas which correspond to different phase portraits. All bounded optical solitons and bounded periodic wave solutions are identified and derived conforming to each region of these phase More >

S. Hanis^*

Intelligent Automation & Soft Computing, Vol.36, No.1, pp. 865-878, 2023, DOI:10.32604/iasc.2023.030597 - 29 September 2022

Abstract In the recent past, the storage of images and data in the cloud has shown rapid growth due to the tremendous usage of multimedia applications. In this paper, a modulated version of the Ikeda map and key generation algorithm are proposed, which can be used as a chaotic key for securely storing images in the cloud. The distinctive feature of the proposed map is that it is hyperchaotic, highly sensitive to initial conditions, and depicts chaos over a wide range of control parameter variations. These properties prevent the attacker from detecting and extracting the keys… More >

Anupam Krishnan¹, Anjana P. Anantharaman^2,*

Molecular & Cellular Biomechanics, Vol.19, No.2, pp. 77-88, 2022, DOI:10.32604/mcb.2022.018369 - 25 March 2022

Abstract Computational Fluid Dynamics has become relevant in the study of hemodynamics, where clinical results are challenging to obtain. This paper discusses a 2-Dimensional transient blood flow analysis through an arterial bifurcation for patients infected with the Coronavirus. The geometry considered is an arterial bifurcation with main stem diameter 3 mm and two outlets. The left outlet (smaller) has a diameter of 1.5 mm and the right outlet (larger), 2 mm. The length of the main stem, left branch and right branch are fixed at 35 mm, 20 mm and 25 mm respectively. Viscosity change that… More >

Haoyu Wan, Heng Zhang, Zhizhu He^*

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.3, pp. 639-651, 2021, DOI:10.32604/fdmp.2021.012106 - 29 April 2021

Abstract Treating coronary bifurcation stenosis is still a challenging task. Existing procedures still display a relatively small rate of success. This paper aims to investigate numerically the effect of bifurcation lesions with different structures on the dynamics of blood flow and related temperature. The problem geometry is parametrically varied by changing the bifurcation angle and radius. A finite volume method is used to simulate the three-dimensional flow. The effects induced by the structure of the stenosis, the artery bifurcation angle and radius, and the inlet velocity of blood are discussed in terms of flow pattern, pressure More >

Ankit Kumar, Balram Dubey^*

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.2, pp. 505-547, 2021, DOI:10.32604/cmes.2021.013206 - 21 January 2021

Abstract In this paper, the impact of additional food and two discrete delays on the dynamics of a prey-predator model is investigated. The interaction between prey and predator is considered as Holling Type-II functional response. The additional food is provided to the predator to reduce its dependency on the prey. One delay is the gestation delay in predator while the other delay is the delay in supplying the additional food to predators. The positivity, boundedness and persistence of the solutions of the system are studied to show the system as biologically well-behaved. The existence of steady… More >

Ali Yousef^1,*, Fatma Bozkurt^1,2, Thabet Abdeljawad^3,4,5

CMC-Computers, Materials & Continua, Vol.66, No.1, pp. 843-869, 2021, DOI:10.32604/cmc.2020.012060 - 30 October 2020

Abstract In this study, we classify the genera of COVID-19 and provide brief information about the root of the spread and the transmission from animal (natural host) to humans. We establish a model of fractional-order differential equations to discuss the spread of the infection from the natural host to the intermediate one, and from the intermediate one to the human host. At the same time, we focus on the potential spillover of bat-borne coronaviruses. We consider the local stability of the co-existing critical point of the model by using the Routh–Hurwitz Criteria. Moreover, we analyze the More >