Abdulsattar Abdullah Hamad¹, Ahmed S. Al-Obeidi², Enas H. Al-Taiy², Osamah Ibrahim Khalaf³, Dac-Nhuong Le^4,5,*

CMC-Computers, Materials & Continua, Vol.66, No.3, pp. 3311-3327, 2021, DOI:10.32604/cmc.2021.013395

Abstract Synchronization is one of the most important characteristics of dynamic systems. For this paper, the authors obtained results for the nonlinear systems controller for the custom Synchronization of two 4D systems. The findings have allowed authors to develop two analytical approaches using the second Lyapunov (Lyp) method and the Gardano method. Since the Gardano method does not involve the development of special positive Lyp functions, it is very efficient and convenient to achieve excessive system SYCR phenomena. Error is overcome by using Gardano and overcoming some problems in Lyp. Thus we get a great investigation into the convergence of error… More >

Dongping Tian^a,b

Intelligent Automation & Soft Computing, Vol.24, No.2, pp. 331-342, 2018, DOI:10.1080/10798587.2017.1293881

Abstract Particle swarm optimization (PSO) is a population based swarm intelligence algorithm that has been deeply studied and widely applied to a variety of problems. However, it is easily trapped into the local optima and premature convergence appears when solving complex multimodal problems. To address these issues, we present a new particle swarm optimization by introducing chaotic maps (Tent and Logistic) and Gaussian mutation mechanism as well as a local re-initialization strategy into the standard PSO algorithm. On one hand, the chaotic map is utilized to generate uniformly distributed particles to improve the quality of the initial population. On the other… More >

M. F. Elettreby^{1, 2, *}, Tamer Nabil^{1, 3}, A. Khawagi⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.3, pp. 907-921, 2020, DOI:10.32604/cmes.2020.08664

Abstract In this paper, a discrete Lotka-Volterra predator-prey model is proposed that considers mixed functional responses of Holling types I and III. The equilibrium points of the model are obtained, and their stability is tested. The dynamical behavior of this model is studied according to the change of the control parameters. We find that the complex dynamical behavior extends from a stable state to chaotic attractors. Finally, the analytical results are clarified by some numerical simulations. More >

Bin Lu¹, Fenlin Liu¹, Xin Ge^1,*, Zhenyu Li²

CMC-Computers, Materials & Continua, Vol.61, No.2, pp. 687-699, 2019, DOI:10.32604/cmc.2019.05633

Abstract Due to the characteristics of chaotic systems, different cryptosystems based on chaos have been proposed to satisfy the security of multimedia data. A plain image-related chaotic algorithm is proposed by Luo et al. with high speed and efficiency. Security weaknesses of the cryptosystem are studied in this paper. It is found that the important secret key information is leaked because an important parameter can be obtained after an inverse operation in the last step of the cryptosystems without secret key. Meanwhile, the value zero is processed improperly in quantification algorithm. Based on the weaknesses, chosen plaintext attack on the cryptosystem… More >

S.J. Zhu, Q.H Zeng, J.J Lou, Q.W He

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.2, pp. 43-44, 2011, DOI:10.3970/icces.2011.018.043

Abstract Line spectra are the most visible signs of the ships' radiated noise spectrum. The potential of chaotifying vibration isolation systems to reduce line spectra and improve its capability of concealment have been recently reported. Basically, as the existing isolation system design is based on linear theory, it is difficult to produce the nonlinear chaotic motion; and if the vibration isolation system(VIS) is designed directly using the nonlinear theory, it is also difficult to produce the chaotic motion because of the difficulties in accurate calculation of vibration isolation device parameters. In this paper, a controller design method is put forward using… More >

G.Ananthakrishna¹

CMES-Computer Modeling in Engineering & Sciences, Vol.7, No.3, pp. 233-240, 2005, DOI:10.3970/cmes.2005.007.233

Abstract We show that the extended Ananthakrishna's model exhibits all the features of the Portevin - Le Chatelier effect including the three types of bands. The model reproduces the recently observed crossover from a low dimensional chaotic state at low and medium strain rates to a high dimensional power law state of stress drops at high strain rates. The dynamics of crossover is elucidated through a study of the Lyapunov spectrum. More >

Shaojiang Zhong^{1, *}

CMC-Computers, Materials & Continua, Vol.60, No.2, pp. 465-479, 2019, DOI:10.32604/cmc.2019.05853

Abstract Based on the three-dimensional classic Chua circuit, a nonlinear circuit containing two flux-control memristors is designed. Due to the difference in the design of the characteristic equation of the two magnetron memristors, their position form a symmetrical structure with respect to the capacitor. The existence of chaotic properties is proved by analyzing the stability of the system, including Lyapunov exponent, equilibrium point, eigenvalue, Poincare map, power spectrum, bifurcation diagram et al. Theoretical analysis and numerical calculation show that this heterogeneous memristive model is a hyperchaotic five-dimensional nonlinear dynamical system and has a strong chaotic behavior. Then, the memristive system is… More >

Mengchu Tian¹, Yuming Bo¹, Zhimin Chen^2,3, Panlong Wu¹, Gaopeng Zhao¹

CMES-Computer Modeling in Engineering & Sciences, Vol.108, No.5, pp. 285-301, 2015, DOI:10.3970/cmes.2015.108.285

Abstract Particle filter based on particle swarm optimization algorithm is not precise enough and easily trapping in local optimum, it is difficult to satisfy the requirement of advanced integrated navigation system. To solve these problems, an improved adaptive particle filter based on chaos particle swarm was proposed and used in GPS/INS integrated navigation system. This algorithm introduced chaos sequence to update the weight and threshold, which could improve the quality of samples and reduce the local optimization and enhance the global searching ability. In addition, the avoid factor was set which made the particles be away from low likelihood area. Finally,… More >

G.J.A. Loeven^1,2, H. Bijl³

CMES-Computer Modeling in Engineering & Sciences, Vol.36, No.3, pp. 193-212, 2008, DOI:10.3970/cmes.2008.036.193

Abstract In this paper a Two-Step approach is presented for uncertainty quantification for expensive problems with multiple uncertain parameters. Both steps are performed using the Probabilistic Collocation method. The first step consists of a sensitivity analysis to identify the most important parameters of the problem. The sensitivity derivatives are obtained using a first or second order Probabilistic Collocation approximation. For the most important parameters the probability distribution functions are propagated using the Probabilistic Collocation method using higher order approximations. The Two-Step approach is demonstrated for flow around a NACA0012 airfoil with eight uncertain parameters in the free stream conditions and geometry.… More >

J.L. Sereno¹, J.C.F. Pereira¹

CMES-Computer Modeling in Engineering & Sciences, Vol.73, No.1, pp. 23-44, 2011, DOI:10.3970/cmes.2011.073.023

Abstract The evolution of a two-dimensional vortex pair in ground effect was studied under the influence of random initial inputs comprising vortex strength (circulation) or initial vortex position. The paper addresses the questions of how do variations and uncertainties of initial conditions translate to the variability of vortex pair evolution. The stochastic solutions were obtained recurring to the Polynomial Chaos Expansion method of random processes applied to the Navier-Stokes equations for a laminar flow. The method quantifies the extent, dependence and propagation of uncertainty through the model system and, in particular, a methodology for the calculation of the vortices trajectory variability,… More >