Van-Truong Nguyen^1,*, Dai-Nhan Duong¹, Dinh-Hieu Phan¹, Thanh-Lam Bui¹, Xiem HoangVan², Phan Xuan Tan³

CMC-Computers, Materials & Continua, Vol.81, No.2, pp. 2337-2356, 2024, DOI:10.32604/cmc.2024.055412 - 18 November 2024

Abstract This paper proposes an adaptive nonlinear proportional-derivative (ANPD) controller for a two-wheeled self-balancing robot (TWSB) modeled by the Lagrange equation with external forces. The proposed control scheme is designed based on the combination of a nonlinear proportional-derivative (NPD) controller and a genetic algorithm, in which the proportional-derivative (PD) parameters are updated online based on the tracking error and the preset error threshold. In addition, the genetic algorithm is employed to adaptively select initial controller parameters, contributing to system stability and improved control accuracy. The proposed controller is basic in design yet simple to implement. The… More >

Shiguang Hu^1,2, Le Ru^1,2,*, Bo Lu^1,2, Zhenhua Wang³, Xiaolin Zhao^1,2, Wenfei Wang^1,2, Hailong Xi^1,2

CMC-Computers, Materials & Continua, Vol.81, No.1, pp. 1879-1903, 2024, DOI:10.32604/cmc.2024.056110 - 15 October 2024

Abstract The strategy evolution process of game players is highly uncertain due to random emergent situations and other external disturbances. This paper investigates the issue of strategy interaction and behavioral decision-making among game players in simulated confrontation scenarios within a random interference environment. It considers the possible risks that random disturbances may pose to the autonomous decision-making of game players, as well as the impact of participants’ manipulative behaviors on the state changes of the players. A nonlinear mathematical model is established to describe the strategy decision-making process of the participants in this scenario. Subsequently, the… More >

Kai Wang^1,2,3, Lihua Yang^1,2,3,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.29, No.3, pp. 1-1, 2024, DOI:10.32604/icces.2024.011018

Abstract Although offset-halves journal bearings (OHJBs) are widely used in marine powertrains, the research on nonlinear tribo-dynamics is still limited, particularly under dynamic loading. To overcome such limitations, this study proposes a novel dynamic model that couples the influences of step load and thermoelastohydrodynamic (TEHD) effect. Based on the numerical model, a transient TEHD analysis for dynamically loaded OHJBs is done. Moreover, a modified stability criterion is developed. Nonlinear behaviors and transient stability of OHJBs under step load are systematically studied. The correlations of bearing characteristics such as the maximum film temperature, minimum film thickness, maximum More >

Jinyu Gu¹, Yingjun Wang^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.29, No.2, pp. 1-1, 2024, DOI:10.32604/icces.2024.010958

Abstract In engineering practice, most components are subjected to variable-amplitude cyclic loading, resulting in fatigue damage, which is one of the main forms of damage in engineering structures. Nonlinear damage rule is developed based on linear damage rule, which can predict the fatigue life of structures more accurately. Therefore, we present a topology optimization method considering nonlinear fatigue damage accumulation in the time domain. For the time domain, we adopted the rainflow counting method to evaluate the stress level generated by cyclic loading and the Basquin equation to describe the S-N curve. We applied Morrow's plastic… More >

Ke Liang^1,*, Zheng Li¹, Zhen Yin¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.29, No.1, pp. 1-1, 2024, DOI:10.32604/icces.2024.011625

Abstract In this work, a finite element based reduced-order technique in the framework of mixed nonlinear kinematics is proposed for the geometrically nonlinear analysis of thin-walled structures [1]. The mixed nonlinear kinematics are established by combining the co-rotational formulation with the updated von Kármán formulation. The co-rotational formulation is selected to calculate the internal force and tangent stiffness of a structure; whereas the third- and fourth-order strain energy derivatives are achieved by the updated von Kármán formulation. For geometrically nonlinear problems with a large deflection, reduced-order models with 1 degree of freedom are constructed using the… More >

Yi Pan¹, Lei Xie^2,*, Hongye Su²

Intelligent Automation & Soft Computing, Vol.39, No.4, pp. 683-696, 2024, DOI:10.32604/iasc.2023.038543 - 06 September 2024

Abstract In the process of fault detection and classification, the operation mode usually drifts over time, which brings great challenges to the algorithms. Because traditional machine learning based fault classification cannot dynamically update the trained model according to the probability distribution of the testing dataset, the accuracy of these traditional methods usually drops significantly in the case of covariate shift. In this paper, an importance-weighted transfer learning method is proposed for fault classification in the nonlinear multi-mode industrial process. It effectively alters the drift between the training and testing dataset. Firstly, the mutual information method is… More >

Bingrui Ju^1,2, Wenxiang Sun², Wenzhen Qu^1,2,*, Yan Gu²

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.1, pp. 267-280, 2024, DOI:10.32604/cmes.2024.052159 - 20 August 2024

Abstract In this study, we propose an efficient numerical framework to attain the solution of the extended Fisher-Kolmogorov (EFK) problem. The temporal derivative in the EFK equation is approximated by utilizing the Crank-Nicolson scheme. Following temporal discretization, the generalized finite difference method (GFDM) with supplementary nodes is utilized to address the nonlinear boundary value problems at each time node. These supplementary nodes are distributed along the boundary to match the number of boundary nodes. By incorporating supplementary nodes, the resulting nonlinear algebraic equations can effectively satisfy the governing equation and boundary conditions of the EFK equation. More >

Javaid Ali¹, Armando Ciancio², Kashif Ali Khan³, Nauman Raza^4,5, Haci Mehmet Baskonus^6,*, Muhammad Luqman¹, Zafar-Ullah Khan⁷

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.3, pp. 2275-2296, 2024, DOI:10.32604/cmes.2024.046923 - 08 July 2024

Abstract This study proposes a structure-preserving evolutionary framework to find a semi-analytical approximate solution for a nonlinear cervical cancer epidemic (CCE) model. The underlying CCE model lacks a closed-form exact solution. Numerical solutions obtained through traditional finite difference schemes do not ensure the preservation of the model’s necessary properties, such as positivity, boundedness, and feasibility. Therefore, the development of structure-preserving semi-analytical approaches is always necessary. This research introduces an intelligently supervised computational paradigm to solve the underlying CCE model’s physical properties by formulating an equivalent unconstrained optimization problem. Singularity-free safe Padé rational functions approximate the mathematical More >

Lili Bai^1,*, Wenhui Li¹, He Ren^1,2, Feng Li¹, Tao Yan¹, Lirong Chen³

CMC-Computers, Materials & Continua, Vol.79, No.3, pp. 4513-4531, 2024, DOI:10.32604/cmc.2024.051348 - 20 June 2024

Abstract Addressing the challenges posed by the nonlinear and non-stationary vibrations in rotating machinery, where weak fault characteristic signals hinder accurate fault state representation, we propose a novel feature extraction method that combines the Flexible Analytic Wavelet Transform (FAWT) with Nonlinear Quantum Permutation Entropy. FAWT, leveraging fractional orders and arbitrary scaling and translation factors, exhibits superior translational invariance and adjustable fundamental oscillatory characteristics. This flexibility enables FAWT to provide well-suited wavelet shapes, effectively matching subtle fault components and avoiding performance degradation associated with fixed frequency partitioning and low-oscillation bases in detecting weak faults. In our approach,… More >

AL-Bukhaiti Khalil¹, Yanhui Liu^1,*, Shichun Zhao¹, Daguang Han²

Structural Durability & Health Monitoring, Vol.18, No.3, pp. 223-254, 2024, DOI:10.32604/sdhm.2024.044751 - 15 May 2024

Abstract This study provides a comprehensive analysis of collision and impact problems’ numerical solutions, focusing on geometric, contact, and material nonlinearities, all essential in solving large deformation problems during a collision. The initial discussion revolves around the stress and strain of large deformation during a collision, followed by explanations of the fundamental finite element solution method for addressing such issues. The hourglass mode’s control methods, such as single-point reduced integration and contact-collision algorithms are detailed and implemented within the finite element framework. The paper further investigates the dynamic response and failure modes of Reinforced Concrete (RC)… More >