Article
Mathematics
Liqin Liu, Chunrui Zhang
Summary: This paper studies a system of four coupled van der Pol oscillators with delay. The conditions for the existence of multiple periodic solutions of the system are given. The spatiotemporal patterns of the system are obtained using symmetric Hopf bifurcation theory. Numerical simulations are used to demonstrate the theoretical results.
Article
Mathematics, Interdisciplinary Applications
Janarthanan Ramadoss, Jacques Kengne, Sosthene Tsamene Tanekou, Karthikeyan Rajagopal, Germaine Djuidje Kenmoe
Summary: This paper discusses the dynamics of a system composed of a van der Pol oscillator linearly coupled to a Duffing oscillator. It investigates the effects of explicit symmetry breaking on the equilibrium points, competing attractors, bifurcation modes, and basins of attraction. The study reveals intricate dynamical features such as critical transitions, hysteresis, the coexistence of bifurcation bubbles, and multiple coexisting attractors resulting from the variation of initial states and parameters.
CHAOS SOLITONS & FRACTALS
(2022)
Article
Mathematics, Interdisciplinary Applications
I. B. Shiroky, O. Gendelman
Summary: This paper revisits the nonconventional synchronization regimes in systems of coupled bi-stable van der Pol oscillators, demonstrating new synchronization phenomena and simplifying the dynamics of the system. The observations reveal a rich set of global and local bifurcations of limit cycles and tori, as well as an unexpected regime of nonstationary asymmetric synchronization.
CHAOS SOLITONS & FRACTALS
(2021)
Article
Mathematics, Interdisciplinary Applications
B. A. Guimfack, R. Mbakob Yonkeu, C. B. Tabi, T. C. Kofane
Summary: This paper investigates the occurrence of P-bifurcation in enzyme-substrate reactions in brain waves and confirms the accuracy of the results through theoretical analysis and numerical simulations. The results demonstrate that fractional-order changes play a dominant role in bifurcation scenarios.
CHAOS SOLITONS & FRACTALS
(2022)
Article
Mathematics, Applied
S. A. Kashchenko
Summary: A study of a ring chain of the coupled Van der Pol equations with two types of unidirectional advective couplings was conducted. The research focused on stability and dynamic behavior, revealing differences when using various couplings, and constructing special nonlinear partial differential equations models.
Article
Physics, Multidisciplinary
E. B. Megam Ngouonkadi, M. Kabong Nono, H. B. Fotsin, M. Ekonde Sone, D. Yemele
Summary: A survey and analysis on coupled VDP and DH oscillators were conducted, showing stable, unstable, and chaotic behaviors, along with a numerical study of the parameters space. The study also discussed the transition from invariant one-torus to invariant two-torus and the occurrence of Arnold's resonance web phenomenon in the mutual coupling case.
Article
Mathematics, Interdisciplinary Applications
Sosthene Tsamene Tanekou, Janarthanan Ramadoss, Jacques Kengne, Germaine Djuidje Kenmoe, Karthikeyan Rajagopal
Summary: This article investigates a fourth-order autonomous dynamical system composed of a Duffing oscillator coupled to a van der Pol oscillator. The study reveals the existence of multiple bifurcation modes and the coexistence of periodicity, chaos, and hyperchaos in the coupled system. The impact of a fractional-order derivative is examined and PSpice simulations confirm the theoretical predictions.
INTERNATIONAL JOURNAL OF BIFURCATION AND CHAOS
(2023)
Article
Mathematics
Yani Chen, Youhua Qian
Summary: This paper examines the influence of two-degree-of-freedom coupled van der Pol oscillators with time delay feedback using normal form and central manifold theories. The results show the relationship between system stability and time delay, as well as the complexity of its dynamical behavior. Practical engineering problems can utilize time delay feedback adjustment to achieve effects such as amplitude death and limit loop based on the characteristics of the system.
Article
Mathematics
Sergey Kashchenko
Summary: The study focuses on the local dynamics of a chain of coupled Van der Pol equation systems near the zero equilibrium state. Transition to a system with continuous spatial variable, identifying critical cases corresponding to Turing bifurcations, and proposing special nonlinear parabolic equations are key aspects. It is found that for systems with a large number of elements, dynamics significantly change with a slight change in the number of elements.
Article
Computer Science, Artificial Intelligence
J. Alidousti, Z. Eskandari, M. Fardi, M. Asadipour
Summary: This paper introduces the effectiveness of using critical normal form coefficients method for bifurcation analysis, focusing on the dynamic behaviors of the discrete BVP model. Different bifurcations such as pitchfork, fold, flip, and resonance are discussed, with thorough investigation into the normal form coefficients and scenarios for each bifurcation. The numerical continuation techniques confirm the analytical results and reveal richer dynamics of the model in higher iterations.
Article
Mathematics
Danjin Zhang, Youhua Qian
Summary: This paper investigates the dynamic behavior of the van der Pol-Rayleigh system using fast-slow analysis and transformation phase portrait methods. It examines the stability and bifurcation behavior of the equilibrium point, identifying the presence of Hopf bifurcation without fold bifurcation. The system's vibration behavior in different modes is analyzed, showing that it is influenced by both fast and slow varying processes. The transformation phase portrait method reveals the mechanisms of different vibration modes, as the system trajectory encounters different attractors in the fast subsystem.
Article
Acoustics
Ashraf T. EL-Sayed
Summary: The study showed that delay positive position feedback control can reduce the vibration response of double Van der Pol oscillators with external forces, and frequency response curves were obtained using perturbation process. The stability analysis revealed optimum stable ranges, with time delays affecting the stability of the system.
JOURNAL OF VIBRATION AND CONTROL
(2021)
Article
Mathematics, Applied
Hebai Chen, Jie Jin, Zhaoxia Wang, Baodong Zhang
Summary: This paper studies the global dynamics of a van der Pol-Duffing oscillator with indefinite degree, exploring various nonlinear phenomena through qualitative and bifurcation analysis.
QUALITATIVE THEORY OF DYNAMICAL SYSTEMS
(2022)
Article
Mathematics, Applied
Hebai Chen, Yilei Tang, Dongmei Xiao
Summary: We investigated the dynamics of a hybrid van der Pol-Rayleigh oscillator used to model self-sustained walking behaviors, revealing new dynamics distinct from traditional oscillators. The global bifurcation diagram and phase portraits of this oscillator were presented in parameter space, with characterization of the locations and amplitudes of periodic oscillations.
PHYSICA D-NONLINEAR PHENOMENA
(2021)
Article
Mathematics, Interdisciplinary Applications
Xindong Ma, Jin Song, Mengke Wei, Xiujing Han, Qinsheng Bi
Summary: This paper reports interesting dynamical behaviors related to PSE of equilibria in a van der Pol-Mathieu-Duffing system with multiple-frequency slow-varying excitations, revealing bifurcations within a narrow parameter interval and two types of compound bursting patterns. The results also show a novel type of relaxation oscillation independent of bifurcations, enriching the knowledge of dynamical behaviors related to PSE and possible routes to complex bursting dynamics.
INTERNATIONAL JOURNAL OF BIFURCATION AND CHAOS
(2021)
Editorial Material
Chemistry, Analytical
Kyandoghere Kyamakya, Fadi Al-Machot, Ahmad Haj Mosa, Hamid Bouchachia, Jean Chamberlain Chedjou, Antoine Bagula
Article
Chemistry, Analytical
Kyandoghere Kyamakya, Jean Chamberlain Chedjou, Fadi Al-Machot, Ahmad Haj Mosa, Antoine Bagula
Article
Chemistry, Analytical
Kyandoghere Kyamakya, Ahmad Haj Mosa, Fadi Al Machot, Jean Chamberlain Chedjou
Article
Green & Sustainable Science & Technology
Taha Benarbia, Kyandoghere Kyamakya
Summary: In recent years, the volume of packages to be delivered by e-commerce businesses has increased, along with demanding customer expectations. To reduce costs and meet the growing demand, businesses have turned to autonomous delivery options such as drones. This paper provides a comprehensive survey of research issues, proposed solutions, and discusses performance levels and future research directions for drone delivery systems.
Article
Chemistry, Analytical
Taraneh Aminosharieh Najafi, Antonio Abramo, Kyandoghere Kyamakya, Antonio Affanni
Summary: A sedentary lifestyle is prevalent in modern societies and can lead to health complications. This paper introduces a new smart chair sensors system that can identify different sitting postures. Extensive experiments and evaluation of seven deep-learning algorithms demonstrate the system's high accuracy and versatility.
Article
Chemistry, Analytical
Kabeh Mohsenzadegan, Vahid Tavakkoli, Kyandoghere Kyamakya
Summary: We propose a new OCR model based on both CNNs and RNNs, which performs robustly under different distortion conditions. Our comprehensive study shows that existing works can improve OCR recognition performance to some extent, but are not always satisfactory, especially under very harsh conditions. Therefore, we suggest a better approach and model architecture, which significantly outperforms previous works.
Article
Chemistry, Analytical
Thulane Paepae, Pitshou N. Bokoro, Kyandoghere Kyamakya
Summary: This study explores the feasibility of using machine learning techniques to predict nitrogen and phosphorus levels in water bodies and proposes a model based on virtual sensors. The results show that the best predictive model, scaler, and imputer are extremely randomized trees, MinMax scaler, and multivariate imputer, respectively. The predictive performance achieves high accuracy in different catchments.
Review
Chemistry, Analytical
Kyandoghere Kyamakya, Vahid Tavakkoli, Simon McClatchie, Maximilian Arbeiter, Bart G. Scholte van Mast
Summary: This paper addresses abnormal behavior detection and forecasting in the activity monitoring of a human in bed, presenting a comprehensive formulation of requirements engineering dossier. The study discusses the anomaly concept, evaluates four major approaches, and provides recommendations for system architecture and overall systems engineering.
Article
Chemistry, Analytical
Hima Deepthi Vankayalapati, Swarna Kuchibhotla, Mohan Sai Kumar Chadalavada, Shashi Kant Dargar, Koteswara Rao Anne, Kyandoghere Kyamakya
Summary: This study proposes a real-time head pose and gaze estimation algorithm that combines appearance and geometric methods for feature extraction and uses conventional discriminant algorithms for classification. The experiments demonstrate that the algorithm achieves high accuracy and stability under different illumination conditions.
Article
Chemistry, Multidisciplinary
Kabeh Mohsenzadegan, Vahid Tavakkoli, Kyandoghere Kyamakya
Summary: This paper proposes a new convolutional neural network (CNN) architecture for improving document-image quality by decreasing the impact of distortions. The proposed model achieves promising performance in character recognition accuracy for even highly degraded document images.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Analytical
Thulane Paepae, Pitshou N. Bokoro, Kyandoghere Kyamakya
Summary: In order to better control eutrophication, reliable information and accurate measurements of phosphorus and nitrogen loading are desired, but high-frequency monitoring is not economically feasible. Therefore, virtual sensing is used to predict these variables using easily measurable inputs. This study utilizes a variational autoencoder to generate synthetic data and verifies its performance using water-quality data from two tributaries of the River Thames in the United Kingdom. Compared to current methods, the new data augmentation approach significantly improves the root mean squared errors, especially when using three predictors. In terms of predictive accuracy and computational cost, k-nearest neighbors and extremely randomized trees are the best-performing algorithms on average.
Article
Green & Sustainable Science & Technology
Taha Benarbia, Kyandoghere Kyamakya, Fadi Al Machot, Witesyavwirwa Vianney Kambale
Summary: The recent boom in artificial intelligence has revolutionized the automotive industry, with significant advancements made by automakers like Tesla, Toyota, Honda, and BMW in the development of e-autonomous vehicles. Shared electric automated vehicle mobility systems have garnered attention from researchers, but the flexibility of these systems poses challenges in terms of fair vehicle distribution. This paper addresses the issues of autonomous repositioning and assignment in order to balance the system's network and meet demand, using stochastic Petri nets for modeling and analysis.
Article
Mathematics
Selain K. Kasereka, Glody N. Zohinga, Vogel M. Kiketa, Ruffin-Benoit M. Ngoie, Eddy K. Mputu, Nathanael M. Kasoro, Kyamakya Kyandoghere
Summary: The paper explores two modeling approaches, equation-based modeling (EBM) and agent-based modeling (ABM), for understanding the dynamics of infectious diseases in the population. A comparative study of these approaches is conducted, highlighting their advantages and disadvantages. Two case studies on the spread of the COVID-19 pandemic are carried out using both approaches. The results show that differential equation-based models are faster but still simplistic, while agent-based models require more machine capabilities but are more realistic and very close to biology. Based on these outputs, it seems that the coupling of both approaches could be an interesting compromise.
Article
Chemistry, Analytical
Ali Deeb, Abdalrahman Ibrahim, Mohamed Salem, Joachim Pichler, Sergii Tkachov, Anjeza Karaj, Fadi Al Machot, Kyamakya Kyandoghere
Summary: This paper presents a method for automatically classifying analog circuits using a Graph Convolutional Network (GCN) model and data augmentation techniques. The circuits' schematics are represented as graphs, and a robust classifier based on GCN is used to determine the label for a given input circuit. The classification performance is improved through data augmentation techniques. Extensive testing demonstrates the high accuracy of the proposed method for analog circuit classification.
Article
Chemistry, Analytical
Venkatachalam Kandasamy, Pavel Trojovsky, Fadi Al Machot, Kyandoghere Kyamakya, Nebojsa Bacanin, Sameh Askar, Mohamed Abouhawwash
Summary: The use of social media as an intelligent platform for sharing thoughts and concerns has led to a comprehensive search of COVID-19 related views and opinions on Twitter, utilizing ensemble deep learning techniques for better prediction of future developments in Twitter discussions.
