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Variable driving conditions can cause an integrated starter generator hybrid powertrain to switch between multiple drive modes. The addition of a permanent magnet synchronous motor (PMSM) gives hybrid powertrains complex electromechanical coupling characteristics. The effects of excitation sources, such as the engine and PMSM, may cause unstable behavior in the drive system, such as speed fluctuations

The problem of event-triggered fixed-time control for state-constrained stochastic nonlinear systems is discussed in this article. Different from the barrier Lyapunov function (BLF)-based and Integral BLF-based schemes that rely on feasibility conditions (FCs), by introducing the nonlinear state-dependent functions, the asymmetric time-varying state constraints are handled without FCs. Combined with

Nonlinear energy sink (NES) refers to a typical passive vibration device connected to linear or weakly nonlinear structures for vibration absorption and mitigation. This study investigates the dynamics of 1-dof and 2-dof NES with nonlinear damping and combined stiffness connected to a linear oscillator. For the system of 1-dof NES, a truncation damping and failure frequency are revealed through bifurcation

The subject of this paper is a nonlocal Hirota equation. Firstly, we provide associated Lax pair and zero curvature condition to establish the integrability. Secondly, we construct N-fold Darboux transformation (DT) by taking the form of determinants. Thirdly, we derive parity-time (PT) symmetric broken bright soliton solutions under zero background and PT symmetric unbroken dark (or antidark) soliton

Nonlinearities in rotating systems have been seen to cause a wide variety of rich phenomena; however, the understanding of these phenomena has been limited because numerical approaches typically rely on “brute force” time simulation, which is slow due to issues of step size and settling time, cannot locate unstable solution families, and may miss key responses if the correct initial conditions are

This paper examines periodic and quasi-periodic (QP) vibration-based energy harvesting (EH) in a nonlinear energy sink (NES) absorber that is coupled to an electric circuit through a piezoelectric mechanism. For this investigation, we excite the primary system by harmonic force. To this system, we add linear delayed feedback controls implementations. The complexification-averaging (CX-A) method is

This paper focuses on the problem of nonlinear system identification by proposing an improved approach for existing frequency-domain nonlinear identification through feedback of the outputs (NIFO) method via separation strategy. Suitable excitation level is difficult to select for the existing NIFO method, and coupling errors are usually caused by the large differences in the numerical magnitude between

The primary object of this study is to measure the complexity of different types of signals. We undertake the experiment to support the hypothesis of inverse dispersion entropy (IDE). Multiscale inverse dispersion entropy (MIDE) is also proposed to measure the intrinsic properties of the dynamic system. In addition, this work forms fractional inverse dispersion entropy (FIDE) and \(s^\alpha \) fractional

A Correction to this paper has been published: https://doi.org/10.1007/s11071-021-06487-z

In this paper, we have considered a deterministic epidemic model with logistic growth rate of the susceptible population, non-monotone incidence rate, nonlinear treatment function with impact of limited hospital beds and performed control strategies. The existence and stability of equilibria as well as persistence and extinction of the infection have been studied here. We have investigated different

Identifying causal relationships is a challenging yet crucial problem in many fields of science like epidemiology, climatology, ecology, genomics, economics and neuroscience, to mention only a few. Recent studies have demonstrated that ordinal partition transition networks (OPTNs) allow inferring the coupling direction between two dynamical systems. In this work, we generalize this concept to the study

With the spread of the novel coronavirus disease 2019 (COVID-19) around the world, the estimation of the incubation period of COVID-19 has become a hot issue. Based on the doubly interval-censored data model, we assume that the incubation period follows lognormal and Gamma distribution, and estimate the parameters of the incubation period of COVID-19 by adopting the maximum likelihood estimation, expectation

In this paper, we construct the discrete higher-order rogue wave (RW) solutions for a generalized integrable discrete nonlinear Schrödinger (NLS) equation. First, based on the modified Lax pair, the discrete version of generalized Darboux transformation is constructed. Second, the dynamical behaviors of first-, second- and third-order RW solutions are investigated in corresponding to the unique spectral

Under investigation in this paper is a discrete modified exponential Toda lattice equation which may describe vibration of particles in a lattice. Firstly, we construct an integrable lattice hierarchy associated with this equation from a \(2\times 2\) matrix spectral problem, and some related integrable properties such as Hamiltonian structures, Liouville integrability and conservation laws of this

This paper addresses the model reduction and the simulation of a damped Euler–Bernoulli–von Kármán pinned beam excited by a distributed force. This nonlinear problem is formulated as a PDE and reformulated as a well-posed state-space system. The model order reduction and simulation are derived by combining two approaches: a Volterra series expansion and truncation and a pseudo-modal truncation defined

Fabricated by high elastic materials, soft actuators provide a prominent solution for soft rehabilitation gloves, soft graspers and locomotion robots. However, the control of soft actuators is a grant challenge due to dynamic modeling error and unavailable system states. This paper proposes an observer-based continuous adaptive sliding mode controller for soft actuators in the presence of system uncertainties

Under investigation is a completely generalized Hirota–Satsuma–Ito equation in (2 + 1)-dimensional. Multiple lump solutions are obtained based on three test functions, including 1-, 2- and 3-order lump solutions. Subsequently, the interaction between lump wave and solitary waves, and the interaction solution between lump wave and periodic wave are studied by using the bilinear form. Final, the stability

The invasion of Indo-Pacific lionfish (Pterois volitans) together with unsustainable harvesting of herbivorous fish has caused major ecological changes in the western Atlantic and Caribbean coral reefs. Developing an effective harvesting policy of herbivorous reef fish and the invasive lionfish is necessary to minimize the adverse ecological impacts. To evaluate the potential efficacy of controlling

In actual networks, the distance between nodes has an effect on load flow. Nodes closer to a node are more attractive, as if there is some kind of gravity between the nodes. For example, vehicles and people usually prefer to a close place in the traffic network. Does the distance between nodes affect the load distribution of the network, and how does this “gravity” affect the cascading dynamics? To

We use the physics-informed neural network to solve a variety of femtosecond optical soliton solutions of the high-order nonlinear Schrödinger equation, including one-soliton solution, two-soliton solution, rogue wave solution, W-soliton solution and M-soliton solution. The prediction error for one-soliton, W-soliton and M-soliton is smaller. As the prediction distance increases, the prediction error

In order to reduce the adverse effects of internal uncertainty and external disturbance in the active front steering (AFS) system of electric vehicles, two chattering-free discrete-time sliding mode (CDSM) AFS controllers are proposed in this paper. First of all, the sideslip angle is estimated by constructing a Luenberger observer and a two-degree-of-freedom model-based parameter tuning scheme is

This paper proposed a discrete-time integral terminal sliding mode (DITSM)-based forward speed tracking control for a robotic fish (RF). Due to the difficulty of quantification for the hydrodynamic model of RF during swimming, the head-yawing effect is considered in the obstructive thrust and then the RF dynamic model is further optimized via a data-driven approach. Compared with the traditional robotic

In this paper, an extended state observer-based adaptive prescribed performance control technique is proposed for a class of nonlinear systems with full-state constraints and uncertainties. An extraordinary feature is that not only the control problem of prescribed performance tracking and full-state constraints are solved simultaneously, but also the parametric uncertainties and disturbances are considered

The spatial partitioning problem of urban traffic network sub-regions has been mainly researched in static mode by considering traffic conditions at a certain time. Nevertheless, traffic flow has strong dynamic characteristics running in urban network; it is necessary to divide the sub-regions according to the correlation of traffic flow in spatiotemporal dimension. Dynamic partitioning is of great

The excitations of nonlinear magnetosonic lump waves induced by orbiting charged space debris particles in the Low Earth Orbital (LEO) plasma region are investigated in the presence of the ambient magnetic field. These nonlinear waves are found to be governed by the forced Kadomtsev–Petviashvili-type model equation, where the forcing term signifies the source current generated by different possible

Electrical and chemical synapses are essential for signal exchange between neurons. The continuous exchange of ion concentration in cells will induce complex time-varying electromagnetic fields, which can further regulate the dynamic response of neural electrical activities. Therefore, it is of practical significance to introduce the magnetic field and electric field into the traditional neuron model

In this paper, weighted link entropy (WLE) and multiscale weighted link entropy (MWLE) are proposed as novel measures to quantify complexity of nonlinear time series. MWLE is different from traditional weighted permutation entropy (WPE) in that its proposal is based on the combination of symbolic ordinal analysis and networks. Besides, the analysis of MWLE takes into account multiple time scales inherent

To investigate the price fluctuation mechanism of stock markets, this research aims to develop a novel stochastic financial model based on Potts dynamics and compound Poisson process. The new model considers two aspects: information interaction among traders and the uncertain events outside the system. Then, three different volatility statistics (return series \(r_t\), absolute return series \(|r_t|\)

Modern control synthesis assumes that observability of a dynamic system is satisfied. However, in particular, observability may not be met due to manufacturing cost. To cope with this challenging dilemma, we consider training a neural network with a large dataset that contains prior information of a given nonlinear vehicle dynamics system. In this paper, we proposed and designed a long short-term memory

Closed forms of stabilizing sets are generally only available for linearized systems. An innovative numerical strategy to estimate stabilizing sets of PI or PID controllers tackling (uncertain) nonlinear systems is proposed. The stability of the closed-loop system is characterized by the sign of the largest Lyapunov exponent (LLE). In this framework, the bottleneck is the computational cost associated

This study carries the novel applications of the Sinc collocation method to investigate the numerical computing paradigm of Schrödinger wave equation and Transport equation as a great level of accuracy and precision. A global collocation-based Sinc function is embedded with a cardinal expansion to discretize initially time derivatives by finite difference method and secondly spatial derivatives are

This paper is devoted to the construction of a nonintrusive interval uncertainty propagation approach for the response bounds evaluation of multibody systems. The motivation for this effort is twofold. First, the traditional methods using the Taylor inclusion function and interval arithmetic usually lead to the wrapping effect. Second, the real-life multibody dynamics models are mostly large systems

This article proposed an improved 2D-logistic-adjusted-Sine map, which has better ergodicity, pseudo-randomness, unpredictability and wider chaotic range than many existing 2D-chaotic maps. Utilizing improved 2D-logistic-adjusted-Sine map generates chaotic sequences, where the initial values of the system are assigned based on SHA 512 hash function. Compared with traditional encryption scheme, the

A Langevin equation is suggested to describe a system driven by correlated Gaussian white noise as well as with positive and negative damping demarcated by a critical velocity. The equation can be transformed into the Fokker–Planck equation by the Kramers–Moyal expansion. The solution of this equation exhibits some non-equilibrium phenomena. In the beginning the distribution curve of velocity/energy

Recently, considering the temporary immunity of individuals who have recovered from certain infectious diseases, Liu et al. (Phys A Stat Mech Appl 551:124152, 2020) proposed and studied a stochastic susceptible-infected-recovered-susceptible model with logistic growth. For a more realistic situation, the effects of quarantine strategies and stochasticity should be taken into account. Hence, our paper

In this paper, the instability of semi-active control systems caused by the utilization of semi-active inerters is analyzed. The purpose of this study is to demonstrate the possibility of inducing instability by applying semi-active inerters in vibration control systems, a phenomenon which is essential for the applications of semi-active inerters but has not been drawn much attention in the existing

US stock returns exhibit mixed Gaussian probabilistic features as well as nonlinear and complex dynamics, but existing agent-based models of stock markets have not focused on replicating or explaining all these phenomena jointly. In this paper, a new agent-based model of the stock market is proposed that can replicate and explain such phenomena jointly. In the new model, stocks are a claim to a dividend

Nonlinear vibration isolation systems with both stiffness and damping nonlinearities are promising for a broad-band and high-efficient isolation performance. In this research, a novel nonlinear isolator is proposed via a compliant mechanism with negative stiffness and wire ropes with hysteretic damping. The compliant mechanism consists of two pairs of tilted flexure beams, and the nonlinear restoring

The periodic transcription output is ubiquitously observed in an isogenic cell population. To understand mechanisms of cyclic behavior in transcription, we extend the gene activation process in the two-state model by assuming that the synthesis rate is periodic. We derive the analytical forms of the mean transcript level and the noise. The limits of them indicate that the mean level and the noise display

In this paper, we study the limit cycle of a nonlinear conveyor belt system by utilizing the perturbation incremental method. We first divide the system into two subclasses. On account of the former is heteroclinic orbit and the latter is not, there are some differences in the process of employing this method. Next two steps are introduced, the perturbation part provides the zero-order perturbation

This paper proposes a new chaotic system based on sine map, i.e., the coupled piecewise sine map (CPSM), which utilizes piecewise mechanism to obtain more uniform probability density distribution of state values, and enhances the complexity of chaotic system by coupling parameters between sub-systems. Then, from the view of resisting the chosen ciphertext attack, a ciphertext sensitive diffusion structure

A nonlinear mathematical model is developed in the time domain to simulate the behaviour of two identical flexibly mounted cylinders in tandem while undergoing vortex-induced vibration (VIV). Subsequently, the model is validated and modified against experimental results. Placing an array of bluff bodies in proximity frequently happens in different engineering fields. Chimney stacks, power transmission

Over the last 9 months, the most prominent global health threat has been COVID-19. It first appeared in Wuhan, China, and then rapidly spread throughout the world. Since no treatment or preventative strategy has been identified until this time, millions of people across the world have been seriously affected by COVID-19. The modelling and prediction of confirmed COVID-19 cases have been given much

This paper analyzes operational space dynamics for redundant robots with un-actuated joints and reveals their highly nonlinear dynamic impacts on operational space control (OSC) tasks. Unlike conventional OSC approaches that partly address the under-actuated system by introducing rigid grasping or contact constraints, we deal with the problem even without such physical constraints which have been overlooked

The work is devoted to the study of a MEMS resonator dynamics under the action of phase-locked and automatic gain control loops. Particular attention is directed to the study of the nonlinearity factor of the resonator elastic restoring force. It was found that the determination of control system parameters based on the stability analysis of the operating resonant mode, in the general case, does not

In this paper, we study the (3+1)-dimensional variable-coefficient Kudryashov–Sinelshchikov (vc-KS) equation, which characterizes the evolution of nonautonomous nonlinear waves in bubbly liquids. The nonautonomous lump solutions of the vc-KS equation are produced via the Hirota bilinear technique. The characteristics of trajectory and velocity of this wave are analyzed with variable dispersion coefficients

The dynamic response of a thin buckled panel in a supersonic wind-tunnel experiment is investigated. Measured time histories of the panel displacement and velocity show co-existing, nonlinear responses with features of periodic and chaotic oscillations. Fully coupled computational analyses are conducted in order to study and interpret the aeroelastic phenomena observed during the experiments. A computationally

Mode-coupling instabilities are known to trigger self-excited vibrations in sliding contacts. Here, the conditions for mode-coupling (or “flutter”) instability in the contact between a spherical oscillator and a moving viscoelastic substrate are studied. The work extends the classical 2-Degrees-Of-Freedom conveyor belt model and accounts for viscoelastic dissipation in the substrate, adhesive friction

In this work, the definition of the constitutive relation of a classical higher-order two-terminal element from Chua’s table is extended to the coupled element. The way and the conditions of introducing the corresponding potential function are shown. The forms of the Lagrangian and Hamiltonian of circuits containing coupled elements are derived. The modeling techniques using coupled elements are demonstrated

This paper deals with the modelling and dynamic analysis of thin or slender flexible bodies characterized by axial motion, contacts and friction interaction. Such mechanical systems can be found in cable applications, in petroleum drilling industry, in biomedical applications and in nuclear equipments. An original combination of the absolute nodal coordinate formulation and the classical finite element

We present a modelling and analysis of the COVID-19 outbreak in India with an emphasis on the socio-economic composition, based on the progress of the pandemic (during its first phase—from March to August 2020) in 11 federal states where the outbreak is the largest in terms of the total number of infectives. Our model is based on the susceptible-exposed-infectives-removed (SEIR) model, including an

Under investigation in this paper is a (3+1)-dimensional nonlinear evolution equation, which was proposed and analyzed to study features and properties of nonlinear dynamics in higher dimensions. Using the Hirota bilinear method, we construct a bilinear Bäcklund transformation, which consists of four equations and involves six free parameters. With test function method and symbolic computation, three

Based on the degenerate Darboux transformation, the n-positon solution of the higher-order Chen–Lee–Liu (HOCLL) equation are obtained by the special limit \(\lambda _{j}\rightarrow \lambda _{1}\) taking from the corresponding n-soliton solution, and using the higher-order Taylor expansion. Using the method of the modulus square decomposition, n-positon is decomposed into n single soliton solutions

This paper focuses on the adaptive decentralized asymptotic tracking control problem for a family of nonlinear pure-feedback interconnected systems. Through the ingenious backstepping-based design, the controllers of all subsystems are developed to mitigate the effects of system interconnections. These controllers only need to update two parameters online in each subsystem; thus, the complexity of

The regular dynamics of active particles coupled by the Morse potential with Van der Pol dissipation is studied numerically and analytically. It was found that in the system under study, stable propagation of soliton-like perturbations and two types of kink, slow and fast, is possible. It is established that parameters of slow kink are determined from the Abel equation of the first kind, and the front

Based on theoretical and experimental investigations, this paper proposes a nonlinear energy sink (NES) with piecewise linear springs to enhance vibration suppression effects. A cubic nonlinear oscillator is coupled with a piecewise linear spring to form an enhanced NES (E-NES). Without adding a new resonance region and changing the resonance frequency of the primary system, the enhanced NES can achieve

The radial basis function network-based state-dependent autoregressive (RBF-AR) model has been widely used in modeling and prediction of nonlinear time series. The parameter identification of RBF-AR model can be reformulated as a separable nonlinear least squares problem. The variable projection (VP) algorithm has been proven to be valuable in solving such problems. However, for ill-posed problems

In this research, the general linear evolution equations (EEs) in (5+1) dimensions are studied. All the mixed second-order derivatives are included in this aforementioned model. Using the Hirota bilinear operator and symbolic computation, the localized solutions–the abundant lump solutions are constructed. Particularly, it is found that only four groups of linear (5+1)-dimensional EEs are found that

Dynamic simulation of mechanical systems can be performed using a multibody system dynamics approach. The approach allows to account systems of other physical nature, such as hydraulic actuators. In such systems, the nonlinearity and numerical stiffness introduced by the friction model of the hydraulic cylinders can be an important aspect to consider in the modeling because it can lead to poor computational