François Pelap

Université de Dschang · Department of Physics

In geological fault modeling, several fragmented blocks are coupled by springs and the motion between them is not transmitted instantly, but with a delay. The dynamics of geological media is investigated by considering the time delay between blocks’ deformations. Our modelization led to a complex-Landau equation, from which we derived solitary wave...

In this paper, we propose a new mathematical model of cardiovascular system coupled with a respiratory system to study the effects of COVID-19 on global blood circulation parameters using the lumped parameters model. We use the fourth-order Runge-Kutta method for solving the sets of equations of motion. We validate our model by showing that the sim...

The effects of fibroblast on the excitable media are investigated using a proposed myocyte–fibroblast Fitzhugh–Nagumo bioheat model. At the cellular level, the model of human excitable cell and fibroblast is modified to incorporate the Penne bioheat equation with the addition of the Joule effect. The spatial discretization is based on the fourth-or...

This paper proposes a new thermoelectric model to examine the behavior of the heart in cooling situations. A modified Karma model with temperature-dependence is exploited to describe the ion exchange dynamics at the mesoscopic scale while the propagation of the action potential is governed by a mono-domain equation at the macroscopic scale. In addi...

In this paper, we study the effect of perturbation stress on the train model of Burridge–Knopoff. We consider periodic perturbation of the periodic normal pressure and the friction parameter. Unlike the undisturbed case where the loading velocity is constant, the “apparent” loading velocity varies with time and with disturbance parameters. It emerg...

This paper considers the Holzapfel–Ogden (HO) model to examine the behavior of the left ventricle myocardium. At the tissue level, we analyze the contributions of the orientation angle of muscle fibers (MFs) and investigate their effects on the occurrence of certain cardiomyopathies and congenital diseases at the organ level. Knowing the importance...

In this paper, the resonance behavior of a spring-block model with fractional-order derivative under periodic stress perturbation is investigated. Using the harmonic balance method, we derive the frequency-response equations for the system consisting of two blocks linked by a linear spring. The results have shown that the fractional-order derivativ...

In this work, the propagation of modulated waves in a nonlinear two-dimensional discrete electrical line is studied. Based on the linear dispersive law, we demonstrate that the network can adopt Hybrid’s behavior due to the fact that, without changing its appearance structure or its parameters values, it can become alternatively, a purely right-han...

This study uses remote sensing technology and GIS technics for structural study of the Haut-Nkam division with the aim of mapping the lineaments that can significantly influence all geo-structures by identifying major geological features and comes out with a new major structural map. Two methods are used: (i) the spatial reclassification of satelli...

This article examines the best fraction of indium (x) and critical depth (H) of a single junction tandem photovoltaic (PV) cell (InxGa1-xN) in the vein to optimize its electrical efficiency. For better investigation, the optical and electronics parameters of a solar cell are determined as a function of the indium fraction and depth of the solar cel...

Careful analysis of long-term wind data in a broad area is essential to estimate the wind energy potential of a region. For this purpose, knowledge of wind speed distribution is an essential task. This paper proposes a comprehensive statistical evaluation of monthly, annual, and interannual variabilities of mean wind speeds and wind power densities...

This article examines the best fraction of indium (x) and critical depth (H) of a single junction tandem photovoltaic (PV) cell (InxGa1-xN) in the vein to optimize its electrical efficiency. For better investigation, the optical and electronics parameters of a solar cell are determined as a function of the indium fraction and depth of the solar cel...

In this paper, we consider the dynamics of modulated waves in a nonlinear two-dimensional discrete electrical lattice made of several well-known anharmonic modified Noguchi lines coupled transversely to one another with a linear inductor. In the linear limit and depending on the chosen frequency domain, we demonstrate that the network behaves eithe...

In this work, we examine the dynamical behaviour of the “single mass-springs” model for earthquake subjected to the strength due to the up flow of magma for the period of volcanism, considering the fractional viscous damping force, the fractional weakening friction and fractional power law of elastic force. The numerical simulation method used in t...

In this paper, the behavior of gap solitary waves is investigated in a two-dimensional electrical line with nonlinear dispersion. Applying the semidiscrete approximation, we show that the dynamics of modulated wave in the network can be described by an extended nonlinear Schrödinger equation. With the aid of the dynamical systems approach, we exami...

This document presents the design of a prototype of a low-cost personal weather station suitable for farmers in rural areas who are or may not be engaged in rudimentary agriculture. This prototype measures several weather data: temperature, relative humidity, wind speed, wind direction, rainfall. For further data analysis, these are transmitted for...

This paper presents intensive investigation of dynamics of high frequency nonlinear modulated excitations in a damped bimodal lattice. The effects of the dissipation are considered through a linear dissipation coefficient whose evolution in terms of the carrier wave frequency is checked. There appears that the dissipation coefficient increases with...

The purpose of the present work is to investigate transient behaviour of a parabolic trough solar collector in the climate conditions of Sahel through the energetic and exergetic analysis. An unsteady state approach of the first and second law of thermodynamic is applied on the heat collector element. The Finite Volume and Gauss quadrature methods,...

This article examines the behavior of a PV module, made with monocrystalline silicon under the effect of an external induced magnetic field and, in the presence of a material housed near a PV module. We establish the expressions of the diffusion coefficient and the distribution of minority carriers of the PV module. From these, output electrical pa...

The objective of this work is to study a monoatomic chain which is described by the Klein–Gordon model with first and second neighbors anharmonic interactions. We consider specifically the case where both of these interactions are of cubic–quartic type and show, through the rotating wave approximation, that envelop waves in our model are governed b...

The present work deals with the performance assessment of the finite volume method (FVM) and discrete transfer method (DTM) in term of their abilities to accurately satisfy conservation of both scattered energy and asymmetry factor of the scattering phase function, after angular discretization and their computational time to calculate the scatterin...

Fractional calculus is suitable to model complex systems with memory and fractal systems. Earthquakes are both complex systems with long-memory and some of their faults have fractal properties. It is fair to claim that a fractional model is very efficient for earthquake modeling. The stability analysis is performed to determine the domain in which...

In recent years, an increasing interest has been devoted to the discovery of new chaotic systems with special properties. In this paper, a novel and singular 3D autonomous system without linear terms is introduced. The singularity of the model is that it is dissipative, possesses rotation symmetry and line of equilibria thus displays complex dynami...

In the framework of a project on simple circuits with unexpected high degrees of freedom, we report an autonomous microwave oscillator made of a CLC linear resonator of Colpitts type and a single general purpose operational amplifier (Op-Amp). The resonator is in a parallel coupling with the Op-Amp to build the necessary feedback loop of the oscill...

The dynamics of modulated waves in a nonlinear bi-inductance transmission line with dissipative elements are examined. We show the existence of two frequency modes and carry out intensive investigations on the low frequency mode. Thanks to the multiple scales method, the behavior of these waves is investigated and the dissipative effects are analyz...

In this work, we investigate backward and forward waves in a coupled nonlinear discrete electrical lattice. It is made of several of the well-known Noguchi electrical transmission line that are transversely coupled to one another by an inductor \(L_{2}\). Based on the linear dispersion law, we show that the behavior of this model depends on the wav...

We consider the problem of the propagation of modulated waves in one-dimensional discrete lattices with linear bandpass-type dispersion relation. We are interested specifically in the cases where the gap frequency f0 and the cutoff frequency fmax verify 0<f0<fmax<2f0. Analytical investigations of such models commonly use the rotating wave approxima...

Multistability analysis has received intensive attention in recently, however, its control in systems with more than two coexisting attractors are still to be discovered. This paper reports numerically the multistability control of five disconnected attractors in a self-excited simplified hyperchaotic canonical Chua’s oscillator (hereafter referred...

A simplified hyperchaotic canonical Chua’s oscillator (referred as SHCCO hereafter) made of only seven terms and one nonlinear function of type hyperbolic sine is analyzed. The system is found to be self-excited, and bifurcation tools associated with the spectrum of Lyapunov exponents reveal the rich dynamical behaviors of the system including hype...

This paper considers a specific plant (pinus family) and examines its complex behavior under the air flow while checking the real-time dynamics of the proposed analog electronic simulator with an active RC realization. It appears that the system can be chaotic and its dynamics depend on the chosen initial conditions. We show the coexistence of mult...

In this work, the qualitative structures of traveling waves are investigated in a bidimensional inductor-capacitor network with quadratic nonlinear dispersion. Applying the continuum limit approximation, we show that the dynamics of small-amplitude signals in the network can be governed by a (2+1)-dimensional partial differential equation. Using a...

In this paper, a novel approach for constructing exact solutions to nonlinear partial differential equations is presented. The method is designed to be a generalization of the well-known sine-Gordon expansion since it is based on the use of the sine-Gordon equation as an auxiliary equation. In contrast to the classic sine-Gordon expansion method, i...

This paper investigates the control of multistability in a self-excited memristive hyperchaotic oscillator using linear augmentation method. Such a method is advantageous in the case of system parameters that are inaccessible. The effectiveness of the applied control scheme is revealed numerically through the nonlinear dynamical tools including bif...

In this work, we investigate solitary waves in a nonlinear two-dimensional discrete electrical lattice. It is made of several of the well-known Noguchi electrical transmission lines, that are transversely or longitudinally coupled to one another by an inductor L2 or L1 and a capacitor C2 or C1 mounted in parallel. The linear dispersion law of the n...

In this paper, we introduce and propose exact and explicit analytical solutions to a novel model of the nonlinear Schrödinger (NLS) equation. This model is derived as the equation governing the dynamics of modulated cutoff waves in a discrete nonlinear electrical lattice. It is characterized by the addition of two terms that involve time derivative...

A modified control scheme based on the combination of online trained neural network and sliding mode techniques is proposed to enhance maximum power extraction for a grid connected permanent magnet synchronous generator (PMSG) wind turbine system. The proposed control method does not need the knowledge of the uncertainty bounds nor the exact model...

The present work describes the propagation of plane and peak solitary waves in a modified extended nonlinear Schrödinger (MENLS) equation that was earlier shown to govern the dynamics of modulated waves in a discrete nonlinear electrical transmission line (DNLETL). Firstly, the analytic expression for the modulational instability gain is found and...

In this contribution, a modified oscillator of Tamasevicius et al. (Electron Lett 33:542–544, 1997) (referred to as the mTCMNL oscillator hereafter) is introduced with antiparallel diodes as nonlinear elements. The model is described by a continuous time of four-dimensional autonomous system with hyperbolic sine nonlinearity based on Shockley diode...

Fractional calculus is suitable for systems with memory and for fractal systems. Earthquakes have both properties. It is fair to claim that a fractional model is very efficient for earthquake modeling. Our study is focused on the effects of the fractional-order derivative on the 'train model' of Burridge-Knopoff. We note that these effects introduc...

We examine the dynamical behaviours of the “single mass-spring” model for earthquakes considering lubrication pressure effects on pre-existing faults and viscous fractional damping. The lubrication pressure supports a part of the load, thereby reducing the normal stress and the associated friction across the gap. During the co-seismic phase, all of...

This paper presents a simple control structure using rotor flux oriented vector technique for a stand-alone permanent magnet synchronous generator (PMSG) associated to PWM rectifier, PWM DC–DC converter and PWM inverter. The DC–DC converter feeding an electronic load is controlled to maintain the dc-bus voltage at a desired constant value. The isol...

In this paper, we consider a class of nonlinear oscillators whose equations of motion are in the form of that of a cubic Duffing oscillator extended by a term which is a quadratic monomial in the velocity and whose coefficient is a rational function of the position. We apply a combination of harmonic balance and Newton method to seek analytical app...

A discrete transfer formulation for analyzing radiative heat transfer through participating medium with highly anisotropic scattering phase function is presented. This formulation used the finite volume method to evaluate integral of the radiative heat transfer problem. Hence, participating media anisotropic scattering phase function along a centre...

We revisit the derivation of the equation modeling envelope waves in a discrete nonlinear electrical transmission line (NLTL) considered a few years back in Physics Letters A 373 (2009) 3801–3809. Using a combination of rotating wave approximation and the Gardner–Morikawa transformation, we show that the modulated waves are described by a new type...

A new version of the modified discrete nonlinear Schrodinger (MDNLS) equation that governs wave propagation in discrete dispersive nonlinear transmission lines is solved by the means of the Jacobi elliptic function method. The contribution of the linear dispersive capacitance is appreciated, and it is established that this equation possesses exact...

A novel modeling of general purpose operational ampli ers (Op-Amps) is made to approximate at best the real model at high frequency. With this new modeling, it appears that certain oscillators usually studied under ideal considerations or under many existing real models of Op-Amps have hidden subtle and attractive chaotic dynamics hitherto unknown,...

This paper deals with the study of the behaviour of a one spring-block model subjected to the strengths due to the motion of the tectonic plates and the upflow of magma during volcanism. Using the direct integration method, we show that the sound velocity decreases (or increases) with the amplitude of the block’s oscillation when the external frequ...

We consider a modified Noguchi electrical transmission line and examine the effects of a linear capacitance C_{s} on the wave characteristics while considering the semidiscrete approximation. It appears that wave modulations in the network are governed by a dispersive nonlinear Schrödinger equation whose coefficients are shown to be a function of C...

A low-cost phonocardiogram (PCG) is proposed to overcome some limitations known with the electrocardiograms (ECG). This small size portable PCG with a graphic LCD is equipped with a mini solar panel. It computes and displays different physical characteristics needed by physicians to ease cardiac auscultations, like the numerous heart beats per minu...

The time dependence of probability and Shannon entropy of a modified damped harmonic oscillator is studied by using single and double Gaussian wave functions through the Feynman path method. We establish that the damped coefficient as well as the system frequency and the distance separating two consecutive waves of the initial double Gaussian funct...

We consider a 1D spring-block model for earthquake dynamics under a modified frictional force, and examine the direction effects of a driving plate's action on these dynamics. This force deals with a frictional parameter that takes into account the heterogeneity of the surface separating the two sides of the faults. We note that the amplitude of th...

The study of 1D spring-block model of earthquake dynamics with consideration of water effects in preexisting fault deals with new forms of frictional force. An analytical study of the equation of motion enables us to establish that motion of geological fault is accelerated by water pressure. In the same setting the critical value of frictional velo...

We propose a new mathematical model of the TNC oscillator and study its impact on the dynamical properties of the oscillator subjected to an exponential nonlinearity. We establish the existence of hyperchaotic behavior in the system through theoretical analysis and by exploiting electronic circuit experiments. The obtained numerical results are fou...

The time dependence of probability and Shannon entropy of a modified damped harmonic oscil-lator is studied by using single and double Gaussian wave functions through the Feynman path method. We establish that the damped coefficient as well as the system frequency and the distance separating two consecutive waves of the initial double Gaussian func...

We consider physical systems described by the modified quintic complex Ginzburg–Landau equation and its derivative forms and examine numerically the dynamics of its shock type wave solution. Discussions on the behaviours of this shock wave are introduced and it is shown how the ratios of diverse velocities of this wave could be exploited to explain...

The dynamics of nonlinear excitations in an electrical bi-inductance transmission line are examined by means of the multiple scales method. In the continuum approximation using an appropriate decoupling ansatz for the voltage of the two different cells, we consider modulated waves and show that their propagation in the network is governed by a nonl...

Dynamics of modulated waves in a nonlinear electrical bi-inductance line are theoretically examined by the means of a perturbation method. It has been recently established that in such lines, modulations of weakly nonlinear dispersive waves are described by the complex Ginzburg-Landau equation (CGLE) for wavenumbers k larger than the critical value...

We consider a shock-type wave solution of the modified quintic complex Ginzburg-Landau equation and make a numerical study of its spatiotemporal stability. Discussions related to the behavior of this front wave are introduced and it is shown how the velocities of the wave can be used to collect information concerning the pattern formation in the sy...

Dynamical systems described by the modified quintic complex Ginzburg Landau equation and its derivative forms are considered and the stability of their bright soliton solution is investigated numerically by means of the split-step Fourier method. Some discussions related to the way of ensuring the stability of this solution are presented.

Wave modulations in the mono-inductance transmission line are studied by the use of a perturbation method. Far from the marginal state, that is for wavenumbers k larger than a critical wavenumber kc the evolution of a wave packet is described by the nonlinear Schrödinger (NLS) equation. Near this critical state of instability, it has been shown the...

Through applications of Hirota's method, we have found some new and useful exact solutions of the 1-D generalized Gradov–Stenflo equation. It is shown that this wave equation admits bright and dark soliton solutions as well as a shock type solution.

The dynamics of modulated waves are studied in the one-dimensional discrete nonlinear electrical transmission line. The contribution of the linear dispersive capacitance is taken into account, and it is shown via the reductive perturbation method that the evolution of such waves in this system is governed by the higher-order nonlinear Schrödinger e...

Focused on the quintic complex Ginzburg-Landau equation used as the basic physical model, we have reviewed the well known Lange and Newell's criterion for modulational stability of Stokes waves. In the past few decades, many theoretical and experimental studies have been devoted to the dispersive nonlinear media. These nonlinear systems exhibit an...

We have formulated a model of an equation that governs dynamics of nonlinear waves in many non-equilibrium systems. Based on this new equation, we have reviewed the well-known Lange and Newell's criterion for modulational instability of Stoke waves. Some exact solutions of this wave equation have also been found through a proper combination of the...

Physical systems concerned here are those in which the one dimensional Modified Complex Ginzburg-Landau equation or one of its derivative forms holds. By using this propagation equation, it is shown that the Lange and Newell's criterion for modulational instability of stokes waves can be recovered by performing the Stuart and Di Prima's method.

Adding dissipative elements to a discrete biinductance transmission line which admits both low frequency (LF) and high frequency (HF) modes, dynamics of a weakly nonlinear modulated wave is investigated theoretically and numerically. In the semidiscrete approximation using a proposed decoupling ansatz for the voltage of the two different cells, it...

For linear partial differential equations, a boundary value problem with nonlocal boundary conditions with respect to the time coordinate is investigated. The equations and the boundary conditions contain pseudodifferential operators with respect to the space coordinate. The criterion of well-posedness, and the condition of the regularity of the pr...