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  Subjects -> AERONAUTICS AND SPACE FLIGHT (Total: 120 journals)
Showing 1 - 30 of 30 Journals sorted by number of followers
AIAA Journal     Hybrid Journal   (Followers: 1194)
SpaceNews     Free   (Followers: 826)
Journal of Spacecraft and Rockets     Hybrid Journal   (Followers: 773)
Journal of Propulsion and Power     Hybrid Journal   (Followers: 615)
Acta Astronautica     Hybrid Journal   (Followers: 495)
Advances in Space Research     Full-text available via subscription   (Followers: 458)
Aviation Week     Full-text available via subscription   (Followers: 437)
Aerospace Science and Technology     Hybrid Journal   (Followers: 428)
IEEE Transactions on Aerospace and Electronic Systems     Hybrid Journal   (Followers: 387)
Journal of Aircraft     Hybrid Journal   (Followers: 337)
Control Systems     Hybrid Journal   (Followers: 315)
Journal of Navigation     Hybrid Journal   (Followers: 281)
IEEE Aerospace and Electronic Systems Magazine     Full-text available via subscription   (Followers: 280)
Aircraft Engineering and Aerospace Technology     Hybrid Journal   (Followers: 264)
Gyroscopy and Navigation     Hybrid Journal   (Followers: 260)
Journal of Guidance, Control, and Dynamics     Hybrid Journal   (Followers: 204)
Space Science International     Open Access   (Followers: 202)
Space Science Reviews     Hybrid Journal   (Followers: 97)
International Journal of Aerospace Engineering     Open Access   (Followers: 82)
Progress in Aerospace Sciences     Full-text available via subscription   (Followers: 81)
Advances in Aerospace Engineering     Open Access   (Followers: 70)
Journal of Aerospace Engineering     Full-text available via subscription   (Followers: 69)
Propulsion and Power Research     Open Access   (Followers: 68)
Aerospace     Open Access   (Followers: 60)
Space Safety Magazine     Free   (Followers: 51)
Space Research Today     Full-text available via subscription   (Followers: 48)
Proceedings of the Institution of Mechanical Engineers Part G: Journal of Aerospace Engineering     Hybrid Journal   (Followers: 46)
International Journal of Aeroacoustics     Hybrid Journal   (Followers: 41)
IEEE Transactions on Circuits and Systems I: Regular Papers     Hybrid Journal   (Followers: 39)
International Journal of Aerodynamics     Hybrid Journal   (Followers: 37)
Journal of Aerospace Information Systems     Hybrid Journal   (Followers: 34)
Canadian Aeronautics and Space Journal     Full-text available via subscription   (Followers: 34)
International Journal of Aerospace Sciences     Open Access   (Followers: 32)
Journal of Aeronautics & Aerospace Engineering     Open Access   (Followers: 31)
CEAS Aeronautical Journal     Hybrid Journal   (Followers: 30)
Space Policy     Hybrid Journal   (Followers: 29)
Journal of Space Weather and Space Climate     Open Access   (Followers: 27)
Aviation Psychology and Applied Human Factors     Hybrid Journal   (Followers: 27)
Russian Aeronautics (Iz VUZ)     Hybrid Journal   (Followers: 24)
Egyptian Journal of Remote Sensing and Space Science     Open Access   (Followers: 24)
International Journal of Aerospace Psychology     Hybrid Journal   (Followers: 23)
Artificial Satellites     Open Access   (Followers: 23)
Annual of Navigation     Open Access   (Followers: 22)
Journal of Aerospace Information Systems     Hybrid Journal   (Followers: 22)
Chinese Journal of Aeronautics     Open Access   (Followers: 21)
Nonlinear Dynamics     Hybrid Journal   (Followers: 20)
Aerospace Medicine and Human Performance     Full-text available via subscription   (Followers: 19)
Journal of Aerodynamics     Open Access   (Followers: 18)
Journal of Aerospace Engineering & Technology     Full-text available via subscription   (Followers: 18)
Aerospace Scientific Journal     Open Access   (Followers: 18)
Journal of Wind Engineering and Industrial Aerodynamics     Hybrid Journal   (Followers: 17)
Research & Reviews : Journal of Space Science & Technology     Full-text available via subscription   (Followers: 17)
International Journal of Space Structures     Full-text available via subscription   (Followers: 17)
Aviation     Open Access   (Followers: 17)
Proceedings of the Human Factors and Ergonomics Society Annual Meeting     Hybrid Journal   (Followers: 16)
Fatigue of Aircraft Structures     Open Access   (Followers: 15)
Aeronautical Journal, The     Hybrid Journal   (Followers: 13)
International Journal of Satellite Communications Policy and Management     Hybrid Journal   (Followers: 13)
Frontiers in Astronomy and Space Sciences     Open Access   (Followers: 12)
Journal of Airline and Airport Management     Open Access   (Followers: 12)
Elsevier Astrodynamics Series     Full-text available via subscription   (Followers: 12)
International Journal of Crashworthiness     Hybrid Journal   (Followers: 12)
International Journal of Space Science and Engineering     Hybrid Journal   (Followers: 11)
COSPAR Colloquia Series     Full-text available via subscription   (Followers: 11)
Journal of Aviation Technology and Engineering     Open Access   (Followers: 11)
International Journal of Micro Air Vehicles     Full-text available via subscription   (Followers: 11)
Air Force Magazine     Full-text available via subscription   (Followers: 10)
International Journal of Space Technology Management and Innovation     Full-text available via subscription   (Followers: 10)
Aviation in Focus - Journal of Aeronautical Sciences     Open Access   (Followers: 10)
Journal of Aeronautical Materials     Open Access   (Followers: 9)
International Journal of Aviation Management     Hybrid Journal   (Followers: 9)
Transportmetrica A : Transport Science     Hybrid Journal   (Followers: 9)
Journal of the Astronautical Sciences     Hybrid Journal   (Followers: 9)
Journal of Aircraft and Spacecraft Technology     Open Access   (Followers: 9)
Population Space and Place     Hybrid Journal   (Followers: 9)
Advances in Aerospace Science and Technology     Open Access   (Followers: 8)
Air Medical Journal     Hybrid Journal   (Followers: 8)
Journal of Space Safety Engineering     Hybrid Journal   (Followers: 8)
Journal of the American Helicopter Society     Full-text available via subscription   (Followers: 8)
International Journal of Applied Geospatial Research     Hybrid Journal   (Followers: 7)
Journal of Aerospace Technology and Management     Open Access   (Followers: 7)
International Journal of Aviation Technology, Engineering and Management     Full-text available via subscription   (Followers: 7)
Aerospace Systems     Hybrid Journal   (Followers: 6)
RocketSTEM     Free   (Followers: 6)
New Space     Hybrid Journal   (Followers: 6)
International Journal of Turbo and Jet-Engines     Hybrid Journal   (Followers: 6)
International Journal of Aviation, Aeronautics, and Aerospace     Open Access   (Followers: 5)
Civil Aviation High Technologies     Open Access   (Followers: 5)
Aviation Advances & Maintenance     Open Access   (Followers: 5)
REACH - Reviews in Human Space Exploration     Full-text available via subscription   (Followers: 5)
Cosmic Research     Hybrid Journal   (Followers: 5)
Unmanned Systems     Hybrid Journal   (Followers: 5)
International Journal of Sustainable Aviation     Hybrid Journal   (Followers: 5)
Aerotecnica Missili & Spazio : Journal of Aerospace Science, Technologies & Systems     Hybrid Journal   (Followers: 4)
Life Sciences in Space Research     Hybrid Journal   (Followers: 4)
Astrodynamics     Hybrid Journal   (Followers: 4)
Space and Polity     Hybrid Journal   (Followers: 4)
Investigación Pecuaria     Open Access   (Followers: 3)
Aerospace technic and technology     Open Access   (Followers: 3)
Journal of Astrobiology & Outreach     Open Access   (Followers: 3)
Journal of KONBiN     Open Access   (Followers: 3)
ASTRA Proceedings     Open Access   (Followers: 3)
Problemy Mechatroniki. Uzbrojenie, lotnictwo, inżynieria bezpieczeństwa / Problems of Mechatronics. Armament, Aviation, Safety Engineering     Open Access   (Followers: 3)
npj Microgravity     Open Access   (Followers: 3)
Journal of Spatial Science     Hybrid Journal   (Followers: 3)
Вісник Національного Авіаційного Університету     Open Access   (Followers: 2)
Journal of Aviation/Aerospace Education & Research     Open Access   (Followers: 2)
Microgravity Science and Technology     Hybrid Journal   (Followers: 2)
MAD - Magazine of Aviation Development     Open Access   (Followers: 2)
Ciencia y Poder Aéreo     Open Access   (Followers: 2)
IEEE Journal on Miniaturization for Air and Space Systems     Hybrid Journal   (Followers: 2)
International Journal of Aeronautical and Space Sciences     Hybrid Journal   (Followers: 2)
Mekanika : Jurnal Teknik Mesin i     Open Access   (Followers: 1)
Technical Soaring     Full-text available via subscription   (Followers: 1)
Journal of the Australasian Society of Aerospace Medicine     Open Access   (Followers: 1)
Advances in Astronautics Science and Technology     Hybrid Journal   (Followers: 1)
Journal of Engineering and Technological Sciences     Open Access   (Followers: 1)
Transport and Aerospace Engineering     Open Access   (Followers: 1)
Open Aerospace Engineering Journal     Open Access   (Followers: 1)
Spatial Information Research     Hybrid Journal   (Followers: 1)
Science and Education : Scientific Publication of BMSTU     Open Access   (Followers: 1)
Gravitational and Space Research     Open Access  
Perspectives of Earth and Space Scientists i     Open Access  

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Similar Journals
Journal Cover
Nonlinear Dynamics
Journal Prestige (SJR): 1.468
Citation Impact (citeScore): 4
Number of Followers: 20  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1573-269X - ISSN (Online) 0924-090X
Published by Springer-Verlag Homepage  [2656 journals]
  • Correction to: Robust control of reaction wheel bicycle robot via adaptive
           integral terminal sliding mode
    • Abstract: A correction to this paper has been published: https://doi.org/10.1007/s11071-021-06473-5
      PubDate: 2021-05-05
       
  • Suppression of a nonplanar motion in an externally excited string by the
           addition of viscosity based on velocity feedback control
    • Abstract: This study concerns the out-of-plane motion of a vertically disposed string with one end fixed and the other subjected to a harmonic excitation. Excited in its primary resonance, the string can vibrate in the direction orthogonal to the excitation direction through nonlinear coupling effects and has out-of-plane motion. To suppress this out-of-plane motion, we propose a boundary control method that modifies the boundary condition of the fixed upper end, i.e., we move the fixed upper end in the direction orthogonal to the external excitation. The unstable range for trivial steady state motion in this direction, which exists in the neighborhood of the primary resonance condition, changes to a stable range under suitable feedback gain. The out-of-plane motion is then suppressed for any excitation frequency. Experiments conducted using a simple apparatus confirmed the validity of the proposed method adopting boundary control.
      PubDate: 2021-05-05
       
  • A power-form method for dynamic systems: investigating the steady-state
           response of strongly nonlinear oscillators by their equivalent
           Duffing-type equation
    • Abstract: This paper aims to apply a transformation method that replaces the elastic forces of the original equation of motion with a power-form elastic term. The accuracy obtained from the derived equivalent equations of motion is evaluated by studying the finite-amplitude damped, forced vibration of a vertically suspended load body supported by incompressible, homogeneous, and isotropic viscohyperelastic elastomer materials. Numerical integrations of the original equations of two oscillators described by neo-Hookean and Mooney–Rivlin viscohyperelastic elastomer material models, and their equivalent equations of motion, are compared to the frequency–amplitude steady-state solutions obtained from the harmonic balance and the averaging methods. It is shown from numerical integrations and approximate steady-state solutions that the equivalent equations predict well the original system dynamic response despite having higher system nonlinearities.
      PubDate: 2021-05-05
       
  • Input-to-state stability of hybrid stochastic systems with unbounded
           delays and impulsive effects
    • Abstract: In this paper, we investigate input-to-state stability (ISS) problem for a general model of hybrid stochastic systems with unbounded delays and impulsive effects, in which stochastic disturbances involve white noise and Markov chain. Firstly, we establish a novel differential inequality with unbounded delays and variable inputs, which extends and improves some existing results. Then, by using the obtained inequality, the sufficient conditions are derived to determine ISS properties on impulsive robustness and impulsive stabilization for the impulsive stochastic systems with unbounded delays. The results not only show that the ISS properties still remain under certain impulsive perturbations for some continuous stable systems, but also indicate that an unstable system can be successfully stabilized to be input-to-state stable by impulses even if the corresponding continuous system is unstable. The obtained criteria are applied to study the ISS problems for impulsive stochastic neural networks and the systems of energy-storing electrical circuit. Finally, two numerical examples and their simulations are given to illustrate the validity of theoretical results.
      PubDate: 2021-05-05
       
  • Vibration reduction of a quadrotor with a cable-suspended payload using
           polynomial trajectories
    • Abstract: This paper considers a transportation system consisting of a quadrotor with a cable-suspended payload. The main focus of this paper is to investigate the effect of polynomial trajectories on the vibration of the cable-suspended payload and to show which polynomial trajectory results in less vibration. A mathematical analysis and a parametric study were carried out to investigate the effect of the degree of the polynomial trajectory on its kinematic behavior. A conjecture relates the degree of the polynomial trajectory and its kinematic behavior to the corresponding payload vibration was introduced. The base excitation model of vibratory systems was proposed as the model of the transportation system of interest. The vibration analysis of both the transportation system and the polynomial trajectories was conducted analytically to show which polynomial trajectory has the least payload vibration. A second stage of payload vibration reduction was provided by introducing a method to reduce the transmitted vibration from the quadrotor to the payload for any quadrotor trajectory. A roadmap to design the transportation task that can reduce the payload vibration was proposed. Both the simulation and the experimental results were presented, discussed and analyzed to verify the findings of this paper.
      PubDate: 2021-05-05
       
  • Nonlinear feedback anti-control of limit cycle and chaos in a mechanical
           oscillator: theory and experiment
    • Abstract: Though engineers believe that self-excited oscillation and chaos is detrimental, recent research has revealed that self-excited periodic and chaotic oscillation can be effectively utilized in many engineering processes and devices for significant benefits. Then a simple nonlinear acceleration feedback controller is proposed to generate self-excited periodic and chaotic oscillation in a mechanical oscillator. Analytical expressions relating the amplitude of limit cycles and control parameters are obtained by the method of multiple time scales. Analytical results are verified by numerical simulations performed in MATLAB–SIMULINK. Existence of chaotic oscillations is confirmed by numerical simulations. An extensive parametric study is carried out to reveal the nature of the chaotic oscillations and its dependence on the controller parameters. Theoretical results are finally verified by experiments. It is generally observed that the same controller can be used to induce both periodic and chaotic oscillations just by flipping the phase of the controller. This is possibly the first example where the same controller can be utilized to generate periodic and chaotic oscillation in a mechanical system. The findings of the paper are believed to be used in macro- and micro-mechanical systems.
      PubDate: 2021-05-05
       
  • Synchronization control for networked mobile robot systems based on
           Udwadia–Kalaba approach
    • Abstract: This paper addresses the problem of synchronization control for networked multi-mobile robot systems from the perspective of analytical mechanics. By reformulating the task requirement as a constrained motion problem, a unified synchronization algorithm for networked multi-mobile robot systems with or without leaders is proposed in combination with algebraic graph theory and the Udwadia–Kalaba approach. With the proposed algorithm, the networked mobile robot system can achieve synchronization from arbitrary initial conditions for the leaderless case and realize accurate trajectory tracking with explicitly given reference trajectories for the leader-following case. Numerical simulations of a networked wheeled mobile robot system are performed under different network structures and various trajectory requirements to show the performance of the proposed control algorithm.
      PubDate: 2021-05-04
       
  • Stabilization of stochastic complex networks with switching jump
           diffusions based on adaptive aperiodically intermittent control
    • Abstract: In this article, the exponential stabilization of stochastic complex networks with time delays, uncertainties and switching jump diffusions (SCNTDUSJD) is investigated via adaptive aperiodically intermittent control. It deserves mentioning that switching jump diffusions are state dependent and adaptive aperiodically intermittent control is applied to study the stabilization of SCNTDUSJD for the first time. Primarily, the Lyapunov function of SCNTDUSJD is constructed. Based on graph theory and the Lyapunov method, some sufficient conditions are given to ensure the exponential stability of SCNTDUSJD, which reflects that the controller plays an important role in the realization of stabilization. At the same time, our results can be applied to stochastic coupled oscillators with switching jump diffusions. Finally, in order to explain the effectiveness of theoretical results, relative numerical results are presented.
      PubDate: 2021-05-04
       
  • An ergodic-averaging method to differentiate covariant Lyapunov vectors
    • Abstract: Covariant Lyapunov vectors or CLVs span the expanding and contracting directions of perturbations along trajectories in a chaotic dynamical system. Due to efficient algorithms to compute them that only utilize trajectory information, they have been widely applied across scientific disciplines, principally for sensitivity analysis and predictions under uncertainty. In this paper, we develop a numerical method to compute the directional derivatives of the first CLV along its own direction; the norm of this derivative is also the curvature of one-dimensional unstable manifolds. Similar to the computation of CLVs, the present method for their derivatives is iterative and analogously uses the second-order derivative of the chaotic map along trajectories, in addition to the Jacobian. We validate the new method on a super-contracting Smale–Williams Solenoid attractor. We also demonstrate the algorithm on several other examples including smoothly perturbed Arnold Cat maps, and the Lorenz’63 attractor, obtaining visualizations of the curvature of each attractor. Furthermore, we reveal a fundamental connection of the derivation of the CLV self-derivative computation with an efficient computation of linear response of chaotic systems.
      PubDate: 2021-05-04
       
  • Synchronization structures in the chain of rotating pendulums
    • Abstract: The collective behavior of the ensembles of coupled nonlinear oscillator is one of the most interesting and important problems in modern nonlinear dynamics. In this paper, we study rotational dynamics, in particular space-time structures, in locally coupled identical pendulum-type elements chains that describe the behavior of phase-locked-loop systems, distributed Josephson junctions, coupled electrical machines, etc. The control parameters in the considered chains are: dissipation, coupling strength, and number of elements. In the system under consideration, the realized modes are synchronous in frequency and synchronous (in-phase) or asynchronous (out-of-phase) in phase. In the low dissipation case, the in-phase synchronous rotational regime instability region boundaries are theoretically found and the bifurcations leading to the loss of its stability are determined. The analysis was carried out for chains of arbitrary length. The existence of various out-of-phase synchronous rotational modes types is revealed: completely asynchronous in phases and the cluster in-phase synchronization regime. Regularities of transitions from one type of out-of-phase synchronous mode to another are established. It was found that at certain coupling parameter values, the coexistence of stable in-phase and out-of-phase synchronous modes is possible. It was found that for arbitrary chain length, the number of possible stable out-of-phase modes is always one less than the chain elements number. Analytical results are confirmed by numerical simulations.
      PubDate: 2021-05-04
       
  • A multilayer neural dynamic controller design method of quadrotor UAV for
           completing time-varying tasks
    • Abstract: In order to track the time-varying trajectory efficiently and accurately, a multilayer neural dynamic controller is proposed and exploited for quadrotor unmanned aerial vehicles (UAVs). Previous UAV controllers based on neural dynamic methods used forces and torques as control variables. However, in fact, the real control variables of a UAV are the PWM waves for controlling motors. What is more, the motors are always modeled as one-order systems since the existence of inertia and friction, which means that using forces and torques as control variables is not proper and may lead to low precision and inefficient tracking for UAVs. To solve this problem, a new UAV controller which uses exactly what inputs to motors as control variables is designed, so that the designed controller is more practical for UAVs. In the design process, a multilayer neural dynamic controller is obtained by applying the neural dynamic method to position layer, velocity, torque layer and motor layer successively. Both theoretical analysis and computer simulation results verify the effectiveness, convergence, stability and accuracy of the proposed multilayer neural dynamic controller for tracking time-varying trajectories.
      PubDate: 2021-05-04
       
  • Complex dynamics in a discrete SIS epidemic model with Ricker-type
           recruitment and disease-induced death
    • Abstract: In this paper, we investigate the complex dynamics in a discrete SIS epidemic model with Ricker-type recruitment and disease-induced death. It is shown that the model has a unique disease-free equilibrium if the basic reproduction number \({\mathcal {R}}_{0}\le 1\) and a unique endemic equilibrium if \({\mathcal {R}}_{0}> 1\) . Sufficient conditions for the locally asymptotic stability of the equilibria are obtained. A detailed bifurcation analysis at the endemic equilibrium reveals that the model undergoes a sequence of bifurcations, including transcritical bifurcation, flip bifurcation and Neimark–Sacker bifurcation, as the parameters vary. Various numerical simulations, including bifurcation diagrams, phase portraits, maximum Lyapunov exponents and feasible sets, are carried out to present complex periodic windows, period-28 points, multiple chaotic bands, fractal basin boundaries, chaotic attractors and the coexistence of period points and three invariant tori, which not only illustrate the theoretical results but also demonstrate more complex dynamical behaviors of the model.
      PubDate: 2021-05-03
       
  • Evolutionary behavior and novel collision of various wave solutions to
           (3+1)-dimensional generalized Camassa–Holm Kadomtsev–Petviashvili
           equation
    • Abstract: In the present paper, taking advantage of the bilinear method, we attained N-soliton solutions of the (3+1)-dimensional generalized Camassa–Holm Kadomtsev–Petviashvili (gCH-KP) equation. By combining the long wave limit method and the complex conjugate method to N-soliton solutions, M-lump wave solutions including one-lump wave, two-lump wave and three-lump wave and two types of hybrid solutions including hybrid solution between lump wave and solitons and between M-lump wave and soliton were obtained. In addition, several groups of images exhibited their dynamic structure and physical properties with physically interpreted via symbolic computation. Finally, resonant multi-soliton wave solutions were obtained by carrying out the linear superposition principle and the progresses of wave motions with physical interpretation represented graphically. Furthermore, the received results have immensely augmented the exact solutions of (3+1)-dimensional gCH-KP equation on the available literature and enabled us to understand the nonlinear dynamic system deeply. In addition, the proposed methods will be a strong boost to the calculation method of nonlinear equations.
      PubDate: 2021-05-03
       
  • Compensation process and generation of chirped femtosecond solitons and
           double-kink solitons in Bose–Einstein condensates with time-dependent
           atomic scattering length in a time-varying complex potential
    • Abstract: We consider the one-dimensional (1D) cubic-quintic Gross–Pitaevskii (GP) equation, which governs the dynamics of Bose–Einstein condensate matter waves with time-varying scattering length and loss/gain of atoms in a harmonic trapping potential. We derive the integrability conditions and the compensation condition for the 1D GP equation and obtain, with the help of a cubic-quintic nonlinear Schrödinger equation with self-steepening and self-frequency shift, exact analytical solitonlike solutions with the corresponding frequency chirp which describe the dynamics of femtosecond solitons and double-kink solitons propagating on a vanishing background. Our investigation shows that under the compensation condition, the matter wave solitons maintain a constant amplitude, the amplitude of the frequency chirp depends on the scattering length, while the motion of both the matter wave solitons and the corresponding chirp depend on the external trapping potential. More interesting, the frequency chirps are localized and their feature depends on the sign of the self-steepening parameter. Our study also shows that our exact solutions can be used to describe the compression of matter wave solitons when the absolute value of the s-wave scattering length increases with time.
      PubDate: 2021-05-03
       
  • Dynamics of spatiotemporal modulated damped signals in a nonlinear RLC
           transmission network
    • Abstract: The dynamics of spatiotemporal modulated damped signals in a nonlinear LC transmission network with dissipative elements are investigated analytically. The complex cubic Ginzburg–Landau (GL) equation governing slowly modulated wave propagation is presented. Considering linear wave propagating in the network, we derive in terms of the propagating frequency the spatial decreasing rate (linear dissipation parameter) and show that its must important contribution comes from the dissipative element of the shunt branch. The modulational instability (MI) criterion of modulated Stokes wave propagating in the network is investigated and the analytical expression of the MI growth rate is derived; we show that in the case of weak dissipation, there are no significant changes for the bandwidth frequency where the network may exhibit MI. Exact and approximative envelope soliton-like solutions of the derived GL equation are presented and used to investigate the dynamics of spatiotemporal modulated damped signals along the network. We show that the solution parameters can be used for managing the evolution of the envelope soliton signals along the network. Our investigation shows that the amplitude decays in both space (cell number n) and time t, while the velocity remains constant when the envelope soliton signal propagates along the dissipative network.
      PubDate: 2021-05-03
       
  • Chaotic time series prediction using echo state network based on selective
           opposition grey wolf optimizer
    • Abstract: Chaos prediction of nonlinear system is of great significance for proposing control strategies early. On the other hand, echo state network (ESN) as an artificial neural recursive network is widely used in time series prediction, while it has significant disadvantages due to the random input weight matrix. This work proposes a chaos prediction model based on ESN optimized by the selective opposition grey wolf optimizer (SOGWO). Firstly, the input weight matrix of ESN is restructured to express the position of gray wolf optimizer (GWO). Secondly, the selective opposition strategy is introduced into the GWO to enhance the exploration and exploitation capability. Thirdly, the optimal network is achieved by iteratively updating the position of SOGWO where the input weight is replaced by optimal search agent. Finally, taking two typical chaotic time series of Mackey–Glass and Lorenz as the objects, the effectiveness of the proposed SOGWO-ESN is verified by numerical simulation. The experimental results of SOGWO-ESN are compared with those of the traditional echo state network, the network model optimized by the particle swarm optimization (PSO) and the traditional gray wolf optimizer. The results imply that the proposed SOGWO-ESN has better prediction performance and is able to accurately predict a much longer period of time.
      PubDate: 2021-05-03
       
  • The dynamics of an omnidirectional pendulum harvester
    • Abstract: The pendulum applied to the field of mechanical energy harvesting has been studied extensively in the past. However, systems examined to date have largely comprised simple pendulums limited to planar motion and to correspondingly limited degrees of excitational freedom. In order to remove these limitations and thus cover a broader range of use, this paper examines the dynamics of a spherical pendulum with translational support excitation in three directions that operate under generic forcing conditions. This system can be modelled by two generalised coordinates. The main aim of this work is to propose an optimisation procedure to select the ideal parameters of the pendulum for an experimental programme intended to lead to an optimised pre-prototype. In addition, an investigation of the power take-off and its effect on the dynamics of the pendulum is presented with the help of Bifurcation diagrams and Poincaré sections.
      PubDate: 2021-05-03
       
  • Spike-adding and reset-induced canard cycles in adaptive integrate and
           fire models
    • Abstract: We study a class of planar integrate and fire models called adaptive integrate and fire (AIF) models, which possesses an adaptation variable on top of membrane potential, and whose subthreshold dynamics is piecewise linear . These AIF models therefore have two reset conditions, which enable bursting dynamics to emerge for suitable parameter values. Such models can be thought of as hybrid dynamical systems. We consider a particular slow dynamics within AIF models and prove the existence of bursting cycles with N resets, for any integer N. Furthermore, we study the transition between N- and \((N+1)\) -reset cycles upon vanishingly small parameter variations and prove (for \(N=2\) ) that such transitions are organised by canard cycles. Finally, using numerical continuation we compute branches of bursting cycles, including canard-explosive branches, in these AIF models, by suitably recasting the periodic problem as a two-point boundary-value problem .
      PubDate: 2021-05-03
       
  • Color image encryption using orthogonal Latin squares and a new 2D chaotic
           system
    • Abstract: Recently, many image encryption schemes have been developed using Latin squares. When encrypting a color image, these algorithms treat the color image as three greyscale images and encrypt these greyscale images one by one using the Latin squares. Obviously, these algorithms do not sufficiently consider the inner connections between the color image and Latin square and thus result in many redundant operations and low efficiency. To address this issue, in this paper, we propose a new color image encryption algorithm (CIEA) that sufficiently considers the properties of the color image and Latin square. First, we propose a two-dimensional chaotic system called 2D-LSM to address the weaknesses of existing chaotic systems. Then, we design a new CIEA using orthogonal Latin squares and 2D-LSM. The proposed CIEA can make full use of the inherent connections of the orthogonal Latin squares and color image and executes the encryption process in the pixel level. Simulation and security analysis results show that the proposed CIEA has a high level of security and can outperform some representative image encryption algorithms.
      PubDate: 2021-05-02
       
  • A fractional-order multistable locally active memristor and its chaotic
           system with transient transition, state jump
    • Abstract: Fractional calculus is closer to reality and has the same memory characteristics as memristor. Therefore, a fractional-order multistable locally active memristor is proposed for the first time in this paper, which has infinitely many coexisting pinched hysteresis loops under different initial states and wide locally active regions. Through the theoretical and numerical analysis, it is found that the fractional-order memristor has stronger locally active and memory characteristics and wider nonvolatile ranges than the integer-order memristor. Furthermore, this fractional-order memristor is applied in a chaotic system. It is found that oscillations occur only within the locally active regions. This chaotic system not only has complex and rich nonlinear dynamics such as infinitely many discrete equilibrium points, multistability and anti-monotonicity but also produces two new phenomena that have not been found in other chaotic systems. The first one is transient transition: the behavior of local chaos and local period transition alternately occurring. The second is state jump: the behavior of local period-4 oscillation or local chaotic oscillation jumping to local period-2 oscillation. Finally, the circuit simulation of the fractional-order multistable locally active memristive chaotic system using PSIM is carried out to verify the validity of the numerical simulation results.
      PubDate: 2021-05-02
       
 
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