Subjects -> TRANSPORTATION (Total: 214 journals)
    - AIR TRANSPORT (9 journals)
    - AUTOMOBILES (26 journals)
    - RAILROADS (10 journals)
    - ROADS AND TRAFFIC (9 journals)
    - SHIPS AND SHIPPING (43 journals)
    - TRANSPORTATION (117 journals)

TRANSPORTATION (117 journals)                     

Showing 1 - 53 of 53 Journals sorted by number of followers
Journal of Navigation     Hybrid Journal   (Followers: 185)
Accident Analysis & Prevention     Hybrid Journal   (Followers: 132)
Transportation Research Part A: Policy and Practice     Hybrid Journal   (Followers: 38)
Transportation Research Part B: Methodological     Hybrid Journal   (Followers: 38)
Urban, Planning and Transport Research     Open Access   (Followers: 33)
Transportation     Hybrid Journal   (Followers: 32)
Transportation Research Record : Journal of the Transportation Research Board     Full-text available via subscription   (Followers: 29)
Transportation Research Part C: Emerging Technologies     Hybrid Journal   (Followers: 29)
Journal of Transport and Land Use     Open Access   (Followers: 27)
Transportation Science     Full-text available via subscription   (Followers: 26)
Journal of Transport Geography     Hybrid Journal   (Followers: 22)
European Transport Research Review     Open Access   (Followers: 22)
Nonlinear Dynamics     Hybrid Journal   (Followers: 20)
Public Transport     Hybrid Journal   (Followers: 18)
International Journal of Sustainable Transportation     Hybrid Journal   (Followers: 18)
Cities in the 21st Century     Open Access   (Followers: 17)
Open Journal of Safety Science and Technology     Open Access   (Followers: 16)
Transportation Journal     Full-text available via subscription   (Followers: 16)
Transport     Open Access   (Followers: 16)
Economics of Transportation     Partially Free   (Followers: 16)
Journal of Transportation Technologies     Open Access   (Followers: 13)
International Journal of Intelligent Transportation Systems Research     Hybrid Journal   (Followers: 13)
IET Electrical Systems in Transportation     Open Access   (Followers: 13)
Case Studies on Transport Policy     Hybrid Journal   (Followers: 13)
Journal of Advanced Transportation     Hybrid Journal   (Followers: 12)
International Journal of Traffic and Transportation Engineering     Open Access   (Followers: 12)
Journal of Transport & Health     Hybrid Journal   (Followers: 12)
Journal of Transport History     Hybrid Journal   (Followers: 12)
EURO Journal of Transportation and Logistics     Open Access   (Followers: 12)
Sport, Education and Society     Hybrid Journal   (Followers: 12)
Transport Reviews: A Transnational Transdisciplinary Journal     Hybrid Journal   (Followers: 11)
IET Intelligent Transport Systems     Open Access   (Followers: 11)
Modern Transportation     Open Access   (Followers: 11)
International Journal of Crashworthiness     Hybrid Journal   (Followers: 11)
Proceedings of the Institution of Mechanical Engineers Part F: Journal of Rail and Rapid Transit     Hybrid Journal   (Followers: 11)
International Journal of Physical Distribution & Logistics Management     Hybrid Journal   (Followers: 11)
Journal of Transport and Supply Chain Management     Open Access   (Followers: 10)
Journal of Sport & Social Issues     Hybrid Journal   (Followers: 10)
Journal of Transportation Safety & Security     Hybrid Journal   (Followers: 9)
International Journal of Transportation Science and Technology     Open Access   (Followers: 9)
Travel Behaviour and Society     Full-text available via subscription   (Followers: 9)
Transportmetrica A : Transport Science     Hybrid Journal   (Followers: 8)
Transportation Infrastructure Geotechnology     Hybrid Journal   (Followers: 8)
International Journal of Mobile Communications     Hybrid Journal   (Followers: 8)
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 8)
International Journal of Electric and Hybrid Vehicles     Hybrid Journal   (Followers: 8)
Pervasive and Mobile Computing     Hybrid Journal   (Followers: 8)
Journal of Waterway Port Coastal and Ocean Engineering     Full-text available via subscription   (Followers: 7)
Journal of Modern Transportation     Full-text available via subscription   (Followers: 7)
Journal of Supply Chain Management Science (JSCMS)     Open Access   (Followers: 7)
Mobility in History     Full-text available via subscription   (Followers: 7)
IEEE Vehicular Technology Magazine     Full-text available via subscription   (Followers: 7)
Journal of Mechatronics, Electrical Power, and Vehicular Technology     Open Access   (Followers: 6)
International Journal of Heavy Vehicle Systems     Hybrid Journal   (Followers: 6)
Transportation Research Procedia     Open Access   (Followers: 6)
European Journal of Transport and Infrastructure Research (EJTIR)     Open Access   (Followers: 6)
World Review of Intermodal Transportation Research     Hybrid Journal   (Followers: 5)
International Journal of Applied Logistics     Full-text available via subscription   (Followers: 5)
Applied Mobilities     Hybrid Journal   (Followers: 5)
Transportation Letters : The International Journal of Transportation Research     Hybrid Journal   (Followers: 4)
Vehicular Communications     Full-text available via subscription   (Followers: 4)
Logistics & Sustainable Transport     Open Access   (Followers: 4)
Transport Problems     Open Access   (Followers: 4)
IEEE Open Journal of Intelligent Transportation Systems     Open Access   (Followers: 4)
Journal of Traffic and Transportation Engineering (English Edition)     Open Access   (Followers: 4)
Transport and Telecommunication     Open Access   (Followers: 4)
Research in Transportation Business and Management     Partially Free   (Followers: 4)
Transactions on Transport Sciences     Open Access   (Followers: 4)
Journal of Transportation and Logistics     Open Access   (Followers: 3)
TRANSPORTES     Open Access   (Followers: 3)
Journal of Transportation Security     Hybrid Journal   (Followers: 3)
World Electric Vehicle Journal     Open Access   (Followers: 3)
Journal of Big Data Analytics in Transportation     Hybrid Journal   (Followers: 2)
Transportation Research Interdisciplinary Perspectives     Open Access   (Followers: 2)
International Journal of Vehicle Systems Modelling and Testing     Hybrid Journal   (Followers: 2)
Travel Medicine and Infectious Disease     Hybrid Journal   (Followers: 2)
International Journal of Transportation Engineering     Open Access   (Followers: 2)
Sport, Ethics and Philosophy     Hybrid Journal   (Followers: 2)
Streetnotes     Open Access   (Followers: 2)
Packaging, Transport, Storage & Security of Radioactive Material     Hybrid Journal   (Followers: 2)
Danish Journal of Transportation Research / Dansk Tidsskrift for Transportforskning     Open Access   (Followers: 1)
eTransportation     Open Access   (Followers: 1)
Decision Making : Applications in Management and Engineering     Open Access   (Followers: 1)
Transportation Safety and Environment     Open Access   (Followers: 1)
Journal of Intelligent and Connected Vehicles     Open Access   (Followers: 1)
Logistics     Open Access   (Followers: 1)
International Journal of Ocean Systems Management     Hybrid Journal   (Followers: 1)
Asian Transport Studies     Open Access   (Followers: 1)
Romanian Journal of Transport Infrastructure     Open Access   (Followers: 1)
Open Transportation Journal     Open Access   (Followers: 1)
International Journal of Services Technology and Management     Hybrid Journal   (Followers: 1)
Synthesis Lectures on Mobile and Pervasive Computing     Full-text available via subscription   (Followers: 1)
Emission Control Science and Technology     Hybrid Journal   (Followers: 1)
Botswana Journal of Technology     Full-text available via subscription   (Followers: 1)
Transportation Geotechnics     Full-text available via subscription   (Followers: 1)
Les Dossiers du Grihl     Open Access   (Followers: 1)
Recherche Transports Sécurité     Hybrid Journal   (Followers: 1)
Transportmetrica B : Transport Dynamics     Hybrid Journal   (Followers: 1)
Transportation Engineering     Open Access   (Followers: 1)
Journal of Public Transportation     Open Access  
Maritime Transport Research     Open Access  
Communications in Transportation Research     Open Access  
IET Smart Cities     Open Access  
Journal on Vehicle Routing Algorithms     Hybrid Journal  
Transportation in Developing Economies     Hybrid Journal  
Vehicles     Open Access  
Periodica Polytechnica Transportation Engineering     Open Access  
Transportation Systems and Technology     Open Access  
LOGI ? Scientific Journal on Transport and Logistics     Open Access  
Promet : Traffic &Transportation     Open Access  
IFAC-PapersOnLine     Open Access  
Revista Transporte y Territorio     Open Access  
Транспортні системи та технології перевезень     Open Access  
Geosystem Engineering     Hybrid Journal  
Logistique & Management     Hybrid Journal  
IATSS Research     Open Access  
Transport in Porous Media     Hybrid Journal  

           

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  [2469 journals]
  • The effect of dynamic normal force on the stick–slip vibration
           characteristics

    • Free pre-print version: Loading...

      Abstract: Abstract In the experiment, we observed such a phenomenon: the alternating normal force changes the vibration state of a friction system. A single-degree-of-freedom mathematical model was used in this paper to discuss the effects of a constant and alternating normal force on the stick–slip vibration characteristics for different dynamic and static friction coefficients. Under the condition that the applied constant normal force continues to increase, the vibration amplitude of the system, the amplitude of the limit cycle, and the adhesion time of the system increase. When the difference between the dynamic and static friction coefficients (DSFCs) is small, the system has a complete and clear limit cycle. When the dynamic friction coefficient is reduced, the difference between DSFCs increases, and the limit cycle of the system is deformed. The friction system has more abundant dynamic vibration characteristics under an alternating normal force than a constant normal force. The vibration state of the system presents a single-cycle stick–slip vibration when the alternating normal force excites the multi-order harmonic response of the friction system, and the excitation frequency of the alternating normal force is the same as the main response frequency of the system with the highest energy or the low-order even-order main frequency. In contrast, the system exhibits various vibration modes when the excitation frequency of the alternating normal force is dissimilar to the main frequency of the system's highest energy response or is consistent with the odd-order main frequency. In addition, increasing the difference between DSFCs or using very high excitation frequencies and excitation amplitudes increases the likelihood of the system entering a chaotic vibration state.
      PubDate: 2022-06-27
       
  • Nonlinear dynamic instability of edge-cracked functionally graded
           graphene-reinforced composite beams

    • Free pre-print version: Loading...

      Abstract: Abstract This work investigates nonlinear dynamic instability of edge-cracked functionally graded (FG) graphene nanoplatelet (GNP)-reinforced composite (GNPRC) beams consist of perfectly bonded layers. GNPs with randomly orientations are uniformly dispersed in each individual layer, and GNP concentration varies along beam thickness. Micromechanics models are employed to estimate the effective material properties of the GNPRCs. Considering von Kármán-type nonlinear kinematics, nonlinear ordinary differential equations governing the motions are derived by using Lagrange equation together with Ritz method on the basis of a rotational spring model and the first-order shear deformation theory. The eigenvalue equation is derived using the Bolotin’s method and solved through an iteration procedure to determine the unstable region. Numerical analysis is conducted to study the effects of geometric nonlinearity and crack on the dynamic instability of FG-GNPRC beams in different situations.
      PubDate: 2022-06-27
       
  • Customized fastSLAM algorithm: analysis and assessment on real mobile
           platform

    • Free pre-print version: Loading...

      Abstract: Abstract The task of simultaneous localization and mapping (SLAM) allows a mobile robot to localize itself in the unknown environment, while building the map of the surrounding landscape. It is frequently used for the navigation of autonomous mobile robots. Despite the fact that there are plenty available solutions, real applications encounter various application constraints. The present work addresses the subject of the modified fastSLAM application using custom lidar as the detection sensor. Available localization solutions are assessed, their constraints are identified and corresponding solutions are proposed. The algorithm is implemented, tested using simulations and finally applied to the existing mobile platform. Its validation considers various practical aspects of its operation in real-time environment.
      PubDate: 2022-06-27
       
  • Low-thrust Lambert transfer based on two-stage constant-vector thrust
           control method

    • Free pre-print version: Loading...

      Abstract: Abstract The low-thrust Lambert transfer refers to that the spacecraft achieves the orbital transfer whose boundary conditions are represented by two sets of orbital elements at initial and final time by the low-thrust propulsion system. The modulus and direction of the low-thrust solutions in previous methods change with time, which leads to high control requirements for the engine. In this paper, to reduce the requirements of the engine, a practical two-stage constant-vector thrust control method is proposed, in which the magnitude and direction of the thrust are deemed as segmental constant value in TNH frame, where three components of the thrust are ft, fn, and fh. First, the mathematical model of the two-stage constant-vector thrust is formulated, and a rapid algorithm is presented to obtain the solution based on the linearized sensitivity matrix, which describes the relationship between the constant-vector thrust and the change of the orbital elements approximately. Furthermore, two low-thrust Lambert strategies based on the two-stage constant-vector thrust are presented for cases of short-time transfer and long-time transfer. A sequence of numerical simulations demonstrated the efficiency of the proposed approaches. The proposed control strategies are solved rapidly, and they are also suitable for different types of orbits with J2 perturbation, which are practical options for engineering applications.
      PubDate: 2022-06-27
       
  • Modal coupled vibration behavior of piezoelectric L-shaped resonator
           induced by added mass

    • Free pre-print version: Loading...

      Abstract: Abstract This paper studies the mode coupling behavior and complex nonlinear dynamics of a piezoelectric driven L-shaped beam considering the added mass. To realize natural frequency adjustment and energy exchange among different modes, the added mass is delicately designed. The nonlinear governing equations, representing the first and second modes, are obtained by the Hamilton principle and Galerkin method. Perturbation and bifurcation analyses show that mode coupled vibration can lead to complex dynamic phenomena such as amplitude jump, amplitude saturation, double Hopf bifurcation and amplitude persistence. The physical conditions of amplitude jump, the critical voltage of amplitude saturation and the discriminant formula of double Hopf bifurcation are deduced theoretically and verified numerically. To be more convincing, an experimental test system is set up to observe the nonlinear dynamic behaviors. It is found that when the driving frequency is less than 26.18 Hz or more than 26.52 Hz, the first-order mode vibration jumps under the bifurcation driving voltage, which is qualitatively consistent with the theoretical results. Through mechanism investigation on subcritical Hopf bifurcation induced structure jumping phenomenon, the linear relationship between bifurcation voltage and perturbation mass is deduced. Both theoretical and experimental results demonstrate that small disturbance of added mass can significantly affect the bifurcation voltage of modal coupled vibration, which can realize the detection of micro-mass. The research results of this paper provide theoretical basis and experimental support for the development of micro-resonance device.
      PubDate: 2022-06-27
       
  • Continuously asymptotic tracking of disturbed interconnected systems with
           unknown control directions

    • Free pre-print version: Loading...

      Abstract: Abstract Recently, the fruitful results on robust control for large-scale interconnected systems have been reported, but most of them are contingent upon “known control directions” and/or only acquire uniformly ultimately bounded performance in the presence of disturbances. Of particular interest in this paper is to develop a continuous and decentralized control algorithm for such systems, which can release the need to know the control directions, guarantee robustness against general system uncertainties (e.g., exogenous disturbances, unknown interactions), and achieve asymptotic output tracking. To this end, we apply a new Nussbaum function to the decentralized controller to identify the control directions despite global interactions. Then resorting to the robust-integral-of-sign-of-error (RISE) technique, we develop a closed-loop system that fully eliminates the effects of the system uncertainties while preserving the control variables’ continuity. Additionally, to synthesize the new Nussbaum function and the RISE method, a second-order filter designed for generating feasible feedback signals is constructed. Lyapunov-based stability analysis and numerical simulations are carried out to validate the robustness and the asymptotic convergence of the interconnected system under the proposed control scheme.
      PubDate: 2022-06-27
       
  • How synaptic plasticity affects the stochastic resonance in a modular
           neuronal network

    • Free pre-print version: Loading...

      Abstract: Abstract This work mainly investigates how synaptic plasticity influences the stochastic resonance dynamics of delay-coupled FitzHugh–Nagumo neurons in a modular neuronal network subjected to bounded noise. This modular neuronal network is consisted of two small-world subnetworks. The couplings between different neurons are of synaptic plasticity, which is regulated by a modified Oja’s learning rule. Numerical results show that the classical phenomenon of stochastic resonance can occur at an intermediate amplitude of bounded noise on this network. Also, the result reveals that appropriately tuned delays can induce multiple stochastic resonances, appearing at every integer multiple of the period of weak period signal. Moreover, when incorporating synaptic plasticity into this modular neuronal network, we find that the bounded noise-induced stochastic resonance is almost quantitatively unchanged upon increasing synaptic learning rate, i.e., the phenomenon is robust to the synaptic plasticity. Interestingly, the delay-induced multiple stochastic resonances are slightly restrained by the increase in synaptic learning rate. These present findings could be helpful to understand the important role of synaptic plasticity on neural coding in realistic neuronal network.
      PubDate: 2022-06-27
       
  • Spatiotemporal dynamics induced by nonlocal competition in a diffusive
           predator-prey system with habitat complexity

    • Free pre-print version: Loading...

      Abstract: Abstract In this paper, we study a delayed diffusive predator–prey model with nonlocal competition in prey and habitat complexity. The local stability of coexisting equilibrium is studied by analyzing the eigenvalue spectrum. Time delay inducing Hopf bifurcation is investigated by using time delay as bifurcation parameter. We give some conditions for determining the bifurcation direction and the stability of the bifurcating periodic solution by utilizing the normal form method and center manifold theorem. Our results suggest that only nonlocal competition and diffusion together can induce stably spatial inhomogeneous bifurcating periodic solutions.
      PubDate: 2022-06-27
       
  • Nonlinear dynamic mechanisms of angular contact ball bearings with
           waviness and cage whirl motion

    • Free pre-print version: Loading...

      Abstract: Abstract This paper proposes a nonlinear dynamic model of angular contact ball bearings with waviness and cage whirl motion. This original model establishes the interaction between balls, cage and bearing rings so that waviness can change the contacts between balls and raceways real-timely to influence the dynamic behaviors of the bearing system, which is a novel solution to a known problem. On this basis, the significance of cage whirl motion to the dynamic mechanism of the bearing system is elaborated. Next, the sliding of the ball with time is calculated to study the interactions between balls, cage and bearing rings and further investigate the dynamic mechanism of the bearing system. Also, the effects of waviness orders and amplitudes on the dynamic mechanism are revealed. It is found that the abrupt change in the sliding of the ball causes the low-frequency vibration in the bearing system, while waviness gives rise to the high-frequency vibration. The results show sparse waviness with tiny amplitude should be manufactured for improving the stability of cage motion and mitigating the vibration of inner ring.
      PubDate: 2022-06-27
       
  • Long-memory recursive prediction error method for identification of
           continuous-time fractional models

    • Free pre-print version: Loading...

      Abstract: Abstract This paper deals with recursive continuous-time system identification using fractional-order models. Long-memory recursive prediction error method is proposed for recursive estimation of all parameters of fractional-order models. When differentiation orders are assumed known, least squares and prediction error methods, being direct extensions to fractional-order models of the classic methods used for integer-order models, are compared to our new method, the long-memory recursive prediction error method. Given the long-memory property of fractional models, Monte Carlo simulations prove the efficiency of our proposed algorithm. Then, when the differentiation orders are unknown, two-stage algorithms are necessary for both parameter and differentiation-order estimation. The performances of the new proposed recursive algorithm are studied through Monte Carlo simulations. Finally, the proposed algorithm is validated on a biological example where heat transfers in lungs are modeled by using thermal two-port network formalism with fractional models.
      PubDate: 2022-06-25
       
  • Barrier Lyapunov function-based fixed-time FTC for high-order nonlinear
           systems with predefined tracking accuracy

    • Free pre-print version: Loading...

      Abstract: Abstract This article proposes a fixed-time adaptive fault-tolerant control methodology for a larger class of high-order (powers are positive odd integers) nonlinear systems subject to asymmetric time-varying state constraints and actuator faults. In contrast with the state-of-the-art control methodologies, the distinguishing features of this study lie in that: (a) high-order asymmetric time-varying tan-type barrier Lyapunov function (BLF) is devised such that the state variables can be convergent to the preassigned compact sets all the time provided their initial values remain therein, which not only preserves the constraints satisfaction, but warrants the validity of the adopted neural network approximator; (b) the proposed control design ensures the tracking errors converge to specified residual sets within fixed time and makes the size of the convergence regions of tracking errors adjustable a priori by means of a new BLF-based tuning function and a projection operator; (c) a variable-separable lemma is delicately embedded into the control design to extract the control terms in a “linear-like” fashion which not only overcomes the difficulty that virtual control signals appear in a non-affine manner, but also solves the problem of actuator faults. Comparative simulations results finally validate the effectiveness of the proposed scheme.
      PubDate: 2022-06-25
       
  • Dynamic analysis of the variable stiffness support rotor system with
           elastic rings

    • Free pre-print version: Loading...

      Abstract: Abstract Elastic rings are common rotor supporting structure, which have been widely used in aeroengine rotor support system. However, large inertia force and gyroscopic moment may occur during the operation of aeroengine, which may lead to contact between elastic ring and bearing pedestal, and then introduce variable stiffness into the rotor support system. In this paper, a mathematical model of variable stiffness of elastic ring is proposed and this model is subsequently verified by comparison with simulation analysis and experimental results. Based on this model, a variable stiffness model of an elastic ring-supported rotor is developed by coupling the kinetic equations of the rotor with the deformation of the combined support. Then, the spectrum cascades are used to analyze the dynamic characteristics of the rotor system. In addition, the influences of the variable stiffness of elastic ring on the critical speed of the system are also examined. Finally, some simulation results are verified by experiments on a combined test bench of an elastic ring-supported rotor.
      PubDate: 2022-06-24
       
  • Nonlinear dynamic behavior of a bio-inspired embedded X-shaped vibration
           isolation system

    • Free pre-print version: Loading...

      Abstract: Abstract To improve the vibration isolation performance and bandwidth, loading capacity and supporting stability of passive vibration isolation system by utilizing nonlinearity, a bio-inspired embedded X-shaped vibration isolation (BIE-XVI) structure is proposed considering muscle/tendon contractile functions, joint rotational friction and connecting rod mass simultaneously. Furthermore, the dynamic model with pure linear elements and geometric relationship are established and the nonlinear variation properties are investigated. The effects of the key parameters of the BIE-XVI structure on frequency response characteristics and vibration isolation range are analyzed thoroughly by incremental harmonic balance method in various working conditions. From the parametric investigations, it can be found that the sensitivities of the nonlinear resonance properties are markedly different with respect to the different structure parameters. For longer rod length, larger assembly angle and higher stiffnesses, the hardening nonlinearity is weakened, but the resonance peak does not necessarily decrease. Besides, the softening nonlinearity and hardening nonlinearity can be interconverted with changing isolated mass and excitation amplitude. The BIE-XVI structure can widen the isolation frequency range and reduce the resonance peak to improve the vibration isolation properties by adjusting/designing the structural parameters, which could realize quasi-zero-stiffness property for vibration isolation.
      PubDate: 2022-06-24
       
  • Boundary-layer features in conservative nonlinear oscillations

    • Free pre-print version: Loading...

      Abstract: Abstract This paper considers (1 + 1) dimensional conservative oscillatory systems with polynomial nonlinearities in the double limit of high amplitude (xmax → ∞) and high leading power (x2N+1, N → ∞). In this limit, hitherto not studied in the literature, such systems exhibit behavior akin to boundary layer phenomena: The characteristics of the solution are determined by a vanishingly small segment of the amplitude near ± xmax. The oscillating entity, x(t), tends to a periodic saw-tooth shape of linear segments, the velocity, x′(t), tends to a periodic step-function and the x − x′ phase-space plot tends to a rectangle. This is demonstrated by transforming x and t into scaled variables, η and θ, respectively. η(θ) is (2-π) periodic in θ and bounded ( η(θ) ≤ 1). For large xmax, the zero-order term in an expansion in powers of a small parameter that is proportional to (1/xmax) yields an excellent approximation to the solutions of the scaled equation. The boundary-layer characteristics show up in the double limit by the fact that the deviations of η(θ), η′(θ) and the η − η′ phase-space plot from the sharp asymptotic shapes occur over a narrow range in θ of O(1/N) near the turning points of the oscillations.
      PubDate: 2022-06-24
       
  • Efficient calculation of fractal properties via the Higuchi method

    • Free pre-print version: Loading...

      Abstract: Abstract Higuchi’s method of determining fractal dimension is an important, well-used, research tool that, compared to many other methods, gives rapid, efficient, and robust estimations for the range of possible fractal dimensions. One major shortcoming in applying the method is the correct choice of tuning parameter (kmax); a poor choice can generate spurious results, and there is no agreed upon methodology to solve this issue. We analyze multiple instances of synthetic fractal signals to minimize an error metric. This allows us to offer a new and general method that allows determination, a priori, of the best value for the tuning parameter, for a particular length data set. We demonstrate its use on physical data, by calculating fractal dimensions for a shell model of the nonlinear dynamics of MHD turbulence, and severe acute respiratory syndrome coronavirus 2 isolate Wuhan-Hu-1 from the family Coronaviridae.
      PubDate: 2022-06-23
       
  • Event-triggered-based cooperative game optimal tracking control for
           modular robot manipulator with constrained input

    • Free pre-print version: Loading...

      Abstract: Abstract In this paper, a cooperative game optimal tracking control method based on event-triggered mechanism for constrained input modular robot manipulators (MRMs) system is introduced. According to the joint torque feedback technique, the dynamics model of the constrained input subsystem is established and the global state space equation is derived. The control inputs of n joints in the MRM system with constrained input are taken as n participants of cooperative game, and the tracking control problem of the manipulator system is transformed into the optimal control problem based on the cooperative game. Next, a fusion function containing position and velocity errors is defined to construct the performance index function. In order to improve the control performance and robustness of the manipulator system, part of the known model information is used to devise controller, the model uncertainty is dealt by the neural network (NN) observer, and the optimal compensation control strategy is used to deal with internal disturbance such as sensor measurement error and transmission ripple due to power fluctuations, electromagnetic effects, noise and vibration. Based on the adaptive dynamic programming algorithm and event-triggered mechanism, the optimal tracking control strategy is obtained by approximately solving the event-triggered Hamilton-Jacobi-Bellman equation with the critic NN. The Lyapunov theory proves that trajectory tracking error of MRM system with constrained input is uniformly ultimately bounded. Finally, the experimental results demonstrate the effectiveness of the proposed control method.
      PubDate: 2022-06-23
       
  • A mechanism explaining the metamorphoses of KAM islands in nonhyperbolic
           chaotic scattering

    • Free pre-print version: Loading...

      Abstract: Abstract In the context of nonhyperbolic chaotic scattering, it has been shown that the evolution of the KAM islands exhibits four abrupt metamorphoses that strongly affect the predictability of Hamiltonian systems. It has been suggested that these metamorphoses are related to significant changes in the structure of the KAM islands. However, previous research has not provided an explanation of the mechanisms underlying the metamorphoses. Here, we show that they occur due to the formation of a homoclinic or heteroclinic tangle that breaks the internal structure of the main KAM island. We obtain similar qualitative results in a two-dimensional Hamiltonian system and a two-dimensional area-preserving map. The equivalence of the results obtained in both systems suggests that the same four metamorphoses play an important role in conservative systems.
      PubDate: 2022-06-21
       
  • Practical tracking control under actuator saturation for a class of
           flexible-joint robotic manipulators driven by DC motors

    • Free pre-print version: Loading...

      Abstract: Abstract This paper is devoted to the practical tracking control for a class of flexible-joint robotic manipulators driven by DC motors. Different from the related literature where control constraint is neglected and the disturbances are excluded or only exist in one subsystem, actuator saturation is considered in this paper, while the disturbances are present in all the three subsystems. This leads to the incapability of the traditional schemes on this topic. For this, a novel control design scheme is proposed by skillfully incorporating adaptive dynamic compensation technique, constructive methods of command filters and an auxiliary system for the actuator saturation into the backstepping framework, and in turn to design a practical tracking controller which ensures that all the states of the resulting closed-loop system are bounded and the system output practically tracks the reference signal. It is worthwhile strengthening that a more wider class of reference signals can be tracked since they are only first-order continuously differentiable but twice or more in the related literature. Finally, a numerical example is provided to validate the effectiveness of the proposed theoretical results.
      PubDate: 2022-06-21
       
  • Adaptive fixed-time synchronization of Lorenz systems with application in
           chaotic finance systems

    • Free pre-print version: Loading...

      Abstract: Abstract This paper concerns the problem of fixed-time synchronization of master–slave Lorenz systems. The adaptive control and fixed-time control strategies are successfully integrated so that not only the Lorenz systems can be synchronized within a fixed-time, but also the related controlling gains are not necessary to select beforehand. Distinguished from the conventional fixed-time control schemes, the proposed controller do not contain the signum function anymore, thereby the chattering behavior is avoided owing to its smoothness. The synchronizing condition is deduced according to the theory of fixed-time stability, and the upper bound of settling time is also estimated, which is irrelevant to the initial states of Lorenz systems. Apart from the correctness and effectiveness of theoretical analysis is validated by simulating Lorenz systems, the spirit of adaptive fixed-time control strategy is applied into synchronizing two finance systems finally.
      PubDate: 2022-06-21
       
  • Painlevé integrability and superposition wave solutions of
           Whitham–Broer–Kaup equations

    • Free pre-print version: Loading...

      Abstract: Abstract In this paper, the Painlevé integrability and superposition wave solutions of Whitham–Broer–Kaup (WBK) equations are studied, which can help us increase the diversity of solutions and get more new phenomena. The integrability of WBK equations is discussed by Painlevé analysis method, and the Bäcklund transformation between WBK equations and linear equation is obtained by using the truncated expansion. According to the obtained Bäcklund transformation, some superposition wave solutions of WBK equations are constructed. We analyze the properties of the solutions with the help of the symbolic calculation system Mathematica. Through analysis, there is a mathematical relationship between the number of waves and the number of superposition functions, and in the same case, u and v show similar contours in the solutions of the equations. Furthermore, by superimposing the solutions of the transformed linear equation and introducing arbitrary functions, we obtain superposition wave solutions of the nonlinear evolution equations. Also, it has been observed that the results obtained in this work have been presented for the first time.
      PubDate: 2022-06-21
       
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
 


Your IP address: 18.232.177.219
 
Home (Search)
API
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-