Types Of Synchronization Research Articles

Quaternion anti-synchronization of a novel realizable fractional chaotic model

The main aim of this work is to generalize the chaotic unified model using the quaternion mathematics and fractional derivatives. A novel 8.1-fractional order, 9-dimensions, quaternion unified chaotic system is constructed. The 8.1-fractional order electronic circuit that realize the novel system is designed. Using the graph theory tools, the complexity of the proposed novel 8.1-fractional order, 9-dimensions, quaternion unified chaotic system is calculated. In addition, the substantial contribution in this work appears in introducing an extraordinary type of quaternion synchronizations. We call this novel type “quaternion anti synchronization” (QAS). QAS has unusual properties and characteristics that distinguish it from all the types of synchronizations previously studied in the literature. The QAS of fractional unified model with quaternion variables is studied. The validity of the analytical results is confirmed in QAS of fractional unified system with effective numerical simulation.

Correlation Analysis of Synchronization Type and Degree in Respiratory Neural Network.

Pre-Bötzinger complex (PBC) is a necessary condition for the generation of respiratory rhythm. Due to the existence of synaptic gaps, delay plays a key role in the synchronous operation of coupled neurons. In this study, the relationship between synchronization and correlation degree is established for the first time by using ISI bifurcation and correlation coefficient, and the relationship between synchronization and correlation degree is discussed under the conditions of no delay, symmetric delay, and asymmetric delay. The results show that the phase synchronization of two coupling PBCs is closely related to the weak correlation, that is, the weak phase synchronization may occur under the condition of incomplete synchronization. Moreover, the time delay and coupling strength are controlled in the modified PBC network model, which not only reveals the law of PBC firing transition but also reveals the complex synchronization behavior in the coupled chaotic neurons. Especially, when the two coupled neurons are nonidentical, the complete synchronization will disappear. These results fully reveal the dynamic behavior of the PBC neural system, which is helpful to explore the signal transmission and coding of PBC neurons and provide theoretical value for further understanding respiratory rhythm.

Self-Synchronization of a Vibrating Jaw Crusher with Allowance for Interaction with the Medium Processed

The vibrations of a vibrating jaw crusher model, excited by two self-synchronizing unbalanced-mass vibration exciters, with allowance for the interaction with the processed medium are examined. It is found that the frequency range of stable antiphase synchronization of the exciter rotation required for normal operation of the crusher, depends significantly on the gap between the crusher jaw and the medium element, and a decrease in the initial gap leads to an expansion of the frequency range of exciter stable antiphase synchronization. In the absence of an initial gap and the appearance of medium pressure on the jaws in the superresonance range, the appearance of a stability region of the synchronous-in-phase exciters rotation is possible. It is shown that, at a constant vibration excitation frequency, a change in the initial gap between the jaws and the processed medium can lead to a change in the type of exciter synchronization and, accordingly, vibrations of the jaws.

General decay synchronization of delayed BAM neural networks with reaction\u2013diffusion terms

In this paper, general decay synchronization of delayed bidirectional associative memory neural networks with reaction–diffusion terms is studied. First, a useful lemma is introduced to determine the general decay synchronization of considered systems. Furthermore, a type of nonlinear controller is designed. Then, some sufficient conditions are obtained to insure the general decay synchronization of the drive–response systems via using Lyapunov functional method and Poincaré inequality. Finally, the obtained theoretical results are evaluated by giving one numerical example. The exponential synchronization, polynomial synchronization, and some other types of synchronization can be seen as special cases of the general decay synchronization.

High degree of chaos synchronization in pairs of transverse modes with parity-symmetric polarizations in a thin-slice solid-state vector laser and application to polarimetric secure self-mixing metrology.

A high degree of chaos synchronization among transverse mode pairs with parity-symmetric polarizations was demonstrated in a laser-diode pumped thin-slice c-cut Nd:GdVO4 laser. The amplitude correlation coefficient greater than R>0.994 resulted from a non-reversing mirror symmetric-polarization-dependent structural change in the modal patterns, where chaotic dynamics of the whole system consisting of qualitatively different dynamics, which depend on the polarization crossing angle, resembled that of a chaotic single mode laser. A self-organized sender-receiver type of chaos synchronization of a single pair of modes among an infinite number of parity-symmetric polarizations, the associated chaotic camouflaging, and the extracting experiment of a self-mixing solid-state laser Doppler velocimetry signal were demonstrated.

Networks of forest ecosystems: Mathematical modeling of their biotic pump mechanism and resilience to certain patch deforestation

We propose an innovative mathematical model for studying the dynamics of a complex network of forest ecosystems, in which two forest patches interact which each other through water exchanges. Our model reproduces a recently analyzed principle of constant precipitation quantity over densely forested areas. We perform a stability and bifurcation analysis and show that the distance separating two forest ecosystems can attract a part of the network to an extinction state. We incorporate a randomly generated perturbation modeling deforestation and investigate the effect of the level of deforestation on the equilibrium states of the network. We also exhibit an original type of synchronization in the case of densely distributed forest ecosystems.

A General Method for Fractional-Integer Order Systems Synchronization

This paper investigates different type of synchronization between fractional-order (chaotic, hyperchaotic) systems and integer-order (chaotic, hyperchaotic) systems. Based on the idea of the decomposition of the controller in the response system in two sub-controllers and the stability theory of the linear integer-order system, we design the effective controller to realize the synchronization, Antisynchronization, function projective synchronization, inverse function projective synchronization between fractional-order and integer-order systems. Finally, the fractional-order L¨u’s system and the Lorenz system of integer order are used to demonstrate the effectiveness of the proposed method with numerical simulation.

Quaternion nonlinear Lü model and its novel quaternion complete synchronization

In this work we propose the chaotic nonlinear Lü structure in quaternion form. Our new structure is high dimensional (9D). Highlights and qualities of this model are studied. Also, we present a novel king of quaternion synchronization. We call this new sort of synchronization “quaternion complete synchronization” (QCS). The idea of QCS did not consider in writing and has some unusual properties. Some organizations are conducted using the Lyapunov function to study QCS of two identical Lü attractors with quaternion variables. Numerical studies have shown the validity and accuracy of the analytical results of the control functions. Numerical studies also showed properties that distinguish QCS from the rest of the synchronization types that were previously studied.

Fundamental Concepts of Synchronization

Objects with rhythms naturally synchronize. Synchronization is the coordination of events in order to run the system uniformly. Yet the phenomenon went entirely undocumented until 1665. Since the pioneering description of synchronization by Huygens, the phenomenon has been studied by various researchers in an interdisciplinary manner. Many researchers have contributed to the development of synchronization theory proving that synchronization occurs in coupled non-linear dissipative oscillators. Such oscillators range from mechanical clocks and population dynamics to human heart and neural networks. This article aims to explain the basic principles of synchronization theory. The history and applications of synchronization are discussed in real-world scenarios. We address different types of synchronization with a detailed discussion on the simplest type of synchronization. The phenomenon of synchronization applies to oscillations of different forms—periodic, noisy, and chaotic in nature. Here, we specifically discuss the oscillators which can hold synchronization. In particular, we provide an overview of self-sustained periodic and chaotic oscillators with a detailed description of different forms of these oscillators in phase space. Further, a summary of further research challenges has also been given for the future development of advanced applications based on natural synchronization phenomenon.

Complex modified projective phase synchronization of nonlinear chaotic frameworks with complex variables

In this work we display and examine the definition of complex modified (or altered) projective phase synchronization (CMPPS) of chaotic complex nonlinear frameworks which have not been presented as of late within the writing. This type of complex synchronization can be seen as a generalization in the literature of many types of synchronizations and complex synchronizations. A scheme is outlined to attain CMPPS of chaotic complex nonlinear frameworks based on the stability theory. In CMPPS, we show how nonlinear chaotic systems with complex variables can also be synchronized to a complex constant scaling matrix in a master-slave setup. The obvious change of the complex scaling matrix in CMPPS can furthermore improve the security of communications. The viability and feasibility of the CMPPS are highlighted in the recreation case.

Development of blind frame synchronization for transfer system with differential space-time block coding

The object of this research is the methods and algorithms for frame synchronization used in multi-antenna radio systems (Multiple Input Multiple Output – MIMO). The implementation of radio communication systems and, in particular, MIMO, implies that the demodulator synchronizes the phase of the reference carrier and the time of signal processing processes. Time synchronization is divided into symbolic and frame synchronization. As for the synchronization of the reference carrier and symbol synchronization, these types of synchronization are provided by traditional methods and are not considered in this paper. The frame synchronization in the vast majority of cases is provided by the use of pilot signals (sync words). At their core, they are markers and are periodically embedded in the data stream to indicate the beginning of another new data block. The resources of the transmission system, spent on the transmission of pilot signals, are not used to transmit user information, as a result of which the efficiency of using the time-frequency resource of the system is degraded. To a lesser extent, there are so-called «blind» signal processing methods based on the redundancy properties of the transmitted signal. These methods have no drawbacks from the use of pilot signals and are divided into methods for assessing the state of the communication channel, signal identification, and synchronization. Based on this, such methods are of practical interest.In this work, let’s propose a frame synchronization method for demodulating differential space-time block coding signals using MIMO technology. The synchronization algorithm does not require the use of preambles and sync words, which ensure efficient use of the time-frequency resource. An analysis of the structure of the algorithm and the simulation results show its performance at low signal-to-noise ratios in the transmission system. The algorithm does not require knowledge of the state of the communication channel, has low computational complexity compared to existing analogues, and allows implementation with a different number of transmitting and receiving antennas.

Finite-Time and Fixed-Time Non-chattering Control for Inertial Neural Networks with Discontinuous Activations and Proportional Delay

Based on the framework of Filippov solutions, this paper considers synchronization of inertial neural networks (INNs) with discontinuous activation functions and proportional delay. By designing several non-chattering controllers, both finite-time and fixed-time synchronization are studied. The designed controllers are simple to be implemented and can overcome the effects of both nonidentical uncertainties of Filippov solutions and the proportional delay without inducing any chattering. By designing new Lyapunov functionals and utilizing 1-norm methods, several sufficient conditions are obtained to ensure that the INNs achieve drive-response synchronization in finite time and fixed time, respectively. Moreover, the settling time is estimated for the two types of synchronization. Simulations are provided to illustrate the effectiveness of theoretical analysis.

Mutual synchronization of two flame-driven thermoacoustic oscillators: Dissipative and time-delayed coupling effects.

Low-emissions can-annular gas turbines are prone to develop low-frequency self-excited thermoacoustic oscillations. Such oscillations arise from the coupling between adjacent combustors and can increase wear and thermal stresses. In this experimental study, we explore the mutual synchronization of two thermoacoustic oscillators (i.e., two model combustors) interacting via dissipative and time-delayed coupling, as introduced via a cross-talk section. Unlike most previous studies, our study makes use of a turbulent lean-premixed flame in each combustor, bringing the system configuration closer to that of practical gas turbines. Using stationary and transient measurements, we examine the effect of the cross-talk diameter and length so as to gain insight into the effect of dissipative and time-delayed coupling. We find that strengthening the dissipative coupling promotes mutual synchronization, but that weakening the dissipative coupling leads to weakly coupled or desynchronized oscillations. On operating the two combustors at different conditions, we find a significant reduction in their overall oscillation amplitude for some coupling conditions. On varying the combustor length and examining the transient response, we find elaborate changes in the pressure-heat-release-rate coupling, spontaneous mode transitions between coupled thermoacoustic modes, and the emergence of a rhomboid structure in the phase plane owing to the coexistence of in-phase and out-of-phase synchronization. In the combustion community, these two types of synchronization are known to be associated with push-push modes and push-pull modes. These findings offer new insight into the mutual synchronization of low-frequency, self-excited thermoacoustic oscillations in can-annular gas turbines, paving the way for the development of improved control strategies.

Secure communications via complex phase synchronization of pair complex chaotic structures with a similar structure of linear terms with modifying in nonlinear terms

In this paper, we discuss the idea of complex phase synchronization in complex nonlinear structures with chaotic conduct. The CPHS combines two types of common synchronizations, which are phase synchronization and anti phase synchronization. A general scheme has been proposed to study the CPHS. Through this scheme, complex control functions are assigned to obtain effective CPHS. For example, we study the CPHS in regards pair chaotic complex Lü structures including incompletely evolving for nonlinear terms. Numerical figures are drawn to prove our plan’s validity. The consequences of the CPHS are exploited in secure communications. The error function resulting from the definition of the CPHS was used as a key to retrieve the encrypted message.

Robust modified function projective lag synchronization between two nonlinear complex networks with different-dimensional nodes and disturbances

This paper is concerned with a theoretical investigation on the robust modified function projective lag synchronization (MFPLS) between two complex networks with nonlinear couplings, different-dimensional nodes, parameter disturbances and external disturbances. Some novel robust hybrid controllers are designed to address such synchronization problems for networks with and without disturbances, in which adaptive updated laws of disturbances are adopted to attenuate the disturbances occurred in networks. By utilizing Lyapunov functional method, synchronization criteria are derived by strict theoretical proof. Compared with existing jobs, the proposed model and synchronization type are more general. Two examples are presented to verify our results.

In-Phase and Anti-Phase Synchronization in a Laser Frequency Comb.

Coupled clocks are a classic example of a synchronization system leading to periodic collective oscillations. Already in 1665, Christiaan Huygens described this phenomenon as a kind of "sympathy" among oscillators. In this work, we describe the formation of two types of laser frequency combs as a system of oscillators coupled through the beating of the lasing modes. We experimentally show two completely different types of synchronization in a quantum dot laser-in-phase and splay-phase states. Both states can be generated in the same device, just by varying the damping losses of the system. This modifies the coupling among the oscillators. The temporal laser output is characterized using both linear and quadratic autocorrelation techniques. Our results show that both pulses and frequency-modulated states can be generated on demand within the same device. These findings allow us to connect laser frequency combs produced by amplitude-modulated and frequency-modulated lasers and link these to pattern formation in coupled systems such as Josephson-junction arrays.

Function Projective Synchronization of Complex Networks With Distributed Delays via Hybrid Feedback Control

Due to its applications, some types of synchronization of complex networks have been intensively investigated. In particular, as a more general type of synchronization, function projective synchronization (FPS) has been investigated for complex networks with time delay or with time-varying delay. In this paper, we investigate FPS of complex networks with distributed delays. It is proven that, FPS of such networks can be realized via hybrid feedback control. Finally, two numerical examples are provided to illustrate the effectiveness of the proposed method.

Microfluidic compartmentalization of diffusively coupled oscillators in multisomes induces a novel synchronization scenario.

Stable cell-like multisomes encapsulating the chemical oscillator Belousov-Zhabotinsky were engineered and organized in a linear network of diffusively-coupled chemical oscillators by using microfluidics. The multi-compartmentalization and the spatial configuration resulted in a new global synchronization scenario. After an initial induction interval, all the oscillators started to pulsate in phase with a halved period with respect to the natural one.

A classification of two-tier distribution systems based on mobile depots

Urban freight transport is an important enabling factor for economic growth and social activities in cities but despite its benefits, it also generates important negative externalities including traffic congestion, pollution, noise and overall less safety. Moreover, increased limitations on urban freight transport, including access constraints, limited kerbside and private parking spaces for loading/unloading, and the often prohibitive costs of installing logistics infrastructures in city centres, have further constrained urban freight transport. To address these issues, several city logistics solutions have been proposed, such as two-tier distribution systems and distribution systems based on mobile depots.In this paper, we focus on two-tier urban freight distribution systems based on mobile depots, where little or no physical infrastructure is considered and where storage is not permitted at transfer locations. In these types of systems, coordination and synchronisation between vehicles are essential, and the main objective is to have vehicles at the transfer locations in a need-to-be basis as a way of minimising the negative externalities.We review and analyse 13 cases found in the scientific literature, trial reports and online resources, and propose a classification of these systems based on the level of mobility and accessibility of transportation modes operating at the first-tier. Furthermore, we characterise the main components and operational features of the different systems, including the existence of multi-trips, the types of transport modes used at both tiers, transported loads and the organisation of the transfer sites (satellites). This work aims to contribute for a clearer characterisation of two-tier urban distribution systems based on mobile depots, to later support the development of the most adequate mathematical models and solution methods to be applied to each variant of this type of systems.

Chaos synchronization of fractional–order discrete–time systems with different dimensions using two scaling matrices

Abstract In this paper, we study the synchronization of fractional–order discrete–time chaotic systems by means of two scaling matrices Θ and Φ. The considered synchronization scheme can be tailored to encompass several types of classical synchronization types. We proposed two nonlinear control strategies for the Θ–Φ synchronization of an m–dimensional drive system and an n–dimensional response system, whereby the synchronization dimension d = m and d = n, respectively. Numerical examples are presented to test the findings of the study.