Application Of Synchronization Research Articles

Dynamic analysis based on a memristive hyperchaotic system with stable unfixed point and its synchronization application

A novel two-memristor hyperchaotic system is obtained by introducing a cubic magnetic-controlled memristor and a hyperbolic sine function memristor. The dynamics of the new system are analyzed by various techniques such as Lyapunov exponents, complexity, 0–1 test, bifurcation diagram and phase diagram. The results demonstrate that the new system exhibits complex dynamic behaviors, including transient chaos, transient transition, intermittent chaos, and offset-boosting. Notably, a rare phenomenon with stable unfixed point has been discovered in this newly proposed system. The largest Lyapunov exponent of the stable unfixed point fluctuates around 0 and remains predominantly less than or equal to 0. Despite this, the new system still partially exhibits chaotic characteristics, indicating that the stable unfixed point can be regarded as a local chaotic attractor. Furthermore, there are four types of coexisting attractors with period-period, chaos-chaos, chaos-stable unfixed point and stable unfixed point-stable unfixed point in the new system. The circuit design is implemented to validate the accuracy of the memristive chaotic system, and the consistency between numerical calculations and simulation results is confirmed. Finally, the coupling synchronization and tracking synchronization methods are designed, which hold practical applications in the field of secure communication, control systems and signal processing.

Advanced medical image encryption techniques using the fractional-order Halvorsen circulant systems: dynamics, control, synchronization and security applications

In this paper, we describe the Halvorsen circulant system (HCS) with a fractional-order Caputo derivative and its qualitative properties. The numerical solution of the fractional order Halvorsen circulant system (FO-HCS) is proposed based on the Adomian decomposition method (ADM). The ADM method is used to solve fractional-order systems. Then, dynamics is analyzed using different methods including Lyapunov exponents, bifurcation diagrams, complexity, and phase diagrams. This paper also investigates the stabilization and synchronization of identical FO-HCS, and stability theory proves adaptive feedback control and synchronization. In addition, using the fractional-order system’s remarkable properties to develop the image encryption technique using the extended fractional sequences. The proposed method uses a keystream generator for high security based on the enhanced fractional Halvorsen circulant chaotic behavior. The simulation results confirm that it can resist various attacks, including statistical analysis, differential attacks, brute-force attacks, known plaintext attacks, and chosen plaintext attacks, with high security, and low computational complexity. Finally, the results of the simulation and its performance prove that it's effective and secure in image data.

Finite-Time pth Moment Asymptotically Bounded for Stochastic Nonlinear Systems and Its Application in Neural Networks Synchronization

Finite-Time <i>p</i>th Moment Asymptotically Bounded for Stochastic Nonlinear Systems and Its Application in Neural Networks Synchronization

Dairy village: the role of veterinary services in unlocking dairy industry potential through assisted reproductive technologies

The “Dairy Village” concept was designed to overcome the constraints of estrus synchronization and AI particularly associated with eletion of the breeding animals and subsequent management of estrous cows in Ethiopia. All necessary inputs, including sexed semen, were acquired before the fieldwork. The knowledge and skill gaps were identified and addressed with the active involvement of veterinarians and AI technicians who underwent specialized training to ensure proper physical and gynecological examinations during the selection of cows and heifers. Accordingly, a refresher training was delivered on topics of reproductive anatomy and physiology, assessment of ovarian status, semen handling, and insemination at the optimal time to establish pregnancy. Besides, awareness creation seminars were held every year on topics of benefits of reproductive technologies and management of breeding cows to 99 smallholder dairy farmers. Only 578 cows/heifers were found fit for breeding out of the 1262 cows/heifers that were brought for evaluation; including 81 animals that spontaneously showed estrus. A total of 497 cows/heifers were synchronized using a single IM injection of Lutalyse. Animals responding to the treatment (404 cow/heifers) and those spontaneously in estrus (81cows/ heifers) were inseminated using sex- sorted HF semen 18-24hrs into the standing estrus. Pregnancy rate was 80% (388/485) and 287 calves were born (96% female). Results of this project indicate that rigorous gynecological examination during the selection of cows prior to estrus synchronization and judicious application of hormonal treatments can yield improve the success of ES/AI projects under field conditions. Furthermore, the dairy village approach to enhanced milk production through efficient use of sex-sorted semen has generated replacement heifers from superior breed that will substantially improve the livelihoods of village farmers.

MEMS Huygens Clock Based on Synchronized Micromechanical Resonators

With the continuous miniaturization of electronic devices, microelectromechanical system (MEMS) oscillators that can be combined with integrated circuits have attracted increasing attention. This study reports a MEMS Huygens clock based on the synchronization principle, comprising two synchronized MEMS oscillators and a frequency compensation system. The MEMS Huygens clock improved short-time stability, improving the Allan deviation by a factor of 3.73 from 19.3 ppb to 5.17 ppb at 1 s. A frequency compensation system based on the MEMS oscillator’s temperature-frequency characteristics was developed to compensate for the frequency shift of the MEMS Huygens clock by controlling the resonator current. This effectively improved the long-term stability of the oscillator, with the Allan deviation improving by 1.6343 × 105 times to 30.9 ppt at 6000 s. The power consumption for compensating both oscillators simultaneously is only 2.85 mW∙°C−1. Our comprehensive solution scheme provides a novel and precise engineering solution for achieving high-precision MEMS oscillators and extends synchronization applications in MEMS.

Adaptive Strategies and its Application in the Mittag-Leffler Synchronization of Delayed Fractional-Order Complex-Valued Reaction-Diffusion Neural Networks

Adaptive Strategies and its Application in the Mittag-Leffler Synchronization of Delayed Fractional-Order Complex-Valued Reaction-Diffusion Neural Networks

Resilient Consensus via Weight Learning and Its Application in Fault-Tolerant Clock Synchronization

This paper addresses the distributed consensus problem in the presence of faulty nodes. A novel weight learning algorithm is introduced such that neither the network connectivity nor a sequence of history records is required to achieve resilient consensus. The critical idea is to dynamically update the interaction weights among neighbors learnt from their credibility measurement. Basically, we define a reward function that is inversely proportional to the state difference to its neighbor, and then adjust the credibility based on the reward derived at the present step and the previous credibility. In such a way, the interaction weights are updated at every step, which integrates the historic information and degrades the influences from faulty nodes. Four classes of faulty nodes are considered, and both fixed and stochastic topologies are involved in this paper. Furthermore, we apply this novel approach in clock synchronization problem. By updating the logical clock skew and offset via the corresponding weight learning algorithms, respectively, the logical clock synchronization is eventually achieved regardless of faulty nodes. Simulations are provided to illustrate the effectiveness of the strategy.

N-dimensional polynomial hyperchaotic systems with synchronization application

n-dimensional polynomial hyperchaotic systems with synchronization application

A new three-dimensional conservative system with non - Hamiltonian energy and its synchronization application

In this paper, a three-dimensional conservative system is proposed. By analyzing the Hamiltonian energy, it is concluded that it is a non-Hamiltonian conservative system. By changing the values of the parameters b, c, the system presents different attractors. Then, by studying the multiple attractors coexisting of the system under different initial values, it can be found that the system has rich coexistence phenomena by changing the parameters. There are various types of coexistence of systems with chaos and chaos coexistence, periods and periods coexistence and chaos and periods coexistence. In addition, the offset-boosting under parameter control is studied by phase diagram. By studying the complexity of the system at two different initial values, the more complex initial value is chosen as the initial state when the system is synchronized. The analog simulation circuit is implemented using Multisim, the actual digital circuit is implemented with field programmable gate array (FPGA). The Matlab phase diagram, the numerical simulation results and the simulated circuit all agree well, proving the feasibility of the new system. Finally, the system is applied to backstepping synchronization, which lays a foundation for the realization of engineering application.

Saturated delayed impulsive effects for fractional order nonlinear system with piecewise Caputo derivative and its application

Fractional order nonlinear systems with saturated delayed impulses and short-term memory is investigated in this paper. Models in this paper are described by piecewise Caputo derivative. First, sufficient conditions for local exponential stability are derived based on the fractional order Lyapunov function method and saturated control theory. Then, the optimization model to estimate the domain of attraction is built, which is constrained by some LMIs. Third, the application of synchronization for fractional order complex dynamical networks via distributed saturated delayed impulsive control is studied. Finally, two numerical examples are given to illustrate the effectiveness of the theoretical results.

Synchronization process expediting in nonlinear oscillators via reconfiguration of the potential well pattern

The synchronization phenomenon has garnered significant attention and extensive study due to its frequency locking effect, finding applications in diverse fields such as communication networks, neuroscience, and multi-robot systems. Fast frequency locking is crucial for synchronization applications, but there have been few investigations on it so far. In this study, we observed that when a nonlinear micro-oscillator synchronizes with a harmonic perturbation, the frequency and phase of the oscillator do not monotonically approach the locking state. Instead, they experience a period of frequency and phase fluctuations that can be divided into two stages: the slipping stage and the oscillation stage. The first slipping stage is affected by the frequency detuning between the perturbation force and oscillator, while the second oscillation stage time is determined by the configuration of the potential well. This configuration can be reconfigured by adjusting the nonlinearity terms of the micro system through phase delay, feedback strength, or perturbation strength. By reconfiguring the potential well pattern, we achieved a fivefold suppression of the synchronization process.

Robust consensus of multi‐agent systems with multiplicative uncertainties and its application in time synchronization

AbstractThis article first studies the robust consensus problem of discrete‐time single‐integrator multi‐agent systems (MASs) with multiplicative uncertainties in switching networks. Under the assumption that the uncertainty is polynomially decaying, we prove that the consensus of the MAS can be achieved by adopting the decaying gain protocol if the switching network is uniformly strongly connected (USC). The convergence rate is quantified in terms of the decay rate of uncertainties. Then, we use the consensus conclusion studying the convergence analysis problem of a typical time synchronization algorithm (the LSTS algorithm proposed in Tian [IEEE Trans Automat Contr. 2017;62(10):5445–5450]) in wireless sensor networks. We prove that the LSTS algorithm can still achieve the bounded time synchronization even if the switching network is USC, a more general topology condition compared with existing convergence results in Tian (IEEE Trans Automat Contr. 2017;62(10):5445–5450). Simulation results are given to verify the correctness of both the consensus conclusion for MASs and convergence conclusion for LSTS algorithm.

On the network of three fractional-order two-stage colpitts oscillators with different time delays: synchronization time and application in cryptography.

On the network of three fractional-order two-stage colpitts oscillators with different time delays: synchronization time and application in cryptography.

Even and odd Laguerre-Gaussian chaoticons in nematic liquid crystal

This paper investigated the propagations of odd and even Laguerre-Gaussian beams in nematic liquid crystal, and found that only the (0, 0) mode of Laguerre-Gaussian beams can form a soliton. As for the other modes of Laguerre-Gaussian beams, many of them will evolve into unbounded states with scattered remnants of energy, while some high order modes can form chaoticons, of which intensity are localized well with little scattering, and propagate over long distance. Additionally, unlike solitons, chaoticons are not sensitive to the power. Even if the incident power deviates from the critical power, some beams can still form chaoticons within a certain deviation range. These results may provide new ways to control the propagation of unstable beams. The evolution and formation of chaoticons have great value to the applications of chaotic synchronization and chaotic secure communication.

Optimum Setting Algorithm Based PI Controller Tuning for SRF-PLL Used Grid Synchronization System

Synchronous reference frame-phase lock loop (SRF-PLL) is most widely used for grid synchronization applications. PLL structure typically consists of a phase detector (PD), loop filter (LF) and voltage control oscillator (VCO). Design and tuning of proportional-integral (PI) controller based LF is a changeling task under distorted grid voltage conditions. Conventional tuning methods such as symmetrical optimum (SO) and Ziegler-Nichols techniques are used to tune the PI controller, resulting in increased phase margin (PM) of the system. However, high bandwidth develops harmonics in the extracted signals under non-ideal grid conditions and affects the stability. In this research article, a new optimum setting algorithm is proposed to tune the PI controller and effective synchronization is achieved. The plant is reduced as a first-order plus dead time delay (FOPDT) model and critical gain; critical frequency of the open loop system transfer function is used to model the LF of the SRF PLL system. The controller parameters are derived such that minimization of time-weighted integral performance criteria is achieved and phase angle, frequency of the grid voltage is accurately extracted. The performance of the proposed optimum setting algorithm for the SRF-PLL grid synchronization technique is discussed in detail and simulation results are presented.

Advanced Synchronous Control of Dual Parallel Motion Systems

Dual parallel motion systems are mechanisms that drive load jointly by dual parallel motion axes. For these special mechanisms, diminishing desynchronization between parallel axes is essential to harness the potential performance of the whole system. However, a wide variety of synchronization applications tend to have great differences in control objectives and mechanical structures, which makes it laborious and time-consuming to design customized control schemes. Meanwhile, existing generalized synchronous control schemes are simply based on state compensation, which finitely offset mechanical coupling effect and limit the synchronization performance. To overcome these drawbacks, a generalized model of dual parallel motion systems is presented in this article, which can categorize the synchronous control objective into one uniform expression. By applying motion decoupling strategy to the generalized model, an advanced composite synchronous control scheme is proposed, which provides a generalized synchronization solution with comprehensively considering the motion coupling effect. Finally, simulation and experimental results on a dual-driven gantry platform verify that the proposed control scheme can significantly improve the synchronization performance.

Novel Zero Circular Convolution Sequences for Detection and Channel Estimations

Multiuser communication systems or multiple access scheme systems favor sequences possessing the ideal periodic cross-correlation function (PCCF) property. In comparison, channel estimation, equalization, and synchronization applications favor sequences possessing the ideal periodic auto-correlation function (PACF) property. However, there is no set of sequences possessing both the ideal PCCF and PACF properties simultaneously, where auto-correlation and cross-correlation balance each other. In this work, sequences possessing the ideal PACF property are used as the base sequences. Then, a modulation technique is applied upon these base sequences to construct a set of zero circular convolution (ZCC) sequences within which an arbitrary pair of two sequences possesses the ideal PCCF property. Compared with least squares (LS) and minimum mean squared error (MMSE) algorithm, the simulation results show that the channel estimation performance of ZCC is better than MMSE and LS algorithms, and the computational complexity of the algorithm is the same as LS algorithm, but far lower than MMSE algorithm. This is the first study on ZCC sequences reported in the literature, in which their fundamental theorems, properties, construction, and applications are investigated. The advantage of possessing the desired PACF and the ideal PCCF properties allows the ZCC sequences to be used in a broader range of applications than other sets of sequences.

A Recent Survey on Control for Synchronization and Passivity of Complex Networks

Over the past few years, dynamical behaviors of complex networks (CNs) and complex networks with multi-weights (CNMWs) have attracted considerable attention on account of their successfully applying in many distinct fields. This paper attempts to introduce some recent progress in the dynamical behaviors (including synchronization and passivity) for CNs and CNMWs under various control approaches. Firstly, we focus on synchronization, passivity, and their extensions for CNs and CNMWs. Secondly, some control methods, such as adaptive control, pinning control, and impulsive control, used in CNs and CNMWs are also discussed, where some of the existing results along these topics are presented in a tutorial-like fashion. Thirdly, we introduce several applications of synchronization in CNs and CNMWs, especially complex human networks and urban public traffic networks. These existing results are summarized and some interesting future investigations are also highlighted in end.

PSXII-4 Estrus Synchronization and Artificial Insemination in Korean Black Goats Using Frozen-Thawed Semen

Abstract Korean black goat (Capra hircus coreanae) populations are dwindling and facing genetic erosion due to artificial insemination. Here, we introduced an estrus synchronization method for Korean black goats to enable crossbreeding with non-native breeds on small farms and investigated the application of estrus synchronization and artificial insemination in Korean black goats. Semen was obtained using electro-ejaculation and preserved using a conventional and simple freezing method. Pre- and post-freezing semen was analyzed using computer-assisted sperm analysis, as per the Food Standards Agency 2011 guidelines. The percentage of motile sperm in the electro-ejaculated samples declined significantly after freezing and thawing. However, this did not influence the artificial insemination results. In addition, the incubation period was positively correlated with sperm motility decline in the frozen-thawed sperm samples. Blood progesterone (P4) and estrogen (E2) concentrations were also analyzed to determine the optimal artificial insemination time in estrus-synchronized Korean black goats. The blood samples were collected from a jugular vein at approximately 0900 daily for 5 days. Subsequently, the serum was obtained using centrifugation and stored at -70°C until analysis. Although the P4 and E2 concentrations were generally unaffected by the estrous synchronization method, the controlled internal drug release + prostaglandin F2α + pregnant mare serum gonadotropin method yielded a 42.9% parturition rate after artificial insemination. In the present study, an offspring from an estrus-synchronized Korean black goat was successfully produced by artificial insemination using frozen-thawed semen. The successful cryopreservation of semen for artificial insemination was substantiated with sperm motility and pregnancy rates. In the future, additional studies of estrus synchronization for the artificial insemination of Korean black goats are needed. Our results are expected to significantly contribute to the Korean black goat breeding industry.

On the satellite clock datum stability of RT-PPP product and its application in one-way timing and time synchronization

On the satellite clock datum stability of RT-PPP product and its application in one-way timing and time synchronization