|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | A perturbation-incremental scheme for studying Hopf bifurcation in delayed differential systems显示文摘A new method, called perturbation-incremental scheme (PIS), is presented to investigate the periodic solution derived from Hopf bifurcation due to time delay in a system of first-order delayed differential equations. The method is summarized as three steps, namely linear analysis at critical value, perturba- tion and increment for continuation. The PIS can bypass and avoid the tedious calculation of the center manifold reduction (CMR) and normal form. Meanwhile, the PIS not only inherits the advantages of the method of multiple scales (MMS) but also overcomes the disadvantages of the incremental harmonic balance (IHB) method. Three delayed systems are used as illustrative examples to demonstrate the validity of the present method. The periodic solution derived from the delay-induced Hopf bifurcation is obtained in a closed form by the PIS procedure. The validity of the results is shown by their consis- tency with the numerical simulation. Furthermore, an approximate solution can be calculated in any required accuracy. | CHUNG Kwok Wai | 2009 | Science China(Technological Sciences)2009，52，3： | 15 |
| 2 | Synchronization and wave propagation in neuronal network under field coupling显示文摘Electric and chemical synapse play important role in connecting neurons and thus signal propagation can be realized between neurons. External electric stimulus can change the excitability of neuron and then the electrical activities can be modulated completely. Continuous fluctuation of ion concentration in cell can induce complex time-varying electromagnetic field during the exchange of charged ions across the membrane of neuron. Polarization and magnetization in the media(and neuron), which exposed to electromagnetic radiation, can modulate the dynamical response and mode transition in electrical activities of neurons. In this paper, magnetic flux is used to describe the effect of electromagnetic field, and the three-variable HindmarshRose neuron model is updated to propose a four-variable neuron model that the effect of electromagnetic induction and radiation can be explained. Based on the physical law of electromagnetic induction, exchange of charged ions and flow of ion currents will change the distribution of electromagnetic filed in cell, and each neuron will be exposed to the superimposed field triggered by other neurons. Therefore, signal exchange could occur even synapse coupling between neurons is removed in the case of field coupling. A chain network is proposed to investigate the signal exchange between neurons under field coupling when synapse coupling is not available. It is found that field coupling between neurons can change the collective behaviors in electrical activities. A statistical factor of synchronization and spatial patterns are calculated, these results confirmed that field coupling is effective for signal communication between neurons. In the end, open problems are suggested for readers' extensive guidance in this field. | LV Mi MA Jun YAO YuanGen ALZAHRANI Faris | 2019 | Science China(Technological Sciences)2019，62，3： | 12 |
| 3 | Secure Impulsive Synchronization in Lipschitz-Type Multi-Agent Systems Subject to Deception Attacks显示文摘Cyber attacks pose severe threats on synchronization of multi-agent systems.Deception attack,as a typical type of cyber attack,can bypass the surveillance of the attack detection mechanism silently,resulting in a heavy loss.Therefore,the problem of mean-square bounded synchronization in multi-agent systems subject to deception attacks is investigated in this paper.The control signals can be replaced with false data from controllerto-actuator channels or the controller.The success of the attack is measured through a stochastic variable.A distributed impulsive controller using a pinning strategy is redesigned,which ensures that mean-square bounded synchronization is achieved in the presence of deception attacks.Some sufficient conditions are derived,in which upper bounds of the synchronization error are given.Finally,two numerical simulations with symmetric and asymmetric network topologies are given to illustrate the theoretical results. | Wangli He Zekun Mo Qing-Long Han Feng Qian | 2020 | IEEE/CAA Journal of Automatica Sinica2020，7，5： | 10 |
| 4 | Spatial sampling of terahertz fields with sub-wavelength accuracy via probe-beam encoding显示文摘Recently,computational sampling methods have been implemented to spatially characterize terahertz(THz)fields.Previous methods usually rely on either specialized THz devices such as THz spatial light modulators or complicated systems requiring assistance from photon-excited free carriers with high-speed synchronization among multiple optical beams.Here,by spatially encoding an 800-nm near-infrared(NIR)probe beam through the use of an optical SLM,we demonstrate a simple sampling approach that can probe THz fields with a single-pixel camera.This design does not require any dedicated THz devices,semiconductors or nanofilms to modulate THz fields.Using computational algorithms,we successfully measure 128×128 field distributions with a 62-μm transverse spatial resolution,which is 15 times smaller than the central wavelength of the THz signal(940μm).Benefitting from the noninvasive nature of THz radiation and sub-wavelength resolution of our system,this simple approach can be used in applications such as biomedical sensing,inspection of flaws in industrial products,and so on. | Jiapeng Zhao Yiwen E Kaia Williams Xi-Cheng Zhang Robert W.Boyd | 2019 | Light(Science & Applications)2019，8，1： | 10 |
| 5 | 端信息跳变中的分布式时间戳同步技术(英文)显示文摘End hopping is an active and effective technology for defending against adversaries in the network warfare.Synchronization is a key technology of end hopping.However,the common synchronization methods are insufficient for end hopping.Based on timestamp synchronization,this paper proposes a novel method of Distributed Timestamp Synchronization(DTS)to improve the capacity of synchronization.DTS uses a list of timestamp servers which are located all over the Internet to synchronize timestamp,and a list of clock offsets to adjust the synchronized timestamp.DTS can overcome the main deficiencies(request overwhelming and boundary failure)of timestamp synchronization.Experiments show that DTS is a feasible synchronization technology for end hopping. | 林楷 贾春福 翁臣 | 2011 | China Communications2011，8，4： | 9 |
| 6 | Theory for Constructing Generalized Synchronization and Applications显示文摘The approaches for constructing directionally coupled generalized synchronization (GS) systems are presented, which are available for the driving system and the respond system that are in GS via a given diffeomorphism transformation. Examples are proposed for illustrating the methods. | Xiaodan Zhang, Lequan Min (Applied Science School, University of Science and Technology Beijing, Beijing 100083, China) | 2000 | International Journal of Minerals,Metallurgy and Materials2000，14，3： | 9 |
| 7 | Time synchronization and carrier frequency control of CAPS navigation signals generated on the ground显示文摘The Chinese Area Positioning System (CAPS) works without atomic clocks on the satellite, and the CAPS navigation signals transmitted on the ground may achieve the same effect as that with high-performance atomic clocks on the satellite. The primary means of achieving that effect is through the time synchronization and carrier frequency control of the CAPS navigation signals generated on the ground. In this paper the synchronization requirements of different time signals are analyzed by the formation of navigation signals, and the theories and methods of the time synchronization of the CAPS navigation signals generated on the ground are also introduced. According to the conditions of the high-precision satellite velocitymeasurement signal source, the carrier frequency and its chains of the navigation signals are constructed. CAPS velocity measurement is realized by the expected deviation of real time control to the carrier frequency, and the precision degree of this method is also analyzed. The experimental results show that the time synchronization precision of CAPS generating signals is about 0.3 ns and the precision of the velocity measurement signal source is about 4 cm/s. This proves that the theories and methods of the generating time synchronization and carrier frequency control are workable. | WU HaiTao BIAN YuJing LU XiaoChun LI XiaoHui WANG DanNi | 2009 | Science China(Physics,Mechanics & Astronomy)2009，52，3： | 8 |
| 8 | On PID control for synchronization of complex dynamical network with delayed nodes显示文摘Over the past two decades, synchronization, as an interesting collective behavior of complex dynamical networks, has been attracting much attention. To reveal and analyze the inherent mechanism of synchronization in complex dynamical networks with time delays in nodes, this paper attempts to use PD and PI control protocols to achieve synchronization. Based on a classical network model, we investigate the PD and PI control for synchronization of complex dynamical networks with delayed nodes and obtain some sufficient conditions. By using Lyapunov functions and appropriate state transformations, we prove that global synchronization can be achieved via the above control protocols. Finally, some simulation examples are illustrated to validate the effectiveness of the proposed theoretical results. | GU HaiBo Lv JinHu LIN ZongLi | 2019 | Science China(Technological Sciences)2019，62，8： | 7 |
| 9 | 0.75 Gbit/s high-speed classical key distribution with mode-shift keying chaos synchronization of Fabry–Perot lasers显示文摘High-speed physical key distribution is diligently pursued for secure communication.In this paper,we propose and experimentally demonstrate a scheme of high-speed key distribution using mode-shift keying chaos synchronization between two multi-longitudinal-mode Fabry–Perot lasers commonly driven by a super-luminescent diode.Legitimate users dynamically select one of the longitudinal modes according to private control codes to achieve mode-shift keying chaos synchronization.The two remote chaotic light waveforms are quantized to generate two raw random bit streams,and then those bits corresponding to chaos synchronization are sifted as shared keys by comparing the control codes.In this method,the transition time,i.e.,the chaos synchronization recovery time is determined by the rising time of the control codes rather than the laser transition response time,so the key distribution rate is improved greatly.Our experiment achieved a 0.75-Gbit/s key distribution rate with a bit error rate of 3.8×10^(−3)over 160-km fiber transmission with dispersion compensation.The entropy rate of the laser chaos is evaluated as 16 Gbit/s,which determines the ultimate final key rate together with the key generation ratio.It is therefore believed that the method pays a way for Gbit/s physical key distribution. | Hua Gao Anbang Wang Longsheng Wang Zhiwei Jia Yuanyuan Guo Zhensen Gao Lianshan Yan Yuwen Qin Yuncai Wang | 2021 | Light(Science & Applications)2021，10，9： | 7 |
| 10 | Robustness and breakup of the spiral wave in a two-dimensional lattice network of neurons显示文摘The robustness and breakup of spiral wave in a two-dimensional lattice networks of neurons are investigated. The effect of small- world type connection is often simplified with local regular connection and the long-range connection with certain probability. The network effect on the development of spiral wave can be better described by local regular connection and changeable long-range connection probability than fixed long-range connection probability because the long-range probability could be changeable in realistic biological system. The effect from the changeable probability for long-range connection is simplified by multiplicative noise. At first, a stable rotating spiral wave is developed by using appropriate initial values, parameters and no-flux boundary conditions, and then the effect of networks is investigated. Extensive numerical studies show that spiral wave keeps its alive and robust when the intensity of multiplicative noise is below a certain threshold, otherwise, the breakup of spiral wave occurs. A statistical factor of synchronization in two-dimensional array is defined to study the phase transition of spiral wave by checking the membrane potentials of all neurons corresponding to the critical parameters(the intensity of noise or forcing current)in the curve for factor of synchronization. The Hindmarsh-Rose model is investigated, the Hodgkin-Huxley neuron model in the presence of the channel noise is also studied to check the model independence of our conclusions. And it is found that breakup of spiral wave is easier to be induced by the multiplicative noise in presence of channel noise. | MA Jun 1,2, TANG Jun 2 , ZHANG AiHua 3 & JIA Ya 2 1 Department of Physics, Lanzhou University of Technology, Lanzhou 730050, China 2 Department of Physics, Central China Normal University, Wuhan 430079, China 3 College of Electrical and Information Engineering, Lanzhou University of Technology, Lanzhou 730050, China | 2010 | Science China(Physics,Mechanics & Astronomy)2010，53，4： | 6 |
| 11 | Phase coupling synchronization of FHN neurons connected by a Josephson junction显示文摘Avariety of nonlinear circuits can be tamed to reproduce the main dynamical properties in neural activities for biological neurons while designing reliable artificial synapses for connecting these neural circuits becomes a challenge.In this paper,a Josephson junction is used to build coupling channel for connecting two FitzHugh-Nagumo neural circuits driven by periodical voltage source.The hybrid synapse is designed by using a linear resistor paralleled with a Josephson junction,which can estimate the effect of external magnetic field by generating additive phase error between the junction.Indeed,it activates nonlinear coupling due to phase diversity in the Josephson junction.The coupled circuits are estimated in dimensionless dynamical systems by applying scale transformation on the variables and parameters in neural circuits.In fact,the intrinsic parameters of coupling channel are adjusted to detect the occurrence of synchronization.Bifurcation analysis is calculated to predict and confirm the occurrence of synchronization between two neural circuits.It is found that synchronization can be stabilized between two FHN neural circuits by selecting appropriate values for parameters in the Josephson junction involved in the coupling channel.It gives useful guidance for implementing artificial synapse for signal processing in neural circuits. | ZHANG Yin WANG ChunNi TANG Jun MA Jun REN GuoDong | 2020 | Science China(Technological Sciences)2020，63，11： | 6 |
| 12 | Parameter identification and synchronization of spatiotemporal chaos in an uncertain Gray-Scott system显示文摘The zero-asymptotic property of sliding variables in discrete systems is extended to a continuous one and applied to partial differential equations which describe spatiotemporal chaos. A method of chaos synchronization and parameter identifi-cation is proposed. The synchronization controllers and the parameter recognizers are designed. The uncertain Gray-Scott system is taken as an example to verify the effectiveness of the method. Simulation results show that the identification vari-ables in the parameter recognizers may take the place of the unknown parameters in both target and response systems. Global synchronization of the two spatio-temporal chaotic systems with uncertain parameters may be realized quickly after controllers are added. | LüLing LI Yi GUO ZhiAn | 2008 | Science China(Physics,Mechanics & Astronomy)2008，51，11： | 5 |
| 13 | Altered Local Field Potential Relationship Between the Parafascicular Thalamic Nucleus and Dorsal Striatum in Hemiparkinsonian Rats显示文摘The thalamostriatal pathway is implicated in Parkinson's disease(PD); however, PD-related changes in the relationship between oscillatory activity in the centromedian-parafascicular complex(CM/Pf, or the Pf in rodents) and the dorsal striatum(DS) remain unclear.Therefore, we simultaneously recorded local field potentials(LFPs) in both the Pf and DS of hemiparkinsonian and control rats during epochs of rest or treadmill walking. The dopamine-lesioned rats showed increased LFP power in the beta band(12 Hz–35 Hz) in the Pf and DS during both epochs, but decreased LFP power in the delta(0.5 Hz–3 Hz) band in the Pf during rest epochs and in the DS during both epochs, compared to control rats. In addition,exaggerated low gamma(35 Hz–70 Hz) oscillations after dopamine loss were restricted to the Pf regardless of the behavioral state. Furthermore, enhanced synchronization of LFP oscillations was found between the Pf and DS after the dopamine lesion. Significant increases occurred in the mean coherence in both theta(3 Hz–7 Hz) and beta bands,and a significant increase was also noted in the phase coherence in the beta band between the Pf and DS during rest epochs. During the treadmill walking epochs, significant increases were found in both the alpha(7 Hz–12 Hz)and beta bands for two coherence measures. Collectively,dramatic changes in the relative LFP power and coherence in the thalamostriatal pathway may underlie the dysfunction of the basal ganglia-thalamocortical network circuits in PD, contributing to some of the motor and non-motor symptoms of the disease. | Haiyan Zhang Jing Yang Xuenan Wang Xiaomeng Yao Hongyu Han Yunfeng Gao Hongli Chang Tianyu Xiang Shuang Sun Yanan Wang Xiusong Wang Min Wang | 2019 | Neuroscience Bulletin2019，35，2： | 5 |
| 14 | Decentralized attitude synchronization tracking control for multiple spacecraft under directed communication topology显示文摘This paper studies the attitude synchronization tracking control of spacecraft formation flying with a directed communication topology and presents three different controllers. By introducing a novel error variable associated with rotation matrix, a decentralized attitude synchronization controller, which could obtain almost global asymptotical stability of the closed-loop system, is developed. Then, considering model uncertainties and unknown external disturbances, we propose a robust adaptive attitude synchronization controller by designing adaptive laws to estimate the unknown parameters. After that, the third controller is proposed by extending this method to the case of time-varying communication delays via Lyapunov–Krasovskii analysis. The distinctive feature of this work is to address attitude coordinated control with model uncertainties, unknown disturbances and time-varying delays in a decentralized framework, with a strongly connected directed information flow. It is shown that tracking and synchronization of an arbitrary desired attitude can be achieved when the stability condition is satisfied. Simulation results are provided to demonstrate the effectiveness of the proposed control schemes. | Zheng Zhong Xu Ying Zhang Lisong Song Shenmin | 2016 | Chinese Journal of Aeronautics2016，29，4： | 5 |
| 15 | A threshold effect of coupling delays on intra-layer synchronization in duplex networks显示文摘This paper investigates the impact of inter-layer coupling functions and intra-layer coupling delays on intra-layer synchronization regions and sychronizability. It is found that the inter-layer coupling functions have great influence on intra-layer synchronization regions, as well as on the intra-layer synchronizability. In particular, there exists an inter-layer coupling function such that the inter-layer coupling strength neither improves nor weakens the intra-layer synchronizability. Furthermore, no matter which one of three inter-layer coupling functions is chosen, a small intra-layer delay always keeps the intra-layer synchronized regions almost unchanged, implying that the small delay neither enhances nor suppresses the intra-layer synchronizability. At the same time the delay greatly frustrates the synchronizability in each layer when it is greater than some threshold. Our results may have potential applications for interconnected technological networks where communication delays are inevitably present. | TANG LongKun LU JunAn Lü JinHu | 2018 | Science China(Technological Sciences)2018，61，12： | 4 |
| 16 | Robust Finite-time Synchronization of Non-identical Fractional-order Hyperchaotic Systems and Its Application in Secure Communication显示文摘This paper proposes a novel adaptive sliding mode control(SMC) method for synchronization of non-identical fractional-order(FO) chaotic and hyper-chaotic systems. Under the existence of system uncertainties and external disturbances,finite-time synchronization between two FO chaotic and hyperchaotic systems is achieved by introducing a novel adaptive sliding mode controller(ASMC). Here in this paper, a fractional sliding surface is proposed. A stability criterion for FO nonlinear dynamic systems is introduced. Sufficient conditions to guarantee stable synchronization are given in the sense of the Lyapunov stability theorem. To tackle the uncertainties and external disturbances, appropriate adaptation laws are introduced. Particle swarm optimization(PSO) is used for estimating the controller parameters. Finally, finite-time synchronization of the FO chaotic and hyper-chaotic systems is applied to secure communication. | Hadi Delavari Milad Mohadeszadeh | 2019 | IEEE/CAA Journal of Automatica Sinica2019，6，1： | 4 |
| 17 | Modified Functional Projective Synchronization of the Unidirectional and Bidirectional Hybrid Connective Star Network with Coupling Time-Delay显示文摘An unidirectional and bidirectional hybrid connective star network model with coupling time-delay is constructed in this paper. According to synchronization error systems, adaptive controllers for each node are structured by using the linear system stability method and the Lyapunov stability method. These adaptive controllers can realize the modified functional projective synchronization between each node of star network and an isolated node by argument and analysis. Finally, the corrective and effective of the adaptive controllers are illustrated by some numerical examples. | LI Dekui | 2019 | Wuhan University Journal of Natural Sciences2019，24，4： | 4 |
| 18 | Frame synchronization for underwater acoustic communication based on maximum likelihood estimation显示文摘Traditional frame synchronization methods for underwater acoustic communication(UWAC) merely depend on correlation coefficient when synchronization signal detection is concerned and,hence,false triggering and missed synchronization can hardly be avoided in complex UWAC channels.In order to solve this problem,firstly,we analyze the effects of interference from noise,multipath and Doppler on frame synchronization;then we propose a new frame synchronization scheme based on parameter estimation.By exploiting the parameter estimation technique,we detect the synchronization signal according to the estimated parameters,thus the false triggering rate and missed synchronization rate can be reduced.We also simplify the maximum likelihood estimation to reduce computational cost.Simulation results indicate that this new scheme outperforms the traditional method in terms of delay resolution and correlation coefficient.Both static and mobile communication experimental results show that the correlation coefficient of the new scheme is higher than that of the traditional one.Moreover,the detection ability of the receiver is improved,which helps to avoid false triggering and missed synchronization. | GUO Zheng YAN Shefeng XU Lijun QIN Ye | 2016 | Chinese Journal of Acoustics2016，35，4： | 4 |
| 19 | Identifying topologies and system parameters of uncertaintime-varying delayed complex networks显示文摘Node dynamics and network topologies play vital roles in determining the network features and network dynamical behaviors.Thus it is of great theoretical significance and practical value to recover the topology structures and system parameters of uncertain complex networks with available information. This paper presents an adaptive anticipatory synchronization-based approach to identify the unknown system parameters and network topological structures of uncertain time-varying delayed complex networks in the presence of noise. Moreover, during the identification process, our proposed scheme guarantees anticipatory synchronization between the uncertain drive and constructed auxiliary response network simultaneously. Particularly, our method can be extended to several special cases. Furthermore, numerical simulations are provided to verify the effectiveness and applicability of our method for reconstructing network topologies and node parameters. We hope our method can provide basic insight into future research on addressing reconstruction issues of uncertain realistic and large-scale complex networks. | WANG Xiong GU HaiBo WANG QianYao Lü JinHu | 2019 | Science China(Technological Sciences)2019，62，1： | 4 |
| 20 | TD-SCDMA系统中的DwPTS同步技术显示文摘文章针对TD-SCDMA子帧结构的特点,在对TD-SCDMA中的下行同步过程做了简要分析之后,给出了解决下行同步中搜寻DwPTS的方法。同时,论文还介绍了使用功率特征窗搜寻DwPTS的算法,并用所述的方案进行了MATLAB仿真,很好地实现了下行同步,最后提出了存在的一些关键性问题。 | 栗世涛 陈贤亮 | 2007 | 信息安全与通信保密2007，29，9： | 4 |
您所在的机构暂未开通此部分的功能，请联系管理员