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1.
By only designing the internal coupling, quasi synchronization of heterogeneous complex networks coupled by N nonidentical Duffing-type oscillators without any external controller is investigated in this paper. To achieve quasi synchronization, the average of states of all nodes is designed as the virtual target. Heterogeneous complex networks with two kinds of nonlinear node dynamics are analyzed firstly. Some sufficient conditions on quasi synchronization are obtained without designing any external controller. Quasi synchronization means that the states of all nonidentical nodes will keep a bounded error with the virtual target. Then the heterogeneous complex network with impulsive coupling which means the network only has coupling at some discrete impulsive instants, is further discussed. Some sufficient conditions on heterogeneous complex network with impulsive coupling are derived. Based on these results, heterogeneous complex network can still reach quasi synchronization even if its nodes are only coupled at discrete impulsive instants. Finally, two examples are provided to verify the theoretical results.  相似文献   

2.
In this paper, the synchronization control problem is considered for the delayed hybrid-coupled heterogeneous networks, i.e., complex networks with nonidentical dynamical nodes. Some effective control schemes are designed under which the whole network is globally asymptotically synchronized to an arbitrary objective trajectory. By imposing the open-loop control on the whole network together with the feedback control only on a small fraction of the nodes, an easy-to-verify sufficient condition is derived to guarantee the asymptotic synchronization of the complex network under study. Furthermore, to decrease the feedback control gains, the idea of adaptive control scheme is combined together, and the verified conditions are further weakened. Finally, by introducing the impulses to the open-loop network and using the improved Halanay inequality, other novel synchronization criteria are developed for the complex network. Comparisons of the obtained theoretical results as well as the detail pinning schemes are also given. Numerical examples of the undirected scale-free network and the directed small-world network are illustrated to demonstrate the applicability and efficiency of the proposed theoretical results.  相似文献   

3.
This paper investigates the generalized matrix projective synchronization problem of general colored networks with different-dimensional node dynamics. A general colored network consists of colored nodes and edges, where the dimensions of colored node dynamics can be different in addition to the difference of the inner coupling matrices between any pair of nodes. For synchronizing a colored network onto a desired orbit with respect to the given matrices, open-plus-closed-loop controllers are designed. The closed-loop controllers are chosen as adaptive feedback and intermittent controllers, respectively. Based on the Lyapunov stability theory and mathematical induction, corresponding synchronization criteria are derived. Noticeably, many existing synchronization settings can be regarded as special cases of the present synchronization framework. Numerical simulations are provided to verify the theoretical results.  相似文献   

4.
关键核心技术的自主可控是实现产业安全可持续发展的重要保障。为了分析不同攻击策略下供应链网络的鲁棒性,基于国内外专利数据构建了海洋工程装备制造业供应链关键核心技术网络,通过网络结构分析发现网络中半数核心节点企业为国外企业,然后分别采用随机攻击和蓄意攻击两种策略对网络中的节点和边进行度攻击和介数攻击仿真分析,发现对核心节点的蓄意攻击会造成供应链网络鲁棒性急剧下降,阐明了我国海洋工程装备制造业存在较强的“卡脖子”隐患。  相似文献   

5.
尹发根 《科技广场》2011,(5):126-129
研究了节点带有时滞且节点之间的通信也带有时滞的复杂动态网络的自适应同步问题。基于稳定性理论,设计了复杂网络同步的自适应控制器。该控制器结构简单,易于应用。最后,以环状耦合的时滞Lorenz系统为例进行数值仿真,检验了结果的正确性和设计方法的有效性。  相似文献   

6.
In this paper, the problem of the mean square exponential synchronization in Lagrange sense for the uncertain complex network is investigated. A complex network usually appears some uncertain phenomena, which includes varying topology structure, destroyed nodes, and the noise disturbance from circumstance. Based on the Lyapunov stability theory and the Kronecker product analysis technique, some conditions to guarantee the complex network mean square exponential synchronization in Lagrange sense are provided. Finally, two numerical examples are provided to illustrate the effectiveness of the method proposed.  相似文献   

7.
User-created automation applets to connect IoT devices and applications have become popular and widely available. Exploring those applets enables us to grasp the patterns of how users are utilizing and maximizing the power of connection by themselves, which can deliver practical implications for IoT service design. This study builds an IoT application network with the data of the IFTTT(if this then that) platform which is the most popular platform for self-automation of IoT services. The trigger-action relationships of the IFTTT applets currently activated are collected and used to construct an IoT application network whose nodes are IoT service channels, and links represent their connections. The constructed IoT network is then embedded by the node2vec technique, an algorithmic framework for representational learning of nodes in networks. Clustering the embedded nodes produces the four clusters of IoT usage patterns: Smart Home, Activity Tracking, Information Digest, and Lifelogging & Sharing. We also predict the IoT application network using node2vec-based link prediction with several machine learning classifiers to identify promising connections between IoT applications. Feasible service scenarios are then generated from predicted links between IoT applications. The findings and the proposed approach can offer IoT service providers practical implications for enhancing user experiences and developing new services.  相似文献   

8.
In this paper, the problem of pinning and impulsive synchronization between two complex dynamical networks with non-derivative and derivative coupling is investigated. A hybrid controller, which contains a pinning controller and a pinning impulsive controller, is proposed simultaneously. Based on the Lyapunov stability theory and mathematical analysis technique, some novel criteria of synchronization are derived, which can guarantee that the response network asymptotically synchronizes to the drive network by combining pinning control and pinning impulsive control. Moreover, the restrictions about non-derivative coupling matrix, impulsive intervals and the number of pinned nodes are removed. Numerical examples are presented finally to illustrate the effectiveness of the theoretical results.  相似文献   

9.
This investigation establishes the global synchronization of an array of coupled memristor-based neural networks with delays. The coupled networks that are considered can incorporate both the internal delay in each individual network and the transmission delay across different networks. The coupling scheme, which consists of a nonlinear term and a sign term, is rather general. In particular, it can be asymmetric, and admits the coexistence of excitatory and inhibitory connections. Based on an iterative approach, the problem of synchronization is transformed into solving a corresponding linear system of algebraic equations. Subsequently, the respective synchronization criteria, which depend on whether the transmission delay exists, are derived respectively. Three examples are given to illustrate the effectiveness of the theories presented in this paper. The synchronization of the systems in two examples cannot be handled by existing techniques.  相似文献   

10.
李钢  王聿达  崔蓉 《现代情报》2021,40(12):27-35
[目的/意义] 在大规模社交网络中快速搜索关键节点对于舆情的引导和控制具有重要意义。[方法/过程] 本文提出一种适用于社交网络的局部中心性关键节点识别算法,该方法综合评估了节点的K壳、自身的聚集特性以及邻居的扩散特性和节点自身传播状态,同时体现了节点在空间上的网络位置和邻居的拓扑结构以及在时间上演化特征,评价指标更加全面高效。[结果/结论] 实验结果表明,该方法识别的关键节点对网络鲁棒性的影响与介数中心性接近,但计算仅基于节点局部信息,时间复杂度低。剔除这些节点后网络的连通性受到较大影响,网络聚类系数降低,平均路径长度增加。同时,利用SIR传播模型模拟验证,以该算法识别的关键节点为初始传播源可提升信息传播范围和平均传播速度。  相似文献   

11.
Precise time synchronization is an enabling technology for mission-critical time-sensitive Industrial Internet of Things (IIoT). However, the crystal oscillator clock which is widely used in IIoT may suffer from periodic disturbances caused by repetitive motion or periodic vibration. To improve the time synchronization of distributed nodes subject to periodic disturbances, this paper proposes a novel disturbance rejection framework, General-Proportional-Integral-Observer-based Disturbance Compensation (GPIO-DC), with the proof of stability, and combined with a 2-freedom control design strategy to optimize both the disturbance rejection and clock tracking performance. And the GPIO’s unique feature of blocking zeros are fully exploited to reject the periodic disturbance at its frequencies and a zero-pole optimal design algorithm is given. With the disturbance being compensated, a disturbance-free minimum variance time synchronization protocol for a complex network is developed and optimized by using Linear Matrix Inequality (LMI) to minimize the variance of networked synchronization errors. The performance of the proposed method is devalued by intensive simulation. Comparing with recent relevant research, the proposed method achieves a better performance in disturbance rejection and minimum variance.  相似文献   

12.
基于社会资本理论的网络组织演化机制新阐释   总被引:1,自引:0,他引:1  
杨桂菊 《软科学》2007,21(4):5-8
从社会资本的两个维度——网络位置与嵌入性网络资源出发,构建了网络组织演化机制的理论模型,指出网络组织演化的实质是组织成员在网络利益最大化动机的驱使下,不断地复制与重构网络关系,向核心的网络位置以及丰富的网络资源方向演化的过程。  相似文献   

13.
王绍博  段伟  秦娅风  邓昭 《资源科学》2022,44(5):1079-1089
当前,汛情、疫情等突发事件对于交通站点的影响愈发明显,作为当今旅客跨区域出行的重要交通工具,高铁网络的连通性也会遭受不同程度的冲击。基于此背景,本文以高铁网络相对完善的长三角为例,通过模拟连续节点失效、单个节点失效情景下网络特征值的变化,揭示其网络的脆弱性特点。结果发现:①长三角高铁网络已形成层级结构明显、社团组织结构清晰的网络化结构,同时整体呈现“小世界、多中心”的复杂网络特征。②当度值排序前20%、中间20%的节点失效时,高铁网络结构变得更加松散,节点间联系中转的次数明显增加,直接联系和相对可达性水平明显降低,网络呈现较高的脆弱性。而当度值排序后20%节点失效时,高铁网络结构变得更加紧密,网络集聚水平有所提升,节点间联系中转的次数有所减少,对整体网络稳定性的影响相对较小。③单个节点失效背景下,高铁网络受冲击程度相对可控,基本可以维系高铁网络的正常运行。但不同节点对于高铁网络的脆弱性影响呈现明显的异质性特点,上海、南京、杭州、合肥等中心城市节点失效背景下网络呈现较高的脆弱性,而宿迁、泰州、马鞍山、淮北等周边城市节点失效时对网络稳定性影响相对较小。未来,应立足高铁网络脆弱性的空间分异特征,针对性的布局应急处置设施、谋划替代通勤线路、打造高铁互联互通联盟等,提高长三角高铁网络应对突发事件的能力。  相似文献   

14.
This paper deals with the synchronization control of power complex networks with switching parameters. In the meantime, the node state constraints are considered during the synchronization process. Admittedly, synchronization problem encountered in power complex networks is becoming progressively important due to the increasing connection and disconnection operations resulting from sustainable energy and controllable load. Hereon, the network model considering switching parameters of each node is established to describe the topology variation of power systems that may be confronted in practical terms. Then, by utilizing the adaptive backstepping technique with a barrier Lyapunov function (BLF), a novel synchronization controller is constructed recursively which accomplishes the nodes full states tracking within the predefined transient behavior. Owing to the characteristic of BLF, the designed controller as well as its adaptive law could guarantee both the constrained state of each node restricted by a prescribed range and the synchronization performance. Meanwhile, the bounded output of the system could track the desired trajectory. Finally, scenario simulations are performed to demonstrate the effectiveness and superiority of the proposed method.  相似文献   

15.
《Journal of The Franklin Institute》2023,360(13):10251-10274
In this paper, in order to obtain a smaller estimation of settling time, reduce chattering caused by sign function and improve network communication efficiency, the fixed-time (FXT) synchronization of delayed BAM neural networks is analyzed based on some new FXT stability results and non-chattering quantized controllers. Firstly, by comprehensively discussing the conditions of power laws in differential inequalities, a new FXT stability lemma is presented and a smaller upper bound of settling time is estimated. Then, unlike previous controllers with sign functions, a non-chattering quantized state feedback control and a non-chattering quantized pinning control are designed, and some sufficient conditions are derived to ensure FXT synchronization of the established system. Finally, two numerical simulations are given to verify the effectiveness of the theoretical results. The results show that compared with the previous researches, this paper provides a smaller upper bound. However, the convergence time of the uncontrolled nodes is indirectly affected by the coupling of the controlled nodes and is much longer than the estimated upper bound.  相似文献   

16.
This paper is devoted to the non-fragile exponential synchronization problem of complex dynamical networks with time-varying coupling delays via sampled-data static output-feedback controller involving a constant signal transmission delay. The dynamics of the nodes contain s quadratically restricted nonlinearities, and the feedback gain is allowed to have norm-bounded time-varying uncertainty. The control design is based on a Lyapunov–Krasovskii functional, which consists of the sum of terms assigned to the individual nodes, i.e., it is constructed without merging the complex dynamical network’s nodes into a single large-scale system. In this way, the proposed design method has substantially reduced computational complexity and improved conservativeness, and guaranties non-fragile exponential stability of the error system. The sufficient stability condition is expressed in terms of linear matrix inequalities that are solvable by standard tools. The efficiency of the proposed method is illustrated by numerical examples.  相似文献   

17.
首先分析了CERNET网络节点的管理体系、网络连接、硬件资源、软件资源、维护工作等,并对比分析了CERNET用户与CNNIC全国普查用户的群体特点,明确了CERNERT用户使用网络的目的、需要的信息资源等综合需求,以用户需求为导向,得出CERNET应该在发展定位、收费方式、资源建设、网络带宽和网络维护服务方面加快发展的结论。  相似文献   

18.
19.
In this paper, the globally exponential synchronization problem of dynamical networks with nonlinearly coupling function is considered. Hybrid pinning control strategies are established to force the states of the network to follow some objective trajectory. The impulsive pinning controllers are used to control a fringe of nodes at the impulsive instants, while during the impulsive instants, pinning state-feedback controllers are designed to achieve the control objective. Finally, the validity of the developed techniques is evidenced by an illustrative example.  相似文献   

20.
This paper investigates the research question if senders of large amounts of irrelevant or unsolicited information – commonly called “spammers” – distort the network structure of social networks. Two large social networks are analyzed, the first extracted from the Twitter discourse about a big telecommunication company, and the second obtained from three years of email communication of 200 managers working for a large multinational company. This work compares network robustness and the stability of centrality and interaction metrics, as well as the use of language, after removing spammers and the most and least connected nodes. The results show that spammers do not significantly alter the structure of the information-carrying network, for most of the social indicators. The authors additionally investigate the correlation between e-mail subject line and content by tracking language sentiment, emotionality, and complexity, addressing the cases where collecting email bodies is not permitted for privacy reasons. The findings extend the research about robustness and stability of social networks metrics, after the application of graph simplification strategies. The results have practical implication for network analysts and for those company managers who rely on network analytics (applied to company emails and social media data) to support their decision-making processes.  相似文献   

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