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1.
As an important technology to improve network reliability, fault diagnosis has gained wide attention in complex dynamical networks. However, few studies focused on detecting the structure of broken edges when faults occur. In this paper, due to the natural sparsity of complex dynamical networks, a completely data-driven method based on compressive sensing is established to detect the structure of faulty edges from limited measurements. The least absolute shrinkage and selection operator algorithm is applied to solve the reconstruction problem. In addition, the method is also applicable to multilayer networks. The faulty edges in both the intralayer network and the interlayer network can be fully identified. Compared with other methods, the main advantages of the proposed method lie in two aspects. First, the structure of faulty edges can be obtained directly with limited measurements. Second, the proposed method is less time consuming and more efficient due to less data processing. Numerical simulations involving single-layer, multilayer and real-world complex dynamical networks are given to demonstrate the accuracy of detecting the structure of faulty edges from the proposed method.  相似文献   

2.
In this paper, we study a distributed state estimation problem for Markov jump systems (MJS) over sensor networks, in which each sensor node connects with each other through wireless networks with communication delays. We assume that each sensor node maintains a buffer to store delayed data transmitted from neighbor nodes. A distributed multiple model filter is designed by using the interacting multiple model methods (IMM) and a recursive delays compensation method. In order to ensure the stability, two stability conditions are derived for boundedness of estimation errors and boundedness of error covariance. Finally, the effectiveness of the proposed methods is illustrated by simulations and experiments of maneuvering target tracking.  相似文献   

3.
《Journal of The Franklin Institute》2021,358(18):10193-10212
In this paper, the non-fragile state estimation problem is investigated for a class of continuous-time delayed complex networks. In the addressed complex network model, the outputs only from partial network nodes are used to fulfill the state estimation task. For improving the efficiency of resource utilization, a dynamic event-triggering mechanism is applied in the design of estimator, where an auxiliary time-varying parameter is introduced to dynamically modulate the triggering condition. Our intention is to obtain the gain parameters of the desired non-fragile state estimator, which can tolerate the norm-bounded gain perturbation. In virtue of a novel Lyapunov functional and matrix inequality technique, sufficient conditions are provided to ensure robustly exponential boundedness for estimation error dynamics, and gain matrices of the estimator are computed based on certain matrix inequalities. An illustrative simulation is presented to show the validity of the non-fragile estimator proposed.  相似文献   

4.
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   

5.
The paper proposes a decentralized state estimation method for the control of network systems, where a cooperative objective has to be achieved. The nodes of the network are partitioned into independent nodes, providing the control inputs, and dependent nodes, controlled by local interaction laws. The proposed state estimation algorithm allows the independent nodes to estimate the state of the dependent nodes in a completely decentralized way. To do that, it is necessary for each independent node of the network to estimate the control input components computed by the other independent nodes, without requiring communication among the independent nodes. The decentralized state estimator, including an input estimator, is developed and the convergence properties are studied. Simulation results show the effectiveness of the proposed approach.  相似文献   

6.
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   

7.
宿瑞  王成 《资源科学》2018,40(5):958-966
村落空间网络是以农村居民点为节点、线性设施为依托、节点相互作用而构成的复杂网络。开展村落空间网络及其节点中心性研究能够理清节点在网络中的关键位置与影响范围,为农村居民点规划建设、整体网络结构优化提供理论借鉴。本文以重庆市江津区燕坝村为例,运用复杂网络理论与方法构建村落空间网络,进而辨析网络中心点及其辐射强度与辐射范围,厘定出农村居民点体系优化重组模式。结果表明：① 村落空间网络具有典型的非均衡层次结构、小世界特征与无标度特性,网络整体的联系程度较低;② 依据中心点的辐射能力划分其等级,形成Ⅰ级中心点、Ⅱ级中心点和Ⅲ级节点共同作用的网络节点体系;③ 基于此,从“整体-局部-个体”3个影响层次,构建了中心村（Ⅰ级中心点）扩散型、基层村（Ⅱ级中心点）增长型、散居农村居民点（Ⅲ级节点）挖潜型3类优化重组模式。  相似文献   

8.
In this paper, the problem of finite-horizon H∞ state estimation is investigated for a class of discrete time-varying complex networks with multiplicative noises and random coupling strengths. The network nodes and estimators are connected via a constrained communication network which allows only one node to send measurement data at each transmission instant. The Round-Robin protocol is introduced to determine which node obtains the access to the network at certain transmission instant. The aim of the addressed problem is to design a set of time-varying estimator parameters such that the prescribed H∞ performance is guaranteed over a finite horizon. By using the stochastic analysis approach and completing-the-square method, sufficient conditions are derived for the existence of the desired estimators in terms of the solution to backward recursive Riccati difference equations. Finally, a numerical example is provided to validate the feasibility and effectiveness of the proposed results.  相似文献   

9.
一种参数可调的网络节点重要性度量方法   总被引：1，自引：0，他引：1       下载免费PDF全文
摘要：对网络节点进行重要性评估,发掘重要性节点已经成为网络研究中的一个基本问题。然而,由于现有的大部分中心性度量方法仅仅考虑单一指标,所以这些方法很难捕获节点之间的细微差别。因此,本文提出了一种带有可调参数的网络上节点重要性度量的新方法。其主要原则是网络中节点的重要性不但与节点本身的度具有一定的关系,而且与节点的邻居节点的度大小,节点的介数也存在一定的关联。在艾滋病患者性关系网络上的研究表明：与其他的几个典型的中心性判别方法相比,该方法能够比较细致地描述网络中各节点之间的差异性,并具有很强适用性。  相似文献   

10.
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   

11.
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   

12.
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   

13.
In social networks, identifying influential nodes is essential to control the social networks. Identifying influential nodes has been among one of the most intensively studies of analyzing the structure of networks. There are a multitude of evaluation indicators of node importance in social networks, such as degree, betweenness and cumulative nomination and so on. But most of the indicators only reveal one characteristic of the node. In fact, in social networks, node importance is not affected by a single factor, but is affected by a number of factors. Therefore, the paper puts forward a relatively comprehensive and effective method of evaluation node importance in social networks by using the multi-objective decision method. Firstly, we select several different representative indicators given a certain weight. We regard each node as a solution and different indicators of each node as the solution properties. Then through calculating the closeness degree of each node to the ideal solution, we obtain evaluation indicator of node importance in social networks. Finally, we verify the effectiveness of the proposed method experimentally on a few actual social networks.  相似文献   

14.
In practice, it is almost impossible to directly add a controller on each node in a complex dynamical network due to the high control cost and the difficulty of practical implementation, especially for large-scale networks. In order to address this issue, a pinning control strategy is introduced as a feasible alternative. The objective of this paper is first to recall some recent advancements in global pinning synchronization of complex networks with general communication topologies. A systematic review is presented thoroughly from the following aspects, including modeling, network topologies, control methodologies, theoretical analysis methods, and pinned node selection and localization schemes (pinning strategies). Fully distributed adaptive laws are proposed subsequently for the coupling strength as well as pinning control gains, and sufficient conditions are obtained to synchronize and pin a general complex network to a preassigned trajectory. Moreover, some open problems and future works in the field are also discussed.  相似文献   

15.
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   

16.
This study investigates on a strong correlation between complex network (CN) controllability (characterized by the number of required driver nodes) and graph symmetry (described by automorphism groups) in undirected and unweighted networks. Based on the properties of permutation products of elementary automorphisms, novel necessary conditions for CN controllability are presented which are computationally more effective than previous method. In addition, a novel index of symmetry is proposed upon which a more meaningful understanding of symmetry impact on CN controllability can be comprehended. Based on this new index, a modification strategy is suggested aiming to satisfy CN controllability with a lower number of driver nodes. The study shows that the proposed modification approach can result in a minimal set of driver nodes with a reasonable computational complexity. Further, the critical components of complex networks, in terms of their impact on the number of required driver nodes, are identified. The results of the proposed methodologies have been verified for several synthetic and real test systems including small, medium, and large power networks.  相似文献   

17.
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   

18.
在企业创新网络演化模型的基础上提出节点的创新能力概念,构建企业创新网络级联失效可靠性模型,并对动荡、动态平衡和萎缩3种类型网络进行仿真实验研究。仿真数据表明:随机攻击节点条件下,动荡网络的节点失效率高于其他两种网络,但在攻击度中心性较高节点时动态平衡网络的节点级联失效率要高于动荡网络;随着度中心性变小,动态平衡网络的节点失效率逐渐低于动荡网络,而萎缩网络的节点失效率则一直处于最低;除此之外,如果攻击流介数中心性节点,动荡网络的创新能力损失率一直较高。实验结果表明,动荡网络的网络综合创新能力最高,但是可靠性较低。  相似文献   

19.
This paper investigates a stochastic impulsive coupling protocol for synchronization of linear dynamical networks based on discrete-time sampled-data. The convergence of the networks under the proposed protocol is discussed, and some sufficient conditions are showed to guarantee almost sure exponential synchronization. Moreover, this coupling protocol with a pinning control scheme is developed to lead the state of all nodes to almost sure exponentially converge to a virtual synchronization target. It is shown that the almost sure exponential synchronization can be achieved by only interacting based on the stochastic feedback information at discrete-time instants. Some numerical examples are finally provided to present the effectiveness of the proposed stochastic coupling protocols.  相似文献   

20.
为了提高无线传感器网络的能量利用率和延长网络的生命周期,本文提出了基于负载平衡的无线传感器网络路由算法。首先,将网络划分成多个网格,根据网格内节点的负载情况定义网格的状态,结合网格的地理位置和网格负载状态选择路由网格;其次,根据节点剩余能量和负载大小在选择的网格内选取一个合适的节点开始数据的收发工作;最后,通过模拟实验将本文算法与GPSR算法和GEAR算法进行比较。仿真结果表明,该算法有效改善了网络的负载均衡,延长了网络的生存期,并提高了网络的吞吐量。  相似文献   

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