首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 593 毫秒
1.
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   

2.
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   

3.
A link addition problem is considered for a directed linear network in order to improve the network robustness. The robustness of network is quantified through a well-known measure of stability margin. Optimal identification of links such that the stability margin is maximized by their addition, requires solving a complex combinatorial problem. Here two efficient methods are proposed for suboptimal link addition by exploiting the sensitivity being embedded in the derivative of singular value and Lagrange multiplier. Numerical tests are presented to demonstrate the efficacy of the proposed methods.  相似文献   

4.
In this paper, we investigate the output synchronization of networked SISO nonlinear systems that can be transformed into semi-strict feedback form. Due to parameter uncertainty, the agents have heterogeneous dynamics. Combined backstepping method together with graph theory, we construct an augmented Laplacian potential function for analysis and a distributed controller is designed recursively for each agent such that its output can be synchronized to its neighbors' outputs. The distributed controller of each agent has three parts: state feedback of itself, neighborhood information transmitted through the network and adaptive parameter updaters both for itself and its neighbors. Moreover, distributed tuning function is designed to minimize the order of the parameter updater. It is proved that when the undirected graph is connected, all agents’ outputs in the network can be synchronized, i.e., cooperative output synchronization of the network is realized. Simulation results are presented to verify the effectiveness of the proposed controllers.  相似文献   

5.
Time-varying edge weights represent dynamical interactions between any two nodes in multi-agent systems (MASs). In this paper, we consider a synchronization problem for heterogeneous MASs over directed graphs with time-varying edge weights from a control-theoretic perspective. We seek for an adaptive control protocol that drives the synchronization error in the presence of time-varying edge weights to converge in terms of asymptotic stability. We propose a class of observer networks for estimating leaders and output regulation equation solvers built on directed graphs with time-varying edge weights. Finally, we use a simulation study to verify the effectiveness of the proposed protocol.  相似文献   

6.
新兴技术跨界创新推动了知识网络的跨界融合演变。基于德温特专利数据库，以虚拟现实技术为研究对象，运用社会网络分析法，通过构建专利引文网络，研究新兴技术知识网络跨界融合的知识流动路径演化和网络态势。结果表明：新兴技术知识流动路径按照“单向路径-混向路径-双向路径”模式演化，核心企业和外围企业的不断增加拓宽了双向路径的发展空间；知识流动路径数量的激增和方向的分散导致企业和地区知识网络跨界融合的涌现，呈现出异质性知识增加、知识连接灵活、网络规模扩大的跨界融合特征；中心企业与中心地区通过“中心地区自引、非中心地区引中心地区”的知识流动偏好进一步强化跨界融合能力，体现出明显的先发优势。  相似文献   

7.
This paper researches the consensus issue for multi-agent systems on matrix-weighted directed fixed and undirected switching network topologies by sampled data control method which saves resources and is more practical. Using the sampled information, the distributed control laws are designed under two network topologies, respectively. Under directed fixed network topology, the consensus conditions based on the sampling period and the eigenvalues of Laplacian matrix are deduced by matrix theory and analysis theory. Under undirected switching network topology, by using Lyapunov stability theory, the consensus conditions based on the sampling period and switched network topologies are built. Lastly, two simulation examples are offered to verify the validity of the obtained results.  相似文献   

8.
In this paper, we design two distributed output consensus controllers for heterogeneous linear systems based on internal model principle and then study the quantization effect on the controllers when uniform quantizers are used in the communication channels. The first controller considers the general situation when the internal model state matrix of the system may be unstable and the communication graphs are strongly connected directed graphs. We prove that the bound of the consensus error is proportional to the quantizer parameter with a coefficient related to the size of the network and the property of the communication graphs. The second controller considers the situation when the internal model state matrix is neutrally stable and the communication graphs are undirected connected graphs. In this case, we derive a better bound of the consensus error which is proportional to the quantizer parameter and the coefficient is unrelated to the size of the network when the linear systems are homogeneous. Simulation examples are provided to illustrate the theoretical results.  相似文献   

9.
Links in most real networks often change over time. Such temporality of links encodes the ordering and causality of interactions between nodes and has a profound effect on network dynamics and function. Empirical evidence has shown that the temporal nature of links in many real-world networks is not random. Nonetheless, it is challenging to predict temporal link patterns while considering the entanglement between topological and temporal link patterns. Here, we propose an entropy-rate-based framework, based on combined topological–temporal regularities, for quantifying the predictability of any temporal network. We apply our framework on various model networks, demonstrating that it indeed captures the intrinsic topological–temporal regularities whereas previous methods considered only temporal aspects. We also apply our framework on 18 real networks of different types and determine their predictability. Interestingly, we find that, for most real temporal networks, despite the greater complexity of predictability brought by the increase in dimension, the combined topological–temporal predictability is higher than the temporal predictability. Our results demonstrate the necessity for incorporating both temporal and topological aspects of networks in order to improve predictions of dynamical processes.  相似文献   

10.
科技型小微企业协同创新能力增进机制研究   总被引：4，自引：0，他引：4       下载免费PDF全文
网络与知识已成为提升科技型小微企业协同创新能力的关键,探索不同属性网络与知识促进协同创新能力提升是否存在差异?通过系统文献梳理,构建了协同创新网络、知识整合与协同创新能力之间关系的理论模型。以198家浙江科技型小微企业为样本,采用多元回归、结构方程、中介效应检验等方法对相关假设进行实证检验。研究结果表明：（1）协同创新网络中的异质性网络与同质化网络均能提升科技型小微企业协同创新能力,但前者的作用明显大于后者;（2）异质性知识整合在异质性网络与协同创新能力之间存在完全中介的作用,而同质化知识整合在同质化网络与协同创新能力之间存在部分中介效应。  相似文献   

11.
王成金  王伟 《资源科学》2016,38(4):631-644
中国作为煤炭生产和消费的大国,保障煤炭供应是国民经济建设的战略性任务,并影响着国家运输网络构建与进出口贸易。本文在回顾20世纪70年代末期以来中国煤炭进出口发展过程的基础上,刻画了中国从煤炭净出口国向净进口国转变及进出口关系的演变过程;详细分析了中国港口的煤炭进口和出口吞吐量格局的演变过程、基本特征及区域集聚性,认为近年来中国煤炭进出口“南进北出”格局向“南进北出又北进”格局迅速转变;进而绘制了中国煤炭进口的国别网络和中转配送网络,指出部分沿海港口成为煤炭一程接卸和二程配送的枢纽。然后,从煤炭供需关系与耗能产业扩张、煤炭产业政策、市场价格机制、运输瓶颈与生态文明建设等因素,深入分析了中国煤炭进出口格局快速演变的动力机制,并指出中国煤炭进口量的近期爆发性增长是一种短期市场行为,未来仍将保持在高位,但增长速度将下滑。  相似文献   

12.
A social choice procedure is modeled as a Nash game among the social agents. The agents are communicating with each other through a social communication network modeled by an undirected graph and their opinions follow a dynamic rule modelling conformity. The agents’ criteria for this game are describing a trade off between self-consistent and manipulative behaviors. Their best response strategies are resulting in a dynamic rule for their actions. The stability properties of these dynamics are studied. In the case of instability, which arises when the agents are highly manipulative, the stabilization of these dynamics through the design of the network topology is formulated as a constrained integer programming problem. The constraints have the form of a Bilinear Matrix Inequality (BMI), which is known to result in a nonconvex feasible set in the general case. To deal with this problem a Genetic Algorithm, which uses an LMI solver during the selection procedure, is designed. Finally, through simulations we observe that in the case of topologies with few edges, e.g. a star or a ring, the isolation of the manipulative agents is an optimal (or suboptimal) design, while in the case of well-connected topologies the addition or the rewiring of just a few links can diminish the negative effects of manipulative behaviors.  相似文献   

13.
查询结果合并是分布式信息检索的重要步骤。本文依据选中信息集中文档重叠的程度以及信息集的同构、异构性，将查询结果的合并策略分3种情况进行分析：选中的信息集所含文档没有或有少量的重叠，选中的信息集同构，选中的信息集异构且所含文档有部分重叠。指出查询结果合并策略的深入研究，对于促进分布式检索技术的发展具有积极意义。  相似文献   

14.
移动无线自组网络，通过多跳接入Internet，卫星网和第三代移动系统，构成了下一代无线Ad-hoc互联网，实现了异构网络的融合和资源共享。在下一代移动无线网络环境下，带宽和功率受限，存在着各种传输误差。根据这些特性，本文采用基于方向的小波分形的插值算法，提出了一种适用于移动无线Ad-hoc网络的视频传输的服务质量（Quality of Service,简称QOS）控制方法，模拟结果表明，该算法与现存算法（双线性内插）相比，具有更优的性能（信噪比），并能适应网络带宽的动态变化。  相似文献   

15.
Fractional-order calculus has been studied deeply because many networked systems can only be described with fractional-order dynamics in complex environments. When different agents of networked systems show diverse individual features, fractional-order dynamics with heterogeneous characters will be used to illustrate the multi-agent systems (MAS). Based on the distinguishing behaviors of agents, a compounded fractional-order multi-agent systems(FOMAS) is presented with diverse dynamical equations. Suppose multiple leader agents existing in FOMAS, containment consensus control of FOMAS with directed weighted topologies is studied. By applying frequency domain analysis theory of the fractional-order operator, an upper bound of delays is obtained to ensure containment controls of heterogenous FOMAS with communication delays. The consensus results of delayed fractional-order dynamics in this paper can be expanded to the integer-order models. Finally, the results are verified by simulation examples.  相似文献   

16.
We study the large-scale topology and dynamics of maps of alliances in a major segment of the biotechnology industry. The results point to the joint dynamics of network and innovation. The study demonstrates that the network is scale-free. Competition for links translates into a dynamic exponent that seems to follow the fitter-get-richer model of network growth, with preferential attachment to firms holding key technologies. This network also shows a small-world effect. This work highlights the strategic importance of understanding the growth dynamics and structure of collaboration networks for the building of leading positions in industries led by sustained radical change.  相似文献   

17.
技术联盟网络知识转移影响因素的案例研究   总被引：4，自引：0，他引：4  
本文采用案例分析对技术联盟网络知识转移影响因素进行了研究,从网络特征因素具体分析了网络异质性、网络稳定性、网络联接强度、网络规模、网络中心性对技术联盟知识转移的影响.在此基础上,比较分析了股权式技术联盟和契约式技术联盟的差异.研究结果表明:技术联盟网络异质性不利于知识转移;网络稳定性、联接强度、网络规模有利于知识在网络间的转移;网络中心性对知识转移有好的影响也有不利影响,但总体来说,有利影响大于不利影响.相对于契约式联盟,股权式联盟网络异质性更低,稳定性、联接强度、中心性、平均企业规模更强,但网络企业总数往往低于契约式技术联盟网络.  相似文献   

18.
This paper investigates general linear dynamical networks (GLDNs), distributed relative-state feedback control, and pinning control. For symmetric GLDNs under distributed relative-state feedback control, some necessary and sufficient conditions for asymptotic stability are proposed. While for the asymmetric case, some sufficient conditions are derived. If the obtained stability conditions are not satisfied, one can design some pinning controllers to asymptotically stabilize the GLDNs. Compared with the existing results, the considered dynamical network model is more general, and the obtained theoretical results are novel.  相似文献   

19.
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   

20.
The problem of bifurcation for delayed fractional neural networks(FNNs) with single delay has been considerably researched. It is more realistic to portray the dynamical properties of FNNs with multiple delays, but this has been not investigated before. This paper attempts to conduct a research on the stability and bifurcation for a FNN with double delays. The criteria of heterogeneous delays-induced bifurcations are decidedly procured. Then, the influence of solitary delay on the bifurcation point is ulteriorly displayed by delicate computation. It is demonstrated that the stability performance of the proposed FNN can be undermined or enhanced by varying properly time delay. Finally, illustrative examples are addressed to validate the availability of the proposed results.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号