Leader-following consensus of fractional-order multi-agent systems via adaptive control

This article focuses on the consensus problem of leader-following fractional-order multi-agent systems (MASs) with general linear and Lipschitz nonlinear dynamics. First, the distributed adaptive protocols for linear and nonlinear fractional-order MASs are constructed, respectively. We allow the control coupling gains to be time varying for each agent. Moreover, the adaptive modification schemes for the control gain are designed, which renders smaller control gains and thus requires smaller amplitude on the control input without sacrificing consensus convergence. Second, based on fractional-order Lyapunov stability theorem and Barbalat's lemma, two novel sufficient conditions in terms of linear matrix inequalities are provided to ensure that the leader-following consensus can be obtained in the case for any undirected connected communication graph. Furthermore, we show that the proposed algorithm also works for consensus of agents with intrinsic Lipschitz nonlinear dynamics. As a result, the proposed framework requires no global information and thus can be implemented in a fully distributed manner. Finally, the numerical simulations are given to demonstrate the effectiveness of obtained the theoretical results.     

Average consensus in networks of dynamic agents with switching topologies and multiple time-varying delays

In this paper, we discuss average consensus problem in undirected networks of dynamic agents with fixed and switching topologies as well as multiple time-varying communication delays. By employing a linear matrix inequality method, we prove that all the nodes in the network achieve average consensus asymptotically for appropriate communication delays if the network topology is connected. Particularly, several feasible linear matrix inequalities are established to determine the maximal allowable upper bound of time-varying communication delays. Numerical examples are given to demonstrate the effectiveness and the sharpness of the theoretical results.     

大规模电力系统不对称短路的分块射影解法

本文把网络的分块射影法用于大规模电力系统不对称短路的分析计算。研究表明：该方法对短路计算是可行的。一旦求出了射影张量，即可重复用于后续的计算，只需改变故障所在的那一个子网络的射影张量。本文提出的网络分块射影算法为大规模电力系统的分析计算提供了一条崭新的途径。     

异构空间信息的分级共识模型研究

Internet上异构、分布的空间信息因各自独立、相对封闭而无法相互沟通和协作,从而形成了空间信息孤岛。论文利用计算机的知识表示理论和Ontology技术能够明确表达相关领域共识的特点,探索性地提出了异构空间信息的分级共识模型。该模型为解决上述问题提供了一条切实可行的新思路。     

基于AutoCAD2000的图解法确定工艺转角

提出了基于AutoCAD2 0 0 0的图解法求解机械加工过程中工艺转角的问题 ,并针对具体的应用实例给出了圆满的解答 ,并验证了其精度。     

一种基于门限签名的区块链共识算法

针对区块链应用于物联网环境下的特点和要求,分析了目前广泛应用于联盟链的实用拜占庭容错算法（PBFT）的弊端以及目前应用于共识网络中的门限签名算法存在的普遍问题,提出改进的共识算法。首先,新共识机制将网络中的节点分组用部分节点的两两通信代替所有节点的两两通信减少通信量;其次,将组合公钥的思想引入到门限签名中,减少了通信量与计算量;最后,在节点之间引入信用分机制,优化视图切换协议。仿真结果表明,新提出的共识算法在数据吞吐量以及通信时延方面有了明显的提升,并且得到了通信量最低时的最佳分组方式。     

微博影响力评价研究

微博作为一种被广泛使用的网络平台,其多样的特性满足了人们信息获取、人际交流等多方面的新需求,微博已成为人们日常生活的重要组成部分之一。微博影响力作为微博研究的一个热点,对于优化微博的信息整合、传输,对于深入了解微博发展方向、维护网络内容安全、促进网络发展具有非常重要的理论和实践意义。文章对当前主要的微博影响力评价方法进行了梳理和分析,并提出了针对中国微博的影响力评价模型。     

Hybrid function projective synchronization of chaotic systems with uncertain time-varying parameters via Fourier series expansion

In this paper, the hybrid function projective synchronization (HFPS) of different chaotic systems with uncertain periodically time-varying parameters is carried out by Fourier series expansion and adaptive bounding technique. Fourier series expansion is used to deal with uncertain periodically time-varying parameters. Adaptive bounding technique is used to compensate the bound of truncation errors. Using the Lyapunov stability theory, an adaptive control law and six parameter updating laws are constructed to make the states of two different chaotic systems asymptotically synchronized. The control strategy does not need to know the parameters thoroughly if the time-varying parameters are periodical functions. Finally, in order to verify the effectiveness of the proposed scheme, the HFPS between Lorenz system and Chen system is completed successfully by using this scheme.