Pinning synchronization of fractional‐order complex networks with adaptive coupling weights

This work studies the issue of synchronization control for a type of fractional‐order complex networks, in which the adaptive coupling matrix is considered under the directed topology structure. A pinning control strategy, with the free selection of pinning nodes, is adopted for the synchronization goal. Then, by absorbing the information of eigenvectors and adaptive laws for the coupling matrix, a new Lyapunov function is constructed, by which, and with the assistance of Gronwall inequality and network features, the sufficient condition for Mittag‐Leffler synchronization of the fractional‐order network is established. Accordingly, an easy verifiable algebraic criterion is further derived by means of some matrix inequalities. Besides, we also discuss the effect of outer coupling strength on the achievement of network synchronization. Finally, a numerical experiment is performed to show the evidence of the correctness and effectiveness of the proposed results.     

A low‐voltage band‐gap reference circuit with second‐order analyses

A new band‐gap reference (BGR) circuit employing sub‐threshold current is proposed for low‐voltage operations. By employing the fraction of V_BE and the sub‐threshold current source, the proposed BGR circuit with chip area of 0.029mm² was fabricated in the standard 0.18µm CMOS triple‐well technology. It generates reference voltage of 170 mV with power consumption of 2.4µW at supply voltage of 1 V. The agreement between simulation and measurement shows that the variations of reference voltage are 1.3 mV for temperatures from ?20 to 100^°C, and 1.1 mV per volt for supply voltage from 0.95 to 2.5 V, respectively. Copyright © 2010 John Wiley & Sons, Ltd.     

Stability and synchronization of directed complex dynamical networks with random packet loss: the continuous‐time case and the discrete‐time case

This paper presents models for both the continuous‐time and discrete‐time directed complex dynamical networks (CDNs) with random packet loss, respectively. The packet loss may take place in the communication between every two neighbor nodes. The exponential mean‐square stability and the exponential mean‐square synchronization for both the continuous‐time and discrete‐time CDNs with random packet loss are investigated, respectively, by defining the packet loss probability matrix. In addition, two special cases, the CDN with synchronous packet loss and the CDN with node‐dependent packet loss, are discussed. Numerical examples are provided for illustrations. Copyright © 2012 John Wiley & Sons, Ltd.     

Adaptive synchronization of fractional‐order complex networks via pinning control

Adaptive synchronization of a class of fractional‐order complex networks is investigated in this paper. On the basis of the fractional‐order system stability theory, adaptive synchronization criteria of fractional‐order complex networks with 0 < q < 1 is achieved. Furthermore, pinning control method is then suggested to control the networks, and adaptive strategy is employed to tune the control gains and coupling strength. Because the nodes with high degree may not be the center of the networks, a new attempt to choose the pinned nodes on the basis of the closeness centrality scheme is proposed. Finally, numerical simulations are given to verify the effectiveness of the proposed approach based on the closeness centrality scheme. Copyright © 2012 John Wiley & Sons, Ltd.     

浙江省电力通信同步网研究

在对同步网的同步方式、基准时钟和时钟分配方式进行探讨的基础上,提出了浙江电力通信同步网规划和各个业务网络的同步实现。     

Oscillation and convergence behaviours exhibited in an ‘unstable’ second‐order digital filter with saturation‐type non‐linearity

This letter explains the oscillatory behaviours exhibited in a second‐order digital filter with saturation‐type non‐linearity via the Hopf bifurcation theorem. It is shown that depending on the bifurcation parameter, the state variables may converge to zero even when the eigenvalues of the system matrix are outside the unit circle. Copyright © 2004 John Wiley & Sons, Ltd. abstract     

Digital compensation of second‐ and third‐order nonlinear distortions generated by blocker signals

Deeply integrated systems in chips commonly include a digital and an analog front end on the same die. These analog front‐end schemes for wireless communications could be implemented under the concept called software‐defined radio (SDR). Digital signal processing is commonly used to perform signal filtering and channel equalization, and, recently, to improve front‐end radio performance by removing the undesirable effects of the analog front‐end imperfections. These wide‐band SDR are currently implemented without the surface acoustic wave (SAW) filter, because it is difficult to integrate a highly configurable one, as is required in wide‐band systems. An analog front end without this filter has no efficient protection against blocker signal effects, specifically against nonlinear distortions due to the analog front‐end imperfections. This paper proposes an algorithm to simultaneously remove second‐ and third‐order nonlinear distortions caused by a blocker signal, departing from a behavioral model and a band‐pass sampling pure digital algorithm to recover the blocker signal information. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Mittag‐Leffler state estimator design and synchronization analysis for fractional‐order BAM neural networks with time delays

This paper deals with the extended design of Mittag‐Leffler state estimator and adaptive synchronization for fractional‐order bidirectional associative memory neural networks with time delays. By the aid of Lyapunov direct approach and Razumikhin‐type method, a suitable fractional‐order Lyapunov functional is constructed and a new set of novel sufficient condition are derived to estimate the neuron states via available output measurements such that the ensuring estimator error system is globally Mittag‐Leffler stable. Then, the adaptive feedback control rule is designed, under which the considered FBNNs can achieve Mittag‐Leffler adaptive synchronization by means of some fractional‐order inequality techniques. Moreover, the adaptive feedback control may be utilized even when there is no ideal information from the system parameters. Finally, two numerical simulations are given to reveal the effectiveness of the theoretical consequences.     

Signal separation using second‐ and high‐order statistics

This paper presents two methods for signal separation. In either method, the fundamental criterion for separation relies on reducing to zero, or at least minimizing, the output cross‐correlation or cross‐cumulant functions of a decoupling multi‐input–multi‐output system that is fed with mixed signals. In one of the approaches used, the parameters of this system are determined through solving — in a least‐squares sense — a linearized set of equations describing the deviations from zero of either the cross‐correlation or cross‐cumulant functions when evaluated for different lags. An alternative rapidly convergent adaptive algorithm is also described for minimizing the cross‐correlation or cross‐cumulant functions. The paper also considers both FIR and IIR representations of the decoupling system. It shows that using IIR functions in the decoupling system does not offer any merit over the FIR case. Illustrative examples are given to show the performance of the proposed algorithms. Copyright © 2000 John Wiley & Sons, Ltd.     

Stability analysis and robust synchronization of fractional‐order competitive neural networks with different time scales and impulsive perturbations

This article mainly examine a class of robust synchronization, global stability criterion, and boundedness analysis for delayed fractional‐order competitive type‐neural networks with impulsive effects and different time scales. Firstly, by endowing the robust analysis skills and a new class of Lyapunov‐Krasovskii functional approach, the error dynamical system is furnished to be a robust adaptive synchronization in the voice of linear matrix inequality (LMI) technique. Secondly, by ignoring the uncertain parameter terms, the existence of equilibrium points are established by means of topological degree properties, and the solution representation of the considered network model are provided. Thirdly, a novel global asymptotic stability condition is proposed in the voice of LMIs, which is less conservative. Finally, our analytical results are justified with two numerical examples with simulations.     

电力系统中的时间同步网

首先探讨了在电力系统继电保护、自动经系统以及通信信息网中引入时间同步网的必要性，然后结合电信网时间同步网建设的经验，提出建设电力系统时间同步网的一些设想和初步的解决方案，特别是建设综合的主从等级结构的树形网结构的时间同步网的思路。     

Gasoline engine air filter health monitoring by second‐order sliding modes

This paper presents a novel and cheap methodology to classify healthy and clogged air filter. Air filter is an integral part of air intake system of spark ignition engine and is responsible to deliver clean air for combustion process. A clogged air filter may hamper engine power and its drivability performance. As a consequence, its health monitoring becomes mandatory. This task is accomplished by modeling the air filter effects on air flow through inlet manifold pressure by incorporating a newly introduced air filter discharge coefficient (C_af) in its dynamics. The estimation of C_af gives an idea about the health of air filter, as no sensor can be installed to measure it. A second‐order sliding mode observer is employed to estimate immeasurable C_af. Super twisting‐based sliding mode observer requires manifold pressure, engine angular speed, and load torque as input. A successful implementation has been carried out to diagnose clogged and healthy air filter of commercial vehicle engine compliant to on‐board diagnostics version‐II. This characterizes ‘ C_af’ as a clean indicator of air filter health classification. Copyright © 2012 John Wiley & Sons, Ltd.     

Sliding mode disturbance observer control based on adaptive synchronization in a class of fractional‐order chaotic systems

In this paper, a fractional‐order Dadras‐Momeni chaotic system in a class of three‐dimensional autonomous differential equations has been considered. Later, a design technique of adaptive sliding mode disturbance‐observer for synchronization of a fractional‐order Dadras‐Momeni chaotic system with time‐varying disturbances is presented. Applying the Lyapunov stability theory, the suggested control technique fulfils that the states of the fractional‐order master and slave chaotic systems are synchronized hastily. While the upper bounds of disturbances are unknown, an adaptive regulation scheme is advised to estimate them. The recommended disturbance‐observer realizes the convergence of the disturbance approximation error to the origin. Finally, simulation results are presented in one example to demonstrate the efficiency of the offered scheme on the fractional‐order Dadras‐Momeni chaotic system in the existence of external disturbances.     

Composite learning fuzzy synchronization for incommensurate fractional‐order chaotic systems with time‐varying delays

This paper presents a composite learning fuzzy control to synchronize two different uncertain incommensurate fractional‐order time‐varying delayed chaotic systems with unknown external disturbances and mismatched parametric uncertainties via the Takagi‐Sugeno fuzzy method. An adaptive controller together with fractional‐order composite learning laws is designed based on both a parallel distributed compensation technology and a fractional Lyapunov criterion. The boundedness of all variables in the closed‐loop system and the Mittag‐Leffler stability of tracking error can be guaranteed. T‐S fuzzy systems are provided to tackle unknown nonlinear functions. The distinctive features of the proposed approach consist in the following: (1) a supervisory control law is designed to compensate the lumped disturbances; (2) both the prediction error and the tracking error are used to estimate the unknown fuzzy system parameters; (3) parameter convergence can be ensured by an interval excitation condition. Finally, the feasibility of the proposed control strategy is demonstrated throughout an illustrative example.     

Finite‐time synchronization and adaptive synchronization of memristive recurrent neural networks with delays

This paper solves the finite‐time synchronization and adaptive synchronization problems of drive‐response memristive recurrent neural networks with delays under two control methods. First, the state‐feedback control rule containing delays and the adaptive control rule are designed for realizing synchronization of drive‐response memristive recurrent neural networks in finite time. Then, on the basis of the Lyapunov stability theory, many algebraic sufficient conditions are obtained to guarantee finite‐time synchronization and adaptive synchronization of drive‐response memristive recurrent neural networks via two control methods, which are easily verified. In addition, the estimation of the upper bounds of the settling time of finite‐time synchronization is obtained. Lastly, to illustrate the effectiveness of the obtained theoretical results, two examples are given.     

Adaptive function Q‐S synchronization of chaotic systems with unknown parameters

This work investigates the adaptive function Q‐S synchronization of non‐identical chaotic systems with unknown parameters. The sufficient conditions for achieving Q‐S synchronization with a desired scaling function of two different chaotic systems (including different dimensional systems) are derived based on the Lyapunov stability theory. By the adaptive control technique, the control laws and the corresponding parameter update laws are proposed such that the Q‐S synchronization of non‐identical chaotic systems is to be achieved. Finally, four illustrative numerical simulations are also given to demonstrate the effectiveness of the proposed scheme. Copyright © 2009 John Wiley & Sons, Ltd.     

Exponentially decaying DC offset removal for phasor measurement using second‐order differential

This letter proposes an exponentially decaying DC offset removal scheme for phasor measurement in power systems. Considering the features of the parameters of the transmission lines (i.e., the reactance X is much larger than the resistance R of a transmission line), the second‐order differential of a faulted current signal can be utilized to suppress the DC offset to a great degree. Then the full‐cycle Fourier algorithm (FFA) is employed to calculate the phasors of the periodic components correctly. Simulation studies demonstrate that the proposed scheme can remove the DC offset to a great degree, leading to higher accuracy and faster convergence in phasor calculation than FFA. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

电网备用调度系统的数据同步与采集解决方案

针对目前电网备用调度系统存在的备用效果差等现象。结合省级电网备用调度系统的工程实践,在分析研究电网备用调度各应用系统的备用工作方式、主调与备调自动化系统之间的数据同步、备调自动化系统数据采集方案的基础上．提出了可真正实现备用的备调自动化系统建设方案。通过对备调与主调EMS,HMS,TMR,OMS等系统的模型参数、实时数据和历史数据同步方式的研究,对主、备调数据同步的通信带宽进行了量化计算。独特地配置备调的调度数据网络,使地区调度、厂站在不需调试和改变IP地址的情况下实现与备调的网络通信。     

Second‐order intermodulation cancelation and conversion‐gain enhancement techniques for CMOS active mixers

In this paper, two new techniques are proposed to improve the second‐order input intercept point (IIP2) and conversion‐gain in double‐balanced Gilbert‐cell complementary metal‐oxide semiconductor (CMOS) mixers. The proposed IIP2 improvement technique is based on canceling the common‐mode second‐order intermodulation (IM2) component at the output current of the transconductance stage. Additionally, the conversion‐gain is improved by increasing the fundamental component of the transconductance stage output current and creating a negative capacitance to cancel the parasitic capacitors. Moreover, in the proposed IM2 cancelation technique, by decreasing the bias current of the switching transistors, the flicker noise of the mixer is reduced. The proposed mixer has been designed with input frequency and output bandwidth equal to 2.4 GHz and 20 MHz, respectively. Spectre‐RF simulation results show that the proposed techniques simultaneously improve IIP2 and conversion‐gain by approximately 23.2 and 5.7 dB, respectively, in comparison with the conventional mixer with the same power consumption. Also, the noise figure (NF) at 20 kHz, where the flicker noise is dominant, is reduced by 4.9 dB. The average NF is increased nearly 0.9 dB, and the value of third‐order input intercept point (IIP3) is decreased approximately 1.8 dB. Copyright © 2014 John Wiley & Sons, Ltd.     

基于．NET的智能型电网调度操作票管理系统

随着电网的发展,日常运行操作的数量和频度日益增大,计算机辅助开票系统应运而生。文中介绍了一种智能型电网调度操作票管理系统,它采用最新的计算平台．NET Frameworks,构建了4层体系结构,实现了如用户权限区分管理、操作票流程强制管理、自动规范操作票生成、根据典型票自动拟票等多种功能,且实践证明有效。