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1.
This paper considers the synchronization problem of coupled chaotic neural networks with time delay in the leakage term and parametric uncertainties using sampled-data control. Motivated by the achievements from both the stability of neural networks with time delay in the leakage term and the synchronization issue of coupled chaotic neural networks with parametric uncertainties, Lyapunov stability theory combining with linear matrix inequalities is employed to derive sufficient criteria ensuring the coupled chaotic neural networks to be completely synchronous. This paper presents an illustrative example and uses simulated results of this example to show the feasibility and effectiveness of the proposed sampled-data controller.  相似文献   

2.
In this study, a novel nonautonomous version of autonomous Chua's circuit is presented. The proposed nonautonomous version of Chua's circuit was designed by placing a sinusoidal source to the inner structure of the nonlinear resistor, namely, Chua's diode. The circuit's chaotic dynamics have been investigated by PSpice simulations and laboratory experiments.  相似文献   

3.
In this paper, modelling and simulation of Chua's chaotic oscillator, which exhibits rich chaotic behaviours, are presented by using the bond graph model. Up to now modelling of Chua's chaotic oscillator using bond graph model is not yet developed. The non-linear resistor in the circuit is modelled in this contribution by linear time-invariant components and ideal switches using piecewise linearization approach. The bond graph model of all the circuit including switches is then generated. Simulations are provided via the computer program called as BOMAS using the obtained bond graph model. Finally, Chua's circuit is verified experimentally. It is shown that all experimental and simulation results well agree with the chaotic behaviours of Chua's circuit.  相似文献   

4.
In this issue, the robust synchronization for a class of uncertain Cohen–Grossberg neural networks is studied, in which neuron activations are modelled by discontinuous functions(or piecewise continuous functions). Pinning state-feedback and adaptive controllers are designed to achieve global robust exponential synchronization and global robust asymptotical synchronization of drive-response-based discontinuous Cohen–Grossberg neural networks. By applying the theory of non-smooth analysis theory and the method of generalized Lyapunov functional, some criteria are given to show that the coupled discontinuous Cohen–Grossberg neural networks with parameter uncertainties can realized global robust synchronization. Some examples and numerical simulations are also shown to verify the validity of the proposed results.  相似文献   

5.
产业网络的复杂性研究与实证   总被引:16,自引:1,他引:16  
本文从复杂网络的角度提出了产业网络的三个层次的复杂性水平:要素、联系和系统动力学。通过对三个层次复杂性水平的分析得到,企业在产业网络中的地位是不同的,而且产业网络是一个具有无标度特性的复杂网络。本文还给出了产业网络的宏观和微观系统动力学模型,同时应用中国半导体产业网络对复杂性进行了实证。最后,得出结论:成员之间联系的本质和动态特性是产业网络复杂性的关键方面。  相似文献   

6.
根据Kolmogorov连续性定理,本文建立了混沌—神经网络(C-ANN)预测模型;提出了基于遗传算法和神经网络的混沌预测模型与方法(C-ANN-GA混合预测方法);解决了混沌时间序列的非解析式预测问题;使混沌时间序列预测方法得到了新的改进和发展。  相似文献   

7.
The paper attempts to develop a mathematical model of the national innovation system (NIS) of Taiwan, particularly with regard to its integrated circuit (IC) industry. The method utilised is that of system dynamics (SD). Drawing on both questionnaire/in-depth interviews and computer simulation, the paper aims to increase insights into the dynamic processes of the Taiwanese IC industry system of innovation and understand the interdependence and interaction among capital flows, human resource flows, knowledge and technology flows, and product flows in the NIS. The paper concludes with some simulations of policy alternatives confronting the IC industry and the Taiwanese government.  相似文献   

8.
9.
This paper presents an effective approach for controlling chaos. First, a neural-network (NN) model is employed to approximate the chaotic system. Then, a linear differential inclusion (LDI) state-space representation is established for the dynamics of an NN model. Based on the LDI state-space representation, a fuzzy controller is proposed to tame the chaotic system. If the designed fuzzy controller cannot suppress the chaos, a high frequency signal, commonly called dithers, is simultaneously injected into the chaotic system. According to the relaxed method, an appropriate dither is introduced to steer the chaotic motion into a periodic orbit or a steady state. If the frequency of dither is high enough, the trajectory described by the dithered chaotic system and that of its corresponding mathematical model—the relaxed system can be made as close as desired. This phenomenon enables us to get a rigorous prediction of the dithered chaotic system’s behavior by obtaining the behavior of the relaxed system. Finally, a numerical example with simulations is given to illustrate the concepts discussed throughout this paper.  相似文献   

10.
在本文中,主要阐述了DIS实验系统在电子电路实验教学中的优势。 DIS实验系统借助于传感器、数据采集器和计算机等先进信息技术工具优化传统实验环境,把实验过程变得易于操作,使电路中的物理规律变得易于理解和掌握。同时为学生的探究实验提供更多的途径和工具,更新、丰富了电子电路实验教学的内容。  相似文献   

11.
In this paper, we develop themes from complexity and chaos theory that help to explain the technological change process. We apply two quantifiers, correlation dimensions and Lyapunov exponents, to examine the signs and degrees of chaotic technological dynamics. To illustrate our ideas, we study the development of electronic displays from 1976 to 2010, using patent data. The results of the chaos model are matched against the profiles of patent citations. Our analysis contributes to the development of a chaotic model of technological change.  相似文献   

12.
万旭 《科技通报》2000,16(5):385-388
从三值GaAs逻辑输出级电路的等效开关模型出发,探索了适用于指导GaAs极性变换电路的设计。设计的电路已用PSPICE程序予以模型,结果表明,它们具有正确的逻辑功能与理想的瞬态特性。  相似文献   

13.
裂隙化岩体广泛存在于地表浅层,为主要的地下水渗透介质之一,而裂隙网络构成地下水及溶质在裂隙化岩体中运移的主要甚至唯一导水通道.根据图论知识将裂隙网络概化为非连通图,采用图这种数据结构表示三维裂隙网络数据.编写了计算机程序识别裂隙化岩体中沿水力梯度方向的渗流路径,剔除对渗流无贡献的裂隙,可明显缩短裂隙网络地下水渗流与溶质运移数值模拟计算时间,使大尺度裂隙网络渗流与溶质运移模拟研究与工程应用的可行性显著提高.  相似文献   

14.
神经网络和传统线性模型结合为处理混沌时间序列提供了新的途径。将Elman神经网络和单整自回归移动平均模型结合起来,同时分析我国进出口贸易量时间序列中的线性和非线性两部分,得到更准确的预测精度。实证表明,复合模型吸收两类方法的优点,较单一模型能够更有效地预测我国进出口数据。  相似文献   

15.
During the recent years several chaotic image encryption algorithms have been proposed, but most of them encountered some drawbacks such as small key space, low speed, lack of robustness and low security. In this paper, we have proposed an image algorithm based on the combination of a one-dimensional polynomial chaotic map and a piecewise nonlinear chaotic map. Theoretical analysis and computer simulations, both confirm that the new algorithm possesses high security, robust fast encryption speed for practical image encryption and solves the problem of small key space.  相似文献   

16.
17.
In this paper, we study the existence of strange attractors in a switch-controlled Chua's circuit. This circuit is obtained from the original Chua's circuit by adding externally controlled switches to it in such a way to modulate the system state variables. This investigation is conducted from the perspective of a recent chaos theory of rank one maps. The externally controlled switches are used for the purposes of realizing the general settings of the theory. Both synchronous and asynchronous switch control schemes providing periodic kicks in various directions are investigated, and their effects on the resulting chaotic attractors are discussed. The results of the numerical simulations presented are in close agreement with the expectations of the theory.  相似文献   

18.
Multiplex networks involve different types of synchronization due to their complex spatial structure. How to control multiplex networks to achieve different types of synchronization is an interesting topic. This paper considers the fixed-time synchronization of multiplex networks under sliding mode control (SMC). Firstly, for realizing three types of synchronization of multiplex networks in a fixed time, a unified sliding mode surface (SMS) is established. After that, based on the theory of SMC, a sliding mode controller (SMCr) which is more intelligent and has a simpler form than those in the existing literature is put forward for multiplex networks. It can not only guarantee the emergence of sliding mode motion, but also can realize three different kinds of synchronization by adjusting some parameters or even one parameter of the controller. Based on some theories of fixed-time stability, this paper deduces several sufficient conditions for the trajectories of the system to reach the preset SMS in a fixed time, and derives some sufficient conditions for multiplex networks to realize three different types of fixed-time synchronization. At the same time, the settling time which can reveal what factors determine the fixed-time synchronization in multiplex networks is obtained. Finally, in numerical simulations, different chaotic systems are set for each layer of multiplex networks to represent the nodes of different layers, which can prove that the theoretical results are practical and effective.  相似文献   

19.
This paper investigates the problem of finite-time outer-synchronization for discrete-time complex networks with Markov jump topology in the presence of communication delays and possible information losses and its application to image encryption. A hybrid control, which is subject to both stochastic jumps and deterministic switches, is proposed to realize finite-time and stochastic outer-synchronization for the concerned networks. By utilizing a stochastic Lyapunov functional combined with the average dwell-time method, sufficient conditions are found such that the synchronization error dynamical system is stochastically stable in finite-time. Two numerical examples are presented to illustrate the effectiveness of the proposed method. Finally, the complex network consists of four coupled Lorenz systems are utilized to generate chaotic sequences and a new chaotic image cryptosystem is constructed to transmit encrypted images based on the synchronized drive-response complex networks. Experiments are conducted by using numerical simulation, and the security is analyzed in terms of key space, key sensitivity, histogram distributions, correlation coefficients, information entropy and differential attack measures. The experimental results show that the proposed chaotic image cryptosystem has the advantages of high security against some classical attacks.  相似文献   

20.
   近年来,商业模式创新成为创业失败企业再发展的战略工具之一,商业模式创新路径研究广受关注,但鲜有研究涉及失败学习对商业模式创新的路径研究。基于经验学习理论和资源依赖理论,本文从知识管理和环境动态性视角,探讨了失败学习对商业模式创新的影响及其内在作用机制。基于215份企业调查数据,采用分层回归、Bootstrap等方法开展实证研究,结果表明:失败学习对商业模式创新有显著正向影响;知识管理3个维度都中介了失败学习与商业模式创新间的关系;环境动态性在知识获取与商业模式创新以及知识创造与商业模式创新的关系中均未起到调节作用;环境动态性不仅正向调节知识整合与商业模式创新间的关系,而且对知识整合在失败学习与商业模式创新关系间的中介作用具有显著的调节作用。研究结论进一步丰富了商业模式创新路径的研究成果,为企业商业模式创新实践提供了参考。  相似文献   

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