An improved impulsive control approach to robust lag synchronization between two different chaotic systems     

马铁东  浮洁  孙跃 《海洋学报(英文版)》2010,29(9)

In this paper, a novel robust impulsive lag synchronization scheme for different chaotic systems with parametric uncertainties is proposed. Based on the theory of impulsive functional differential equations and a new differential inequality, some new and less conservative sufficient conditions are established to guarantee that the error dynamics can converge to a predetermined region. Finally, some numerical simulations for the Lorenz system and Chen system are given to demonstrate the effectiveness and feasibility of the proposed method. Compared with the existing results based on so-called dual-stage impulsive control, the derived results reduce the complexity of impulsive controller, moreover, a larger stable region can be obtained under the same parameters, which can be shown in the numerical simulations finally.  相似文献   

Synchronization between fractional-order chaotic systems and integer orders chaotic systems (fractional-order chaotic systems)     

周平  程元明  邝菲 《海洋学报(英文版)》2010,29(9)

Based on the idea of tracking control and stability theory of fractional-order systems, a controller is designed to synchronize the fractional-order chaotic system with chaotic systems of integer orders, and synchronize the different fractional-order chaotic systems. The proposed synchronization approach in this paper shows that the synchronization between fractional-order chaotic systems and chaotic systems of integer orders can be achieved, and the synchronization between different fractional-order chaotic systems can also be realized. Numerical experiments show that the present method works very well.  相似文献   

Cognitive radio resource allocation based on coupled chaotic genetic algorithm   总被引：1，自引：0，他引：1  

俎云霄  周杰  曾昶畅 《海洋学报(英文版)》2010,29(11)

A coupled chaotic genetic algorithm for cognitive radio resource allocation which is based on genetic algorithm and coupled Logistic map is proposed. A fitness function for cognitive radio resource allocation is provided. Simulations are conducted for cognitive radio resource allocation by using the coupled chaotic genetic algorithm, simple genetic algorithm and dynamic allocation algorithm respectively. The simulation results show that, compared with simple genetic and dynamic allocation algorithm, coupled chaotic genetic algorithm reduces the total transmission power and bit error rate in cognitive radio system, and has faster convergence speed.  相似文献   

海洋激流的观测实验及分析讨论   总被引：5，自引：1，他引：5  

修日晨  张自历  刘爱菊 《海洋学报》2004,26(2):118-124

海洋中存在着冲击力极强的海洋激流,这已是不争的事实.从20世纪70年代起,一些国家就开始对大洋海底激流进行现场观测.据报道,他们所观测到的异常的底层流速的最大值仅为0.4m/s,却被视之为海底激流加以分析研究[1～5].  相似文献   

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秦永宽  黄声享  赵卿 《大地测量与地球动力学》2008,28(6):96-100

?????С???????????????????LS-SVM??????????μ???????????????????μ????????н???С???????????C-C??????????????????????????????????????????????????????????????????LS-SVM??????н?????????BP??????????????????????????????????????С???????LS-SVM????????????????????н??????Ч????  相似文献   

混沌理论在变形分析与预报中的应用     

鲁金金  黎小浪  文鸿雁  王式太 《地理空间信息》2012,(1):137-138,145,5

由于受到各种环境因素及仪器本身的影响,变形监测被看作为一个复杂系统。它本身的各种参变量是不确定的、随机的,表现为复杂的非线性行为。运用现代混沌理论,对变形监测时间序列进行探索性研究,把混沌时间序列理论引入到变形分析研究中,对该理论的建立及预测方法进行了讨论。通过实例表明混沌时间序列预测方法对变形数据序列的预测具有比较好的精度。  相似文献   

Mud volcanoes, olistostromes and Argille scagliose in the Mediterranean region   总被引：1，自引：0，他引：1  

ANGELO CAMERLENGHI  GIAN ANDREA PINI† 《Sedimentology》2009,56(1):319-365

Tectonic and sedimentary mélanges, rocks with block-in-matrix fabric often referred to as 'chaotic', are widespread in the circum-Mediterranean collisional orogenic belts as well as in submerged Mediterranean Arcs. These rock types have been defined originally as 'Argille scagliose' (Bianconi, 1840) and 'olistostromes' (Flores, 1955, 1959) in the outcrops of the Apennine chain (Italy). Both terminology and concepts have undergone a rather complex evolution through time owing to the gradual recognition of similar chaotic bodies in all the circum-Mediterranean orogenic belts. Submarine mud volcanoes of the Mediterranean region, also composed by block-in-matrix, more commonly referred to as mud breccias, have a much younger history. These mud breccias were discovered in 1981 and, since then, a growing number of sea-going geophysical and geological expeditions have allowed the recognition of a major mud volcano belt in the Eastern Mediterranean and of a number of mud diapirs and mud volcano fields from the Black Sea to the Gulf of Cadiz. Structural, textural and genetic similarities between the mud breccias of the Mediterranean mud volcanoes and the olistostromes and Argille scagliose of the Apennines were noted from the very beginning, but the matter has not been the focus of any detailed study. In this paper, the use of the terms in the geological literature is analysed, the distribution of these rock units in the Mediterranean region explored and the assumed genetic processes are identified in order to formulate a common genetic model that can be applied to the evolution of the circum-Mediterranean sedimentary basins.  相似文献   

Experimental observation of strong mixing due to internal wave focusing over sloping terrain     

Arno Swart  Astrid Manders  Uwe Harlander  Leo R.M. Maas 《Dynamics of Atmospheres and Oceans》2010

This paper reports on experimental observation of internal waves that are focused due to a sloping topography. A remarkable mixing of the density field was observed. This result is of importance for the deep ocean, where internal waves are believed to play a role in mixing. The experiments were performed on the rotating platform at the Coriolis Laboratory, Grenoble. The rotation, its modulation and density stratification were set to be in the internal wave regime. After applying various data processing techniques we observe internal wave rays, which converge to a limiting state: the wave attractor. At longer time scales we observe a remarkably efficient mixing of the density field, possibly responsible for driving observed sheared mean flows and topographic Rossby waves. We offer the hypothesis that focusing of internal waves to the wave attractor leads to the mixing.  相似文献   

Mechanisms of variability and predictability of the tropical coupled ocean-atmosphere system     

B. N. Goswami  Sudha Selvarajan  V. Krishnamurthy 《Journal of Earth System Science》1993,102(1):49-72

A conceptual model is proposed to explain the observed aperiodicity in the short term climate fluctuations of the tropical coupled ocean-atmosphere system. This is based on the evidence presented here that the tropical coupled ocean-atmosphere system sustains a low frequency inter-annual mode and a host of higher frequency intra-seasonal unstable modes. At long wavelengths, the low frequency mode is dominant while at short wavelengths, the high frequency modes are dominant resulting in the co-existence of a long wave low frequency mode with some short wave intra-seasonal modes in the tropical coupled system. It is argued that due to its long wavelength, the low frequency mode would behave like a linear oscillator while the higher frequency short wave modes would be nonlinear. The conceptual model envisages that an interaction between the low frequency linear oscillator and the high frequency nonlinear oscillations results in the observed aperiodicity of the tropical coupled system. This is illustrated by representing the higher frequency intra-seasonal oscillations by a nonlinear low order model which is then coupled to a linear oscillator with a periodicity of four years. The physical mechanism resulting in the aperiodicity in the low frequency oscillations and implications of these results on the predictability of the coupled system are discussed.  相似文献   

基于多种度量的电离层TEC混沌预测分析     

孙佳龙  郭金运  郭淑艳 《地球物理学进展》2013,28(3)

利用东经120°,北纬45°上空的2008年年积日101～150 d时间段内共600个电离层格网TEC数据为时间序列样本,分析了该点上空电离层TEC参数的混沌特性,发现其关联维数为2.2632,嵌入维数为5,最大Lyapunov指数为λ=0.0833,表明该点上空电离层TEC时间序列具有混沌的特征,存在混沌现象.采用加权一阶局域法对TEC时间序列进行预测时,在有效预报尺度内,利用各种度量进行预报得到的中误差都随着预报天数的增加而逐渐增大,但预报的相对误差却是在一定幅度范围内上下波动.采用四种距离度量以及皮尔森相关系数和Jaccard相似系数进行预报,其预测结果或者平均中误差较大,或者平均相对误差较大,结果不理想.其中,采用标准化欧氏距离得到的平均中误差最大,达到5.107TECU,而采用皮尔森相关系数得到的平均中误差最小,为5.078TECU;对于平均相对误差而言,由切比雪夫距离得到的平均相对误差最大,为0.185,而Jaccard相似系数得到的平均相对误差最小,为0.166.而采用余弦相似度得到的预测结果,其平均中误差和平均相对误差都很小,分别为5.079TECU和0.167.因此,在一阶局域混沌预测时,采用余弦相似度作为衡量相空间轨迹的差异性是较为合适的.  相似文献