Rank Histograms are suitable tools to assess the quality of ensembles within an ensemble prediction system or framework. By counting the rank of a given variable in the ensemble, we are basically making a sample analy...Rank Histograms are suitable tools to assess the quality of ensembles within an ensemble prediction system or framework. By counting the rank of a given variable in the ensemble, we are basically making a sample analysis, which does not allow us to distinguish if the origin of its variability is external noise or comes from chaotic sources. The recently introduced Mean to Variance Logarithmic （MVL） Diagram accounts for the spatial variability, being very sensitive to the spatial localization produced by infinitesimal perturbations of spatiotemporal chaotic systems. By using as a benchmark a simple model subject to noise, we show the distinct information given by Rank Histograms and MVL Diagrams. Hence, the main effects of the external noise can be visualized in a graphic. From the MVL diagram we clearly observe a reduction of the amplitude growth rate and of the spatial localization （chaos suppression）, while from the Rank Histogram we observe changes in the reliability of the ensemble. We conclude that in a complex framework including spatiotemporal chaos and noise, both provide a more complete forecasting picture.展开更多
We study quantum motion around a classical heteroclinic point of a single trapped ion interacting with a strong laser standing wave. We construct a set of exact coherent states of the quantum system and from the exact...We study quantum motion around a classical heteroclinic point of a single trapped ion interacting with a strong laser standing wave. We construct a set of exact coherent states of the quantum system and from the exact solutions reveal that quantum signatures of chaos can be induced by the adiabatic interaction between the trapped ion and the laser standing wave, where the quantum expectation values of position and momentum correspond to the classically chaotic orbit. The chaotic region on the phase space is illustrated. The energy crossing and quantum resonance in time evolution and the exponentially increased Heisenberg uncertainty are found. The results suggest a theoretical scheme for controlling the unstable regular and chaotic motions.展开更多
According to the nonlinear theory, the experiments have been conducted on sample ECG (electrocardiogram) signals of healthy human beings, coronary heart disease patients and adult canines. On the basis of the analyses...According to the nonlinear theory, the experiments have been conducted on sample ECG (electrocardiogram) signals of healthy human beings, coronary heart disease patients and adult canines. On the basis of the analyses of the power spectra, the computation of the correlation dimension and the Lyapunov exponent to a large number of ECG signals, the following conclusions are shown: through the comparative research, (1) the analyses of the power spectra, the computation of the correlation dimension and the Lyapunov exponent to the ECG signals reflect the whole dynamic characteristics of the hearts, and they may become a new method of researching ECG quantitatively to an early diagnose of heart disease. (2) Under normal physiological conditions the cardiac activities are chaotic, while under pathologic conditions the cardiac activities approach regularity. (3) On the basis of the comparative research of human beings and canines, it is revealed that chaos may be a quantitative index to measure the evolution展开更多
Breakthrough innovation is seen as a leading technology and industrial development direction, by which enterprises obtain the key for winning sustainable competitive advantage. In this paper, a chaos model is develope...Breakthrough innovation is seen as a leading technology and industrial development direction, by which enterprises obtain the key for winning sustainable competitive advantage. In this paper, a chaos model is developed to examine how the breakthrough innovation evolves with the changed external environment ability and internal power. Numerical simulations based on chaos theory illustrate that the breakthrough innovation leads to chaos through the period-doubling bifurcation, and the chaos is the result of nonlinear interaction which is a qualitative change in the process between internal dynamics and external factors. The general conditions in which the breakthrough innovation comes to chaos instead of being in good order are gotten. The results show that the breakthrough innovation has chaotic characteristics and has a very sensitive dependence on the initial conditions in the process of running. The chaotic evolution can reflect the nonlinear character of the breakthrough innovation development and it can provide theoretical guidance for the application of chaos and chaotic control of innovation management.展开更多
In this paper, we explain why the chaotic mutation （CM） model of J. M. Bahi and C. Michel （2008） simulates the genes mutations over time with good accuracy. It is firstly shown that the CM model is a truly chaotic...In this paper, we explain why the chaotic mutation （CM） model of J. M. Bahi and C. Michel （2008） simulates the genes mutations over time with good accuracy. It is firstly shown that the CM model is a truly chaotic one, as it is defined by Devaney. Then, it is established that mutations occurring in genes mutations have indeed a same chaotic dynamic, thus making relevant the use of chaotic models for genomes evolution. Transposition and inversion dynamics are finally investigated.展开更多
长期演进(Long Term Evolution,LTE)作为当前主流的无线通信技术之一,其性能优化是当前研究的热点。文章针对LTE网络中的资源分配问题展开研究,通过分析正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)技术的基本原理,...长期演进(Long Term Evolution,LTE)作为当前主流的无线通信技术之一,其性能优化是当前研究的热点。文章针对LTE网络中的资源分配问题展开研究,通过分析正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)技术的基本原理,深入探讨其资源分配问题。针对传统粒子群优化(Particle Swarm Optimization,PSO)算法在资源分配过程中存在的局限性,文章研究一种基于混沌优化的PSO算法,以提高算法的全局搜索能力和收敛速度。通过在NS-3仿真平台上进行实验验证,结果表明混沌优化的PSO算法在不同网络负载情况下均能有效增加系统吞吐量,相比传统PSO算法具有更好的性能表现。展开更多
现有电力系统稳定器(power system stabilizer,PSS)和直流调制多使用本地信号作为控制器反馈输入信号,控制器间的交互作用可能降低甚至破坏系统稳定性。提出了一种基于广域测量信号的PSS与直流调制协调策略,首先通过留数法选择对于振荡...现有电力系统稳定器(power system stabilizer,PSS)和直流调制多使用本地信号作为控制器反馈输入信号,控制器间的交互作用可能降低甚至破坏系统稳定性。提出了一种基于广域测量信号的PSS与直流调制协调策略,首先通过留数法选择对于振荡模态可观性较强的广域信号作为阻尼控制器备选反馈信号;其次通过相对增益方法选择使PSS和直流调制交互影响最小的备选信号作为最佳反馈信号;而后设计分散控制器,并运用基于混沌和差分进化的混合粒子群优化算法对PSS和直流调制控制器参数进行协调优化。最后,通过EPRI 36节点系统仿真验证了协调策略的正确性和有效性。展开更多
基金support from MEC,Spain,through Grant No.CGL2007-64387/CLIthe AECID,Spain,for support through projects A/013666/07 and A/018685/08
文摘Rank Histograms are suitable tools to assess the quality of ensembles within an ensemble prediction system or framework. By counting the rank of a given variable in the ensemble, we are basically making a sample analysis, which does not allow us to distinguish if the origin of its variability is external noise or comes from chaotic sources. The recently introduced Mean to Variance Logarithmic （MVL） Diagram accounts for the spatial variability, being very sensitive to the spatial localization produced by infinitesimal perturbations of spatiotemporal chaotic systems. By using as a benchmark a simple model subject to noise, we show the distinct information given by Rank Histograms and MVL Diagrams. Hence, the main effects of the external noise can be visualized in a graphic. From the MVL diagram we clearly observe a reduction of the amplitude growth rate and of the spatial localization （chaos suppression）, while from the Rank Histogram we observe changes in the reliability of the ensemble. We conclude that in a complex framework including spatiotemporal chaos and noise, both provide a more complete forecasting picture.
基金The project supported by National Natural Science Foundation of China under Grant No.10575034the Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics of China under Grant No.T152504
文摘We study quantum motion around a classical heteroclinic point of a single trapped ion interacting with a strong laser standing wave. We construct a set of exact coherent states of the quantum system and from the exact solutions reveal that quantum signatures of chaos can be induced by the adiabatic interaction between the trapped ion and the laser standing wave, where the quantum expectation values of position and momentum correspond to the classically chaotic orbit. The chaotic region on the phase space is illustrated. The energy crossing and quantum resonance in time evolution and the exponentially increased Heisenberg uncertainty are found. The results suggest a theoretical scheme for controlling the unstable regular and chaotic motions.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 69974008)the Chinese Postdoctoral Science Foundation and the Natural Science Foundation of Liaoning Province (Grant No. 972194).
文摘According to the nonlinear theory, the experiments have been conducted on sample ECG (electrocardiogram) signals of healthy human beings, coronary heart disease patients and adult canines. On the basis of the analyses of the power spectra, the computation of the correlation dimension and the Lyapunov exponent to a large number of ECG signals, the following conclusions are shown: through the comparative research, (1) the analyses of the power spectra, the computation of the correlation dimension and the Lyapunov exponent to the ECG signals reflect the whole dynamic characteristics of the hearts, and they may become a new method of researching ECG quantitatively to an early diagnose of heart disease. (2) Under normal physiological conditions the cardiac activities are chaotic, while under pathologic conditions the cardiac activities approach regularity. (3) On the basis of the comparative research of human beings and canines, it is revealed that chaos may be a quantitative index to measure the evolution
基金Supported by the National Natural Science Foundation of China(71572028,71872027)the Research Funds of Civil Aviation Flight University of China(XM3882).
文摘Breakthrough innovation is seen as a leading technology and industrial development direction, by which enterprises obtain the key for winning sustainable competitive advantage. In this paper, a chaos model is developed to examine how the breakthrough innovation evolves with the changed external environment ability and internal power. Numerical simulations based on chaos theory illustrate that the breakthrough innovation leads to chaos through the period-doubling bifurcation, and the chaos is the result of nonlinear interaction which is a qualitative change in the process between internal dynamics and external factors. The general conditions in which the breakthrough innovation comes to chaos instead of being in good order are gotten. The results show that the breakthrough innovation has chaotic characteristics and has a very sensitive dependence on the initial conditions in the process of running. The chaotic evolution can reflect the nonlinear character of the breakthrough innovation development and it can provide theoretical guidance for the application of chaos and chaotic control of innovation management.
文摘In this paper, we explain why the chaotic mutation （CM） model of J. M. Bahi and C. Michel （2008） simulates the genes mutations over time with good accuracy. It is firstly shown that the CM model is a truly chaotic one, as it is defined by Devaney. Then, it is established that mutations occurring in genes mutations have indeed a same chaotic dynamic, thus making relevant the use of chaotic models for genomes evolution. Transposition and inversion dynamics are finally investigated.
文摘长期演进(Long Term Evolution,LTE)作为当前主流的无线通信技术之一,其性能优化是当前研究的热点。文章针对LTE网络中的资源分配问题展开研究,通过分析正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)技术的基本原理,深入探讨其资源分配问题。针对传统粒子群优化(Particle Swarm Optimization,PSO)算法在资源分配过程中存在的局限性,文章研究一种基于混沌优化的PSO算法,以提高算法的全局搜索能力和收敛速度。通过在NS-3仿真平台上进行实验验证,结果表明混沌优化的PSO算法在不同网络负载情况下均能有效增加系统吞吐量,相比传统PSO算法具有更好的性能表现。
文摘现有电力系统稳定器(power system stabilizer,PSS)和直流调制多使用本地信号作为控制器反馈输入信号,控制器间的交互作用可能降低甚至破坏系统稳定性。提出了一种基于广域测量信号的PSS与直流调制协调策略,首先通过留数法选择对于振荡模态可观性较强的广域信号作为阻尼控制器备选反馈信号;其次通过相对增益方法选择使PSS和直流调制交互影响最小的备选信号作为最佳反馈信号;而后设计分散控制器,并运用基于混沌和差分进化的混合粒子群优化算法对PSS和直流调制控制器参数进行协调优化。最后,通过EPRI 36节点系统仿真验证了协调策略的正确性和有效性。
