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Human systems dynamics: Toward a computational model

AIP conference Proceedings 2012年第1期1479卷 634-637页

作者： Glenda H. Eoyang Human Systems Dynamics Institute' 50 East Golden Lake Road Circle Pines Minnesota 55014 USA

A robust and reliable computational model of complex human systems dynamics could support advancements in theory and practice for social systems at all levels, from intrapersonal experience to global politics and economics. Models of human interactions have evolved from traditional, Newtonian systems assumptions, which served a variety of practical and theoretical needs of the past. Another class of models has been inspired and informed by models and methods from nonlinear dynamics, chaos, and complexity science. None of the existing models, however, is able to represent the open, high dimension, and nonlinear self-organizing dynamics of social systems. An effective model will represent interactions at multiple levels to generate emergent patterns of social and political life of individuals and groups. Existing models and modeling methods are considered and assessed against characteristic pattern-forming processes in observed and experienced phenomena of human systems. A conceptual model, CDE Model, based on the conditions for self-organizing in human systems, is explored as an alternative to existing models and methods. While the new model overcomes the limitations of previous models, it also provides an explanatory base and foundation for prospective analysis to inform real-time meaning making and action taking in response to complex conditions in the real world. An invitation is extended to readers to engage in developing a computational model that incorporates the assumptions, meta-variables, and relationships of this open, high dimension, and nonlinear conceptual model of the complex dynamics of human systems.

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chaos theory based control of contact force in electric railway transportation system

Chaos theory based control of contact force in electric rail...

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International conference on Environment and Electrical Engineering (EEEIC)

作者： Rusu-Anghel Stela Miklos Cristina Topor Marcel Department of Electrical Engineering and Informatics Faculty of Engineering of Hunedoara University Polytechnica of Timisoara Hunedoara Romania

Improved current collection performance is one of the key requirements for railway speed-up, which is an issue of great importance in railway electric traction. At high speeds, the catenary-pantograph contact force can become zero, leading to contact loss, with well-known consequences. Some mathematical models have been developed, predicting the dynamic behaviour of this assembly and the contact force, but all of them have some degree of imprecision, (disregarding the phenomena difficult to model). They also can not be used in real time to control of contact force between the pantograph and catenary. In the present study, the contact force is divided into two components: 1) a deterministic one, corresponding to the mathematical model, 2) another one, with chaotic evolution, corresponding to the phenomena that can not be modelled. Finally, a control system is designed in order to control the pantograph dynamic regime, based on two subsystems: one for the deterministic component of the contact force, and another one for the chaotic component (using specific methods of chaotic systems). Both systems were simulated, showing promising results. Although they have been on DSP hardware implemented, they could not carry out industrial experiments.

关键词： Force Mathematical model chaos dynamics Atmospheric modeling Low pass filters nonlinear dynamical systems

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Performance Improvement of Heuristic Algorithms for Large Scale Combinatorial Optimization Problems using Lebesgue Spectrum Filter

Performance Improvement of Heuristic Algorithms for Large Sc...

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International Joint conference on Neural Networks

作者： Tomohiro Kato Mikio Hasegawa Kazuyuki Aihara Department of Electrical Engineering Tokyo University of Science Institute of Industrial Science The University of Tokyo

ISBN: (纸本)9781467314886

In this paper, we analyze effectiveness of a new metaheuristic approach, which utilizes ideal spatio-temporal chaotic dynamics generated by Lebesgue Spectrum Filter (LSF). In the previous researches on the additive chaotic noise to the heuristic searches for combinatorial optimization problems, it has been shown that the chaotic sequences with negative autocorrelation improve the performance of asynchronously updated algorithms, such as mutually connected neural networks, asynchronous heuristic searches and so on. The effectiveness of chaos can be understood by the conventional theory of the chaotic CDMA, which showed that the cross-correlation between the sequences with negative autocorrelation becomes lowest. The spatio-temporal chaotic searching dynamics with such lowest cross-correlation has been shown effective to improve asynchronously updated combinatorial optimization algorithms. In this paper, as such asynchronously updated combinatorial optimization algorithms, we introduce the 2-exchange method, the k-opt method, the Lin-Kernighan method, and the Or-opt method, and improve the performance of them by applying the LSF. Our numerical simulation results show that the performances of all above heuristic methods could be improved by using negative autocorrelation.

关键词： Component Combinatorial Optimization Problems K-opt Lin-Kernighan Or-opt nonlinear dynamics Lebesgue Spectrum Filter

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chaos theory : modeling, simulation and applications : selected papers from the 3rd Chaotic Modeling

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2011年

作者： Chaotic Modeling Simulation and Applications International conference

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Characterization of hyperchaotic states in the parameter-space of a modified Lorenz system

Characterization of hyperchaotic states in the parameter-spa...

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International conference on chaos and nonlinear dynamics - Dynamic Days South America

作者： Correia, Marcos J. Rech, Paulo C. Univ Estado Santa Catarina Dept Fis BR-89223100 Joinville Brazil

In this paper we report a new four-dimensional autonomous system, constructed from a Lorenz system by introducing an adequate feedback controller to the third equation. We use a numerical method that considers the second largest Lyapunov exponent value as a measure of hyperchaotic motion, to construct a two-dimensional parameter-space color plot for this system. Different levels of hyperchaos are represented in this plot by a continuously changing yellow-red scale. Practical applications of this plot includes, by instance, walking in the parameter-space of hyperchaotic systems along suitable paths.

关键词： Numerical methods

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Statistical approach to quantum chaotic ratchets: First results and open problems

Statistical approach to quantum chaotic ratchets: First resu...

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International conference on chaos and nonlinear dynamics - Dynamic Days South America

作者： Dana, Itzhack Bar Ilan Univ Minerva Ctr IL-52900 Ramat Gan Israel

This paper is a brief review of a new approach to the quantum-chaotic ratchet effect, introduced recently to address for the first time the sensitivity of the effect to the initial state in a global fashion. This is done by studying statistical properties of the ratchet current over well-defined sets of initial states. First results concern the semiclassical full-chaos regime, where the current is strongly sensitive to the initial state. Natural initial states in this regime are those that are phase-space uniform with the maximal possible resolution of one Planck cell. General arguments, for a class of paradigmatic model systems and for special quantum-resonance values of a scaled Planck constant (h) over bar, predict that the distribution of the momentum current over all such states is a zero-mean Gaussian with variance similar to D (h) over bar (2)/(2 pi(2)), where D is the chaotic-diffusion coefficient. This prediction is well supported by extensive numerical evidence. The average strength of the effect, measured by the variance above, is significantly larger than that for the usual momentum states and other states. Open problems, concerning extensions of these first results in different directions, are discussed.

关键词： Phase space methods

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A new method of generation of nonlinear normal modes for nonlinear dynamics of disordered structures

A new method of generation of nonlinear normal modes for non...

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3rd International conference on Computational methods in Structural dynamics and Earthquake Engineering, COMPDYN 2011

作者： Facchini, L. Rizzo, M. University of Florence Via S. Marta 3 50139 Firenze Italy

Structural response can be affected by randomness under two different points of view - either in the forcing process and/or in the structural behaviour. Various approaches can be employed to investigate the structural response, among which polynomial chaos (Ghanem, Spanos [1]) and perturbation approaches (Liu et al. [2], Chiostrini and Facchini [3]) can be found. Both kinds of approaches require the investigation of the response variation in dependence on the (random) structural parameters, thus - often dramatically - increasing the number of degrees of freedom of the examined system. In case of linearity of the system response, a modal reduction approach can be effectively employed together with perturbation techniques;on the other hand, for some kind of nonlinear systems, such reduction approach (Bucher [4], Geschwindner [5]) might fail to give satisfactory results unless a very large number of modes is employed in the analysis (Betti et al. [6]). The task of reducing the number of degrees of freedom of nonlinear systems has therefore to be accomplished by means of alternative procedures, such as the introduction of nonlinear normal modes.

关键词： nonlinear systems

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A RANSAC-Based ISOMAP for Filiform Manifolds in nonlinear Dynamical Systems-An Application to chaos in a Dripping Faucet

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21st International conference on Artificial Neural Networks, ICANN 2011

作者： Suetani, Hiromichi Akaho, Shotaro Kagoshima Univ Grad Sch Sci & Engn 1-21-35 Korimoto Kagoshima 8900065 Japan Sci & Technol Agcy PRESTO Decoding & Controlling Brain Informat Nagano Japan RIKEN Advanced Sci Inst RIKEN HYU Collaboration Res Ctr Flucto Order Funct Res Team Saitama 351 0198 Japan Nat Inst Advanced Ind Sci & Technol Ibaraki 305 8568 Japan

ISBN: (纸本)9783642217371;9783642217388

Trajectories generated from a chaotic dynamical system are lying on a nonlinear manifold in the state space. Even if the dimensionality of such a manifold is much lower than that of the full state space, we need many state variables to trace a motion on it as far as we remain to employ the original coordinate, so the resulting expression of the dynamics becomes redundant. In the present study, we employ one of the manifold learning algorithms, ISOMAP, to construct a new nonlinear coordinate that globally covers the manifold, which enables us to describe the dynamics on it as a low-dimensional dynamical system. Here, in order to improve the conventional ISOMAP, we propose an approach based on a combination with RANSAC for pruning the misconnected edges in the neighboring graph. We show that a clear deterministic relationship is extracted from time series of a mass-spring model for the chaotic dripping faucet using the proposed method.

关键词： Manifold learning ISOMAP kernel methods RANSAC chaotic dynamical systems

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A Simple Method for Visualizing the Phase Space of Chaotic dynamics System

A Simple Method for Visualizing the Phase Space of Chaotic D...

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International conference on Green Building, Materials and Civil Engineering (GBMCE 2011)

作者： Zhou, Linna Zhu, Shijian Lou, Jingjun Naval Univ Engn Ship & Power Engn Inst Wuhan 430074 Peoples R China

ISBN: (纸本)9783037852033

The chaotic dynamics system is so complex that the traditional methods of nonlinear numerical approximation can't intuitively reflect the characteristics of chaotic behaviors. We propose a simple method for visualizing the phase space of chaotic dynamics system. With the help of the visualization technology based on VTK(Visualization Toolkit), we can quickly render the phase space of the system with different phase values and this can help us explore the inner rule of chaotic dynamics system.

关键词： chaos dynamics system Phase space VTK Visualization

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nonlinear dynamics OF BUCK CONVERTER

NONLINEAR DYNAMICS OF BUCK CONVERTER

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8th International Scientific and Practical conference on Environment, Technology, Resources

作者： Pikulin, Dmitry Riga Tech Univ Fac Elect & Telecommun Azenes 12 Riga Latvia

ISBN: (纸本)9789984440712

This paper is concerned with the problem of modeling and simulation of piecewise linear systems with the pulse width modulation control. Models of this kind of systems are widely used in engineering practice, in particular in power electronic converters. The research provides the study of chaos and bifurcations in one of the switching converters - step-down converter under voltage mode control, operating in discontinuous and continuous current modes, using Matlab and Simulink simulation environment. Various types of models, including discrete - time maps, switched state - space models are examined in order to detect their suitability and reliability in numerical investigation of nonlinear phenomena in DC-DC converters. Some analytical methods for the search of periodic regimes and their stability estimation were also used in order to validate numerically obtained results and evaluate the accuracy of models used As direct simulation does not accurately pinpoint bifurcation points and computes only stable invariant sets, some aspects and advantages of numerical path-following are also discussed

关键词： bifurcation diagrams buck converter chaos path - following simulation tools

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