共查询到20条相似文献,搜索用时 0 毫秒
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This paper firstly introduces the control methods to fractals and give the definition of synchronization of Julia sets between two different systems. Especially, the gradient control method is taken on the classic Julia sets of complex quadratic polynomial Zn+1 = zn^2+ c, which realizes its Julia sets control and synchronization. The simulations illustrate the effectiveness of the method. 相似文献
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A visualization of Julia sets of the complex Henon map system with two complex variables is introduced in this paper.With this method,the optimal control function method is introduced to this system and the control and synchronization of its Julia sets are achieved.Control and synchronization of generalized Julia sets are also achieved with this optimal control method.The simulations illustrate the efficacy of this method. 相似文献
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FU JingLi CHEN BenYong FU Hao ZHAO GangLing LIU RongWan & ZHU ZhiYan Institute of Mathematical Physics Zhejiang Sci-Tech University Hangzhou China Faculty of Mechanical Engineering & Automation China Jingye Engineering Corporation Limited Shenzhen Branch Shenzhen Shanghai University 《中国科学:物理学 力学 天文学(英文版)》2011,(2)
The theory of velocity-dependent symmetries(or Lie symmetry) and non-Noether conserved quantities are presented corresponding to both the continuous and discrete electromechanical systems.Firstly,based on the invariance of Lagrange-Maxwell equations under infinitesimal transformations with respect to generalized coordinates and generalized charge quantities,the definition and the determining equations of velocity-dependent symmetry are obtained for continuous electromechanical systems;the Lie's theorem and ... 相似文献
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We present a new generation of nano‐electromechanical systems (NEMS), which are realized by doping the semiconductor base material. In contrast to the traditional approach these doped NEMS (D‐NEMS) do not require a metallization layer. This makes them far lighter and hence increases resonance frequency and quality factor. Additionally, D‐NEMS can be tuned from the conductive state into an insulating one. This will enable a host of new device designs, like mechanically tunable pin‐junctions and nanomechanical single electron switches. We demonstrate D‐NEMS fabrication and operation from the intrinsic, to the light, and to the heavy regime of doping. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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We discuss the fractal dimension of the infinite cluster at the percolation threshold. Using sealing theory and renormalization group we present an explicit expression for the two-point correlation function within percolation clusters. The fractal dimension is given by direct integration of this function.See especially Ref. 1 for a discussion of the general aspects of percolation. 相似文献
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We study networks that display community structure--groups of nodes within which connections are unusually dense. Using methods from random matrix theory, we calculate the spectra of such networks in the limit of large size, and hence demonstrate the presence of a phase transition in matrix methods for community detection, such as the popular modularity maximization method. The transition separates a regime in which such methods successfully detect the community structure from one in which the structure is present but is not detected. By comparing these results with recent analyses of maximum-likelihood methods, we are able to show that spectral modularity maximization is an optimal detection method in the sense that no other method will succeed in the regime where the modularity method fails. 相似文献
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Irini S. Reljin Milka L. Avramov-Ivi? Goran I. Plavec Gordana M. Bogdanovi? 《Physica A》2008,387(14):3563-3573
Multifractal (MF) approach was applied for the analysis of ultraviolet/visible (UV/VIS) spectra as an independent confirmation of the diagnostic efficacy of UV/VIS spectral analysis of intraperitoneal fluids, ascites, taken from patients with a known clinical diagnosis. Recently, it was reported that from UV/VIS spectra differentiation of malignant from benign ascites is possible. Here, it was shown that by using MF analysis of UV/VIS spectra, the objective classification of UV/VIS spectra is possible. The applicability of UV/VIS analysis and MF classification of spectra were evaluated on N=68 cases, of which M=64 and B=4 were clinically confirmed as malignant and benign, respectively. The overall diagnostic efficacy was 89.71% when using on-line analysis of UV/VIS spectra (61 out of 68 samples were positively recognized: 58 malignant and 3 benign), and even 95.59% by using off-line MF classsification (65 out of 68 samples were classified correctly: 63 malignant and 2 benign). It can be inferred that UV/VIS spectral analysis of ascites, combined with MF analysis, could be suggested as a successful and safe screening method in the evaluation of intraperitoneal fluids. 相似文献
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For one-dimensional expanding mapsT with an invariant measure we consider, in a parameter space, the envelope
n
of the real lines associated to any couple of points of the orbit, connected byn iterations ofT. If the map hass inverses and is piecewise linear, then the sets
n
are just the union ofs
n
points and converge to the invariant Cantor set ofT. A correspondence between all the sets and their measures is established and allows one to associate the atomic measure on 1 to the completly continuous measure on the Cantor set. If the map is nonlinear, hyperbolic, and hass inverses, the sets
n
are homeomorphic to the Cantor set; they converge to the Cantor set ofT and their measures converge to the measure of the Cantor set whenn. The correspondence between the sets
n
allows one to define converging approximation schemes for the map an its measure: one replaces each of thes
n
disjoint sets with a point in a convenient neighborhood and a probability equal to its measure and transforms it back to the original set 1. All the approximations with linear Cantor systems previously proposed are recovered, the converging proprties being straightforward in the present scheme. Moreover, extensions to higher dimensionality and to nondisconnected repellers arte possible and are briefly examined. 相似文献
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P. Van Mieghem H. Wang X. Ge S. Tang F. A. Kuipers 《The European Physical Journal B - Condensed Matter and Complex Systems》2010,76(4):643-652
Newman’s measure for (dis)assortativity, the linear degree correlation coefficient $\rho _{D}$ , is reformulated in terms of the total number N k of walks in the graph with k hops. This reformulation allows us to derive a new formula from which a degree-preserving rewiring algorithm is deduced, that, in each rewiring step, either increases or decreases $\rho _{D}$ conform our desired objective. Spectral metrics (eigenvalues of graph-related matrices), especially, the largest eigenvalue $\lambda _{1}$ of the adjacency matrix and the algebraic connectivity $\mu _{N-1}$ (second-smallest eigenvalue of the Laplacian) are powerful characterizers of dynamic processes on networks such as virus spreading and synchronization processes. We present various lower bounds for the largest eigenvalue $\lambda _{1}$ of the adjacency matrix and we show, apart from some classes of graphs such as regular graphs or bipartite graphs, that the lower bounds for $\lambda _{1}$ increase with $\rho _{D}$ . A new upper bound for the algebraic connectivity $\mu _{N-1}$ decreases with $\rho _{D}$ . Applying the degree-preserving rewiring algorithm to various real-world networks illustrates that (a) assortative degree-preserving rewiring increases $\lambda _{1}$ , but decreases $\mu _{N-1}$ , even leading to disconnectivity of the networks in many disjoint clusters and that (b) disassortative degree-preserving rewiring decreases $\lambda _{1}$ , but increases the algebraic connectivity, at least in the initial rewirings. 相似文献
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B. Xu H.-T. Wang Y. P. Wang 《The European Physical Journal B - Condensed Matter and Complex Systems》2010,75(4):489-495
A ferrimagnetic spin model composed of S = 1/2 spin-dimers and S = 5/2 spin-chains is studied by combining
the bond-operator representation (for S = 1/2 spin-dimers) and Holstein-Primakoff transformation (for S = 5/2 spins).
A finite interaction J
DF between the spin-dimer and the spin chain makes the spin chains ordered
antiferromagnetically and the spin dimers polarized. The effective interaction between the spin chains,
mediated by the spin dimers, is calculated up to the third order. The staggered magnetization in the spin dimer is
shown proportional to J
DF. Due to the triplon-magnon interaction, the degeneracy of the triplons is lifted
and the hybridized triplon-like excitations show different behaviors near the vanishing J
DF. A mode with
longitudinal polarization is identified. The hybridized magnon-like excitations are also studied.
These results are compared with the experiments on Cu2Fe2Ge4O13. 相似文献
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We study the Schrödinger equation with potentials admitting quasinormal modes using the asymptotic iteration method (AIM). We also study non-Hermitian PT symmetric potentials using AIM. The spectra, in all cases, are found to be in excellent agreement with exact results. 相似文献
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H. Nakao Y. Kuramoto 《The European Physical Journal B - Condensed Matter and Complex Systems》1999,11(2):345-360
Multi-scaling properties in quasi-continuous arrays of chaotic maps driven by long-wave random force are studied. The spatial
pattern of the amplitude X(x,t) is characterized by multi-affinity, while the field defined by its coarse-grained spatial derivative exhibits multi-fractality. The strong behavioral similarity of the X- and Y-fields respectively to the velocity and energy dissipation fields in fully-developed fluid turbulence is remarkable, still
our system is unique in that the scaling exponents are parameter-dependent and exhibit nontrivial q-phase transitions. A theory based on a random multiplicative process is developed to explain the multi-affinity of the X-field, and some attempts are made towards the understanding of the multi-fractality of the Y-field.
Received 16 November 1998 相似文献
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N.N. Khuri 《Physics letters. [Part B]》1979,82(1):83-88
A Borel type summation of perturbation series with a conformal map of the Borel variable is considered for the case where renormalon singularities are present. Application of this method to λφ4/4! field theory in four dimensions allows us to compute a sum for the Gell-Mann-Low function, β(λ), for . This sum has an ultraviolet stable zero of . The case of quantum electrodynamics is also briefly considered. 相似文献
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The influence of chromomagnetic hyperfine interaction onB andT hadrons is studied. The colour magnetic moments are related to the hyperfine splittings of hadrons. 相似文献
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Mitchell J. Feigenbaum 《Journal of statistical physics》1987,46(5-6):925-932
The grand canonical version of the spectrum of singularities formalism is presented, relying naturally upon certain Markov transition graphs. The structure of a graph is simply determined by the close return times of the dynamical system described. Thus, an intimate connection exists between the shape of the singularity curve and a small but interesting set of dynamical properties. 相似文献