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1.
Symbolic dynamics of cellular automata is introduced by coarse-graining the temporal evolution orbits. Evolution languages are defined. By using the theory of formal languages and automata, the complexity of evolution languages of the elementary cellular automaton of rule 146 is studied and it is proved that its width 1-evolution language is regular, but for every n ≥ 2 its width n-evolution language is not context-free but context-sensitive. Also, the same results hold for the equivalent (under conjugation) elementary cellular automaton of rule 182.  相似文献   

2.
Human language may have started from a consistent set of mappings between meanings and signals. These mappings, referred to as the early vocabulary, are considered to be the results of conventions established among the agents of a population. In this study, we report simulation models for investigating how such conventions can be reached. We propose that convention is essentially the product of self‐organization of the population through interactions among the agents and that cultural selection is another mechanism that speeds up the establishment of convention. Whereas earlier studies emphasize either one or the other of these two mechanisms, our focus is to integrate them into one hybrid model. The combination of these two complementary mechanisms, i.e., self‐organization and cultural selection, provides a plausible explanation for cultural evolution, which progresses with high transmission rate. Furthermore, we observe that as the vocabulary tends to convergence there is a uniform tendency to exhibit a sharp phase transition. © 2002 Wiley Periodicals, Inc.  相似文献   

3.
In the early nineties of the previous century, leaf languages were introduced as a means for the uniform characterization of many complexity classes, mainly in the range between P (polynomial time) and PSPACE (polynomial space). It was shown that the separability of two complexity classes can be reduced to a combinatorial property of the corresponding defining leaf languages. In the present paper, it is shown that every separation obtained in this way holds for every generic oracle in the sense of Blum and Impagliazzo. We obtain several consequences of this result, regarding, e. g., universal oracles, simultaneous separations and type‐2 complexity.  相似文献   

4.
Complex Systems Science aims to understand concepts like complexity, self‐organization, emergence and adaptation, among others. The inherent fuzziness in complex systems definitions is complicated by the unclear relation among these central processes: does self‐organisation emerge or does it set the preconditions for emergence? Does complexity arise by adaptation or is complexity necessary for adaptation to arise? The inevitable consequence of the current impasse is miscommunication among scientists within and across disciplines. We propose a set of concepts, together with their possible information‐theoretic interpretations, which can be used to facilitate the Complex Systems Science discourse. Our hope is that the suggested information‐theoretic baseline may promote consistent communications among practitioners, and provide new insights into the field. Published 2008 Wiley Periodicals, Inc. Complexity, 2009  相似文献   

5.
The discovery of a simple functional the optimization of which by a dynamical process results in extraordinary structural organization in partially ordered sets is reported in this article. As partially ordered sets are one of the most prevalent and fundamental objects in Mathematics and are ubiquitous in nature, physics, engineering and technology in general, and since any system amenable to mathematical analysis can be represented as a partially ordered set, the discovery is proposed as an explanation for the phenomena of emergence and self‐organization in dynamical systems. © 2011Wiley Periodicals, Inc. Complexity, 17,19–38, 2011  相似文献   

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7.
Complex systems are fascinating because emergent phenomena are often unpredictable and appear to arise ex nihilo. The other side of this fascination, however, is a certain difficulty in comprehending complex systems, particularly for students. To help students more fully understand emergence and self‐organization, a course on complexity theory was designed to not only be about these two concepts, but itself embody them. The principal design tool was a course wiki. Here, we quantitatively demonstrate that this course wiki self‐organized into a scale‐free network. This is particularly notable given the small size of the network. We conclude by noting a few qualitative examples of emergence, as well as offering recommendations for the future use of wikis in teaching complexity theory. © 2010 Wiley Periodicals, Inc. Complexity 16: 41–48, 2011  相似文献   

8.
Chromosomes exhibit several features indicating that its spatiotemporal dynamics is self‐organized. It has been recently suggested that a negative correlation between genome size and mean chromosome number would also be a fingerprint of selforganization, related to how human language is organized at the level of words and syllables. However, the vast dominance of non‐coding DNA in eukaryotic genomes should prevent an interpretation of genome/chromosome size based on functional trade‐offs related to information storage and transmission. Moreover, the reported negative correlation is shown to be an inevitable consequence of the definitions of chromosome and genome length and it is thus unrelated to any type of special generative process. © 2010 Wiley Periodicals, Inc. Complexity 16: 20–23, 2010  相似文献   

9.
The ubiquity of scale‐free patterns in ecological systems has raised the possibility that these systems operate near criticality. Critical phenomena (CP) require the tuning of parameters and typically exhibit a narrow scaling region in which power laws hold. Here we show that an individual‐based predator‐prey model exhibits scaling properties similar to CP, generated by a percolation‐like transition but with a broader scaling region. There are no drastic changes in ecological quantities across this critical point and species coexist broadly in parameter space. The implications of these findings for the stability of ecological systems “near” criticality is discussed. © 2003 Wiley Periodicals, Inc.  相似文献   

10.
We prove that a certain binary linear code associated with the incidence matrix of a quasi‐symmetric 2‐(37, 9, 8) design with intersection numbers 1 and 3 must be contained in an extremal doubly even self‐dual code of length 40. Using the classification of extremal doubly even self‐dual codes of length 40, we show that a quasi‐symmetric 2‐(37, 9, 8) design with intersection numbers 1 and 3 does not exist.  相似文献   

11.
Menzerath‐Altmann law is a general law of human language stating, for instance, that the longer a word, the shorter its syllables. With the metaphor that genomes are words and chromosomes are syllables, we examine if genomes also obey the law. We find that longer genomes tend to be made of smaller chromosomes in organisms from three different kingdoms: fungi, plants, and animals. Our findings suggest that genomes self‐organize under principles similar to those of human language. © 2009 Wiley Periodicals, Inc. Complexity, 2010  相似文献   

12.
In this study, to demonstrate the language‐like behavior of protein length distribution in proteomes, a quantitative linguistic distribution model, Menzerath–Altmann model, was adopted. A total of 10 proteomes from completely sequenced representative organisms (archaea, bacteria, and eukarya domains) were examined. The results showed that the protein length distribution in the complete set of proteomic proteins, or at least in a wide range for each proteome, can be described reasonably well using the distribution model without considering any complex underlying mechanisms. The deliberation of the model parameters confirmed the evolutionary trend and the model parameters were observed to be related to organismal complexity. © 2014 Wiley Periodicals, Inc. Complexity 20: 12–21, 2014  相似文献   

13.
It is known that all doubly‐even self‐dual codes of lengths 8 or 16, and the extended Golay code, can be constructed from some binary Hadamard matrix of orders 8, 16, and 24, respectively. In this note, we demonstrate that every extremal doubly‐even self‐dual [32,16,8] code can be constructed from some binary Hadamard matrix of order 32. © 2004 Wiley Periodicals, Inc.  相似文献   

14.
Sertac Eroglu 《Complexity》2015,21(1):268-282
In a genome, genes (coding constituents) are interrupted by intergenic regions (noncoding constituents). This study provides a general picture of the large‐scale self‐organization of coding, noncoding, and total constituent lengths in genomes. Ten model genomes were examined and strong correlations between the number of genomic constituents and the constituent lengths were observed. The analysis was carried out by adopting a linguistic distribution model and a structural analogy between linguistic and genomic constructs. The proposed linguistic‐based statistical analysis may provide a fundamental basis for both understanding the linear structural formation of genomic constituents and developing insightful strategies to figure out the function of genic and intergenic regions in genomic sequences. © 2014 Wiley Periodicals, Inc. Complexity 21: 268–282, 2015  相似文献   

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This paper presents extended artificial physics optimization (EAPO), a population-based, stochastic, evolutionary algorithm (EA) for multidimensional search and optimization. EAPO extends the physicomimetics-based Artificial Physics Optimization (APO) algorithm by including each individual’s best fitness history. Including the history improves EAPO’s search capability compared to APO. EAPO and APO invoke a gravitational metaphor in which the force of gravity may be attractive or repulsive, the aggregate effect of which is to move individuals toward local and global optima. A proof of convergence is presented that reveals the conditions under which EAPO is guaranteed to converge. Discrete-time linear system theory is used to develop a second-order difference equation for an individual’s stochastic position vector as a function of time step. Stable solutions require eigenvalues inside the unit circle, leading to explicit convergence criteria relating the run parameters {miwG}. EAPO is tested against several benchmark functions with excellent results. The algorithm converges more quickly than APO and with better diversity.  相似文献   

17.
In this paper, we consider the Crank‐Nicolson extrapolation scheme for the 2D/3D unsteady natural convection problem. Our numerical scheme includes the implicit Crank‐Nicolson scheme for linear terms and the recursive linear method for nonlinear terms. Standard Galerkin finite element method is used to approximate the spatial discretization. Stability and optimal error estimates are provided for the numerical solutions. Furthermore, a fully discrete two‐grid Crank‐Nicolson extrapolation scheme is developed, the corresponding stability and convergence results are derived for the approximate solutions. Comparison from aspects of the theoretical results and computational efficiency, the two‐grid Crank‐Nicolson extrapolation scheme has the same order as the one grid method for velocity and temperature in H1‐norm and for pressure in L2‐norm. However, the two‐grid scheme involves much less work than one grid method. Finally, some numerical examples are provided to verify the established theoretical results and illustrate the performances of the developed numerical schemes.  相似文献   

18.
This article deals with the web‐spline‐based finite element approximation of quasi‐Newtonian flows. First, we consider the scalar elliptic p‐Laplace problem. Then, we consider quasi‐Newtonian flows where viscosity obeys power law or Carreau law. We prove well‐posedness at the continuous as well as the discrete level. We give some error bounds for the solution of quasi‐Newtonian flow problem based on the web‐spline method. Finally, we provide the numerical results for the p‐Laplace problem. © 2014 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq31: 54–77, 2015  相似文献   

19.
In this article, the steady‐state flow of a Hagen‐Poiseuille modelin a circular pipe is considered and entropy generation due tofluid friction and heat transfer is examined. Because of variationin fluid viscosity, the entropy generation in the flow varies. Inhis model, Arrhenius law is applied for temperature equation‐dependent viscosity, and the influence of viscosity parameters on the entropy generation number and distribution of temperature and velocity is investigated. The governing momentum and energy equations, which are coupled due to the dissipative term in the energy equation, were solved by analytical techniques. The solutions of equations via perturbation method and homotopy perturbation method are obtained and then compared with those of numerical solutions. It is found that the fluid viscosity influences considerably the temperature distribution in the fluid close to the pipe wall, and increasing pipe wall temperature enhances the rate of entropy generation. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 27: 529–540, 2011  相似文献   

20.
Weber integrals and Beltrami integrals are studied, which arise in the multipole expansions of spherical random fields. These integrals define spectral averages of squared spherical Bessel functions with Gaussian or exponentially cut power‐law densities. Finite series representations of the integrals are derived for integer power‐law index μ, which admit high‐precision evaluation at low and moderate Bessel index n. At high n, numerically tractable uniform asymptotic approximations are obtained on the basis of the Debye expansion of modified spherical Bessel functions in the case of Weber integrals. The high‐n approximation of Beltrami integrals can be reduced to Legendre asymptotics. The Airy approximation of Weber and Beltrami integrals is derived as well, and numerical tests are performed over a wide range of Bessel indices by comparing the exact finite series expansions of the integrals with their high‐index asymptotics. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

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