Extinction events and species lifetimes in a simple ecological modelA model for large-scale evolution recently introduced by Amaral and Meyer is studied analytically and numerically. Species are located at different trophic levels and become extinct if their prey…Barbara Drossel·May 18, 1998SaveLearn
Statistics of extinction and survival in Lotka-Volterra systemsWe analyze purely competitive many-species Lotka-Volterra systems with random interaction matrices, focusing the attention on statistical properties of their asymptotic states. Generic features of…Guillermo Abramson, Damian Zanette·May 15, 1998SaveLearn
Dynamics of Individual Specialization and Global Diversification in CommunitiesWe discuss a model of an economic community consisting of N interacting agents. The state of each agent at any time is characterized, in general, by a mixed strategy profile drawn from a space of…Vivek S. Borkar, Sanjay Jain, Govindan Rangarajan·Apr 30, 1998SaveLearn
Collective Behaviour and Diversity in Economic Communities: Some Insights from an Evolutionary GameMany complex adaptive systems contain a large diversity of specialized components. The specialization at the level of the microscopic degrees of freedom, and diversity at the level of the system as a…Vivek S. Borkar, Sanjay Jain, Govindan Rangarajan·Apr 30, 1998SaveLearn
Critical Exponent of Species-Size Distribution in EvolutionWe analyze the geometry of the species- and genotype-size distribution in evolving and adapting populations of single-stranded self-replicating genomes: here programs in the Avida world. We find that…Chris Adami, Ryoichi Seki, Robel Yirdaw·Apr 2, 1998SaveLearn
Generic Emergence of Power Law Distributions and Lévy-Stable Intermittent Fluctuations in Discrete Logistic SystemsThe dynamics of generic stochastic Lotka-Volterra (discrete logistic) systems of the form Solomon96a wi (t+1) = λ(t) wi (t) + a w (t) - b wi (t) w(t) is studied by computer…Ofer Biham, Ofer Malcai, Moshe Levy et al.·Mar 29, 1998SaveLearn
Large-scale evolution and extinction in a hierarchically structured environmentA class of models for large-scale evolution and mass extinctions is presented. These models incorporate environmental changes on all scales, from influences on a single species to global effects.…C. Wilke, S. Altmeyer, T. Martinetz·Mar 10, 1998SaveLearn
Diversity, Stability, Recursivity, and Rule Generation in Biological System: Intra-inter Dynamics ApproachBasic problems for the construction of a scenario for the Life are discussed. To study the problems in terms of dynamical systems theory, a scheme of intra-inter dynamics is presented. It consists of…Kunihiko Kaneko·Feb 20, 1998SaveLearn
Emergence of Rules in Cell Society: Differentiation, Hierarchy, and StabilityA dynamic model for cell differentiation is studied, where cells with internal chemical reaction dynamics interact with each other and replicate. It leads to spontaneous differentiation of cells and…Chikara Furusawa, Kunihiko Kaneko·Feb 13, 1998SaveLearn
Conditional exponents, entropies and a measure of dynamical self-organizationIn dynamical systems composed of interacting parts, conditional exponents, conditional exponent entropies and cylindrical entropies are shown to be well defined ergodic invariants which characterize…R. Vilela Mendes·Feb 5, 1998SaveLearn
Invariant closure for the Fokker-Planck equationWe develop the principle of dynamic invariance to obtain closed moment equations from the Fokker-Planck kinetic equation. The analysis is carried out to explicit formulae for computation of the…Ilya V. Karlin, V. B. Zmievskii·Feb 4, 1998SaveLearn
Modelling coevolution in multispecies communitiesWe introduce the Webworld model, which links together the ecological modelling of food web structure with the evolutionary modelling of speciation and extinction events. The model describes dynamics…Guido Caldarelli, Paul G. Higgs, Alan J. McKane·Jan 25, 1998SaveLearn
Probabilistic Analysis of the Number Partitioning ProblemGiven a sequence of N positive real numbers \a1,a2,..., aN \, the number partitioning problem consists of partitioning them into two sets such that the absolute value of the difference of…F F Ferreira, J F Fontanari·Jan 14, 1998SaveLearn
Geometric statistical inferenceFinite sample size corrections to the reparametrization-invariant solution of the inverse problem of probability are computed, and shown to converge uniformly to the correct distribution.Vipul Periwal·Dec 31, 1997SaveLearn
Adaptive Competition, Market Efficiency, Phase Transitions and Spin-GlassesWe analyze a simple model of adaptive competition which captures essential features of a variety of adaptive competitive systems in the social and biological sciences. Each of N agents, at each time…Robert Savit, Radu Manuca, Rick Riolo·Dec 23, 1997SaveLearn
Effects of neutral selection on the evolution of molecular speciesWe introduce a new model of evolution on a fitness landscape possessing a tunable degree of neutrality. The model allows us to study the general properties of molecular species undergoing neutral…M. E. J. Newman, Robin Engelhardt·Dec 15, 1997SaveLearn
Sentient NetworksIn this paper we consider the question whether a distributed network of sensors and data processors can form "perceptions" based on the sensory data. Because sensory data can have…George Chapline·Dec 13, 1997SaveLearn
Cellular automaton rules conserving the number of active sitesThis paper shows how to determine all the unidimensional two-state cellular automaton rules of a given number of inputs which conserve the number of active sites. These rules have to satisfy a…Nino Boccara, Henryk Fuks·Dec 12, 1997SaveLearn
Early-time critical dynamics of lattices of coupled chaotic mapsThe early-time critical dynamics of continuous, Ising-like phase transitions is studied numerically for two-dimensional lattices of coupled chaotic maps. Emphasis is laid on obtaining accurate…Philippe Marcq, Hugues Chate·Dec 10, 1997SaveLearn
Experiences with iterated traffic microsimulations in DallasThis paper reports experiences with iterated traffic microsimulations in the context of a Dallas study. ``Iterated microsimulations'' here means that the information generated by a…Kai Nagel·Dec 10, 1997SaveLearn
Multiresolution wavelet analysis of heartbeat intervals discriminates healthy patients from those with cardiac pathologyWe applied multiresolution wavelet analysis to the sequence of times between human heartbeats (R-R intervals) and have found a scale window, between 16 and 32 heartbeats, over which the widths of the…Stefan Thurner, Markus C. Feurstein, Malvin C. Teich·Nov 26, 1997SaveLearn
Absence of self-organized criticality in a random-neighbor version of the OFC stick-slip modelWe report some numerical simulations to investigate the existence of a self-organized critical (SOC) state in a random-neighbor version of the OFC model for a range of parameters corresponding to a…S. T. R. Pinho, C. P. C. Prado, O. Kinouchi·Nov 25, 1997SaveLearn
A condition for the genotype-phenotype mapping: CausalityThe appropriate choice of the genotype-phenotype mapping in combination with the mutation operator is important for a successful evolutionary search process. We suggest a measure to quantify the…Bernhard Sendhoff, Martin Kreutz, Werner von Seelen·Nov 4, 1997SaveLearn
TRANSIMS traffic flow characteristicsKnowledge of fundamental traffic flow characteristics of traffic simulation models is an essential requirement when using these models for the planning, design, and operation of transportation…Kai Nagel, Paula Stretz, Martin Pieck et al.·Oct 21, 1997SaveLearn
Self-Organized Criticality with Complex Scaling Exponents in the Train ModelThe train model which is a variant of the Burridge-Knopoff earthquake model is investigated for a velocity-strengthening friction law. It shows self-organized criticality with complex scaling…Franz-Josef Elmer·Oct 12, 1997SaveLearn