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Erratum: New resampling method to assess the accuracy of the maximal Lyapunov exponent estimation (Physica D (2001) 155 (101-111) PII: S0167278901002676)
No full textThe correct affiliations of the second author are given above
New resampling method to assess the accuracy of the maximal Lyapunov exponent estimation
No full textIn this paper, we propose a novel method to assess standard errors and confidence intervals for the maximal Lyapunov exponent estimated on time continuous chaotic systems. The method is based on resampling the original series by means of spline interpolation in the time domain. In such a way, new time series of increased size are obtained, and the sample distribution of the estimators is constructed. The method is explained and tested on the basis of computer simulations both for clean and noisy series. We give evidence that the distribution of the maximal Lyapunov exponent calculated by this method fairly agrees with the one obtained by true series with different initial conditions. An empirical criterion for the choice of the parameters of the resampling is also suggested. © 2001 Elsevier Science B.V
The mathematical structure of the genetic code: a tool for inquiring on the origin of life
No full textIn this paper we present a review and some new thoughts on our work about the mathematical structure of the genetic code. The model proposed is a new theoretical tool that allows a fresh insight on many open problems related to the origin, the evolution and the present structure of the
genetic machinery. In particular,we show that such model implies the existence of dichotomic classes, quantities that might play a preeminent role in the management of the genetic information including error control mechanisms. We introduce and use techniques for the analysis of dependent sequences in order to study the correlation structure of series of dichotomic classes derived from protein coding segments of DNA. The results show the existence of a complex context-dependent correlation structure; such dependence gives important information about coding and decoding strategies that nature has implemented along evolutionary times on DNA and RNA sequences
Testing Chaotic dynamics in systems with two positive Lyapunov exponents: a bootstrap solution
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The non-power model of the genetic code: A paradigm for interpreting genomic information
No full textIn this article, we present a mathematical framework based on redundant (non-power) representations of integer numbers as a paradigm for the interpretation of genomic information. The core of the approach relies onmodelling the degeneracy of the genetic code. The model allows one to explain many features and symmetries of the genetic code and to uncover hidden symmetries. Also, it provides us with new tools for the analysis of genomic sequences. We review briefly three main areas: (i) the Euplotid nuclear code, (ii) the vertebrate mitochondrial code, and (iii) the main coding/decoding strategies used in the three domains of life. In every case, we show how the non-power model is a natural unified framework for describing degeneracy and deriving sound biological hypotheses on protein coding. The approach is rooted on number theory and group theory; nevertheless, we have kept the technical level to a minimum by focusing on key concepts and on the biological implications
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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