1,721,020 research outputs found
On the relationships between ancient exact science and musical acoustics
No full textThis work discusses the Hellenistic origin of some concepts underlying modern harmonic science. The framing of some ancient works in a long-term perspective allows us to highlight with particular evidence a drastic cultural break, which occurred around the middle of the second century B.C., following which important conceptual tools for the theoretical modeling of musical acoustic phenomena, such as coincidences, resonances and harmonics, underwent a significant process of fragmentation and decontextualization before reaching the hands of humanists and scientists in the first modern age, to the point of promoting, in the eyes of historians, an image of ancient harmonic science as a mere metaphysics dominated by mysticism and numerology [An expanded Italian version of this article has appeared in Isola (2021b).]
Recurrence and algorithmic information
Full text linkIn this paper, we initiate a somewhat detailed investigation of the relationships between quantitative recurrence indicators and algorithmic complexity of orbits in weakly chaotic dynamical systems. We mainly focus on examples
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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Lyapunov spectra of coupled map lattices
No full textThe relationship between the Lyapunov spectrum of diffusively coupled one-dimensional maps and the spectrum of the discrete Schrödinger operator is stressed. As a result, an analytic expression is derived for the Lyapunov spectrum for uniformly expanding maps. It is also shown that for a coupling strength larger than a critical value, the spectrum extends to - ∞. © 1990
Series expansions for Maass forms on the full modular group from the Farey transfer operators
Full text linkWe deepen the study of the relations previously established by Mayer, Lewis and Zagier, and the authors, among the eigenfunctions of the transfer operators of the Gauss and the Farey maps, the solutions of the Lewis-Zagier three-term functional equation and the Maass forms on the modular surface . In particular we introduce an ``inverse'' of the integral transform studied by Lewis and Zagier, and use it to obtain new series expansions for the Maass cusp forms and the non-holomorphic Eisenstein series restricted to the imaginary axis. As corollaries we obtain further information on the Fourier coefficients of the forms, including a new series expansion for the divisor function
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