1,721,024 research outputs found
Non-sequential recursive pair substitution: some rigorous results
No full textWe present rigorous results on some open questions on NSRPS, the
non-sequential recursive pairs substitution method. In particular, starting from
the action of NSRPS on finite strings we define a corresponding natural action
on measures and we prove that the iterated measure becomes asymptotically
Markov. This certifies the effectiveness of NSRPS as a tool for data compression
and entropy estimation
Some aspects of the inertial spin model for flocks and related kinetic equations
Full text linkIn this paper, we study the macroscopic behavior of the inertial spin (IS) model. This model has been recently proposed to describe the collective dynamics of flocks of birds, and its main feature is the presence of an auxiliary dynamical variable, a sort of internal spin, which conveys the interaction among the birds with the effect of better describing the turning of flocks. After discussing the geometrical and mechanical properties of the IS model, we show that, in the case of constant interaction among the birds, its mean-field limit is described by a nonlinear Fokker-Planck equation, whose equilibria are fully characterized. Finally, in the case of non-constant interactions, we derive the kinetic equation for the mean-field limit of the model in the absence of thermal noise, and explore its macroscopic behavior by analyzing the mono-kinetic solutions
MEAN-FIELD LIMIT FOR PARTICLE SYSTEMS WITH TOPOLOGICAL INTERACTIONS
Full text linkThe mean-field limit for systems of self-propelled agents with “topological interaction” cannot be obtained by means of the usual Dobrushin approach. We get results by adapting to the multidimensional case the techniques developed by Trocheris in 1986 to treat the Vlasov-Poisson equation in one dimension
On the propagation of a perturbation in an anharmonic system
No full textWe give a not trivial upper bound on the velocity of disturbances in an infinitely extended anharmonic system at thermal equilibrium. The proof is achieved by combining a control on the non equilibrium dynamics with an explicit use of the state invariance with respect to the time evolution
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
Quel che resta di un calice trecentesco.
No full textL'articolo pubblica il piede di un calice trecentesco, rimontato in un calice ottocentesco
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
Antiquaria cristiana e memorie agatine a Catania: materiali e documenti dalla chiesa di Sant’Agata la Vetere e dagli archivi cittadini
No full textUna inedita cassa reliquiario nella chiesa di Sant'Agata la Vetere a Catania, riallestita dopo il terremoto del 1693, offre lo spunto per una riflessione sui processi di elaborazione dei simboli dell'identità cittadina.
An unpublished reliquary box in the church of Sant'Agata la Vetere in Catania, reorganized after the earthquake of 1693, offers an opportunity to reflect on the processes of elaboration of the symbols of the city's identity
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