1,720,977 research outputs found
Spontaneous Negative Entropy Increments in Granular Flows
No full textThe entropy inequality, commonly taken as an axiom of continuum mechanics, is found to be spontaneously violated in macroscopic granular media undergoing collisional dynamics. The result falls within the fluctuation theorem of nonequilibrium thermodynamics, which is known to replace the Second Law for finite systems. This phenomenon amounts to the system stochastically displaying negative increments of entropy. The focus is on granular media in Couette flows, consisting of monosized circular disks (with 10 to 104 disks of diameters 0.01 m to 1 m) with frictional-Hookean contacts simulated by molecular dynamics accounting for micropolar effects. Overall, it is determined that the probability of negative entropy increments diminishes with the Eulerian velocity gradient increasing, while it tends to increase in a sigmoidal fashion with the Young modulus of disks increasing. This behavior is examined for a very wide range of known materials: from the softest polymers to the stiffest (i.e., carbyne). The disks' Poisson ratio is found to have a weak effect on the probability of occurrence of negative entropy increments
Probability-Based Approach for Inverse Stochastic Structural Problems
No full textThe topic of this paper is related to the inverse stochastic mechanic problems, in which it is necessary to estimate the unknown mechanical and geometrical random quantities of the structures once the external loads and displacement responses are probabilistically known. In particular, in this work, a probability-based approach for inverse stochastic problems, working directly in terms of probability density functions (PDFs), is presented. This approach has been possible thanks to the application of the probability transformation method (PTM), which has been recently introduced for the solution of many stochastic analysis problems
Lo spazio complesso della democrazia. un nuovo realismo Oltre il «disagio» della teoria democratica
No full textIl saggio esamina la produzione teorica di Carlo Galli per evidenziarne le sollecitazioni utili a ripensare la democrazia in chiave "realistica"
La politica della paura all’ombra del Leviatano
No full textIl saggio ricostruisce l'elaborazione teorica della modernità politica e la sua crisi odierma alla luce delle trasformazioni dell'utilizzo politico della passione della paur
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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