1,721,626 research outputs found
Intertwining operators for symmetric hyperbolic systems on globally hyperbolic manifolds
No full textIn this paper, a geometric process to compare solutions of symmetric hyperbolic systems on (possibly different) globally hyperbolic manifolds is realized via a family of intertwining operators. By fixing a suitable parameter, it is shown that the resulting intertwining operator preserves Hermitian forms naturally defined on the space of homogeneous solutions. As an application, we investigate the action of the intertwining operators in the context of algebraic quantum field theory. In particular, we provide a new geometric proof for the existence of the so-called Hadamard states on globally hyperbolic manifolds
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
Sepolture urbane nell’Apulia tardoantica e altomedievale. Il caso di Herdonia
No full textThe practice of burying the dead within the city walls, although initially sporadic, grew to become common practice as from the sixth century B.C. This was a clear infringement of the law as laid down in the mid fifth century, in the Twelve Tables. Former studies have concentrated on the practice of burying the dead in those areas of Rome and Northern Italy leaving the areas of Southern Italy much neglected. The aim of this paper is to amend this neglect by analysing the practice of burying the dead within the urban area in the city of Herdonia which is one of the most studied archeological sites of Southern Italy, thus a good example of the social and cultural situation of Apulia in the late Roman and early medieval period. In view of the lack of documentation pertaining to the chronology of the tombs in the city of Herdonia prior to the medieval period, this research will focus on the spread of urban burials in terms of space and quantity so as to understand how frequent the law infringement of the Twelve Tables was during its enforcement up until the mid Ninth century A.C.This research will also try to ascertain whether the practice of burying within the city walls and the decision to infringe the law of the Twelve Tables was caused by a radical change of ideas concerning the conception of death
Uso irriguo di acque reflue urbane depurate su due colture orticole in successione: pomodoro da industria e finocchio
No full text-Deformed Harmonic Oscillators
No full textWe analyze systematically several deformations arising from two-dimensional harmonic oscillators which can be described in terms ofD-pseudo bosons. They all give rise to
exactly solvable models, described by non self-adjoint hamiltonians whose eigenvalues and eigenvectors can be found adopting the quite general framework of the so-called
D-pseudo bosons. In particular, we show that several models previously introduced in the literature perfectly fit into this scheme
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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