1,720,970 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Photonique topologique dans les réseaux bidimensionnels d'atomes
No full textThis thesis investigates the propagation of light in atomic lattices, with a focus on systems that offertopological protection against disorder. Such systems can be found across various scales: planetary waves,electronic transport, and optics. This work lies at the intersection of three major fields of physics: quantummechanics, wave physics, and topological insulators.Specifically, the primary subject of this thesis is a two-dimensional honeycomb lattice composed ofpoint scatterers for light, typically cold atoms. The lattice spacing is chosen to promote the emergence ofcollective effects while maintaining a distance between atoms much larger than their size. This lattice isplaced in a transverse magnetic field, which breaks time-reversal symmetry and opens a photonic bandgap via the Zeeman effect. The calculation of a topological invariant proves the existence of a topologicalphase that can vanish when inversion symmetry is also broken.We then study the robustness of this topological phase against disorder, introduced directly in thepositions of the scatterers. Anderson localization is examined in this context. Conversely, we demonstratehow disorder itself can give rise to a topological phase, known as an Anderson topological insulator, whichhad never yet been observed for light in a two-dimensional atomic lattice.Using a magnetic field can be challenging in experimental realizations, so we seek to avoid it. Toachieve this, we deform the lattice cells, which emulates time-reversal symmetry breaking. We first studya simple tight-binding model and then the model of interaction via electromagnetic waves.Cette thèse étudie la propagation de la lumière dans les réseaux d’atomes avec une emphase sur les systèmes qui offrent une protection topologique face au désordre. Des systèmes de ce type peuvent se rencontrer à différentes échelles: ondes planétaires, transport électronique et optique. Ce travail se situe à la croisée de trois grands champs de la physique que sont la mécanique quantique, la physique des ondes et les isolants topologiques.Plus précisément, l’objet d’étude principal de cette thèse est un réseau à deux dimensions en nidd’abeille constitué de diffuseurs ponctuels pour la lumière, typiquement des atomes froids. Le pas de réseau est choisi de façon à favoriser l’apparition d’effets collectifs tout en gardant la distance entre atomes bien plus grande que leur taille. Ce réseau est placé dans un champ magnétique transverse, cela brise lasymétrie par renversement du temps et ouvre une bande interdite photonique par effet Zeeman. Le calcul d’un invariant topologique permet de prouver l’existence d’une phase topologique qui peut disparaître quand on brise également la symétrie par inversion.On étudie ensuite la résistance de cette phase topologique face au désordre, introduit directement sur les positions des diffuseurs. La localisation d’Anderson est étudiée dans ce contexte. Puis à l’inverse on montre comment le désordre lui-même peut-être à l’origine d’une phase topologique, cette situationse nomme isolant topologique d’Anderson et n’avait jamais été observé pour la lumière dans un réseau d’atomes en deux dimensions.L’utilisation d’un champ magnétique peut s’avérer contraignante dans le cadre de réalisations expérimentales, on cherche donc à s’en passer. Pour cela on joue sur des déformations des cellules du réseau.Cela permet d’émuler une brisure de symétrie par renversement du temps. On étudie d’abord un modèle plus simple, de liaisons fortes, puis le modèle d’interaction par les ondes électromagnétiques
Remote Forwarding of Human-Machine Interfaces for Industrial Controls
No full textThis report deals with the remote display forwarding software Xpra and its possible use at CERN. It shows the various possibilities and limits of Xpra when employed within an industrial control setting and concludes about the ability of Xpra as a potential replacement for Windows Terminal Server
Photonique topologique dans les réseaux bidimensionnels d'atomes
No full textThis thesis investigates the propagation of light in atomic lattices, with a focus on systems that offertopological protection against disorder. Such systems can be found across various scales: planetary waves,electronic transport, and optics. This work lies at the intersection of three major fields of physics: quantummechanics, wave physics, and topological insulators.Specifically, the primary subject of this thesis is a two-dimensional honeycomb lattice composed ofpoint scatterers for light, typically cold atoms. The lattice spacing is chosen to promote the emergence ofcollective effects while maintaining a distance between atoms much larger than their size. This lattice isplaced in a transverse magnetic field, which breaks time-reversal symmetry and opens a photonic bandgap via the Zeeman effect. The calculation of a topological invariant proves the existence of a topologicalphase that can vanish when inversion symmetry is also broken.We then study the robustness of this topological phase against disorder, introduced directly in thepositions of the scatterers. Anderson localization is examined in this context. Conversely, we demonstratehow disorder itself can give rise to a topological phase, known as an Anderson topological insulator, whichhad never yet been observed for light in a two-dimensional atomic lattice.Using a magnetic field can be challenging in experimental realizations, so we seek to avoid it. Toachieve this, we deform the lattice cells, which emulates time-reversal symmetry breaking. We first studya simple tight-binding model and then the model of interaction via electromagnetic waves.Cette thèse étudie la propagation de la lumière dans les réseaux d’atomes avec une emphase sur les systèmes qui offrent une protection topologique face au désordre. Des systèmes de ce type peuvent se rencontrer à différentes échelles: ondes planétaires, transport électronique et optique. Ce travail se situe à la croisée de trois grands champs de la physique que sont la mécanique quantique, la physique des ondes et les isolants topologiques.Plus précisément, l’objet d’étude principal de cette thèse est un réseau à deux dimensions en nidd’abeille constitué de diffuseurs ponctuels pour la lumière, typiquement des atomes froids. Le pas de réseau est choisi de façon à favoriser l’apparition d’effets collectifs tout en gardant la distance entre atomes bien plus grande que leur taille. Ce réseau est placé dans un champ magnétique transverse, cela brise lasymétrie par renversement du temps et ouvre une bande interdite photonique par effet Zeeman. Le calcul d’un invariant topologique permet de prouver l’existence d’une phase topologique qui peut disparaître quand on brise également la symétrie par inversion.On étudie ensuite la résistance de cette phase topologique face au désordre, introduit directement sur les positions des diffuseurs. La localisation d’Anderson est étudiée dans ce contexte. Puis à l’inverse on montre comment le désordre lui-même peut-être à l’origine d’une phase topologique, cette situationse nomme isolant topologique d’Anderson et n’avait jamais été observé pour la lumière dans un réseau d’atomes en deux dimensions.L’utilisation d’un champ magnétique peut s’avérer contraignante dans le cadre de réalisations expérimentales, on cherche donc à s’en passer. Pour cela on joue sur des déformations des cellules du réseau.Cela permet d’émuler une brisure de symétrie par renversement du temps. On étudie d’abord un modèle plus simple, de liaisons fortes, puis le modèle d’interaction par les ondes électromagnétiques
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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