1,720,971 research outputs found
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
Majorana Fermions and Topological Superconductivity 1D Topological classification of CII phases
Full text linkIn the last decades, topology has established itself as a fundamental principle in condensed
matter physics. Not only does topology explain the incredible robustness of
certain physical quantities such as the Hall conductivity, but as a result of the bulkboundary
correspondence it also accounts for robust exotic fermionic edge states, e.g.
Majorana zero modes in superconductors. In this thesis the field of topological quantum
matter is reviewed with particular emphasis on one-dimensional non-interacting
superconducting systems and symmetry-protected topological phases. By taking off
from Kitaev’s model of p-wave superconductivity and the tenfold classification of
topological superconductors and insulators, we also investigate the notion of gapless
phases of matter addressing the issue what happens at a topological phase transition
in one dimension. For the symmetry classes BDI and CII, which both are known to
host topological superconductors in 1D, we obtain an N×Z-classification of gapless
phases. In addition to the conventional topological Z-invariant, the other classification
is provided by conformal field theory, a framework frequently used when
studying critical phenomena
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Quantum Theory of Exciton-Exciton Interactions in Atomically Thin Semiconductors [Elektronisk resurs]
No full textAtomically thin materials such as transition-metal dichalcogenides (TMDs) have emerged as an unprecedented platform for engineering future optoelectronic devices and studying exotic quantum phases of matter. In particular, the strong Coulomb interaction in these materials enables the formation of tightly-bound excitons, electron-hole pairs with neither purely fermionic nor bosonic character. These intriguing quasiparticles dominate the optical response, dynamics and transport properties of TMDs. The aim of this thesis is to investigate the impact of exciton-exciton interactions on optics, relaxation dynamics and diffusion in 2D materials. Based on the density-matrix formalism, we develop equations of motion which are used to study intriguing and technologically relevant phenomena in the high-excitation regime where interexcitonic interactions dominate. We shed light on the fundamentally different interactions between intra- and interlayer excitons in TMD monolayers and bilayers, respectively. Exciton-exciton interactions in monolayers are governed by quantum-mechanical exchange interactions and interlayer excitons in heterobilayers interact predominantly via dipole-dipole repulsion. Furthermore, we demonstrate the crucial importance of optically-dark recombination channels in exciton-exciton annihilation and reveal the dominant role of dipole-dipole repulsion in interlayer exciton transport. Finally, we show that interactions between layer-hybridized excitons are electrically tunable and that electric fields can be used to boost and control the exciton propagation in van der Waals heterostructures. Our material-specific and predictive theory has allowed us to predict experimental observations, such as density-dependent exciton line-shifts and exciton-exciton annihilation rates, that have been verified through joint theory-experiment collaborations. Overall, this thesis provides microscopic insights into exciton-exciton interactions, which are expected to play a central role in the optimal operation of optoelectronic devices and the realization of strongly correlated electron-hole systems
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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