1,720,960 research outputs found
Topological flat Wannier-Stark bands
Get PDFWe analyze the spectrum and eigenstates of a quantum particle in a bipartite two-dimensional tight-binding dice
network. In the absence of a dc bias, it hosts a chiral flatband with compact localized eigenstates. In the presence
of a dc bias, the energy spectrum consists of a periodic repetition of one-dimensional energy band multiplets,
with one member in the multiplet being strictly flat. The corresponding flatband eigenstates cease to be compact,
and are localized exponentially perpendicular to the dc field direction, and superexponentially along the dc field
direction. The band multiplets are characterized by a topological quantized winding number (Zak phase), which
changes at specific values of the varied dc field strength. These changes are induced by gap closings between the
flat and dispersive bands, and reflect the number of these closings. © 2018 American Physical Society
Conductance transition with interacting bosons in an Aharonov-Bohm cage
Get PDFWe study transport of interacting bosons through an Aharonov-Bohm cage - a
building block of flat band networks - with coherent pump and sink leads. In
the absence of interactions the cage is insulating due to destructive
interference. We find that the cage stays insulating up to a critical value of
the pump strength in the presence of mean field interactions, while the quantum
regime induces particle pair transport and weak conductance below the critical
pump strength. A swift crossover from quantum into the classical regime upon
further pump strength increase is observed. We solve the time dependent master
equations for the density matrix of the many body problem both in the
classical, pure quantum, and pseudoclassical regimes. We start with an empty
cage and switch on driving. We characterize the transient dynamics, and the
complexity of the resulting steady states and attractors. Our results can be
readily realized using experimental platforms involving interacting ultracold
atoms and photons on finetuned optical lattices.Comment: 5 pages, 4 figure
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
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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