1,720,966 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
Topological effects in graphene based nanostructures
No full textBu tez çalışmasında uzun menzilli yüklü Coulomb safsızlıklı aralıklı grafen koninin enerji spektrumu üzerindeki homojen manyetik alanın etkileri pertürbasyon teorisi çerçevesinde incelenmiştir. Topolojik kusurlar nedeniyle açısal momentum kanallarının dejenereliğinin kalkması yanı sıra, karşılık gelen enerji seviyelerinin boyutu homojen bir manyetik alanın devreye girmesiyle arttığı tespit edilmiştir. Dahası, grafende elektronların A_1g fonon çiftlenimi Rashba spin-yörünge etkileşmesi varlığında incelenmiştir. Elektron-fonon sistemini sürekli limit çerçevesinde tanımlamak için Fröhlich tipi Hamiltoniyen kullanılmıştır. A_1g simetrisine sahip en yüksek frekanslı bölge sınır fononu ile yük taşıyıcılarının etkileşmesinin kiral simetriyi kırmaksızın band aralığı yarattığı belirlenmiştir. Buna ek olarak, Rashba spin-yörünge çiftleniminin ve Haldane kütle teriminin birleştirilmiş etkilerinin elektron-A_1g fonon etkileşimi üzerindeki etkileri araştırılmıştır. Haldane kütlesinin devreye girmesi ile mevcut kiral simetrinin kırıldığı ve vadi dejenereliğinin ortadan kalktığı tespit edilmiştir.In this thesis, the effect of homogenous magnetic field on the energy spectrum of gapped graphene cones with long range charged Coulomb impurity is investigated within the framework of perturbation theory. It is found that, besides lifting the degeneracy of angular momentum channels due to topological defects, the size of the corresponding splitting is enhanced by introduction of a homogenous magnetic field. Also, interaction of electrons with A_1g phonon coupling is examined in the presence of Rashba spin-orbit coupling in graphene. We use Fröhlich type Hamiltonian to describe the electron-phonon system within the continuum limit. It is found that interaction of charge carriers with the highest frequency zone boundary phonon mode with A_1g symmetry induces a band gap without breaking chiral symmetry. Additionally, we investigate the simultaneous effects of Rashba spin-orbit coupling and Haldane mass term on electron-A_1g phonon interaction. By the introduction of Haldane mass term, it is found that existing chiral symmetry is broken and valley degeneracy is lifted
The Effect of Tilted Magnetic Field in Graphene Cone
No full textAbstractWe investigate the combined effect of both homogeneous and tilted magnetic fields on the energy spectrum of gapped graphene cones together with long range Coulomb impurity in the framework of perturbation theory. The results illustrate that the tilted magnetic field can significantly affect the spectrum of single particle low-energy effective Hamiltonian, besides lifting the degeneracy of angular momentum channels in the presence of topological defects. The breaking of the electron-hole symmetry by magnetic fields is explained as a direct consequence of sub band Landau-level coupling
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
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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