1,720,980 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
Factorized ground state in dimerized spin chains
No full textPACS numbers: 03.67.Mn, 75.10.Jm, 64.70.TgThe possibility of observing factorized ground states in dimerized spin systems is studied. A
set of sufficient conditions is derived which allows one to establish whether or not it is possible
to have factorization both in nearest-neighbour and long-range Hamiltonians. These conditions
can be derived by forcing factorization for each of the pairwise terms of the total Hamiltonian.
Due to the peculiar structure of a dimerized chain, an antiferromagnetic factorized ground
state of the kind | %i, | %i, | -i, | -i (forbidden in regular chains) is possible.This work was funded by the ECusCo project no.
2008501047. The author is supported by the Spanish Ministry
of Science and Innovation through the programme Juan de la
CiervaPeer reviewe
Spontaneous PT symmetry breaking and quantum phase transitions in dimerized spin chains
No full textThe occurrence of parity-time reversal PT symmetry breaking is discussed in a non-Hermitian spin chain.
The Hermiticity of the model is broken by the presence of an alternating, imaginary, transverse magnetic field.
A full real spectrum, which occurs if and only if all the eigenvectors are PT symmetric, can appear only in
presence of dimerization, i.e., only if the hopping amplitudes between nearest-neighbor spins assume alternate
values along the chain. In order to make a connection between such system and the Hermitian world, we study
the critical magnetic properties of the model and look for the conditions that would allow to observe the same
phase diagram in the absence of the imaginary field. Such procedure amounts to renormalizing the spin-spin
coupling amplitudes.This work was partially funded by CoQuSys under
Project No. 200450E566. The author is supported by the
Spanish Ministry of Science and Innovation through the program Juan de la CiervaPeer reviewe
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
Monogamy properties of quantum and classical correlations
No full textPACS number(s): 03.67.MnIn contrast with entanglement, as measured by concurrence, in general, quantum discord does not possess the property of monogamy; that is, there is no tradeoff between the quantum discord shared by a pair of subsystems and the quantum discord that both of them can share with a third party. Here, we show that, as far as monogamy is considered, quantum discord of pure states is equivalent to the entanglement of formation. This result allows one to analytically prove that none of the pure three-qubit states belonging to the subclass of W states is monogamous. A suitable physical interpretation of the meaning of the correlation information as a quantifier of monogamy for the total information is also given. Finally, we prove that, for rank 2 two-qubit states, discord and classical correlations are bounded from above by single-qubit von Neumann entropies.Funding from the CoQuSys (200450E566)
project is acknowledged. The author is supported by the
Spanish Ministry of Science and Innovation through the
program “Juan de la CiervaPeer reviewe
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