1,721,000 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
Design of active devices based on rare-earth-doped glass/glass ceramic: from the material characterization to the device parameter refinement
No full textThe accurate knowledge of the rare-earth spectroscopic parameters is fundamental for the design of both fiber and integrated active devices. The lifetimes, the branching ratios, the up-conversion, the cross-relaxation, the energy transfer coefficients of the rare-earths must be preliminarily identified before the design. The particle swarm optimization (PSO) is an efficient global search approach; when applied to rare-earth-doped host materials and devices, it permits the rare-earth spectroscopic characterization starting from optical gain measurements. The model for the peculiar case of a SiO2 - SnO2 : Er3+ glass ceramic system is illustrated. Two different, direct and indirect, pumping schemes are considered for the rare-earth spectroscopic characterization. In the direct pumping scheme, a pump at 378 nm wavelength is used to excite the erbium ions. The SnO2 does not take part in the excitation process. On the contrary, in the indirect pumping scheme the SnO2 is involved by exploiting the absorption band around 307 nm wavelength via a proper pump. In this case, the energy transfer between the SnO2 and the Er3+ ions occurs during the amplification process. The fabricated SiO2 - SnO2 : Er3+ glass ceramic slab waveguide is simulated via a finite element method (FEM) code and a homemade code is used to solve the rate equations. In order to identify the value of the SnO2-Er3+ energy transfer coefficient, the ratio between the two simulated optical gains at 1533 nm wavelength, with the direct and indirect pumping schemes, is compared with the ratio between the two emission intensity measurements
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
Comparative study of infrared fiber laser models
No full textThe modeling and design of fiber lasers is an essential element of their development process. One of the areas of particular interest during the last years is the development of lanthanide ion-doped fiber lasers which operate at wavelengths exceeding 2000 nm. There are two main host glass materials developed for this purpose: fluoride and chalcogenide. One of the main specific aims of this contribution is therefore to comparatively study the properties of various numerical algorithms applicable to the design and modeling of fiber lasers operating at wavelengths exceeding 2000 nm. Hence, the convergence properties of selected algorithms implemented within various software environments are studied with a particular focus on the CPU time and calculation residual
Global optimization via evolutionary approach of a Dy3+:ZBLAN fiber amplifier for MID-IR applications
No full textA Dy3+-doped ZBLAN fiber amplifier based on an in-band pumped configuration is designed and optimized via an evolutionary approach. In the proposed model, the rate equations are coupled with the power propagation equations for the pump and signal beams. The complete amplifier model allows the definition of the fitness function to be optimized. Realistic values for optical and spectroscopic parameters are considered. For a fiber with dopant concentration of 2000 ppm, by employing an input pump power of 1 W at 2.72 μm wavelength, an optical gain of about 15.56 dB at 2.95 μm wavelength is obtained
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
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