1,721,096 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
Self-switching with a nonlinear birefringent loop mirror
No full textWe investigate switching characteristics of the nonlinear birefringent loop mirror which consists of a symmetric directional coupler, a birefringent fiber, and a symmetry-breaking element that converts linearly polarized light to circularly polarized light, and vice versa, The condition for total reflection in the linear regime is obtained using the Jones matrix formalism, The switching curves have been obtained through numerical computations both in the nondispersive pulse regime and in the soliton-like pulse regime. Parameter values suitable for practical applications of our device as an intensity filter are obtained
Thermo-sensitive microparticles of PNIPAM-grafted ethylcellulose by spray-drying method
No full textThe thermo-sensitive polymer, PNIPAM-grafted ethylcellulose, was synthesized and it was confirmed by FTIR spectroscopy that PNIPAM was successfully grafted onto ethylcellulose. Microparticles were prepared by the spray-drying method using a B-191 Mini Spray Dryer. Their morphology, observed by scanning electron microscopy (SEM), showed irregular spheres with rugged surfaces, and narrow size distribution. In a model delivery system, ethylcelullose-g-PNIPAM was used as the polymer wall material and allopurinol was used as the model drug. The release rate of allopurinol from ECGPN8 microparticles was slower at 40degreesC (above the LCST) than that of 25degreesC (below the LCST), probably due to the collapse of PNIPAM chains by temperature. Although PNIPAM was the large part of wall material, the thermo-sensitive release behavior was not so obvious. It is believed that the release of allopurinol from the microparticles is more dependent on the porous structure of microparticles than the conformational change of PNIPAM, created by the rapid evaporation of solvent during the spray-drying process
FIBEROPTIC DC MAGNETIC-FIELD SENSOR WITH BALANCED DETECTION TECHNIQUE
No full textWe describe a balanced detection technique that suppresses undesirable effects due to residual signals for the detection of dc and low-frequency magnetic fields with interferometric fiber-optic sensors using metallic glass. The detection technique utilizes a square-wave magnetic field modulation that translates the residual signal outside of the detection band-width. Experimental results are presented that shows effective suppression of the residual signal
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
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