1,721,071 research outputs found
25. Craig (Christopher P.), Form as Argument in Cicero's Speeches. A study of Dilemma
No full textHinard François. 25. Craig (Christopher P.), Form as Argument in Cicero's Speeches. A study of Dilemma. In: Revue des Études Grecques, tome 112, Juillet-décembre 1999. p. 770
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
Further studies of radiation trapping in Er3+ doped chalcogenide glasses
No full textAbsorption and emission bands in trivalent erbium ions Er3+ are known to strongly overlap, which means that in heavily doped samples, it is possible to observe the effects of sequential radiation absorption and re-emission processes that involve the Er3+ ions. In particular, this effect of “radiation trapping” (RT) or “radiation/ excitation diffusion” is responsible for the dependence of the measured photoluminescence (PL) lifetime and PL spectrum shape in Er3+ chalcogenide glasses on the rare-earth doping concentration and sample size.[1,2]. It is worth mentioning here that the original name “excitation diffusion” originates from Milne’s paper where he pointed out the formal similarity of equations describing the effect with those for normal diffusion [3].In present paper we present the results of experiments which are design to maximize the effect of RT by passing the light along the bulk of a chalcogenide glass sample as shown in Figure 1 (b-d). We carry out experiments on samples having regular cylindrical shape, which allows us to do some simple calculations predicting the shape and lifetime of PL (see Equations (1-3) in Figure 1). The results of these predictions appear to be in a very good agreement with experimental data as shown in Figure 1(a). These results show that RT effectively “stirs” the excitation inside of sample, evenly distributing it throughout the whole volume of the sample.&more..
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
Ga-La-S-Se glass for visible and thermal imaging - dataset
No full textExperiments on novel chalcogenide glass. Data is all included in GLSSe.xlsx. It includes thermal, mechanical and optical measurements. Data was plotted using Microsoft Excel 2013.</span
Radiation trapping in selected Er<sup>3+</sup> doped chalcogenide glasses and the extraction of the nonradiative lifetime
No full textRadiation trapping (RT) is a phenomenon wherein photons are emitted, absorbed and re-emitted many times before they leave the volume of the material. Trivalent Er3+ ions are particularly prone to RT because there is a whole set of strongly overlapping emission and absorption bands including 4I13/2−4I15/2 and 4I11/2−4I15/2 bands. The effect of RT on the PL decay time was investigated experimentally in this work in a variety of Er3+-doped GeGaS, GeGaSe, GaLaS(O) glasses. Sample geometry (powders, plates, disks, cylinders) and size were varied and the samples were also immersed in glycol, a liquid with high refractive index. PL decay times were measured and compared with the Judd-Ofelt results. A simple model of RT was developed and applied to the above mentioned bands. By comparing model conclusions with experimental data for different sample sizes, we were able to separate the direct relaxation of the 4I11/2 state to ground 4I15/2 state and relaxation via the intermediate 4I13/2 state; and hence obtain an approximate nonradiative lifetime
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