1,720,964 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Preionization and gain studies in fluorine based excimer laser gas discharges
Get PDFFluorine-based excimer gas lasers are powerful sources of coherent radiation in the UV and VUV part of the electro-magnetic spectrum. Due to their short wavelengths and high output power they are widely employed in high resolution material processing like micromachining and in lithography. In this field pattern sizes several times shorter than the used wavelength can be achieved using an immersion technique. However due to the short duration of the laser pulse (typically of few tens of ns for commercially available fluorine-based excimer lasers), the laser pulse makes only a few round-trips inside the laser resonator cavity. As the result, the optical quality of the laser beam of such an excimer laser is poor, leading to non optimal focusing conditions. The purpose of this work was to investigate different methods and techniques to produce excimer lasers, based on fluorine containing gas mixtures, emitting optical pulse lengths of 100 ns or longer. In order to achieve this goal we have studied different gas discharge excitation techniques in a small scale discharge chamber (0.5 – 4 cm discharge gap, 5 cm electrodes diameter) at gas pressures varying from 2 to 5 bar. We have thoroughly investigated a pre - main pulse gas discharge pumping scheme with X-ray preionization and a single pulse excitation scheme with X-ray preionization. As preionization source we investigated two homemade X-ray sources. We have developed a high voltage open barrier discharge device producing a fast electron beam directly in the gas. It was shown that it was possible to generate soft X-ray radiation (10 – 100 keV) directly in gases by means of this beam. With this and with an earlier developed traditional X-ray source the produced electron densities in different gases and gas mixtures have been measured. During our experiments we discovered that, apart from the well known direct electron generation in the gas, a substantial part of the measured preionization electrons were generated indirectly by the Xrays via the photo-electric effect at the electrode. With the single pulse excitation scheme we succesfully ignited a homogeneous discharge and were able to sustain it as a stable, homogeneous pulsed gas discharge in gas mixtures typically containing 5 % of Ar and 0.1 % of F2 at a total gas pressure of 2 bar and an electrode distance of 1 cm. In this laser gas mixture the typical achieved peak power deposition density was 1 – 2 MW cm-3 with a pulse duration (FWHM) of ~ 100 ns. Under these conditions the observed spontaneous emission intensity was 119 kW cm-3 at the ArF* excimer wavelenth (193 nm). The width of this emission signal was ~ 60 ns (FWHM). With a probe laser (λ = 193 nm) the amplification of the probe signal in the excited laser medium was measured. Under the same conditions a net gain was measured of ~ 34±20 % cm-1 with a FWHM of ~ 60 ns. The combination of such high gain and the reasonably long optical pulse duration makes our gas discharge excitation system a promising device for the development of small scale fluorine-based excimer gas lasers. The short resonator length of several cm will result in a higher number of the intra cavity round-trips and thus to a better beam quality compared to the usual excimer lasers
Improving the Computational Model for Approximation of Particle Functions over Diameter of Dust in the Work Area and at the Border of the Sanitary Protection Zone
No full textAbstractThis paper describes the basic ways of solving the problem of experimental data approximation. Disperse composition of crushed gypsum dust was analyzed; the analysis results are presented herein. Approximating function of particulate dust composition function is a piecewise function, defined as a three-tier spline “direct-parabola-hyperbole.” The approximation aims at finding seven function factors and two nodal points. The least square method was used to estimate the unknown parameters of regression models for the sample data. To apply this method to experimental data, a program complex calculation models for the approximation of the integral representation of the mass distribution function of particles in the dust diameter in CAS Maple was presented. It defines a function that describes the distribution of the particulate composition of the dust released from the open warehouse storage of crushed gypsum rock with the smallest error
Environmental and Working Area Dust Emission from the Gypsum Warehouse
No full textAbstractThe work analyses the emissions analysis for gypsum binder production. The major air pollutant is the suspended solids composed of a mixture of particles in air, which can be either solid or liquid and be a complex mixture of organic and inorganic substances. Studies have shown that excessive concentrations of inorganic dust (gypsum dust) generated by the open gypsum warehouse storage and thus the contribution of emission sources into total concentration of inorganic dust (dust plaster) average vary from 66,28% to 87,67%. The highest excessive concentrations of inorganic dust are registered at the border of regulated areas: up to 20% SiO2 (plaster dust) (from 5,9 to 16,0 shares of maximum allowable concentration (MAC))
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