1,720,954 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
Transition of electrons beams between vacuum and plasma in the external injection into a laser wakefield accelerator
No full textUrýchľovanie brázdovou vlnou je efektívna metóda zrýchlenia elektrónov v plazme, ktorá umožňuje generovať vysoké gradienty elektrického poľa. Tradičné schémy vstrekovania elektrónov do brázdovej vlny však môžu často trpieť nedostatočnou kontrolou. Preto rastie záujem o skúmanie externého vstrekovania, pri ktorom sa zväzky elektrónov vstrekujú z externého urýchľovača. Prudký prechod z vákua do plazmy avšak môže zapríčiniť zhoršenie parametrov elektrónového zväzku. Z toho dôvodu sa v rámci tejto práce uskutočnili 2D a 3D particle-in-cell simulácie pomocou kódu Smilei. Konkrétne boli analyzované (desiatky mikrónov dlhé) hustotné nábehy plazmy rôznych dĺžok s lineárnym alebo parabolickým nárastom, aby sa určil ich vplyv na vstrekovanie elektrónového zväzku a vývoj jeho parametrov v čase. S daným súborom parametrov simulácie bol navrhnutý 400-μm hustotný nábeh plazmy konvexného parabolického profilu ako najefektívnejší pri zachovaní relatívneho energetického rozptylu a priečnej emitancie elektrónového zväzku.Laser wakefield acceleration is an efficient method for electron acceleration in plasmas that ensures high electric field gradients. However, traditional injection schemes of electrons into the wakefield can often suffer from a lack of control. Consequently, there is a growing interest in investigating external injection, in which electron bunches are injected from a separate accelerator. Nevertheless, a sharp vacuum-plasma transition can cause deterioration of the bunch parameters. Therefore, in this work, 2D and 3D particle-in-cell simulations using the Smilei code were performed. Short (tens-of-micron scale) plasma density ramps of different lengths with a linear or parabolic increase were examined to determine their influence on the injection of the electron bunch and its parameters. With a given set of simulation parameters, the 400-μm plasma density ramp of a convex parabolic profile was suggested as the most effective one in preserving the relative energy spread and transverse emittance of the electron bunch
Characterisation of plasma waves generated by intense laser pulses
Full text linkDosiahnutie generácie vysoko intenzívnych laserových impulzov umož- ňuje v dnešnej dobe vytvorenie urýchľovača častíc s vysokými gradientmi poľa, a teda s kompaktným a veľmi účinným urýchľovaním v porovnaní s konvenčnými typmi urýchľovačov. V rámci tejto práce je zhrnutých niekoľko metód laserového urýchľovania elektrónov v plazme, hlavne dva režimy urýchľovania brázdovou vl- nou, lineárny a bublinový režim. Taktiež je popísaná základná fyzika generovania brázdovej vlny v podkritickej plazme. Vývoj brázdových vĺn je kľúčovou súčasťou pochopenia všetkých plazmových urýchľovačov poháňaných laserovým impulzom. Zahrnuté je aj detailné porovnanie medzi diagnostickými metódami brázdovej vlny. V práci sú zároveň opísané a porovnané dve najzákladnejšie metódy rekonštrukcie obrazu, a to spätná projekcia a filtrovaná spätná projekcia. V závere je navrhnutá najefektívnejšia konfigurácia projekcií založených na počiatočných uhlových para- metroch pomocou indexu štrukturálnej podobnosti (SSIM) s použitím MATLAB knižnice.Nowadays, achieving the generation of high-intensity laser pulses enables the construction of a particle accelerator with very high field gradients and thus compact, and very efficient acceleration compared to the conventional types of ac- celerators. Several methods of laser-driven plasma-based electron acceleration are described. Mostly, two regimes laser wakefield acceleration, linear and bubble re- gimes, are explained. The basic physics of plasma wakefield wave generation in underdense plasma is also reviewed. The evolution of plasma wake is a key element of understanding laser-driven plasma wakefield accelerators. A detailed comparison between the optical diagnostics of laser wakefield structure is presented here. Two of the most fundamental projection reconstruction methods, backprojection and fil- tered back projection, are described and compared. In conclusion, we propose the most effective configuration of projections based on initial angular parameters using structural similarity index (SSIM) using MATLAB library
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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