1,721,200 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
Remote light source for silicon photonic transceivers in mobile fronthaul applications
No full textThe design and experimental characterisation of a depolarised light source for feeding a remote transceiver based on silicon photonics are presented. Since the transceiver only works in TE mode, the source is designed to deliver, over up to 10 km standard single-mode fibre links, a continuous-wave light with almost constant power along this polarisation direction, whatever be the random polarisation rotation because of the fibre link. The depolarised light source is realised by combining the output of two independent distributed feedback lasers, having orthogonal polarisation and controlled frequency difference. The transmission performance and stability of the remote light source are successfully tested
N,N′-bis[(3-hydroxy-4(4H)-oxypyran-2-yl)methyl]-N,N′-dimethylethylene-1,2-diammonium tetrachloridoplatinate(II) dihydrate
No full textThe title compound (C16H22N2O 6)[PtCl4]·2H2O, shows antiproliferative activity in eight tumor cell lines. The asymmetric unit consists of one solvent water molecule on a general position, and one half of each of the polyammonium cation and the tetrachloridoplatinate(II) anion, both of them located on centers of inversion. In the crystal, the cations are connected via hydrogen bonding between the carbonyl O atoms and the hydroxyl H atoms into zigzag chains that elongate in the c-axis direction. In addition, the carbonyl O atom is hydrogen-bonded to the water molecule which, in turn, interacts with the [PtCl4]2- anion. Finally, the chains are linked by N-H +⋯Cl interactions into a three-dimensional network
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
Chimica. Principi generali con esercizi
No full textUn libro realizzato come testo per il primo corso di chimica presente nei vari Corsi di Laurea del nostro sistema universitario. Sono trattati i principi generali alla base della chimica che devono essere bagaglio imprescindibile per uno studente che affronta un qualsiasi percorso di laurea scientifica dal futuro chimico al biologo, dal geologo al biotecnologo, dal nutrizionista al medico, dall’ingegnere al farmacista, dall’agronomo al fisico e così via. Ad integrazione di questi principi, e per facilitare la verifica da parte dello studente della comprensione degli argomenti trattati, sono stati inseriti alla fine di ogni capitolo sia
un paragrafo concernente gli obiettivi minimi che dovrebbero essere acquisiti sia una serie di domande di autovalutazione con le quali lo studente può valutare il proprio grado di preparazione. Nel libro è inclusa la stechiometria, cioè quel ramo della chimica che si occupa delle relazioni quantitative nelle trasformazioni chimiche, necessaria per una corretta comprensione di molti degli argomenti trattati e per la loro applicazione reale. Questa è stata sviluppata inserendo, nei capitoli interessati, un’ampia casistica per la risoluzione guidata degli esercizi e una serie di esercizi non risolti per i quali sono state riportate le soluzioni a fine testo. La presenza della parte stechiometrica permette al libro di essere adottato come testo
unico in qualsiasi primo corso di chimica di livello universitario
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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