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
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
Modulo di rivelazione ad alti tassi di conteggio basato su SPAD in InGaAs/InP
No full textLAUREA MAGISTRALEUn numero sempre maggiore di applicazioni si basa sulla rivelazione di impulsi ottici molto deboli (a livello del singolo fotone) ed estremamente rapidi. I rivelatori a stato solido, quali Single-Photon Avalanche Diode (SPAD), hanno vantaggi in termini di affidabilità, compattezza e robustezza. Per le lunghezze d’onda tra i 900 nm e i 1700 nm, si usano SPAD in InGaAs/InP che sono però caratterizzati da un rumore elevato: alto tasso di conteggi di buio e notevole afterpulsing. Per questo motivo, oltre a dover essere raffreddato, è necessario abilitarlo solo in finestre temporali sincrone con il segnale e, dopo la rivelazione di un fotone, disabilitarlo per un tempo (hold-off) dell'ordine dei microsecondi. Questo metodo di abilitazione (gated-mode) impone una forte limitazione al massimo tasso di conteggio ottenibile (< 100 kcps).
Recentemente sono state introdotte tecniche di abilitazione basate su segnali ad alta frequenza (GHz) per ottenere una forte riduzione dell’afterpulsing (riducendo la carica per valanga) al fine di ridurre i tempi di hold-off ( 100 Mcps). Questi metodi richiedono lo sviluppo di tecniche di lettura del debole segnale di valanga in presenza di forti disturbi dovuti all’accoppiamento capacitivo del segnale di abilitazione al nodo di lettura.
In questo lavoro di tesi si è sviluppato un modulo compatto e affidabile basandosi sulla lettura differenziale del segnale e sulla compensazione dei disturbi grazie all’introduzione di un anello di retroazione. In questo modo la forma del segnale di valanga non viene alterata al fine di garantire un risposta temporale ad ampia banda e il sistema è stabile anche in presenza di derive termiche dei componenti.
Durante il presente lavoro sono stati sviluppati i seguenti blocchi: i) generazione della sinusoide di gate, di ampiezza (fino a 7 V) e frequenza (800 MHz – 1.5 GHz) programmabile; ii) lettura del segnale di valanga a larga banda passante (> 3 GHz); iii) cancellazione automatica dell’accoppiamento del segnale di abilitazione; iv) controllo basato su microcontrollore, dell’intero sistema. L’intero sistema è stato poi caratterizzato sperimentalmente.An increasing number of applications is based on the detection of very faint (down to the single-photon level) and extremely fast light pulses. Solid-state detectors, like Single-Photon Avalanche Diodes (SPAD), are advantageous in terms of reliability, compactness and robustness. For the wavelength range between 900 nm and 1700 nm, InGaAs/InP SPAD are employed, but they have high noise: high dark count rate and strong afterpulsing. Therefore, they need to be cooled and enabled in defined time slots synchronous with the signal pulses (gated-mode). Then, afterpulsing is reduced by keeping the detector off after each photon detection for few microseconds (hold-off time), thus limiting the maximum count rate (< 100 kcps).
Recently, few techniques based on high-frequency (GHz) gate signals have been introduced in order to strongly limit afterpulsing (by reducing the avalanche charge) for having short hold-off time ( 100 Mcps). These methods require to develop techniques for reading the faint avalanche signal out of strong disturbances due to the coupling of the gate signal at the read-out node.
In this master thesis, a compact and reliable module has been developed for reading differentially the avalanche signal and compensating the disturbances thanks to the introduction of a feedback loop. With this approach, the avalanche signal is not distorted for having a wide-band temporal response and a stable system despite components thermal drifts.
During this work, the following blocks ware developed: i) generation of the gate sinusoid, with programmable amplitude (up to 7V) and frequency (800 MHz – 1.5 GHz); ii) wideband readout of the avalanche signal (> 3 GHz); iii) automatic suppression of the gate coupling; iv) microcontroller-based supervision of the whole system. Finally, the whole system has been experimentally characterized
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