1,721,033 research outputs found
Guida: A graphical user interface for optical data analysis of isolated pulsars
Full text linkStudying pulsars from ground-based telescopes needs data analysis to be performed according to specific requirements. Because of the periodic behavior of these objects such requirements are expressed in terms of timing. In fact, several factors must be taken into account to correctly extract the period (frequency) and then light curves of pulsars. Until now, analysis software packages have been mainly developed for satellite data and are not completely suitable for optical observations from the ground. A software package called GUIDA has been developed to analyze optical photometric data recorded by the SiFAP instrument, completely conceived and realized at the Physics Department of La Sapienza-Università di Roma. This software package is capable of analyzing data relative to ground observations, including timing corrections, and of deriving corrected pulsar light curves
SiFAP: a simple sub-millisecond astronomical photometer
No full textA new fast photometer based on SiPM technology was developed at the University of Rome "La Sapienza" starting from 2009. A first prototype was successfully tested observing the Crab pulsar at the Loiano telescope of the Bologna Observatory. In this paper we illustrate the improvements we applied to our instrument, concerning new cooled commercial sensors, a new version of our custom dedicated electronics and an upgraded control timing software. Finally we report the results obtained with this instrument on December 2012 on the Crab pulsar at the Loiano telescope to show its goodness and capabilities
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
Precise optical timing of PSR J1023+0038, the first millisecond pulsar detected with Aqueye+ in Asiago
Full text linkWe report the first detection of an optical millisecond pulsar with the fast photon counter
Aqueye+ in Asiago. This is an independent confirmation of the detection of millisecond
pulsations from PSR J1023+0038 obtained with SiFAP at the Telescopio Nazionale Galileo.
We observed the transitional millisecond pulsar PSR J1023+0038 with Aqueye+ mounted at
the Copernicus telescope in 2018 January. Highly significant pulsations were detected. The
rotational period is in agreement with the value extrapolated from the X-ray ephemeris, while
the time of passage at the ascending node is shifted by 11.55 ± 0.08 s from the value predicted
using the orbital period from the X-rays. An independent optical timing solution is derived
over a baseline of a few days that has an accuracy of ∼0.007 in pulse phase (∼12 μs in time).
This level of precision is needed to derive an accurate coherent timing solution for the pulsar
and to search for possible phase shifts between the optical and X-ray pulses using future
simultaneous X-ray and optical observations
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
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