1,721,300 research outputs found
Identifying the 3FHL Catalog. II. Results of the KOSMOS Optical Spectroscopy Campaign
No full textWe present the results of the optical spectroscopy follow up of a sample of 28 unclassified blazars from the Third Fermi-LAT Catalog of High-Energy Sources (3FHL). All the spectra were taken with the 4 m Mayall telescope at Kitt Peak. With this follow-up program, we are able to classify 27 out of 28 objects as BL Lacs, while the remaining one is a flat spectrum radio quasar. We determine a redshift (z) for three of these objects and a lower limit on z for other four sources: the farthest object for which we obtain a redshift has z > 0.836. These results are part of a more extended campaign of optical spectroscopy follow up of 3FHL blazars, aimed to obtain a complete sample of blazars at > 10 GeV, which will then be used to extend our knowledge on blazar emission mechanisms and on the extragalactic background light
Cultural differences in scholastic and non-scholastic environments: reasoning patterns and logical-linguistic questions in European and Chinese cultures
No full text
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
Identifying the 3FHL Catalog. III. Results of the CTIO-COSMOS Optical Spectroscopy Campaign
No full textActive galactic nuclei (AGNs) with their relativistic jets pointed toward the observer form a subclass of luminous gamma-ray sources commonly known as blazars. The study of blazars is essential to improve our understanding of the AGNs emission mechanisms and evolution, as well as to map the extragalactic background light. To do so, however, one needs to classify and measure a redshift for a large sample of these sources correctly. The Third Fermi-LAT Catalog of High-Energy Sources (3FHL) contains approximate to 1160 blazars reported at energies greater than 10 GeV. However, similar to 25% of these sources are unclassified and similar to 50% lack redshift information. To increase the spectral completeness of the 3FHL catalog, we are working on an optical spectroscopic follow-up campaign using 4 m and 8 m telescopes. In this paper, we present the results of the second part of this campaign, where we observed 23 blazars using the 4 m telescope at Cerro Tololo Interamerican Observatory in Chile. We report that all the 23 sources are classified as BL Lacs, a confirmed redshift measurement for three sources, a redshift lower limit for two sources, and a tentative redshift measurement for three sources
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
- …
