1,722,298 research outputs found
Maximum response occurrence time and spectra
No full textTypically, in seismic response analysis, the focus is on absolute maximum response, without specific interest in its
attainment time. The definition of response spectrum, for example, does not provide information about such a time and
the issue is somewhat scarcely investigated in the literature, while it is the subject of the presented very simple study,
where linear and non-linear single-degree-of-freedom systems are investigated when excited by a large set of ground
motion records. For the linear systems, the occurrence time of maximum displacements is measured with respect to: (i)
the initial instant defining the significant duration of the record; (ii) the initial instant defining the bracketed duration of
the record; (iii) the time of occurrence of peak ground acceleration (PGA). For the non-linear systems, the maximum
displacements are measured with respect to the time of occurrence of peak ground acceleration, for two different
hysteretic behaviors, stable and evolutionary, considering several vibration periods and ductility levels. The occurrence
time of inelastic response is compared between the two non-linear systems and to that of the corresponding elastic
system. A characteristic behavior is found for the time of occurrence of the maximum displacement in linear systems
that, as a trend, systematically occurs after the PGA, independently of the vibration period. The occurrence time tends
to get closer to the PGA time as the damping increases. Finally, the comparison of the time of maximum response for
the two non-linear systems and those linear, shows some relationships between the two
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
130: Rosette formation with mouse erythrocytes by lymphocytes from normal donors and patients with various diseases.
No full text- …
