1,720,968 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Ambient vibration tests for modal characterization of an existing steel-concrete composite bridge
No full textThe use of structural health monitoring for a reliable characterization of modal properties is becoming a common solution when dealing with the safety assessment of existing bridges, in order to capture samples of the experimental response of the "real structure". Such non-destructive test approach has also the advantage to be able to capture also potential criticalities that can change the real behavior of the structure with respect to the "as-built" configuration. The present work illustrates the results of experimental measurements carried out on the Carbonifera viaduct, a steel-concrete composite bridge located in the metropolitan area of Venice, northeastern Italy. These tests were conducted in order to determine main natural frequencies, mode shapes, modal damping ratios and to further calibrate an ad-hoc finite element model subsequently used in order to perform a structural assessment of the bridge against traffic and seismic loads
Variations on the Author
Get PDF“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
Experimental detection of the residual prestressing level in pre-tensioned and post-tensioned reinforced concrete beams by means of non-destructive tests
No full textObject of the paper is the execution of an experimental campaign conducted on six prestressed concrete beams (PC) and different levels of prestressing. In the first phase, three beams with straight adherent cables were casted, with the same eccentricity and three different levels of prestressing. For each beam, static tests were carried out until failure, and for each load step several non-destructive tests were carried out, namely dynamic free vibration tests and ultrasonic tests. The beams were instrumented with strain gauges and LVDTs to measure deformation and displacements during load cycles. The same tests were then repeated on three further beams with straight post-tensioned cables, with the possibility of controlling the level of prestressing force. In this case, each of the three beams had a different eccentricity. The variation of non-destructive parameters (such as dynamic characteristics and properties of ultrasonic waves) as a function of the degree of prestressing is evaluated, as well as the increase in the structural damage of the element. In particular, dynamic response data were analyzed in both frequency domain and time domain. Ultrasonic response data were also analyzed, not only in terms of velocity but also through attenuation of the ultrasonic signal. The aim of the study is to improve the techniques currently used for the detection of damage of PC elements with non-destructive tests, by defining a new protocol for the evaluation of residual prestressing force through the use of non-destructive tests. This will allow a more detailed assessment of the condition of the structure with a limited amount of data
Experimental assessment of residual prestressing force in prestressed concrete beams through nondestructive tests
No full textThis work summarizes the outcomes of an experimental campaign carried out on pretensioned prestressed concrete (PC) beams, aimed at assessing the influence of varying prestressing levels on both static and dynamic structural parameters. Three 6m long PC beams were designed and tested in four-point bending, with increasing levels of applied load. At each load step, two nondestructive tests (NDTs) were carried out, namely dynamic free vibration and ultrasonic tests. Dynamic response was analyzed both in frequency and time domains, and non-linear parameters of vibration were assessed. Ultrasonic response data were analyzed too, specifically through the evaluation of ultrasonic signal attenuation, other than in terms of absolute ultrasonic pulse velocity. Additionally, load-carrying capacity, crack pattern, deflection and concrete strains were monitored during the test. Experimental evidences were then analyzed, showing how damage detection can be carried out
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Get PDFWe 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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