1,720,973 research outputs found
Monitoring a steel building using GPS sensors
No full textTo assess the performance of a structure requires the measurement of global and relative displacements at critical points across the structure. They should be obtained in real time and in all weather condition. A Global Navigation Satellite System (GNSS) could satisfy the last two requirements. The American Global Position System (GPS) provides long term acquisitions with sampling rates sufficient to track the displacement of long period structures. The accuracy is of the order of sub centimetres. The steel building which hosts the author
Experimental study on hybrid control of multimodal cable vibrations
No full textThe effectiveness of a hybrid control policy in mitigating the linear and non-linear multimodal cable vibrations is investigated by means of a numerical analysis and a campaign of laboratory tests. The proposed control method is a hybrid solution combining wrapped shape memory alloy wires and an open-loop actuation. By operating in this way, a robust and economical control strategy is obtained which overcomes the damper/actuator localization and the state-tracking difficulties that significantly impair the overall control effectiveness of most of the control solutions already investigated in the literature. The proposed approach has shown, in a separate study, promising vibration mitigation capabilities when the motion was essentially dominated by the first in-plane mode. Here, the capability of the hybrid control policy in mitigating also the nonlinear vibrations of the second in-plane mode is under specific investigation
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
Meta-Material Layout for the Blast Protection of Above-Ground Steel Pipes
No full textThe current study investigates the capacity of the proposed meta-material layout for the blast protection of above-ground steel pipes against explosions. The philosophy of the meta-material layout’s design is described adequately, and the 1D periodic structures’ theory is adopted for the analytical prediction of the layout’s band-gaps. The special characteristics of the blast loading are explained, and specific time-related parameters are calculated. The layout is tested numerically for nine explosion scenarios of various magnitude via the finite element program ABAQUS, and the CONWEP model is selected for the simulation of the explosions. The results demonstrate a significant reduction in the maximum displacements developed on the pipe’s spring line and crown within a blast loading. This study composes an extension of the author’s previous research on buried steel pipes and surface explosion, advancing now the applicability of the meta-material layouts for the cases of above-ground steel pipes towards explosions and blast hazards. The outer goal is the investigation and the further spreading of the beneficial exploitation of meta-materials concepts for the scope of the pipelines’ effective blast protection, readdressing that this way is a major hazard for this type of structure and a gap in the current literature
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