1,720,961 research outputs found
Seismic retrofit and repair of reinforced concrete bridge columns using shape memory alloy spirals
Get PDFThis research focuses on examining the use of shape memory alloy (SMA) spirals in the seismic retrofitting and repair of reinforced concrete (RC) bridge columns. The thermally triggered recovery stress of prestrained SMA spirals is utilized to apply large active confinement pressure at the column’s plastic hinge zone to enhance the flexural ductility of vulnerable columns and limit their post-earthquake damage. Although research has proven that concrete active confinement is a more superior technique to passive confinement, its field application using conventional materials is hindered due to several complications related to the method of application. This research focuses on investigating the new concrete active confinement technique using SMA spirals numerically and experimentally, which is rapid, robust and simple. The research work comprises of: 1) Performing numerical analysis on RC columns retrofitted using SMA spirals (active confinement) and Fiber Reinforced Polymer (FRP) wraps (passive confinement) to examine the superiority of the suggested new confinement technique over current confinement techniques, 2) Investigating experimentally the thermo-mechanical behavior of NiTiNb SMA which is used for this research, 3) Testing concrete cylinders wrapped with SMA spirals and Glass-FRP (GFRP) wraps, 4) Conducting quasi-static lateral cyclic tests on four 1/3-scale RC columns retrofitted with SMA spirals and GFRP wraps, 5) Conducting quasi-static lateral cyclic tests on two severely damaged columns that were repaired using SMA spirals as an emergency repair technique, 6) Utilizing the experimental results of the tested columns to develop and validate numerical models for RC columns retrofitted with SMA spirals, and 7) Utilizing the validated models to conduct a comprehensive parametric study on columns retrofitted with SMA spirals. The results of this experimental and numerical work clearly illustrate that using thermally prestressed SMA spirals to apply external active confinement pressure on concrete columns is an effective, simple, robust, and rapid approach to improve the performance of RC bridge columns.Item withdrawn by Mark Zulauf ([email protected]) on 2012-02-28T21:54:14Z
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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
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
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
A model for estimating horizontal aftershock ground motions for active crustal regions
No full textInconsistent observations on the characteristics of ground motions from aftershocks have been found, while there is increasing attention to effects of aftershock ground motions on structural behaviors. This study examines differences in ground motions from main shock and aftershock earthquakes using the NGA-West2 database, and propose an empirical model to estimate the average horizontal components of peak ground acceleration (PGA), and peak ground velocity (PGV), and 5% damped pseudo spectral acceleration (PSA) at various spectral periods of aftershock earthquakes for tectonically active crustal regions, as a function of aftershock to main shock magnitude ratio, distance ratio, and time-averaged shear-wave velocity in the upper 30 m of soil deposits (V-S30). Spectral accelerations from aftershock earthquakes are smaller than those from main shock earthquakes given the same magnitude, especially at short periods. Performance of the proposed model is evaluated using a mixed-effects residuals analysis. Period-dependent standard deviation of,residuals is also presented.ope
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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