1,720,963 research outputs found
Localizing a Notch in a Steel Frame from Frequency Measurements
No full textMost of the diagnostic techniques via modal analysis are based on an optimality criterion where the stiffness distribution of a chosen reference configuration of the structural system is updated so that the first few natural frequencies closely match with the measured ones at a certain level of deterioration. Despite the common use of these techniques in damage identification, basic questions such as how accurate the reference configuration has to be or which a priori hypotheses are needed to get around the not well-posedness of the diagnostic problem are unclear and still open. With an eye to these questions and to practical use of vibration monitoring on field measurements, in this paper a diagnostic strategy for identifying a localized damage in a multi-storey steel frame is discussed. It was found that the dynamic characterization of the frame at a certain stage of its service is indispensable to defining an accurate analytical model of the structure, viz. to defining a reference configuration of the frame which is useful for identifying possible incremental damages. Moreover, some working hypotheses commonly used in structural diagnostics were found to be crucial in reducing the indeterminacy of the identification problem. The obtained results essentially confirm a more careful resolution on the localization of the damage as its severeness increases
Modal analysis of notched bars: tests and comments on the sensitivity of an identification technique
No full textThe results of most diagnostic techniques based on modal analysis strictly depend on the accuracy of the structural analytical model that one uses, on the measurement errors and on the severeness of the damage to be identified. The sensitivity of a particular damage identification technique is discussed and it is shown that the above aspects are crucial even when dealing with simple structural models
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
Development of analysis tools for structures protected by the damped cable system. Report to European Commission No. EVG1-CT-1999-00013 SPIDER/4.1/UDINE/SSO/02/VF-C, Deliverable No. 8, Research and Technological Development Project SPIDER, January 2002
No full textThis report sums up the activities carried out by Udine University within Task 4.1 of Work-package nr. 4. These activities concerned the improvement of the “j2d” software for the two-dimensional analysis of structures equipped with the damped cable system (DCS), and were particularly aimed at:
• providing greater computational capabilities compared to the first version of the code (among which: the incorporation of the vertical force components induced by cables; direct combinations of the static and dynamic output data; a substantial optimisation of the solving routines, so as to improve the numerical stability of the generated algorithms, and to remarkably reduce the elaboration times; etc);
• adding a newly conceived graphical user interface, to facilitate the use of the program both in input and post-processing phases.
Although many of these improvements have been already included, some important aspects are currently in progress. The general lines of the work to be still carried out are anyway completely planned, and presented in this report as well
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
Bond-slip behavior between stainless steel rebars and concrete
Full text linkMaintenance of reinforced concrete structures is a prevailing topic, especially with regard to lifeline structures and bridges, many of which are now designed with a service life beyond 100 years. Reinforcement made of ordinary (carbon) steel may corrode in aggressive environments. Stainless steel, being much more resistant to corrosion, is a valid solution to facilitate the protection of the works, increasing the service life and reducing the need for repair and maintenance. Despite the potential for stainless steel to reduce maintenance costs, studies investigating the influence of stainless steel on the behavior of reinforced concrete structures are limited. This study investigated the bond behavior of stainless steel rebars by means of experimental tests on reinforced concrete specimens with different concrete cover thicknesses, concrete strengths, and bar diameters. In each case, identical specimens with carbon steel reinforcement were tested for comparison. The failure modes of the specimens were examined, and a bond stress-slip relationship for stainless steel bars was established. This research shows that the bond behavior of stainless steel rebars is comparable to that of carbon steel bars
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
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