1,720,967 research outputs found
Dry Stone Masonry Walls in Bending – Part I: Static Tests
No full textA series of static 1:5-scale tests on dry-stack stone masonry walls were performed with the main objective to verify existing analytical expressions for the computation of the resistance to horizontal loading proportional to the self-weight of masonry. The resistance is expressed by means of a collapse load multiplier, and the experiments were conceived to reproduce various out-of-plane bending failure mechanisms using an inclined plane machine built with steel profiles and with an aluminium platform. The collapse multiplier was calculated from the inclination angle of the platform that caused collapse. Since the walls were constructed without mortar, the shear strength along the joints was given purely by friction. The “bricks” were cut from marble – the selection criteria being the accuracy for the cutting, the hardness and durability of the material, and an appropriate friction coefficient. In total, 42 configurations were tested, varying the length of the walls, the presence and position of openings, the staggering ratio, the quality of the connection between walls, the existence of vertical overburden loads in the walls, and the number of stories. The test results are presented in terms of the measured collapse load multipliers and detailed descriptions of the associated collapse mechanisms
Dry stone masonry walls in bending - Part II: analysis
No full textWith the objective of developing analytical models for evaluation of the lateral strength of dry-stack masonry (DSM) walls subject to horizontal inertial loading, simple collapse mechanisms are proposed, which include a combination of out-of-plane flexural deformation along the main panel and in-plane shear deformation in the connecting return walls. The lateral strength is calculated using a virtual work approach incorporating moment capacities along different types of crack lines and shear resistance of in-plane panels participating in the mechanisms. The proposed treatment of the active in-plane panels assumes that they undergo frictional shear deformation (versus rigid body rocking), in consistency with the zero tensile strength nature of DSM. Allowance is also made for the presence of either restrained or unrestrained overburden loads at the top of the wall, which can generate either a strengthening or weakening effect, respectively. The accuracy of the analysis is assessed by comparing its predictions to the results of experimental tests on DSM reported in the companion study. These comparisons are favorable with respect to both the predicted values of strength and the critical failure mechanisms.Jaroslav Vaculik, Michael C. Griffith, and Guido Magene
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
Second order effects in out-of-plane strength of unreinforced masonry walls subjected to bending and compression
No full textThe recent development of a new Italian seismic code has been an occasion to reconsider the current criteria for seismic design of masonry buildings and their consequences in practice. In this regard, the present research presents and discusses several issues regarding the out-of-plane response of face-loaded unreinforced masonry walls. While the work has been oriented towards the typical structural typologies currently being constructed in Italy, the principles are generic and suitable for other typologies, including those found in Australia and New Zealand, and are considered to be especially relevant for assessing the seismic capacity of walls in existing buildings.P. Morandi, G. Magenes and M. Griffit
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
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