1,720,955 research outputs found
Mechanical characterization of foils with compression in their planes
Full text linkAn experimental-computational procedure is proposed and numerically validated for combined compression and bending tests and for identification of parameters in anisotropic elastic-plastic material models of the mechanical behavior of foils, specifically of paperboards and laminates for liquid containers. From the experimental standpoint, the proposed technique generalizes the instrumentation and “modus operandi” of traditional uni-axial testing with the following novel provisions: the foil specimen is stabilized by two elastic “blocks” of a well known polymeric material (therefore, such system is called “sandwich” herein); “full-field”
displacement measurements by a digital image correlation (DIC) technique are envisaged, and examined by sensitivity analyses with
respect to the sought parameters; the experimental data provided by DIC might be enriched by the digitalized relationship between external loading and imposed displacements in the test; test simulations (“direct analyses”) are performed by finite element modeling and the sought parameters governing the specimen behavior are assessed byminimization of a discrepancy function (inverse analysis); the minimization by mathematical programming is made fast and economical by radial basis functions (RBF) interpolations based on preliminary proper orthogonal decomposition (POD)
A novel formula for resistance reduction in perforated steel plate shear walls
No full textRecently, many researches have been devoted to predicting Perforated Steel Plate Shear Wall (P-SPSW) behaviour, from which some have been able to propose resistance reduction formulas. Nevertheless, new findings have witnessed some nonconformance between the actual response of P-SPSWs and the values predicted by available closed form solutions. In this study, the possible sources of such nonconformances have been investigated and a novel formula for resistance reduction in P-SPSWs has been proposed. To this end, 28 SPSWs having 3~6 stories with aspect ratios ranging from 0.8 to 2.0, have been carefully designed according to the AISC requirements for thin infill panels. Afterwards, the SPSWs were simulated using practical infill panels and by adopting a rectangular perforation layout, the optimum perforation sizes were explored in such a way that the P-SPSW would exhibit a lateral sway similar to the original SPSW. Finally, all design parameters for SPSWs and P-SPSWs were collected in a database and used to propose some improved linear, bilinear and logarithmic formulas. A survey done on the proposed formula revealed an average absolute error less than 4% in estimating the perforation diameters, which is relatively small compared to the error margin of other formulas and, as a result, the formula in question is concluded to be a reliable tool for design purposes. Finally, the proposed formula for diagonal perforation has been successfully verified for estimating the strength reduction in an available experimentally studied single-story P-SPSW
On optimum perforation layout in low-rise steel plate shear walls.
No full textThe design and performance of Steel Plate Shear Walls (SPSW) strongly depends on infill panels. Any unnecessary increase in the thickness of infill panels, which is a common occurrence in low-rise buildings, results in extremely large boundary elements and a noneconomic design. Among the several remedies that have been proposed and discussed by researchers, infill panel perforation has become more popular in SPSW design and construction. As a designer, one should primarily choose a desirable perforation layout, then adopt an approximate stiffness reduction formula and try to replace the infeasible design infill panel with a perforated one which possesses a minimum practical thickness and provides a similar lateral stiffness and strength. In this paper for a 4-story SPSW, primarily designed with practically infeasible thin infill panels, the optimum perforation diameters corresponding to diverse diagonal and rectangular perforation layouts are explored and the results have been compared to those provided by the available stiffness reduction formulas. The optimization outcomes reveal that the uniformly spaced rectangular perforation layouts are more efficient in the sense of SPSW stiffness reduction. Also, the efficiency of stiffness reduction formulas for rectangular perforation layouts have been assessed and the reliable methods introduced. Finally, on the basis of the resulted optimum sets, some formula improvements and design recommendations are concluded which would be useful and beneficial for practicing engineers
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
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
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