1,720,993 research outputs found
A cyclic p-y model for the whole-life response of piles in soft clay
No full textIt is evident from model testing, field studies and theoretical considerations that the strength of a soft clay can reduce and then recover – potentially to above the initial value – as a result of cyclic loading followed by consolidation. For piled foundations and well conductors, these changes in soil strength and the resulting lateral resistance affect their stiffness, capacity and fatigue. This paper introduces a new model for the cyclic lateral ‘p-y’ response of a pile in soft clay, using concepts from critical state soil mechanics, combined with a parallel Iwan model to capture the hysteric response. Example analyses show that the model can capture the general forms of behaviour observed in model tests, and is rapid and simple to implement. The model provides a new basis for whole life modelling of piles and well conductors, allowing changes in stiffness and capacity to be simulated, as well as improved modelling of fatigue accumulation. This approach allows more reliable design, quantifying the benefits and risks associated with evolving soil strength.</p
An evaluation of p–y curves for fatigue analysis of offshore piles and conductors
No full textThe paper evaluates methods for deriving p–y curves for fatigue analysis of slender piles and conductors. Updated ISO standard guidance is compared to a new approach, which is validated by centrifuge tests and based on laboratory measurements of stiffness. This new approach provides a more accurate match to previously-published data on which the ISO guidelines are based. Additionally, a third method is examined —the parallel-Iwan critical state inspired (PICSI) framework——which captures changes in p–y response through cyclic loading and consolidation. Bending moments from a pile–soil Finite Element (FE) analysis using the three methods are compared to data from flexible piles centrifuge testing. Load history effects are evident, with the bending moment profile for a given cyclic amplitude being altered by prior larger cycles, through a changing p–y response. The resulting evolution of the bending moment profile showed migration of the fatigue hotspot along the pile, which improves fatigue life. Whereas the ISO fatigue p–y curves over-predicted the observed stiffness, the alternative simplified p–y method matched the bending moments to ±25% accuracy, and the PICSI framework gave the most accurate bending moment predictions across the full test sequence. These latter two methods are recommended for design use in preference to the ISO approach
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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