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Dynamic Impedance Functions of a Square Foundation Estimated with an Equivalent Linear Approach
No full textLiquefaction Analysis using Shear Wave Velocity
Get PDFThe Andrus and Stokoe curves developed based on shear wave velocity case history databases, are the most widely used in the context of the Seed and Idriss simplified procedure as a deterministic model. Theses curves were developed from the database according to the calculate cyclic stress ratio (CSR) proposed by Seed and Idriss in 1971 with the assumption that the dynamic cyclic shear stress (Ï„d) is always less than the simplified cyclic shear stress (Ï„r) deduced by Seed and Idriss based on their simplifying hypotheses (rd= Ï„d / Ï„r <1). Filali and Sbartai in 2017, showed that rd can in many cases be greater than 1, and they have proposed a correction for the CSR in the range where rd >1. In this paper, we will present a probabilistic study based on the Bayesian method for the evaluation of the liquefaction potential of a soil deposit using a case history database based on shear wave velocity measurement. The result of this analysis shows that by using the corrected version of the simplified method, the boundary curve is moved to a new position. Then, the objective of this study is to present an adjusted mathematical model which characterizes the new position of the boundary curve (CRR) and a new formulation for computing the probability of liquefaction based on the probabilistic shape of the CRR curves using the corrected and the original version of the simplified method
A comparative study between simplified and nonlinear dynamic methods for estimating liquefaction potential
No full textThis paper estimated the liquefaction potential of a saturated soil deposit subjected to a horizontal seismic excitation at its base using the total stress approach. A comparative analysis between the simplified and the nonlinear dynamic methods was used to verify to what extent the simplified method could be reliable. In order to generalise the reliability of the simplified method for any value of the maximum acceleration for the used earthquakes, a correction for the maximum acceleration less than 0.3g was proposed based on the comparison of safety factor values determined by the dynamic method illustrated by the equivalent linear model with lumped masses and the simplified method for a given profile of soil subjected to 38 earthquakes. The nonlinear behaviour of soil was represented by two hyperbolic models: Hardin and Drnevich, and Masing. To determine the cyclic resistance ratio (CRR), the cone penetration test (CPT) based method, the standard penetration test (SPT) based method, and the shear wave velocity based method were used. The safety factor was calculated as the ratio of CRR/CSR, where CSR represents the cyclic stress ratio. The results of the proposed correction have given smaller values of the safety factor compared to the nonlinear dynamic methods for the maximum acceleration less than 0.3g. In other words, by considering this correction, the most unfavourable case is always given by the modified simplified method
Optimization of Shear Wave Velocity (Vs) from a Post-Liquefaction Settlement Using a Genetic Algorithm Multi-Objective NSGA II
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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
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
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