1,721,121 research outputs found
Influence of seismic input characteristics on dissipating devices for bridge structures
No full textThe response of a bridge equipped with elasto-plastic dissipating devices to different types of input excitation has been studied through a stochastic analysis. Several input base acceleration time histories have been generated, according to the generalized Kanai-Tajimi model, through a Monte Carlo technique. For each time history parameters characterising the input base motion have been evaluated and correlated to the structural response. Influence of time history duration, frequency content and maximum amplitude on the structural response has been investigated in terms of maximum displacement, maximum force and dissipated energy. The behaviour of the dissipating elato-plastic device is modelled by the hysteretic differential Bouc-Wen model. The model parameters are estimated basing on results of full scale tests on the device
Estimation of the Piecewise Exponential Model by Bayesian P-Splines via Gibbs Sampling: Robustness and Reliability of Posterior Estimates
Full text linkIn the investigation of disease dynamics, the effect of covariates on the hazard function is a major topic. Some recent smoothed estimation methods have been proposed, both frequentist and Bayesian, based on the relationship between penalized splines and mixed models theory. These approaches are also motivated by the possibility of using automatic procedures for determining the optimal amount of smoothing. However, estimation algorithms involve an analytically intractable hazard function, and thus require ad-hoc software routines. We propose a more user-friendly alternative, consisting in regularized estimation of piecewise exponential models by Bayesian P-splines. A further facilitation is that widespread Bayesian software, such as WinBUGS, can be used. The aim is assessing the robustness of this approach with respect to different prior functions and penalties. A large dataset from breast cancer patients, where results from validated clinical studies are available, is used as a benchmark to evaluate the reliability of the estimates. A second dataset from a small case series of sarcoma patients is used for evaluating the performances of the PE model as a tool for exploratory analysis. Concerning breast cancer data, the estimates are robust with respect to priors and penalties, and consistent with clinical knowledge. Concerning soft tissue sarcoma data, the estimates of the hazard function are sensitive with respect to the prior for the smoothing parameter, whereas the estimates of regression coefficients are robust. In conclusion, Gibbs sampling results an efficient computational strategy. The issue of the sensitivity with respect to the priors concerns only the estimates of the hazard function, and seems more likely to occur when non-large case series are investigated, calling for tailored solutions
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
Dalla cura del sé alla cura del pianeta. Processi multidisciplinari per un design somaestetico e rigenerativo
No full textThe effects of climate change and the collapse of ecosystems are increasingly bringing the issue of care to the forefront, encouraging a holistic approach that emphasises the relationship between human somatic well-being, that of living things and ecosystems. This principle encourages the adoption of a universal perspective of care that considers human and interspecies diversity and concerns care and responsibility at various scales. This contribution explores the possibility of generating design processes that bind twoway care practices between human and non-human agents. The proposed method intersects somatic explorations and environmental bioremediation to design jewellery and wearable artefacts that promote the transition to restorative design.Gli effetti del cambiamento climatico sugli ecosistemi stanno mettendo in evidenza il tema della cura, favorendo un approccio olistico che sottolinea la relazione tra il benessere somatico umano, quello dei viventi e degli ecosistemi. Un principio che incoraggia l’adozione di una prospettiva universale della cura che tiene conto della diversità umana, interspecie e che riguarda l’attenzione e la responsabilità su varie scale. Il presente contributo intende esplorare la possibilità di generare processi progettuali che leghino pratiche di cura biunivoche tra agenti umani e non umani. Il metodo proposto interseca esplorazioni somatiche e biorisanamento ambientale per la progettazione di gioielli e artefatti indossabili che promuovano la transizione verso un design di tipo ricostituente
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