1,721,009 research outputs found
A PARALLEL NON-PROBABILISTICALLY-DOMINATED SORTING GENETIC ALGORITHM FOR ROBUST OPTIMIZATION
Get PDFSuccessful engineering design generally requires the resolution of various conflicting design objectives. In order to identify an optimal design, conflicting objectives are typically considered simultaneously. One of the most powerful tools for resolving such objectives, in a computational setting, is multi-objective optimization. By definition, Pareto solutions are considered optimal because there are no other designs that are superior in all objectives.
In a deterministic optimization the effect of uncertainty is not considered when drawing conclusions, hence we want to extend the concept of Pareto dominance in a probabilistic sense.
In each evolution era, the different chromosomes can be evaluated with respect to the objective functions in parallel. For each one of the chromosome the Simplex Stochastic Collocation is used to handle uncertainty. The method is based on a serial sequential-solution refinement of the probability space until a defined threshold: different simplexes converge at different times.
A nested loop of parallel-serial evaluations is handled by the R-Opt to achieve the best computational efficiency
Multi-Disciplinary Design And Analysis Of Wind Turbines Under Uncertainty
No full textThe performance of wind turbines can be negatively affected by the presence of uncertainties. We introduce a comprehensive multi-physics computational model EOLO that enables the estimation of aerodynamic and structural characteristics assiociated with horizontal axis wind turbines, and use it to study the impact of uncertainties on the aerodynamic performance and noise. We consider variability in the wind conditions, manufacturing tolerances and roughness induced by
insect contamination as sources of uncertainties and treat them within a probabilistic framework using Latin Hypercube Sampling and Stochastic Simplex Colocation. The results demonstrate that these two methods lead to a statistical characterization of the quantity of interest which is considerably faster than classical Monte Carlo methods. In addition, we demonstrate how the uncertainties impact the aerodynamics and noise leading to a largely inferior performance compared to the nominal design. Finally a multi-disciplinary shape optimization of the wind turbine blade is proposed
Optimization under uncertainty of a Formula 1 cooling brake duct
No full textThe aerodynamic characteristics of each wheel configuration, consisting of 30 million cells, is solved numerically using Computational Fluid Dynamics (CFD) on Certainty. Every configuration is slightly modified by morphing the mesh locally depending on the multi-objective optimization algorithm
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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