1,721,653 research outputs found
Highly-efficient and selective photoelectrochemical CO2 reduction by Si photo-electrode with Reduced Anodic Au Thin Film
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Estimation of first-passage probability under stochastic wind excitations by active-learning-based heteroscedastic Gaussian process
No full textIn the processes for designing and assessing structural systems, it is essential to evaluate their reliability against stochastic loads caused by natural or human-made hazards, e.g., wind loads, earthquakes, and collisions. The first-passage probability is a crucial measure of a system's reliability under such conditions. However, the first -passage probability estimation generally requires repetitive dynamic simulations and thus may result in high computational cost. This paper proposes a new active-learning-based surrogate method that efficiently estimates the first-passage probability under stochastic wind excitations to address the computational issue. The proposed method introduces an alternative formulation using the conditional distribution of the maximum response given time-invariant uncertain parameters to handle the high dimensionality of stochastic excitation sequences. The method employs the Gaussian-process-based surrogate model with heteroscedastic noises to fit the distribution parameter functions considering uncertainties arising from the structural system and the environmental loads. In addition, an adaptive training process of surrogates is introduced to identify the best experimental designs achieving efficient convergence. The numerical examples of an eight-story building and a transmission tower demonstrate that the proposed method can produce accurate estimation results with fewer structural simulations than existing methods.N
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
Facile electrochemical synthesis of dilute AuCu alloy nanostructures for selective and long-term stable CO2 electrolysis
No full textElectrochemical CO production from CO2 electrolysis has been considered the most economically viable approach among various candidate products. AuCu bimetallic alloys are currently receiving attention for their potential to tailor catalytic activity. Here, we synthesized a dilute AuCu alloy nanostructure with an AuCu atomic composition ratio of 3% by using a simple electrochemical treatment method on a 200 nm-thick Au thin film. The dilute AuCu alloy catalyst shows an exceptional CO2 reduction activity in terms of selectivity and overpotential for CO production. In addition, the stability property is more significantly enhanced as compared to pure Au nanostructures. In addition, we describe an in situ tailoring method of catalytic activity for Au nanostructures by repeating an electrochemical treatment process that is performed for forming the Au nanostructure. This approach will be a promising and facile strategy not only for reactive Au catalysts but also to increase the stability activity simultaneously by utilizing Cu impurities existing in an aqueous electrolyte for CO2 reduction.
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