1,720,977 research outputs found
Recent advances in the synthesis of colloidal nanowires
No full textWe review critically the advances in the synthesis of colloidal nanowires that have occurred over the past three years, with a focus on those that produced very thin (or "ultrathin") nanowires (similar to 2-3 nm in diameter or less). We discuss the importance of these ultrathin nanowires, especially in light of the emerging evidence of their topological properties and their potential similarities with polymers
Uni- and bivariate statistical analysis of long-term wave climates
No full textFor the probability-based design and assesment of marine structures interacting with sea waves, a reliable knowledge of the long-term wave climate is required. Wave climate data are commonly presented in the form of histograms of spectral wave parameters. The severity of a sea state is usually expressed in terms of significant wave height H, and corresponding wave period T. From the earlier stages of the development of a statistical approach to wave climate, the advantage of an analytical representation of empirical distributions of data through parametric models was recognized. The compactness of analytical description, the standardization of the representation, and the filling of information gaps, led researchers to use specific marginal and bivariate parameter models, suitable for the description of wave height and wave period statistics. A large amount of case studies is present in the literature with regard to the marginal distribution functions of H, and T and with regard to the bivariate distribution functions of Hs and T.Besides the above bivariate models that are based on the marginal distribution functions also exist. The aim of the present study is to find a particular bivariate distribution function for Hs and T, which provides a close fit to long-term (extreme) wave data presenting a deep water wave field. Several types of joint distribution function for H, and T are compared with reference to measured data. The comparison is based on the utility of the distribution functions for predictions of extreme sea states. The report is thus concerned with the estimation of extreme significant wave heights and wave periods (zero-up-crossing periods or spectral peak periods). The present study of bivariate functions is similar to the above mentioned case studies of marginal distributions. It provides a detailed analysis of the influence of the data selection procedure, the parameter estimation method and the chosen distribution function on the estimation of bivariate return values. In total flve bivariate probability models are tested for the joint statistics of Hs and T. These are: 1. the bivariate Log-normal distribution 2. the bivariate Log-normal distribution with correction for skewness (the Fang and Hogben distribution) 3. the bivariate distribution constructed from a marginal distribution for Hs and a conditional distribution for T 4. the bivariate distribution based on a marginal distribution for Hs and a marginal distribution for the (deepwater) wave steepness 5. the bivariate distribution with given marginals developed by Morton and Bowers (1997) The fourth model is proposed by Vrijling (1996). It is based on the assumption that the significant wave height (Hs) and the wave steepness (s) are independent. With in the calculations, first the bivariate distribution of Hs and s is computed by simply taking the product of the marginals of Hs and s. Then the bivariate distribution of Hs and T is determined by transforming the joint model of H, and s. The fifth model is a distribution of the Frechet class. Morton and Bowers (1997) have published an article in which a detailed description is given about the application of the model to extreme wave height and windspeed observations. They obtained good results. No further tests of the model are known to the author. Therefore, the model is included in the present study.Hydraulic EngineeringCivil Engineering and Geoscience
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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