1,721,111 research outputs found
Bandwidth Selection for Kernel Quantile Estimation
No full textIn this article, we summarize some quantile estimators & related bandwidth
selection methods & give two new bandwidth selection methods. By four distributions:
standard normal, exponential, double exponential & log normal we simulated
the methods & compared their efficiencies to that of the empirical quantile. It turns
out that kernel smoothed quantile estimators, with no matter which bandwidth selection
method used, are more efficient than the empirical quantile estimator in most
situations. And when sample size is relatively small, kernel smoothed estimators
are especially more efficient than the empirical quantile estimator. However, no one
method can beat any other methods for all distributions
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
Evolutionary correlation of heterodichogamy and floral longevity
No full textHeterodichogamy, the coexistence of morphs differing in the time when the shift between male and female phases occurs, is a rare sexual dimorphism derived from synchronous dichogamy. In dichogamous populations, plants need to adjust the temporal sex role to deal with the negative frequency dependent selection imposed by population sex ratios. However, such temporal adjustment may be constrained in dichogamous species with bisexual flowers and short floral longevities (<2 days) and therefore the reciprocal floral strategy can easily invade the population, ultimately leading to heterodichogamy. We predict that heterodichogamy has evolved in species with short floral longevities. To test this prediction, we compiled data on floral longevity for 377 dichogamous and heterodichogamous species with bisexual flowers and ran a phylogenetic logistic regression between floral strategy (dichogamy/heterodichogamy) and floral longevity. The results showed that heterodichogamous species had significantly shorter floral longevities than dichogamous species. This result together with the fact that evolutionary transitions always occurred from dichogamy to heterodichogamy supports the conclusion of the existence of a significant and negative evolutionary correlation between the floral longevity and the probability to evolve heterodichogamy from dichogamy in bisexual species. We discuss that the rarity of heterodichogamy in nature may be the result of other selective pressures towards long floral longevity in dichogamous species.S.S gratefully acknowledges funding support from Supported by the Fundamental Research Funds for the Central Universities (lzujbky-2015-89)Peer reviewe
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
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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