1,720,957 research outputs found

    On the Sunspot Group Number Reconstruction: The Backbone Method Revisited

    Get PDF
    We discuss recent papers very critical of the Group Sunspot Number Series (Svalgaard & Schatten [2016]). Unfortunately, we cannot support any of the concerns they raise. We first show that almost always there is simple proportionality between the group counts by different observers and that taking the small, occasional, non-linearities into account makes very little difference. Among other examples: we verify that the RGO group count was drifting the first twenty years of observations. We then show that our group count matches the diurnal variation of the geomagnetic field with high fidelity, and that the heliospheric magnetic field derived from geomagnetic data is consistent with our group number series. We evaluate the ‘correction matrix’ approach [Usoskin et al. 2016] and show that it fails to reproduce the observational data. We clarify the notion of daisy-chaining and point out that our group number series has no daisy-chaining for the period 1794-1996 and therefore no accumulation of errors over that span. We compare with the cosmic ray record for the last 400+ years and find good agreement. We note that the Active Day Fraction method (of Usoskin et al.) has the fundamental problem that at sunspot maximum, every day is an ‘active day’ so ADF is nearly always unity and thus does not carry information about the statistics of high solar activity. This ‘information shadow’ occurs for even moderate group numbers and thus need to be extrapolated to higher activity. The ADF method also fails for ‘equivalent observers’ who should register the same group counts, but do not. We conclude that the criticism of Svalgaard & Schatten [2016] is invalid and detrimental to progress in the important field of long-term variation of solar activity

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Get PDF
    The 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 PDF
    We 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 PDF
    We 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

    Author Index

    No full text
    Nao informado

    koamabayili/VECTRON-author-checklist: VECTRON author checklist

    No full text
    We 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

    Solar activity – past, present, future

    Get PDF
    As our civilization depends increasingly on space-borne assets and on a delicate and vulnerable earth-bound infrastructure, solar activity and its potential impact becomes of increasing importance and relevance. In his famous paper on the Maunder Minimum, Eddy (1976) introduced the notion that the Sun is a variable star on long time scales. After the recent decade of vigorous research based on cosmic ray and sunspot data as well as on geomagnetic activity, an emerging consensus reconstruction of solar wind magnetic field strength has been forged for the last century. The consensus reconstruction shows reasonable agreement among the various reconstructions of solar wind magnetic field the past ~ 170 years. New magnetic indices open further possibilities for the exploitation of historic data. The solar wind is a direct result of solar magnetic activity providing an important link to the effects on the Earth’s environment. Reassessment of the sunspot series (no Modern Grand Maximum) and new reconstructions of Total Solar Irradiance also contribute to our improved knowledge (or at least best guess) of the environment of the Earth System, with obvious implications for management of space-based technological assets or, perhaps, even climate. Several lines of evidence suggest that the Sun is entering a period of low activity, perhaps even a Grand Minimum. Average space weather might be “milder” with decreased solar activity, but the extreme events that dominate technological effects are not expected to disappear. Prediction of solar activity has a poor track record, but the progression of the current Cycle 24 is in accordance with its behavior predicted from the evolution of the solar polar fields, so perhaps there is hope
    corecore