1,720,952 research outputs found

    DETECTING EXOTIC SPHERES VIA FOLD MAPS (Local and global study of singularity theory of differentiable maps)

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    In this survey article, we present two subgroup filtrations of the group of homotopy spheres whose definitions are both based on the existence of certain fold maps subject to index constraints. Both filtrations have recently been introduced and studied by the author in order to obtain new insights into global singularity theory of fold maps from high dimensional manifolds into Euclidean spaces. We discuss fundamental relations of our filtrations to other known filtrations of geometric topology. Moreover, we show how our results can be applied to compute an invariant of Saeki for the Milnor 7-sphere, as well as the value of Banagl's TFT-type aggregate invariant on certain exotic spheres including Kervaire spheres. Along the way, we raise some problems for future study

    CUTTING AND PASTING OF MORSE FUNCTIONS (Research on topology and differential geometry using singularity theory of differentiable maps)

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    Cobordism groups of various types of Morse functions have been studied separately by several authors including Ikegami, Kalmar, Saeki, Yamamoto, and the author. In this article, we propose a conceptually new approach for studying cobordism groups of several types of Morse functions within a single unifying framework. Our method is crucially based on certain cutting and pasting relations for manifolds that have been used before to define SKK-groups of manifolds. We provide an explicit isomorphism between the cobordism group of Morse functions and SKK-groups. Moreover, we sketch an application of our framework to cobordism theory for Morse functions with boundary, and raise some problems for future study concerning Morse functions with index constraints and circle-valued Morse functions

    Topological Gysin Coherence for Algebraic Characteristic Classes of Singular Spaces

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    Brasselet, the second author and Yokura introduced Hodge-theoretic Hirzebruch-type characteristic classes IT1,IT_{1, \ast}, and conjectured that they are equal to the Goresky-MacPherson LL-classes for pure-dimensional compact complex algebraic varieties. In this paper, we show that the framework of Gysin coherent characteristic classes of singular complex algebraic varieties developed by the first and third author in previous work applies to the characteristic classes IT1,IT_{1, \ast}. In doing so, we prove the ambient version of the above conjecture for a certain class of subvarieties in a Grassmannian, including all Schubert subvarieties. Since the homology of Schubert subvarieties injects into the homology of the ambient Grassmannian, this implies the conjecture for all Schubert varieties in a Grassmannian. We also study other algebraic characteristic classes such as Chern classes and Todd classes (or their variants for the intersection cohomology sheaves) within the framework of Gysin coherent characteristic classes

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    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

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    “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

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    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

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    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

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    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
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