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  • × author_ss:"Leydesdorff, L."
  • × theme_ss:"Visualisierung"
  1. Leydesdorff, L.; Persson, O.: Mapping the geography of science : distribution patterns and networks of relations among cities and institutes (2010) 0.00
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    Abstract
    Using Google Earth, Google Maps, and/or network visualization programs such as Pajek, one can overlay the network of relations among addresses in scientific publications onto the geographic map. The authors discuss the pros and cons of various options, and provide software (freeware) for bridging existing gaps between the Science Citation Indices (Thomson Reuters) and Scopus (Elsevier), on the one hand, and these various visualization tools on the other. At the level of city names, the global map can be drawn reliably on the basis of the available address information. At the level of the names of organizations and institutes, there are problems of unification both in the ISI databases and with Scopus. Pajek enables a combination of visualization and statistical analysis, whereas the Google Maps and its derivatives provide superior tools on the Internet.
    Source
    Journal of the American Society for Information Science and Technology. 61(2010) no.8, S.1622-1634
  2. Leydesdorff, L.: Visualization of the citation impact environments of scientific journals : an online mapping exercise (2007) 0.00
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    Abstract
    Aggregated journal-journal citation networks based on the Journal Citation Reports 2004 of the Science Citation Index (5,968 journals) and the Social Science Citation Index (1,712 journals) are made accessible from the perspective of any of these journals. A vector-space model Is used for normalization, and the results are brought online at http://www.leydesdorff.net/jcr04 as input files for the visualization program Pajek. The user is thus able to analyze the citation environment in terms of links and graphs. Furthermore, the local impact of a journal is defined as its share of the total citations in the specific journal's citation environments; the vertical size of the nodes is varied proportionally to this citation impact. The horizontal size of each node can be used to provide the same information after correction for within-journal (self-)citations. In the "citing" environment, the equivalents of this measure can be considered as a citation activity index which maps how the relevant journal environment is perceived by the collective of authors of a given journal. As a policy application, the mechanism of Interdisciplinary developments among the sciences is elaborated for the case of nanotechnology journals.
    Source
    Journal of the American Society for Information Science and Technology. 58(2007) no.1, S.25-38
  3. Rafols, I.; Porter, A.L.; Leydesdorff, L.: Science overlay maps : a new tool for research policy and library management (2010) 0.00
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    Source
    Journal of the American Society for Information Science and Technology. 61(2010) no.9, S.1871-1887