Search (11 results, page 1 of 1)

  • × author_ss:"Leydesdorff, L."
  1. Leydesdorff, L.; Bornmann, L.; Wagner, C.S.: ¬The relative influences of government funding and international collaboration on citation impact (2019) 0.02
    0.02481362 = product of:
      0.07444086 = sum of:
        0.07444086 = sum of:
          0.044655375 = weight(_text_:2001 in 4681) [ClassicSimilarity], result of:
            0.044655375 = score(doc=4681,freq=2.0), product of:
              0.15710425 = queryWeight, product of:
                4.2877507 = idf(docFreq=1650, maxDocs=44218)
                0.03664025 = queryNorm
              0.2842404 = fieldWeight in 4681, product of:
                1.4142135 = tf(freq=2.0), with freq of:
                  2.0 = termFreq=2.0
                4.2877507 = idf(docFreq=1650, maxDocs=44218)
                0.046875 = fieldNorm(doc=4681)
          0.029785486 = weight(_text_:22 in 4681) [ClassicSimilarity], result of:
            0.029785486 = score(doc=4681,freq=2.0), product of:
              0.12830791 = queryWeight, product of:
                3.5018296 = idf(docFreq=3622, maxDocs=44218)
                0.03664025 = queryNorm
              0.23214069 = fieldWeight in 4681, product of:
                1.4142135 = tf(freq=2.0), with freq of:
                  2.0 = termFreq=2.0
                3.5018296 = idf(docFreq=3622, maxDocs=44218)
                0.046875 = fieldNorm(doc=4681)
      0.33333334 = coord(1/3)
    
    Abstract
    A recent publication in Nature reports that public R&D funding is only weakly correlated with the citation impact of a nation's articles as measured by the field-weighted citation index (FWCI; defined by Scopus). On the basis of the supplementary data, we up-scaled the design using Web of Science data for the decade 2003-2013 and OECD funding data for the corresponding decade assuming a 2-year delay (2001-2011). Using negative binomial regression analysis, we found very small coefficients, but the effects of international collaboration are positive and statistically significant, whereas the effects of government funding are negative, an order of magnitude smaller, and statistically nonsignificant (in two of three analyses). In other words, international collaboration improves the impact of research articles, whereas more government funding tends to have a small adverse effect when comparing OECD countries.
    Date
    8. 1.2019 18:22:45
  2. Leydesdorff, L.; Heimeriks, G.: ¬The self-organization of the European information society : the case of "biotechnology" (2001) 0.01
    0.009806437 = product of:
      0.02941931 = sum of:
        0.02941931 = product of:
          0.05883862 = sum of:
            0.05883862 = weight(_text_:2001 in 6524) [ClassicSimilarity], result of:
              0.05883862 = score(doc=6524,freq=5.0), product of:
                0.15710425 = queryWeight, product of:
                  4.2877507 = idf(docFreq=1650, maxDocs=44218)
                  0.03664025 = queryNorm
                0.3745196 = fieldWeight in 6524, product of:
                  2.236068 = tf(freq=5.0), with freq of:
                    5.0 = termFreq=5.0
                  4.2877507 = idf(docFreq=1650, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=6524)
          0.5 = coord(1/2)
      0.33333334 = coord(1/3)
    
    Source
    Journal of the American Society for Information Science and technology. 52(2001) no.14, S.1262-1274
    Year
    2001
  3. Leydesdorff, L.: ¬A sociological theory of communication : the self-organization of the knowledge-based society (2001) 0.01
    0.009115241 = product of:
      0.02734572 = sum of:
        0.02734572 = product of:
          0.05469144 = sum of:
            0.05469144 = weight(_text_:2001 in 184) [ClassicSimilarity], result of:
              0.05469144 = score(doc=184,freq=3.0), product of:
                0.15710425 = queryWeight, product of:
                  4.2877507 = idf(docFreq=1650, maxDocs=44218)
                  0.03664025 = queryNorm
                0.34812197 = fieldWeight in 184, product of:
                  1.7320508 = tf(freq=3.0), with freq of:
                    3.0 = termFreq=3.0
                  4.2877507 = idf(docFreq=1650, maxDocs=44218)
                  0.046875 = fieldNorm(doc=184)
          0.5 = coord(1/2)
      0.33333334 = coord(1/3)
    
    Year
    2001
  4. Leydesdorff, L.: Clusters and maps of science journals based on bi-connected graphs in Journal Citation Reports (2004) 0.01
    0.007442563 = product of:
      0.022327688 = sum of:
        0.022327688 = product of:
          0.044655375 = sum of:
            0.044655375 = weight(_text_:2001 in 4427) [ClassicSimilarity], result of:
              0.044655375 = score(doc=4427,freq=2.0), product of:
                0.15710425 = queryWeight, product of:
                  4.2877507 = idf(docFreq=1650, maxDocs=44218)
                  0.03664025 = queryNorm
                0.2842404 = fieldWeight in 4427, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  4.2877507 = idf(docFreq=1650, maxDocs=44218)
                  0.046875 = fieldNorm(doc=4427)
          0.5 = coord(1/2)
      0.33333334 = coord(1/3)
    
    Abstract
    The aggregated journal-journal citation matrix derived from Journal Citation Reports 2001 can be decomposed into a unique subject classification using the graph-analytical algorithm of bi-connected components. This technique was recently incorporated in software tools for social network analysis. The matrix can be assessed in terms of its decomposability using articulation points which indicate overlap between the components. The articulation points of this set did not exhibit a next-order network of "general science" journals. However, the clusters differ in size and in terms of the internal density of their relations. A full classification of the journals is provided in the Appendix. The clusters can also be extracted and mapped for the visualization.
  5. Leydesdorff, L.; Bihui, J.: Mapping the Chinese Science Citation Database in terms of aggregated journal-journal citation relations (2005) 0.01
    0.007442563 = product of:
      0.022327688 = sum of:
        0.022327688 = product of:
          0.044655375 = sum of:
            0.044655375 = weight(_text_:2001 in 4813) [ClassicSimilarity], result of:
              0.044655375 = score(doc=4813,freq=2.0), product of:
                0.15710425 = queryWeight, product of:
                  4.2877507 = idf(docFreq=1650, maxDocs=44218)
                  0.03664025 = queryNorm
                0.2842404 = fieldWeight in 4813, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  4.2877507 = idf(docFreq=1650, maxDocs=44218)
                  0.046875 = fieldNorm(doc=4813)
          0.5 = coord(1/2)
      0.33333334 = coord(1/3)
    
    Abstract
    Methods developed for mapping the journal structure contained in aggregated journal-journal citations in the Science Citation Index (SCI; Thomson ISI, 2002) are applied to the Chinese Science Citation Database of the Chinese Academy of Sciences. This database covered 991 journals in 2001, of which only 37 originally had English titles; only 31 of which were covered by the SCI. Using factor-analytical and graph-analytical techniques, the authors show that the journal relations are dually structured. The main structure is the intellectual organization of the journals in journal groups (as in the international SCI), but the university-based journals provide an institutional layer that orients this structure towards practical ends (e.g., agriculture). This mechanism of integration is further distinguished from the role of general science journals. The Chinese Science Citation Database thus exhibits the characteristics of "Mode 2" or transdisciplinary science in the production of scientific knowledge more than its Western counterpart does. The contexts of application lead to correlation among the components.
  6. Leydesdorff, L.: ¬The construction and globalization of the knowledge base in inter-human communication systems (2003) 0.00
    0.004964248 = product of:
      0.014892743 = sum of:
        0.014892743 = product of:
          0.029785486 = sum of:
            0.029785486 = weight(_text_:22 in 1621) [ClassicSimilarity], result of:
              0.029785486 = score(doc=1621,freq=2.0), product of:
                0.12830791 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.03664025 = queryNorm
                0.23214069 = fieldWeight in 1621, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.046875 = fieldNorm(doc=1621)
          0.5 = coord(1/2)
      0.33333334 = coord(1/3)
    
    Date
    22. 5.2003 19:48:04
  7. Leydesdorff, L.: Can networks of journal-journal citations be used as indicators of change in the social sciences? (2003) 0.00
    0.004964248 = product of:
      0.014892743 = sum of:
        0.014892743 = product of:
          0.029785486 = sum of:
            0.029785486 = weight(_text_:22 in 4460) [ClassicSimilarity], result of:
              0.029785486 = score(doc=4460,freq=2.0), product of:
                0.12830791 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.03664025 = queryNorm
                0.23214069 = fieldWeight in 4460, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.046875 = fieldNorm(doc=4460)
          0.5 = coord(1/2)
      0.33333334 = coord(1/3)
    
    Date
    6.11.2005 19:02:22
  8. Leydesdorff, L.; Sun, Y.: National and international dimensions of the Triple Helix in Japan : university-industry-government versus international coauthorship relations (2009) 0.00
    0.004964248 = product of:
      0.014892743 = sum of:
        0.014892743 = product of:
          0.029785486 = sum of:
            0.029785486 = weight(_text_:22 in 2761) [ClassicSimilarity], result of:
              0.029785486 = score(doc=2761,freq=2.0), product of:
                0.12830791 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.03664025 = queryNorm
                0.23214069 = fieldWeight in 2761, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.046875 = fieldNorm(doc=2761)
          0.5 = coord(1/2)
      0.33333334 = coord(1/3)
    
    Date
    22. 3.2009 19:07:20
  9. Leydesdorff, L.; Bornmann, L.: How fractional counting of citations affects the impact factor : normalization in terms of differences in citation potentials among fields of science (2011) 0.00
    0.0041368734 = product of:
      0.01241062 = sum of:
        0.01241062 = product of:
          0.02482124 = sum of:
            0.02482124 = weight(_text_:22 in 4186) [ClassicSimilarity], result of:
              0.02482124 = score(doc=4186,freq=2.0), product of:
                0.12830791 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.03664025 = queryNorm
                0.19345059 = fieldWeight in 4186, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=4186)
          0.5 = coord(1/2)
      0.33333334 = coord(1/3)
    
    Date
    22. 1.2011 12:51:07
  10. Hellsten, I.; Leydesdorff, L.: ¬The construction of interdisciplinarity : the development of the knowledge base and programmatic focus of the journal Climatic Change, 1977-2013 (2016) 0.00
    0.0041368734 = product of:
      0.01241062 = sum of:
        0.01241062 = product of:
          0.02482124 = sum of:
            0.02482124 = weight(_text_:22 in 3089) [ClassicSimilarity], result of:
              0.02482124 = score(doc=3089,freq=2.0), product of:
                0.12830791 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.03664025 = queryNorm
                0.19345059 = fieldWeight in 3089, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=3089)
          0.5 = coord(1/2)
      0.33333334 = coord(1/3)
    
    Date
    24. 8.2016 17:53:22
  11. Leydesdorff, L.; Johnson, M.W.; Ivanova, I.: Toward a calculus of redundancy : signification, codification, and anticipation in cultural evolution (2018) 0.00
    0.0041368734 = product of:
      0.01241062 = sum of:
        0.01241062 = product of:
          0.02482124 = sum of:
            0.02482124 = weight(_text_:22 in 4463) [ClassicSimilarity], result of:
              0.02482124 = score(doc=4463,freq=2.0), product of:
                0.12830791 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.03664025 = queryNorm
                0.19345059 = fieldWeight in 4463, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=4463)
          0.5 = coord(1/2)
      0.33333334 = coord(1/3)
    
    Date
    29. 9.2018 11:22:09