Search (9 results, page 1 of 1)

  • × author_ss:"Leydesdorff, L."
  1. Bornmann, L.; Leydesdorff, L.: Which cities produce more excellent papers than can be expected? : a new mapping approach, using Google Maps, based on statistical significance testing (2011) 0.03
    0.025637524 = product of:
      0.05127505 = sum of:
        0.05127505 = product of:
          0.1025501 = sum of:
            0.1025501 = weight(_text_:assessment in 4767) [ClassicSimilarity], result of:
              0.1025501 = score(doc=4767,freq=2.0), product of:
                0.2801951 = queryWeight, product of:
                  5.52102 = idf(docFreq=480, maxDocs=44218)
                  0.050750602 = queryNorm
                0.36599535 = fieldWeight in 4767, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  5.52102 = idf(docFreq=480, maxDocs=44218)
                  0.046875 = fieldNorm(doc=4767)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    The methods presented in this paper allow for a statistical analysis revealing centers of excellence around the world using programs that are freely available. Based on Web of Science data (a fee-based database), field-specific excellence can be identified in cities where highly cited papers were published more frequently than can be expected. Compared to the mapping approaches published hitherto, our approach is more analytically oriented by allowing the assessment of an observed number of excellent papers for a city against the expected number. Top performers in output are cities in which authors are located who publish a statistically significant higher number of highly cited papers than can be expected for these cities. As sample data for physics, chemistry, and psychology show, these cities do not necessarily have a high output of highly cited papers.
  2. Leydesdorff, L.; Zhou, P.; Bornmann, L.: How can journal impact factors be normalized across fields of science? : An assessment in terms of percentile ranks and fractional counts (2013) 0.02
    0.021364605 = product of:
      0.04272921 = sum of:
        0.04272921 = product of:
          0.08545842 = sum of:
            0.08545842 = weight(_text_:assessment in 532) [ClassicSimilarity], result of:
              0.08545842 = score(doc=532,freq=2.0), product of:
                0.2801951 = queryWeight, product of:
                  5.52102 = idf(docFreq=480, maxDocs=44218)
                  0.050750602 = queryNorm
                0.30499613 = fieldWeight in 532, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  5.52102 = idf(docFreq=480, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=532)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
  3. Leydesdorff, L.: ¬The construction and globalization of the knowledge base in inter-human communication systems (2003) 0.01
    0.010314009 = product of:
      0.020628018 = sum of:
        0.020628018 = product of:
          0.041256037 = sum of:
            0.041256037 = weight(_text_:22 in 1621) [ClassicSimilarity], result of:
              0.041256037 = score(doc=1621,freq=2.0), product of:
                0.17771997 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.050750602 = 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)
      0.5 = coord(1/2)
    
    Date
    22. 5.2003 19:48:04
  4. Leydesdorff, L.: Can networks of journal-journal citations be used as indicators of change in the social sciences? (2003) 0.01
    0.010314009 = product of:
      0.020628018 = sum of:
        0.020628018 = product of:
          0.041256037 = sum of:
            0.041256037 = weight(_text_:22 in 4460) [ClassicSimilarity], result of:
              0.041256037 = score(doc=4460,freq=2.0), product of:
                0.17771997 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.050750602 = 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)
      0.5 = coord(1/2)
    
    Date
    6.11.2005 19:02:22
  5. Leydesdorff, L.; Sun, Y.: National and international dimensions of the Triple Helix in Japan : university-industry-government versus international coauthorship relations (2009) 0.01
    0.010314009 = product of:
      0.020628018 = sum of:
        0.020628018 = product of:
          0.041256037 = sum of:
            0.041256037 = weight(_text_:22 in 2761) [ClassicSimilarity], result of:
              0.041256037 = score(doc=2761,freq=2.0), product of:
                0.17771997 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.050750602 = 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)
      0.5 = coord(1/2)
    
    Date
    22. 3.2009 19:07:20
  6. Leydesdorff, L.; Bornmann, L.; Wagner, C.S.: ¬The relative influences of government funding and international collaboration on citation impact (2019) 0.01
    0.010314009 = product of:
      0.020628018 = sum of:
        0.020628018 = product of:
          0.041256037 = sum of:
            0.041256037 = weight(_text_:22 in 4681) [ClassicSimilarity], result of:
              0.041256037 = score(doc=4681,freq=2.0), product of:
                0.17771997 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.050750602 = 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)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Date
    8. 1.2019 18:22:45
  7. 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) 0.01
    0.0085950075 = product of:
      0.017190015 = sum of:
        0.017190015 = product of:
          0.03438003 = sum of:
            0.03438003 = weight(_text_:22 in 4186) [ClassicSimilarity], result of:
              0.03438003 = score(doc=4186,freq=2.0), product of:
                0.17771997 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.050750602 = 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)
      0.5 = coord(1/2)
    
    Date
    22. 1.2011 12:51:07
  8. 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) 0.01
    0.0085950075 = product of:
      0.017190015 = sum of:
        0.017190015 = product of:
          0.03438003 = sum of:
            0.03438003 = weight(_text_:22 in 3089) [ClassicSimilarity], result of:
              0.03438003 = score(doc=3089,freq=2.0), product of:
                0.17771997 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.050750602 = 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)
      0.5 = coord(1/2)
    
    Date
    24. 8.2016 17:53:22
  9. Leydesdorff, L.; Johnson, M.W.; Ivanova, I.: Toward a calculus of redundancy : signification, codification, and anticipation in cultural evolution (2018) 0.01
    0.0085950075 = product of:
      0.017190015 = sum of:
        0.017190015 = product of:
          0.03438003 = sum of:
            0.03438003 = weight(_text_:22 in 4463) [ClassicSimilarity], result of:
              0.03438003 = score(doc=4463,freq=2.0), product of:
                0.17771997 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.050750602 = 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)
      0.5 = coord(1/2)
    
    Date
    29. 9.2018 11:22:09