Search (34 results, page 1 of 2)

  • × author_ss:"Egghe, L."
  • × type_ss:"a"
  • × year_i:[2000 TO 2010}
  1. Egghe, L.: Mathematical study of h-index sequences (2009) 0.03 
    0.027124483 = product of:
  0.067811206 = sum of:
    0.00436753 = weight(_text_:e in 4217) [ClassicSimilarity], result of:
      0.00436753 = score(doc=4217,freq=2.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.07940422 = fieldWeight in 4217, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.0390625 = fieldNorm(doc=4217)
    0.063443676 = weight(_text_:69 in 4217) [ClassicSimilarity], result of:
      0.063443676 = score(doc=4217,freq=2.0), product of:
        0.20963728 = queryWeight, product of:
          5.478287 = idf(docFreq=501, maxDocs=44218)
          0.03826694 = queryNorm
        0.30263546 = fieldWeight in 4217, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          5.478287 = idf(docFreq=501, maxDocs=44218)
          0.0390625 = fieldNorm(doc=4217)
  0.4 = coord(2/5)
    Abstract
    This paper studies mathematical properties of h-index sequences as developed by Liang [Liang, L. (2006). h-Index sequence and h-index matrix: Constructions and applications. Scientometrics, 69(1), 153-159]. For practical reasons, Liming studies such sequences where the time goes backwards while it is more logical to use the time going forward (real career periods). Both type of h-index sequences are studied here and their interrelations are revealed. We show cases where these sequences are convex, linear and concave. We also show that, when one of the sequences is convex then the other one is concave, showing that the reverse-time sequence, in general, cannot be used to derive similar properties of the (difficult to obtain) forward time sequence. We show that both sequences are the same if and only if the author produces the same number of papers per year. If the author produces an increasing number of papers per year, then Liang's h-sequences are above the "normal" ones. All these results are also valid for g- and R-sequences. The results are confirmed by the h-, g- and R-sequences (forward and reverse time) of the author.
    Language
    e
  2. Egghe, L.: Dynamic h-index : the Hirsch index in function of time (2007) 0.02 
    0.015447149 = product of:
  0.03861787 = sum of:
    0.006988047 = weight(_text_:e in 147) [ClassicSimilarity], result of:
      0.006988047 = score(doc=147,freq=2.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.12704675 = fieldWeight in 147, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.0625 = fieldNorm(doc=147)
    0.031629823 = product of:
      0.09488946 = sum of:
        0.09488946 = weight(_text_:evolution in 147) [ClassicSimilarity], result of:
          0.09488946 = score(doc=147,freq=2.0), product of:
            0.2026858 = queryWeight, product of:
              5.29663 = idf(docFreq=601, maxDocs=44218)
              0.03826694 = queryNorm
            0.46816036 = fieldWeight in 147, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              5.29663 = idf(docFreq=601, maxDocs=44218)
              0.0625 = fieldNorm(doc=147)
      0.33333334 = coord(1/3)
  0.4 = coord(2/5)
    Abstract
    When there are a group of articles and the present time is fixed we can determine the unique number h being the number of articles that received h or more citations while the other articles received a number of citations which is not larger than h. In this article, the time dependence of the h-index is determined. This is important to describe the expected career evolution of a scientist's work or of a journal's production in a fixed year.
    Language
    e
  3. Egghe, L.; Rousseau, R.; Hooydonk, G. van: Methods for accrediting publications to authors or countries : consequences for evaluation studies (2000) 0.01 
    0.011585359 = product of:
  0.028963398 = sum of:
    0.0052410355 = weight(_text_:e in 4384) [ClassicSimilarity], result of:
      0.0052410355 = score(doc=4384,freq=2.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.09528506 = fieldWeight in 4384, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.046875 = fieldNorm(doc=4384)
    0.023722364 = product of:
      0.07116709 = sum of:
        0.07116709 = weight(_text_:evolution in 4384) [ClassicSimilarity], result of:
          0.07116709 = score(doc=4384,freq=2.0), product of:
            0.2026858 = queryWeight, product of:
              5.29663 = idf(docFreq=601, maxDocs=44218)
              0.03826694 = queryNorm
            0.35112026 = fieldWeight in 4384, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              5.29663 = idf(docFreq=601, maxDocs=44218)
              0.046875 = fieldNorm(doc=4384)
      0.33333334 = coord(1/3)
  0.4 = coord(2/5)
    Abstract
    One aim of science evaluation studies is to determine quantitatively the contribution of different players (authors, departments, countries) to the whole system. This information is then used to study the evolution of the system, for instance to gauge the results of special national or international programs. Taking articles as our basic data, we want to determine the exact relative contribution of each coauthor or each country. These numbers are brought together to obtain country scores, or department scores, etc. It turns out, as we will show in this article, that different scoring methods can yield totally different rankings. Conseqeuntly, a ranking between countries, universities, research groups or authors, based on one particular accrediting methods does not contain an absolute truth about their relative importance
    Language
    e
  4. Egghe, L.: ¬A universal method of information retrieval evaluation : the "missing" link M and the universal IR surface (2004) 0.01 
    0.008317985 = product of:
  0.020794962 = sum of:
    0.0052410355 = weight(_text_:e in 2558) [ClassicSimilarity], result of:
      0.0052410355 = score(doc=2558,freq=2.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.09528506 = fieldWeight in 2558, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.046875 = fieldNorm(doc=2558)
    0.015553925 = product of:
      0.03110785 = sum of:
        0.03110785 = weight(_text_:22 in 2558) [ClassicSimilarity], result of:
          0.03110785 = score(doc=2558,freq=2.0), product of:
            0.1340043 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.03826694 = queryNorm
            0.23214069 = fieldWeight in 2558, 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=2558)
      0.5 = coord(1/2)
  0.4 = coord(2/5)
    Date
    14. 8.2004 19:17:22
    Language
    e
  5. Egghe, L.: Expansion of the field of informetrics : the second special issue (2006) 0.00 
    0.0020964143 = product of:
  0.010482071 = sum of:
    0.010482071 = weight(_text_:e in 7119) [ClassicSimilarity], result of:
      0.010482071 = score(doc=7119,freq=2.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.19057012 = fieldWeight in 7119, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.09375 = fieldNorm(doc=7119)
  0.2 = coord(1/5)
    Language
    e
  6. Egghe, L.: Expansion of the field of informetrics : origins and consequences (2005) 0.00 
    0.0020964143 = product of:
  0.010482071 = sum of:
    0.010482071 = weight(_text_:e in 1910) [ClassicSimilarity], result of:
      0.010482071 = score(doc=1910,freq=2.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.19057012 = fieldWeight in 1910, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.09375 = fieldNorm(doc=1910)
  0.2 = coord(1/5)
    Language
    e
  7. Egghe, L.: ¬A noninformetric analysis of the relationship between citation age and journal productivity (2001) 0.00 
    0.0018155482 = product of:
  0.009077741 = sum of:
    0.009077741 = weight(_text_:e in 5685) [ClassicSimilarity], result of:
      0.009077741 = score(doc=5685,freq=6.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.16503859 = fieldWeight in 5685, product of:
          2.4494898 = tf(freq=6.0), with freq of:
            6.0 = termFreq=6.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.046875 = fieldNorm(doc=5685)
  0.2 = coord(1/5)
    Abstract
    A problem, raised by Wallace (JASIS, 37,136-145,1986), on the relation between the journal's median citation age and its number of articles is studied. Leaving open the problem as such, we give a statistical explanation of this relationship, when replacing "median" by "mean" in Wallace's problem. The cloud of points, found by Wallace, is explained in this sense that the points are scattered over the area in first quadrant, limited by a curve of the form y=1 + E/x**2 where E is a constant. This curve is obtained by using the Central Limit Theorem in statistics and, hence, has no intrinsic informetric foundation. The article closes with some reflections on explanations of regularities in informetrics, based on statistical, probabilistic or informetric results, or on a combination thereof
    Language
    e
  8. Egghe, L.; Ravichandra Rao, I.K.: Duality revisited : construction of fractional frequency distributions based on two dual Lotka laws (2002) 0.00 
    0.0014823888 = product of:
  0.0074119437 = sum of:
    0.0074119437 = weight(_text_:e in 1006) [ClassicSimilarity], result of:
      0.0074119437 = score(doc=1006,freq=4.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.13475344 = fieldWeight in 1006, product of:
          2.0 = tf(freq=4.0), with freq of:
            4.0 = termFreq=4.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.046875 = fieldNorm(doc=1006)
  0.2 = coord(1/5)
    Abstract
    Fractional frequency distributions of, for example, authors with a certain (fractional) number of papers are very irregular and, therefore, not easy to model or to explain. This article gives a first attempt to this by assuming two simple Lotka laws (with exponent 2): one for the number of authors with n papers (total count here) and one for the number of papers with n authors, n E N. Based an an earlier made convolution model of Egghe, interpreted and reworked now for discrete scores, we are able to produce theoretical fractional frequency distributions with only one parameter, which are in very close agreement with the practical ones as found in a large dataset produced earlier by Rao. The article also shows that (irregular) fractional frequency distributions are a consequence of Lotka's law, and are not examples of breakdowns of this famous historical law.
    Language
    e
  9. Egghe, L.; Rousseau, R.: ¬The influence of publication delays on the observed aging distribution of scientific literature (2000) 0.00 
    0.0013976095 = product of:
  0.006988047 = sum of:
    0.006988047 = weight(_text_:e in 4385) [ClassicSimilarity], result of:
      0.006988047 = score(doc=4385,freq=2.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.12704675 = fieldWeight in 4385, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.0625 = fieldNorm(doc=4385)
  0.2 = coord(1/5)
    Language
    e
  10. Egghe, L.; Liang, L.; Rousseau, R.: ¬A relation between h-index and impact factor in the power-law model (2009) 0.00 
    0.0013976095 = product of:
  0.006988047 = sum of:
    0.006988047 = weight(_text_:e in 6759) [ClassicSimilarity], result of:
      0.006988047 = score(doc=6759,freq=2.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.12704675 = fieldWeight in 6759, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.0625 = fieldNorm(doc=6759)
  0.2 = coord(1/5)
    Language
    e
  11. Egghe, L.; Rousseau, R.: ¬An h-index weighted by citation impact (2008) 0.00 
    0.0013976095 = product of:
  0.006988047 = sum of:
    0.006988047 = weight(_text_:e in 695) [ClassicSimilarity], result of:
      0.006988047 = score(doc=695,freq=2.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.12704675 = fieldWeight in 695, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.0625 = fieldNorm(doc=695)
  0.2 = coord(1/5)
    Language
    e
  12. Egghe, L.: Sampling and concentration values of incomplete bibliographies (2002) 0.00 
    0.0012229083 = product of:
  0.006114541 = sum of:
    0.006114541 = weight(_text_:e in 450) [ClassicSimilarity], result of:
      0.006114541 = score(doc=450,freq=2.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.1111659 = fieldWeight in 450, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.0546875 = fieldNorm(doc=450)
  0.2 = coord(1/5)
    Language
    e
  13. Egghe, L.: Vector retrieval, fuzzy retrieval and the universal fuzzy IR surface for IR evaluation (2004) 0.00 
    0.0012229083 = product of:
  0.006114541 = sum of:
    0.006114541 = weight(_text_:e in 2531) [ClassicSimilarity], result of:
      0.006114541 = score(doc=2531,freq=2.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.1111659 = fieldWeight in 2531, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.0546875 = fieldNorm(doc=2531)
  0.2 = coord(1/5)
    Language
    e
  14. Egghe, L.; Rousseau, R.; Rousseau, S.: TOP-curves (2007) 0.00 
    0.0012229083 = product of:
  0.006114541 = sum of:
    0.006114541 = weight(_text_:e in 50) [ClassicSimilarity], result of:
      0.006114541 = score(doc=50,freq=2.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.1111659 = fieldWeight in 50, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.0546875 = fieldNorm(doc=50)
  0.2 = coord(1/5)
    Language
    e
  15. Egghe, L.: ¬The influence of transformations on the h-index and the g-index (2008) 0.00 
    0.0012229083 = product of:
  0.006114541 = sum of:
    0.006114541 = weight(_text_:e in 1881) [ClassicSimilarity], result of:
      0.006114541 = score(doc=1881,freq=2.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.1111659 = fieldWeight in 1881, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.0546875 = fieldNorm(doc=1881)
  0.2 = coord(1/5)
    Language
    e
  16. Egghe, L.; Liang, L.; Rousseau, R.: Fundamental properties of rhythm sequences (2008) 0.00 
    0.0012229083 = product of:
  0.006114541 = sum of:
    0.006114541 = weight(_text_:e in 1965) [ClassicSimilarity], result of:
      0.006114541 = score(doc=1965,freq=2.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.1111659 = fieldWeight in 1965, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.0546875 = fieldNorm(doc=1965)
  0.2 = coord(1/5)
    Language
    e
  17. Egghe, L.: ¬A rationale for the Hirsch-index rank-order distribution and a comparison with the impact factor rank-order distribution (2009) 0.00 
    0.0012229083 = product of:
  0.006114541 = sum of:
    0.006114541 = weight(_text_:e in 3124) [ClassicSimilarity], result of:
      0.006114541 = score(doc=3124,freq=2.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.1111659 = fieldWeight in 3124, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.0546875 = fieldNorm(doc=3124)
  0.2 = coord(1/5)
    Language
    e
  18. Egghe, L.; Rousseau, R.: Aging, obsolescence, impact, growth, and utilization : definitions and relations (2000) 0.00 
    0.0010482072 = product of:
  0.0052410355 = sum of:
    0.0052410355 = weight(_text_:e in 5154) [ClassicSimilarity], result of:
      0.0052410355 = score(doc=5154,freq=2.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.09528506 = fieldWeight in 5154, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.046875 = fieldNorm(doc=5154)
  0.2 = coord(1/5)
    Language
    e
  19. Egghe, L.: Relations between the continuous and the discrete Lotka power function (2005) 0.00 
    0.0010482072 = product of:
  0.0052410355 = sum of:
    0.0052410355 = weight(_text_:e in 3464) [ClassicSimilarity], result of:
      0.0052410355 = score(doc=3464,freq=2.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.09528506 = fieldWeight in 3464, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.046875 = fieldNorm(doc=3464)
  0.2 = coord(1/5)
    Language
    e
  20. Egghe, L.: Zipfian and Lotkaian continuous concentration theory (2005) 0.00 
    0.0010482072 = product of:
  0.0052410355 = sum of:
    0.0052410355 = weight(_text_:e in 3678) [ClassicSimilarity], result of:
      0.0052410355 = score(doc=3678,freq=2.0), product of:
        0.055003747 = queryWeight, product of:
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.03826694 = queryNorm
        0.09528506 = fieldWeight in 3678, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          1.43737 = idf(docFreq=28552, maxDocs=44218)
          0.046875 = fieldNorm(doc=3678)
  0.2 = coord(1/5)
    Language
    e

Authors

Themes