Search (25 results, page 1 of 2)

  • × year_i:[2000 TO 2010}
  • × author_ss:"Rousseau, R."
  1. Asonuma, A.; Fang, Y.; Rousseau, R.: Reflections on the age distribution of Japanese scientists (2006) 0.02
    0.022779368 = product of:
      0.045558736 = sum of:
        0.045558736 = sum of:
          0.008118451 = weight(_text_:a in 5270) [ClassicSimilarity], result of:
            0.008118451 = score(doc=5270,freq=8.0), product of:
              0.053105544 = queryWeight, product of:
                1.153047 = idf(docFreq=37942, maxDocs=44218)
                0.046056706 = queryNorm
              0.15287387 = fieldWeight in 5270, product of:
                2.828427 = tf(freq=8.0), with freq of:
                  8.0 = termFreq=8.0
                1.153047 = idf(docFreq=37942, maxDocs=44218)
                0.046875 = fieldNorm(doc=5270)
          0.037440285 = weight(_text_:22 in 5270) [ClassicSimilarity], result of:
            0.037440285 = score(doc=5270,freq=2.0), product of:
              0.16128273 = queryWeight, product of:
                3.5018296 = idf(docFreq=3622, maxDocs=44218)
                0.046056706 = queryNorm
              0.23214069 = fieldWeight in 5270, 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=5270)
      0.5 = coord(1/2)
    
    Abstract
    The age distribution of a country's scientists is an important element in the study of its research capacity. In this article we investigate the age distribution of Japanese scientists in order to find out whether major events such as World War II had an appreciable effect on its features. Data have been obtained from population censuses taken in Japan from 1970 to 1995. A comparison with the situation in China and the United States has been made. We find that the group of scientific researchers outside academia is dominated by the young: those younger than age 35. The personnel group in higher education, on the other hand, is dominated by the baby boomers: those who were born after World War II. Contrary to the Chinese situation we could not find any influence of major nondemographic events. The only influence we found was the increase in enrollment of university students after World War II caused by the reform of the Japanese university system. Female participation in the scientific and university systems in Japan, though still low, is increasing.
    Date
    22. 7.2006 15:26:24
    Type
    a
  2. Ahlgren, P.; Jarneving, B.; Rousseau, R.: Requirements for a cocitation similarity measure, with special reference to Pearson's correlation coefficient (2003) 0.02
    0.015505663 = product of:
      0.031011326 = sum of:
        0.031011326 = sum of:
          0.0060511357 = weight(_text_:a in 5171) [ClassicSimilarity], result of:
            0.0060511357 = score(doc=5171,freq=10.0), product of:
              0.053105544 = queryWeight, product of:
                1.153047 = idf(docFreq=37942, maxDocs=44218)
                0.046056706 = queryNorm
              0.11394546 = fieldWeight in 5171, product of:
                3.1622777 = tf(freq=10.0), with freq of:
                  10.0 = termFreq=10.0
                1.153047 = idf(docFreq=37942, maxDocs=44218)
                0.03125 = fieldNorm(doc=5171)
          0.02496019 = weight(_text_:22 in 5171) [ClassicSimilarity], result of:
            0.02496019 = score(doc=5171,freq=2.0), product of:
              0.16128273 = queryWeight, product of:
                3.5018296 = idf(docFreq=3622, maxDocs=44218)
                0.046056706 = queryNorm
              0.15476047 = fieldWeight in 5171, product of:
                1.4142135 = tf(freq=2.0), with freq of:
                  2.0 = termFreq=2.0
                3.5018296 = idf(docFreq=3622, maxDocs=44218)
                0.03125 = fieldNorm(doc=5171)
      0.5 = coord(1/2)
    
    Abstract
    Ahlgren, Jarneving, and. Rousseau review accepted procedures for author co-citation analysis first pointing out that since in the raw data matrix the row and column values are identical i,e, the co-citation count of two authors, there is no clear choice for diagonal values. They suggest the number of times an author has been co-cited with himself excluding self citation rather than the common treatment as zeros or as missing values. When the matrix is converted to a similarity matrix the normal procedure is to create a matrix of Pearson's r coefficients between data vectors. Ranking by r and by co-citation frequency and by intuition can easily yield three different orders. It would seem necessary that the adding of zeros to the matrix will not affect the value or the relative order of similarity measures but it is shown that this is not the case with Pearson's r. Using 913 bibliographic descriptions form the Web of Science of articles form JASIS and Scientometrics, authors names were extracted, edited and 12 information retrieval authors and 12 bibliometric authors each from the top 100 most cited were selected. Co-citation and r value (diagonal elements treated as missing) matrices were constructed, and then reconstructed in expanded form. Adding zeros can both change the r value and the ordering of the authors based upon that value. A chi-squared distance measure would not violate these requirements, nor would the cosine coefficient. It is also argued that co-citation data is ordinal data since there is no assurance of an absolute zero number of co-citations, and thus Pearson is not appropriate. The number of ties in co-citation data make the use of the Spearman rank order coefficient problematic.
    Date
    9. 7.2006 10:22:35
    Type
    a
  3. Rousseau, R.; Ye, F.Y.: ¬A proposal for a dynamic h-type index (2008) 0.00
    0.0033143433 = product of:
      0.0066286866 = sum of:
        0.0066286866 = product of:
          0.013257373 = sum of:
            0.013257373 = weight(_text_:a in 2351) [ClassicSimilarity], result of:
              0.013257373 = score(doc=2351,freq=12.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.24964198 = fieldWeight in 2351, product of:
                  3.4641016 = tf(freq=12.0), with freq of:
                    12.0 = termFreq=12.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.0625 = fieldNorm(doc=2351)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    A time-dependent h-type indicator is proposed. This indicator depends on the size of the h-core, the number of citations received, and recent change in the value of the h-index. As such, it tries to combine in a dynamic way older information about the source (e.g., a scientist or research institute that is evaluated) with recent information.
    Type
    a
  4. Egghe, L.; Liang, L.; Rousseau, R.: ¬A relation between h-index and impact factor in the power-law model (2009) 0.00
    0.0030255679 = product of:
      0.0060511357 = sum of:
        0.0060511357 = product of:
          0.012102271 = sum of:
            0.012102271 = weight(_text_:a in 6759) [ClassicSimilarity], result of:
              0.012102271 = score(doc=6759,freq=10.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.22789092 = fieldWeight in 6759, product of:
                  3.1622777 = tf(freq=10.0), with freq of:
                    10.0 = termFreq=10.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.0625 = fieldNorm(doc=6759)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Using a power-law model, the two best-known topics in citation analysis, namely the impact factor and the Hirsch index, are unified into one relation (not a function). The validity of our model is, at least in a qualitative way, confirmed by real data.
    Type
    a
  5. Egghe, L.; Rousseau, R.: ¬The influence of publication delays on the observed aging distribution of scientific literature (2000) 0.00
    0.00270615 = product of:
      0.0054123 = sum of:
        0.0054123 = product of:
          0.0108246 = sum of:
            0.0108246 = weight(_text_:a in 4385) [ClassicSimilarity], result of:
              0.0108246 = score(doc=4385,freq=8.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.20383182 = fieldWeight in 4385, product of:
                  2.828427 = tf(freq=8.0), with freq of:
                    8.0 = termFreq=8.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.0625 = fieldNorm(doc=4385)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Observed aging curves are influenced by publication delays. In this article, we show how the 'undisturbed' aging function and the publication delay combine to give the observed aging function. This combination is performed by a mathematical operation known as convolution. Examples are given, such as the convolution of 2 Poisson distributions, 2 exponential distributions, a 2 lognormal distributions. A paradox is observed between theory and real data
    Type
    a
  6. Egghe, L.; Rousseau, R.: ¬An h-index weighted by citation impact (2008) 0.00
    0.00270615 = product of:
      0.0054123 = sum of:
        0.0054123 = product of:
          0.0108246 = sum of:
            0.0108246 = weight(_text_:a in 695) [ClassicSimilarity], result of:
              0.0108246 = score(doc=695,freq=8.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.20383182 = fieldWeight in 695, product of:
                  2.828427 = tf(freq=8.0), with freq of:
                    8.0 = termFreq=8.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.0625 = fieldNorm(doc=695)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    An h-type index is proposed which depends on the obtained citations of articles belonging to the h-core. This weighted h-index, denoted as hw, is presented in a continuous setting and in a discrete one. It is shown that in a continuous setting the new index enjoys many good properties. In the discrete setting some small deviations from the ideal may occur.
    Type
    a
  7. Frandsen, T.F.; Rousseau, R.: Article impact calculated over arbitrary periods (2005) 0.00
    0.0026849252 = product of:
      0.0053698504 = sum of:
        0.0053698504 = product of:
          0.010739701 = sum of:
            0.010739701 = weight(_text_:a in 3264) [ClassicSimilarity], result of:
              0.010739701 = score(doc=3264,freq=14.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.20223314 = fieldWeight in 3264, product of:
                  3.7416575 = tf(freq=14.0), with freq of:
                    14.0 = termFreq=14.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046875 = fieldNorm(doc=3264)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    In this paper we address the various formulations of impact of articles, usually groups of articles as gauged by citations that these articles receive over a certain period of time. The journal impact factor, as published by ISI (Philadelphia, PA), is the best-known example of a formulation of impact of journals (considered as a set of articles) but many others have been defined in the literature. Impact factors have varying publication and citation periods and the chosen length of these periods enables, e.g., a distinction between synchronous and diachronous impact factors. It is shown how an impact factor for the general case can be defined. Two alternatives for a general impact factor are proposed, depending an whether different publication years are seen as a whole, and hence treating each one of them differently, or by operating with citation periods of identical length but allowing each publication period different starting points.
    Type
    a
  8. Kretschmer, H.; Rousseau, R.: Author inflation leads to a breakdown of Lotka's law : in and out of context (2001) 0.00
    0.0026849252 = product of:
      0.0053698504 = sum of:
        0.0053698504 = product of:
          0.010739701 = sum of:
            0.010739701 = weight(_text_:a in 5205) [ClassicSimilarity], result of:
              0.010739701 = score(doc=5205,freq=14.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.20223314 = fieldWeight in 5205, product of:
                  3.7416575 = tf(freq=14.0), with freq of:
                    14.0 = termFreq=14.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046875 = fieldNorm(doc=5205)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Fractional counting of authors of multi-authored papers has been shown to lead to a breakdown of Lotka's Law despite its robust character under most circumstances. Kretschmer and Rousseau use the normal count method of full credit for each author on two five-year bibliographies from each of 13 Dutch physics institutes where high co-authorship is a common occurrence. Kolmogorov-Smirnov tests were preformed to see if the Lotka distribution fit the data. All bibliographies up to 40 authors fit acceptably; no bibliography with a paper with over 100 authors fits the distribution. The underlying traditional "success breeds success" mechanism assumes new items on a one by one basis, but Egghe's generalized model would still account for the process. It seems unlikely that Lotka's Law will hold in a high co-authorship environment.
    Type
    a
  9. Egghe, L.; Liang, L.; Rousseau, R.: Fundamental properties of rhythm sequences (2008) 0.00
    0.0026473717 = product of:
      0.0052947435 = sum of:
        0.0052947435 = product of:
          0.010589487 = sum of:
            0.010589487 = weight(_text_:a in 1965) [ClassicSimilarity], result of:
              0.010589487 = score(doc=1965,freq=10.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.19940455 = fieldWeight in 1965, product of:
                  3.1622777 = tf(freq=10.0), with freq of:
                    10.0 = termFreq=10.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.0546875 = fieldNorm(doc=1965)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Fundamental mathematical properties of rhythm sequences are studied. In particular, a set of three axioms for valid rhythm indicators is proposed, and it is shown that the R-indicator satisfies only two out of three but that the R-indicator satisfies all three. This fills a critical, logical gap in the study of these indicator sequences. Matrices leading to a constant R-sequence are called baseline matrices. They are characterized as matrices with constant w-year diachronous impact factors. The relation with classical impact factors is clarified. Using regression analysis matrices with a rhythm sequence that is on average equal to 1 (smaller than 1, larger than 1) are characterized.
    Type
    a
  10. Guns, R.; Rousseau, R.: Simulating growth of the h-index (2009) 0.00
    0.0026473717 = product of:
      0.0052947435 = sum of:
        0.0052947435 = product of:
          0.010589487 = sum of:
            0.010589487 = weight(_text_:a in 2717) [ClassicSimilarity], result of:
              0.010589487 = score(doc=2717,freq=10.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.19940455 = fieldWeight in 2717, product of:
                  3.1622777 = tf(freq=10.0), with freq of:
                    10.0 = termFreq=10.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.0546875 = fieldNorm(doc=2717)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Temporal growth of the h-index in a diachronous cumulative time series is predicted to be linear by Hirsch (2005), whereas other models predict a concave increase. Actual data generally yield a linear growth or S-shaped growth. We study the h-index's growth in computer simulations of the publication-citation process. In most simulations the h-index grows linearly in time. Only occasionally does an S-shape occur, while in our simulations a concave increase is very rare. The latter is often signalled by the occurrence of plateaus - periods of h-index stagnation. Several parameters and their influence on the h-index's growth are determined and discussed.
    Type
    a
  11. Jin, B.; Li, L.; Rousseau, R.: Long-term influences of interventions in the normal development of science : China and the cultural revolution (2004) 0.00
    0.0024857575 = product of:
      0.004971515 = sum of:
        0.004971515 = product of:
          0.00994303 = sum of:
            0.00994303 = weight(_text_:a in 2232) [ClassicSimilarity], result of:
              0.00994303 = score(doc=2232,freq=12.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.18723148 = fieldWeight in 2232, product of:
                  3.4641016 = tf(freq=12.0), with freq of:
                    12.0 = termFreq=12.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046875 = fieldNorm(doc=2232)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Intellectual and technological talents and skills are the driving force for scientific and industrial development, especially in our times characterized by a knowledgebased economy. Major events in society and related political decisions, however, can have a long-term effect an a country's scientific weIl-being. Although the Cultural Revolution took place from 1966 to 1976, its aftermath can still be felt. This is shown by this study of the production and productivity of Chinese scientists as a function of their age. Based an the 1995-2000 data from the Chinese Science Citation database (CSCD), this article investigates the year-by-year age distribution of scientific and technological personnel publishing in China. It is shown that the "Talent Fault" originating during the Cultural Revolution still exists, and that a new gap resulting from recent brain drain might be developing. The purpose of this work is to provide necessary information about the current situation and especially the existing problems of the S&T workforce in China.
    Type
    a
  12. Liang, L.; Rousseau, R.: Yield sequences as journal attractivity indicators : "payback times" for Science and Nature (2008) 0.00
    0.0024857575 = product of:
      0.004971515 = sum of:
        0.004971515 = product of:
          0.00994303 = sum of:
            0.00994303 = weight(_text_:a in 1737) [ClassicSimilarity], result of:
              0.00994303 = score(doc=1737,freq=12.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.18723148 = fieldWeight in 1737, product of:
                  3.4641016 = tf(freq=12.0), with freq of:
                    12.0 = termFreq=12.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046875 = fieldNorm(doc=1737)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Purpose - The yield period of a journal is defined as the time needed to accumulate the same number of citations as the number of references included during the period of study. Yield sequences are proposed as journal attractivity indicators describing dynamic characteristics of a journal. This paper aims to investigate their use. Design/methodology/approach - As a case study the yield sequences of the journals Nature and Science from 1955 onward are determined. Similarities and dissimilarities between these sequences are discussed and factors affecting yield periods are determined. Findings - The study finds that yield sequences make dynamic aspects of a journal visible, as reflected through citations. Exceptional circumstances (here the publication of Laemmli's paper in 1970 in the journal Nature) become clearly visible. The average number of references per article, the citation distribution and the size of the database used to collect citations are factors influencing yield sequences. Originality/value - A new dynamic indicator for the study of journals is introduced.
    Type
    a
  13. Rousseau, R.; Jin, B.: ¬The age-dependent h-type AR**2-index : basic properties and a case study (2008) 0.00
    0.0024857575 = product of:
      0.004971515 = sum of:
        0.004971515 = product of:
          0.00994303 = sum of:
            0.00994303 = weight(_text_:a in 2638) [ClassicSimilarity], result of:
              0.00994303 = score(doc=2638,freq=12.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.18723148 = fieldWeight in 2638, product of:
                  3.4641016 = tf(freq=12.0), with freq of:
                    12.0 = termFreq=12.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046875 = fieldNorm(doc=2638)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Hirsch-type indices are studied with special attention to the AR**2-index introduced by Jin. The article consists of two parts: a theoretical part and a practical illustration. In the theoretical part, we recall the definition of the AR**2-index and show that an alternative definition, the so-called AR**2,1, does not have the properties expected for this type of index. A practical example shows the existence of some of these mathematical properties and illustrates the difference between different h-type indices. Clearly the h-index itself is the most robust of all. It is shown that excluding so-called non-WoS source articles may have a significant influence on the R-and, especially, the g-index.
    Type
    a
  14. Rousseau, R.; Zuccala, A.: ¬A classification of author co-citations : definitions and search strategies (2004) 0.00
    0.0023919214 = product of:
      0.0047838427 = sum of:
        0.0047838427 = product of:
          0.009567685 = sum of:
            0.009567685 = weight(_text_:a in 2266) [ClassicSimilarity], result of:
              0.009567685 = score(doc=2266,freq=16.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.18016359 = fieldWeight in 2266, product of:
                  4.0 = tf(freq=16.0), with freq of:
                    16.0 = termFreq=16.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=2266)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    The term author co-citation is defined and classified according to four distinct forms: the pure first-author co-citation, the pure author co-citation, the general author co-citation, and the special co-authorlco-citation. Each form can be used to obtain one count in an author co-citation study, based an a binary counting rule, which either recognizes the co-citedness of two authors in a given reference list (1) or does not (0). Most studies using author co-citations have relied solely an first-author cocitation counts as evidence of an author's oeuvre or body of work contributed to a research field. In this article, we argue that an author's contribution to a selected field of study should not be limited, but should be based an his/her complete list of publications, regardless of author ranking. We discuss the implications associated with using each co-citation form and show where simple first-author co-citations fit within our classification scheme. Examples are given to substantiate each author co-citation form defined in our classification, including a set of sample Dialog(TM) searches using references extracted from the SciSearch database.
    Type
    a
  15. Rousseau, R.: Journal evaluation : technical and practical issues (2002) 0.00
    0.0023919214 = product of:
      0.0047838427 = sum of:
        0.0047838427 = product of:
          0.009567685 = sum of:
            0.009567685 = weight(_text_:a in 816) [ClassicSimilarity], result of:
              0.009567685 = score(doc=816,freq=16.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.18016359 = fieldWeight in 816, product of:
                  4.0 = tf(freq=16.0), with freq of:
                    16.0 = termFreq=16.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=816)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    This essay provides an overview of journal evaluation indicators. It highlights the strengths and weaknesses of different indicators, together with their range of applicability. The definition of a "quality journal," different notions of impact factors, the meaning of ranking journals, and possible biases in citation databases are also discussed. Attention is given to using the journal impact in evaluation studies. The quality of a journal is a multifaceted notion. Journals can be evaluated for different purposes, and hence the results of such evaluation exercises can be quite different depending on the indicator(s) used. The impact factor, in one of its versions, is probably the most used indicator when it comes to gauging the visibility of a journal on the research front. Generalized impact factors, over periods longer than the traditional two years, are better indicators for the long-term value of a journal. As with all evaluation studies, care must be exercised when considering journal impact factors as a quality indicator. It seems best to use a whole battery of indicators (including several impact factors) and to change this group of indicators depending on the purpose of the evaluation study. Nowadays it goes without saying that special attention is paid to e-journals and specific indicators for this type of journal.
    Type
    a
  16. Rousseau, R.: On Egghe's construction of Lorenz curves (2007) 0.00
    0.0023919214 = product of:
      0.0047838427 = sum of:
        0.0047838427 = product of:
          0.009567685 = sum of:
            0.009567685 = weight(_text_:a in 521) [ClassicSimilarity], result of:
              0.009567685 = score(doc=521,freq=4.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.18016359 = fieldWeight in 521, product of:
                  2.0 = tf(freq=4.0), with freq of:
                    4.0 = termFreq=4.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.078125 = fieldNorm(doc=521)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Contrary to Burrell's statements, Egghe's theory of continuous concentration does include the construction of a standard Lorenz curve.
    Type
    a
  17. Rousseau, R.: Robert Fairthorne and the empirical power laws (2005) 0.00
    0.0023678814 = product of:
      0.0047357627 = sum of:
        0.0047357627 = product of:
          0.009471525 = sum of:
            0.009471525 = weight(_text_:a in 4398) [ClassicSimilarity], result of:
              0.009471525 = score(doc=4398,freq=8.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.17835285 = fieldWeight in 4398, product of:
                  2.828427 = tf(freq=8.0), with freq of:
                    8.0 = termFreq=8.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.0546875 = fieldNorm(doc=4398)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Purpose - Aims to review Fairthorne's classic article "Empirical hyperbolic distributions (Bradford-Zipf-Mandelbrot) for bibliometric description and prediction" (Journal of Documentation, Vol. 25, pp. 319-343, 1969), as part of a series marking the Journal of Documentation's 60th anniversary. Design/methodology/approach - Analysis of article content, qualitative evaluation of its subsequent impact, citation analysis, and diffusion analysis. Findings - The content, further developments and influence on the field of informetrics of this landmark paper are explained. Originality/value - A review is given of the contents of Fairthorne's original article and its influence on the field of informetrics. Its transdisciplinary reception is measured through a diffusion analysis.
    Type
    a
  18. Egghe, L.; Rousseau, R.; Rousseau, S.: TOP-curves (2007) 0.00
    0.0023678814 = product of:
      0.0047357627 = sum of:
        0.0047357627 = product of:
          0.009471525 = sum of:
            0.009471525 = weight(_text_:a in 50) [ClassicSimilarity], result of:
              0.009471525 = score(doc=50,freq=8.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.17835285 = fieldWeight in 50, product of:
                  2.828427 = tf(freq=8.0), with freq of:
                    8.0 = termFreq=8.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.0546875 = fieldNorm(doc=50)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Several characteristics of classical Lorenz curves make them unsuitable for the study of a group of topperformers. TOP-curves, defined as a kind of mirror image of TIP-curves used in poverty studies, are shown to possess the properties necessary for adequate empirical ranking of various data arrays, based on the properties of the highest performers (i.e., the core). TOP-curves and essential TOP-curves, also introduced in this article, simultaneously represent the incidence, intensity, and inequality among the top. It is shown that TOPdominance partial order, introduced in this article, is stronger than Lorenz dominance order. In this way, this article contributes to the study of cores, a central issue in applied informetrics.
    Type
    a
  19. Rousseau, R.: Timelines in citation research (2006) 0.00
    0.0023435948 = product of:
      0.0046871896 = sum of:
        0.0046871896 = product of:
          0.009374379 = sum of:
            0.009374379 = weight(_text_:a in 1746) [ClassicSimilarity], result of:
              0.009374379 = score(doc=1746,freq=6.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.17652355 = fieldWeight in 1746, product of:
                  2.4494898 = tf(freq=6.0), with freq of:
                    6.0 = termFreq=6.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.0625 = fieldNorm(doc=1746)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    The timeline used in ISI's Journal Citation Reports (JCR; Thomson ISI, formerly the Institute for Scientific Information, Philadelphia, PA) for half-life calculations, is not a timeline for (average) cited age. These two timelines are shifted over half a year.
    Type
    a
  20. Frandsen, T.F.; Rousseau, R.; Rowlands, I.: Diffusion factors (2006) 0.00
    0.0022374375 = product of:
      0.004474875 = sum of:
        0.004474875 = product of:
          0.00894975 = sum of:
            0.00894975 = weight(_text_:a in 5587) [ClassicSimilarity], result of:
              0.00894975 = score(doc=5587,freq=14.0), product of:
                0.053105544 = queryWeight, product of:
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.046056706 = queryNorm
                0.1685276 = fieldWeight in 5587, product of:
                  3.7416575 = tf(freq=14.0), with freq of:
                    14.0 = termFreq=14.0
                  1.153047 = idf(docFreq=37942, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=5587)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Purpose - The purpose of this paper is to clarify earlier work on journal diffusion metrics. Classical journal indicators such as the Garfield impact factor do not measure the breadth of influence across the literature of a particular journal title. As a new approach to measuring research influence, the study complements these existing metrics with a series of formally described diffusion factors. Design/methodology/approach - Using a publication-citation matrix as an organising construct, the paper develops formal descriptions of two forms of diffusion metric: "relative diffusion factors" and "journal diffusion factors" in both their synchronous and diachronous forms. It also provides worked examples for selected library and information science and economics journals, plus a sample of health information papers to illustrate their construction and use. Findings - Diffusion factors capture different aspects of the citation reception process than existing bibliometric measures. The paper shows that diffusion factors can be applied at the whole journal level or for sets of articles and that they provide a richer evidence base for citation analyses than traditional measures alone. Research limitations/implications - The focus of this paper is on clarifying the concepts underlying diffusion factors and there is unlimited scope for further work to apply these metrics to much larger and more comprehensive data sets than has been attempted here. Practical implications - These new tools extend the range of tools available for bibliometric, and possibly webometric, analysis. Diffusion factors might find particular application in studies where the research questions focus on the dynamic aspects of innovation and knowledge transfer. Originality/value - This paper will be of interest to those with theoretical interests in informetric distributions as well as those interested in science policy and innovation studies.
    Type
    a