Search (8 results, page 1 of 1)

0.04531533 = product of:
  0.09063066 = sum of:
    0.09063066 = product of:
      0.18126132 = sum of:
        0.18126132 = weight(_text_:2006 in 7119) [ClassicSimilarity], result of:
          0.18126132 = score(doc=7119,freq=5.0), product of:
            0.19682638 = queryWeight, product of:
              4.393044 = idf(docFreq=1485, maxDocs=44218)
              0.0448041 = queryNorm
            0.92091984 = fieldWeight in 7119, product of:
              2.236068 = tf(freq=5.0), with freq of:
                5.0 = termFreq=5.0
              4.393044 = idf(docFreq=1485, maxDocs=44218)
              0.09375 = fieldNorm(doc=7119)
      0.5 = coord(1/2)
  0.5 = coord(1/2)

Source

Information processing and management. 42(2006) no.6, S.1405-1407

Year

2006

0.018881386 = product of:
  0.037762772 = sum of:
    0.037762772 = product of:
      0.075525545 = sum of:
        0.075525545 = weight(_text_:2006 in 194) [ClassicSimilarity], result of:
          0.075525545 = score(doc=194,freq=5.0), product of:
            0.19682638 = queryWeight, product of:
              4.393044 = idf(docFreq=1485, maxDocs=44218)
              0.0448041 = queryNorm
            0.38371658 = fieldWeight in 194, product of:
              2.236068 = tf(freq=5.0), with freq of:
                5.0 = termFreq=5.0
              4.393044 = idf(docFreq=1485, maxDocs=44218)
              0.0390625 = fieldNorm(doc=194)
      0.5 = coord(1/2)
  0.5 = coord(1/2)

Source

Journal of the American Society for Information Science and Technology. 57(2006) no.9, S.1165-1177

Year

2006

0.015175843 = product of:
  0.030351685 = sum of:
    0.030351685 = product of:
      0.06070337 = sum of:
        0.06070337 = weight(_text_:22 in 4992) [ClassicSimilarity], result of:
          0.06070337 = score(doc=4992,freq=2.0), product of:
            0.15689632 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.0448041 = queryNorm
            0.38690117 = fieldWeight in 4992, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.078125 = fieldNorm(doc=4992)
      0.5 = coord(1/2)
  0.5 = coord(1/2)

Date

14. 2.2012 12:53:22

0.01510511 = product of:
  0.03021022 = sum of:
    0.03021022 = product of:
      0.06042044 = sum of:
        0.06042044 = weight(_text_:2006 in 81) [ClassicSimilarity], result of:
          0.06042044 = score(doc=81,freq=5.0), product of:
            0.19682638 = queryWeight, product of:
              4.393044 = idf(docFreq=1485, maxDocs=44218)
              0.0448041 = queryNorm
            0.30697328 = fieldWeight in 81, product of:
              2.236068 = tf(freq=5.0), with freq of:
                5.0 = termFreq=5.0
              4.393044 = idf(docFreq=1485, maxDocs=44218)
              0.03125 = fieldNorm(doc=81)
      0.5 = coord(1/2)
  0.5 = coord(1/2)

Source

Information - Wissenschaft und Praxis. 57(2006) H.8, S.427-432

Year

2006

0.011941638 = product of:
  0.023883276 = sum of:
    0.023883276 = product of:
      0.04776655 = sum of:
        0.04776655 = weight(_text_:2006 in 2009) [ClassicSimilarity], result of:
          0.04776655 = score(doc=2009,freq=2.0), product of:
            0.19682638 = queryWeight, product of:
              4.393044 = idf(docFreq=1485, maxDocs=44218)
              0.0448041 = queryNorm
            0.24268368 = fieldWeight in 2009, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              4.393044 = idf(docFreq=1485, maxDocs=44218)
              0.0390625 = fieldNorm(doc=2009)
      0.5 = coord(1/2)
  0.5 = coord(1/2)

Abstract

The article studies the influence of the query formulation of a topic on its h-index. In order to generate pure random sets of documents, we used N-grams (N variable) to measure this influence: strings of zeros, truncated at the end. The used databases are WoS and Scopus. The formula h=T**1/alpha, proved in Egghe and Rousseau (2006) where T is the number of retrieved documents and is Lotka's exponent, is confirmed being a concavely increasing function of T. We also give a formula for the relation between h and N the length of the N-gram: h=D10**(-N/alpha) where D is a constant, a convexly decreasing function, which is found in our experiments. Nonlinear regression on h=T**1/alpha gives an estimation of , which can then be used to estimate the h-index of the entire database (Web of Science [WoS] and Scopus): h=S**1/alpha, , where S is the total number of documents in the database.

0.011941638 = product of:
  0.023883276 = sum of:
    0.023883276 = product of:
      0.04776655 = sum of:
        0.04776655 = weight(_text_:2006 in 4217) [ClassicSimilarity], result of:
          0.04776655 = score(doc=4217,freq=2.0), product of:
            0.19682638 = queryWeight, product of:
              4.393044 = idf(docFreq=1485, maxDocs=44218)
              0.0448041 = queryNorm
            0.24268368 = fieldWeight in 4217, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              4.393044 = idf(docFreq=1485, maxDocs=44218)
              0.0390625 = fieldNorm(doc=4217)
      0.5 = coord(1/2)
  0.5 = coord(1/2)

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.

0.009105505 = product of:
  0.01821101 = sum of:
    0.01821101 = product of:
      0.03642202 = sum of:
        0.03642202 = weight(_text_:22 in 7659) [ClassicSimilarity], result of:
          0.03642202 = score(doc=7659,freq=2.0), product of:
            0.15689632 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.0448041 = queryNorm
            0.23214069 = fieldWeight in 7659, 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=7659)
      0.5 = coord(1/2)
  0.5 = coord(1/2)

Source

Journal of information science. 22(1996) no.3, S.165-170

0.009105505 = product of:
  0.01821101 = sum of:
    0.01821101 = product of:
      0.03642202 = sum of:
        0.03642202 = weight(_text_:22 in 2558) [ClassicSimilarity], result of:
          0.03642202 = score(doc=2558,freq=2.0), product of:
            0.15689632 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.0448041 = 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)
  0.5 = coord(1/2)

Date

14. 8.2004 19:17:22