Search (1 results, page 1 of 1)

Did you mean:
precises%3a%2fdocuments %2f subject classification schemes%3a bliss%2c henry evelyn %2f bliss bibliographic classification %2f texts%22 1
precises%3a%2f_documents %2f subject classification schemes%3a bliss%2c henry evelyn %2f bliss bibliographic classification %2f texts%22 1
precises%3a%2fdocuments %2f subject classification schemes%3a bliss%2c heery evelyn %2f bliss bibliographic classification %2f texts%22 1
precises%3a%2fdocuments %2f subject classification schemes%3a bliss%2c henry evelyn %2f bloss bibliographic classification %2f texts%22 1
precises%3a%2fdocuments %2f subject classification schemes%3a bloss%2c henry evelyn %2f bliss bibliographic classification %2f texts%22 1

Buxton, A.: Ontologies and classification of chemicals : can they help each other? (2011) 0.03

0.026176075 = product of:
  0.12215501 = sum of:
    0.021217827 = weight(_text_:subject in 4817) [ClassicSimilarity], result of:
      0.021217827 = score(doc=4817,freq=2.0), product of:
        0.10738805 = queryWeight, product of:
          3.576596 = idf(docFreq=3361, maxDocs=44218)
          0.03002521 = queryNorm
        0.19758089 = fieldWeight in 4817, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          3.576596 = idf(docFreq=3361, maxDocs=44218)
          0.0390625 = fieldNorm(doc=4817)
    0.05046859 = weight(_text_:classification in 4817) [ClassicSimilarity], result of:
      0.05046859 = score(doc=4817,freq=18.0), product of:
        0.09562149 = queryWeight, product of:
          3.1847067 = idf(docFreq=4974, maxDocs=44218)
          0.03002521 = queryNorm
        0.5277955 = fieldWeight in 4817, product of:
          4.2426405 = tf(freq=18.0), with freq of:
            18.0 = termFreq=18.0
          3.1847067 = idf(docFreq=4974, maxDocs=44218)
          0.0390625 = fieldNorm(doc=4817)
    0.05046859 = weight(_text_:classification in 4817) [ClassicSimilarity], result of:
      0.05046859 = score(doc=4817,freq=18.0), product of:
        0.09562149 = queryWeight, product of:
          3.1847067 = idf(docFreq=4974, maxDocs=44218)
          0.03002521 = queryNorm
        0.5277955 = fieldWeight in 4817, product of:
          4.2426405 = tf(freq=18.0), with freq of:
            18.0 = termFreq=18.0
          3.1847067 = idf(docFreq=4974, maxDocs=44218)
          0.0390625 = fieldNorm(doc=4817)
  0.21428572 = coord(3/14)

Abstract: The chemistry schedule in the Universal Decimal Classification (UDC) is badly in need of revision. In many places it is enumerative rather than synthetic (giving rules for constructing numbers for any compound required). In principle, chemistry should be the ideal subject for a synthetic classification but many common compounds have complex formulae and a synthetic system becomes unwieldy. Also, all compounds belong to several hierarchies, e.g. chloroquin is a heterocycle, an aromatic compound, amine, antimalarial drug, etc. and rules need to be drawn up as to which ones take precedence and which ones should be taken into account in classifying a compound. There are obvious similarities between a classification and an ontology. This paper looks at existing ontologies for chemistry, especially ChEBI which is one of the largest, to examine how a classification and an ontology might draw on each other and what the problem areas are. An ontology might help in creating an index to a classification (for chemicals not listed or to provide access by facets not used in the classification) and a classification could provide a hierarchy to use in an ontology.
Source: Classification and ontology: formal approaches and access to knowledge: proceedings of the International UDC Seminar, 19-20 September 2011, The Hague, The Netherlands. Eds.: A. Slavic u. E. Civallero