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41.
Knowledge discovery in databases is used to discover useful and understandable knowledge from large databases. A process of
knowledge discovery consists of two steps, the data mining step and the evaluation step. In this paper, evaluating and ranking
the interestingness of summaries generated from databases, which is a part of the second step, is studied using diversity
measures. Sixteen previously analyzed diversity measures of interestingness are used along with three not previously considered
ones, brought from different well-known areas. The latter three measures are evaluated theoretically according to five principles
that a measure must satisfy to be qualified acceptable for ranking summaries. A theoretical correlation study between the
eight measures that satisfy all five principles is presented based on mathematical proofs. An empirical evaluation is conducted
using three real databases. Then, a classification of the eight measures is deduced. The resulting classification is used
to reduce the number of measures to only two, which are the best over all criteria, and that produce non-similar results.
This helps the user interpret the most important discovered knowledge in his decision making process. 相似文献
42.
Bettaieb I Bourgou S Sriti J Msaada K Limam F Marzouk B 《Journal of the science of food and agriculture》2011,91(11):2100-2107
BACKGROUND: Cumin (Cuminum cyminum L.) seeds of two geographic origins, Tunisia (TCS) and India (ICS), were studied regarding their fatty acid and essential oil composition. RESULTS: Oil yields were 17.77 and 15.40% for TCS and ICS respectively. Petroselinic acid (C18:1n‐12) was the major fatty acid in both varieties, with a higher proportion being found in TCS (55.90% of total fatty acids (TFA)) than in ICS (41.42% TFA). Moreover, the most predominant fatty acids were palmitic, petroselenic and linoleic acids, accounting for more than 91% TFA in both varieties. The unsaturated fatty acid content was high: 70.95% TFA in TCS and 62.17% TFA in ICS. Essential oil yields differed significantly (P < 0.05) between the two varieties: 1.21 and 1.62% for ICS and TCS respectively. A total of 40 compounds were identified, 34 of which were present in both essential oils. The two varieties displayed different chemotypes: γ‐terpinene/1‐phenyl‐1,2‐ethanediol for TCS and cuminaldheyde/γ‐terpinene for ICS. CONCLUSION: The study revealed that the biochemical composition of cumin seeds is origin‐dependent and that cumin seeds are rich in an unusual fatty acid, petroselinic acid. Besides, cumin essential oil is a rich source of many compounds, including cuminaldehyde and γ‐terpinene. The overall results suggest the exploitation of cumin seeds as a low‐cost renewable source for industrial processing in the fields of cosmetics, perfumes and pharmaceuticals. Copyright © 2011 Society of Chemical Industry 相似文献
43.
RC two-way slabs strengthened with CFRP strips: experimental study and a limit analysis approach 总被引:5,自引:0,他引:5
This paper deals with strengthening of reinforced concrete (RC) two-way slabs with carbon fibre reinforced plastic (CFRP) strips bonded to the tensile face. The first part deals with an experimental study. The fibre reinforced plastics (FRP) strengthened slab test presents a failure mode with debonding of the external FRP strips from the slab. The second part deals with a limit analysis modelling. The strengthened slab is designed as a three-layered plate. A simplified laminated plate model is used to describe the behaviour of three-layered plate supported in four sides, which is subjected to a load in the centre. The upper bound theorem of limit analysis is used to approximate the ultimate load capacity and identify the different collapse mechanisms. Experimental results are compared with theoretical predictions. 相似文献