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Science and technology literature retrieval system is commonly used by researchers as document retrieval tools. The classic information retrieval models such as Boolean Model [1], Vector Space Model and Probabilistic model neglect the position of query words in every paper. We propose a weighted term frequency model (WTFM) based on term frequency, and through a simulated annealing algorithm to learn...
Ontology can provide a powerful representation of information space and solve many semantic problems. It is wonderful to apply ontology to text classification. This paper proposes a general framework for text classification, which can overcome the limitations of traditional text classification methods. The results of experiment prove that the general framework is applicable across different domains...
This paper proposes a transformation algorithm of abstracting information based on the semantic path, by constructing XML index tree. The signature information of more subtle granularity and significance can be found quickly in the XML document according to the tree and transformation algorithm. Through signing multi-semantic path and information, XML multi-signature can be realized, data security...
Two different skeletons of heterocyclic compounds, quinoline and quinazolinone analogs could be obtained by a novel one-pot synthesis from substituted 3-amino-1H-benzo[f]chromene-2-carbonitrile derivatives and cyclohexanone in DMF in the catalyst of anhydrous zinc chloride under reflux. A plausible mechanism was proposed.
2H-3,1-Pyrazolo[3,4-e]oxazines (5a–c) and tacrine analogies (6a–c) were designed and prepared using 5-amino-4-cyanopyrazole (7) and cycloketones (2a–c) as reactants. The study demonstrated that the new conversion existed in the Friedländer reaction of o-aminocyanopyrazole with cycloketones.
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