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 | Acesso ao texto completo restrito à biblioteca da Embrapa Agricultura Digital. Para informações adicionais entre em contato com cnptia.biblioteca@embrapa.br. |
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Registro Completo |
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Biblioteca(s): |
Embrapa Agricultura Digital. |
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Data corrente: |
03/12/1998 |
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Data da última atualização: |
01/04/2019 |
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Autoria: |
LEE, D. L.; KIM, Y. M.; PATEL, G. |
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Afiliação: |
DIK LUN LEE, Ohio State University; YOUNG MAN KIM, Mitsubishi Materials Corp.; GAURAV PATEL, Ohio State University. |
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Título: |
Efficient signature file methods for text retrieval. |
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Ano de publicação: |
1995 |
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Fonte/Imprenta: |
IEEE Transactions on Knowledge and Data Engineering, v. 7, n. 3, p. 423-435, June 1995. |
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DOI: |
10.1109/69.390248 |
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Idioma: |
Inglês |
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Conteúdo: |
Signature files have been studied extensively, as an access method for textual databases. Many approaches have been proposed for searching signatures files efficiently. However, different methods make different assumptions and use different performance measures, making it difficult to compare their performance. In this paper, we study three basic methods proposed in the literature, namely, the indexed descriptor file, the two-level superimposed coding scheme, and the partitioned signature file approach. The contribution of this paper is two-fold. First, we present a uniform analytical performance model so that the methods can be compared fairly and consistently. The analysis shows that the two-level superimposed coding scheme, if stored in a transposed file, has the best performance. Second, we extend the two-level superimposed coding method into a multilevel superimposed coding method, we obtain the optimal number of levels for the multilevel method and show that for databases with reasonable size the optimal value is much larger than 2, which is assumed in the two-level method. The accuracy of the analytical formula is demonstrated by simulation |
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Palavras-Chave: |
Access methods; Codificação; Performance analysis; Recuperação de textos; Superimposed coding; Text retrieval. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 01845naa a2200229 a 4500
001 1006831
005 2019-04-01
008 1995 bl uuuu u00u1 u #d
024 7 $a10.1109/69.390248$2DOI
100 1 $aLEE, D. L.
245 $aEfficient signature file methods for text retrieval.$h[electronic resource]
260 $c1995
520 $aSignature files have been studied extensively, as an access method for textual databases. Many approaches have been proposed for searching signatures files efficiently. However, different methods make different assumptions and use different performance measures, making it difficult to compare their performance. In this paper, we study three basic methods proposed in the literature, namely, the indexed descriptor file, the two-level superimposed coding scheme, and the partitioned signature file approach. The contribution of this paper is two-fold. First, we present a uniform analytical performance model so that the methods can be compared fairly and consistently. The analysis shows that the two-level superimposed coding scheme, if stored in a transposed file, has the best performance. Second, we extend the two-level superimposed coding method into a multilevel superimposed coding method, we obtain the optimal number of levels for the multilevel method and show that for databases with reasonable size the optimal value is much larger than 2, which is assumed in the two-level method. The accuracy of the analytical formula is demonstrated by simulation
653 $aAccess methods
653 $aCodificação
653 $aPerformance analysis
653 $aRecuperação de textos
653 $aSuperimposed coding
653 $aText retrieval
700 1 $aKIM, Y. M.
700 1 $aPATEL, G.
773 $tIEEE Transactions on Knowledge and Data Engineering$gv. 7, n. 3, p. 423-435, June 1995.
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Registro original: |
Embrapa Agricultura Digital (CNPTIA) |
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Registro Completo
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Biblioteca(s): |
Embrapa Instrumentação. |
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Data corrente: |
17/12/2014 |
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Data da última atualização: |
16/08/2018 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Circulação/Nível: |
A - 1 |
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Autoria: |
AVANSI, W. ARENAL, R. MENDONCA, V. R.; RIBEIRO, C.; LONGO, E. |
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Afiliação: |
CAUE RIBEIRO DE OLIVEIRA, CNPDIA. |
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Título: |
Vanadium-doped TiO2 anatase nanostructures: the role of V in solid solution formation and its effect on the optical properties. |
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Ano de publicação: |
2014 |
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Fonte/Imprenta: |
CrystEngComm [online], v. 16, n. 23, p. 5021-5027, 2014. |
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DOI: |
10.1039/C3CE42356E |
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Idioma: |
Inglês |
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Palavras-Chave: |
Propriedades óticas. |
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Thesaurus NAL: |
vanadium. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 00593naa a2200169 a 4500
001 2002956
005 2018-08-16
008 2014 bl uuuu u00u1 u #d
024 7 $a10.1039/C3CE42356E$2DOI
100 1 $aAVANSI, W. ARENAL, R. MENDONCA, V. R.
245 $aVanadium-doped TiO2 anatase nanostructures$bthe role of V in solid solution formation and its effect on the optical properties.$h[electronic resource]
260 $c2014
650 $avanadium
653 $aPropriedades óticas
700 1 $aRIBEIRO, C.
700 1 $aLONGO, E.
773 $tCrystEngComm [online]$gv. 16, n. 23, p. 5021-5027, 2014.
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