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Registro Completo |
Biblioteca(s): |
Embrapa Agricultura Digital. |
Data corrente: |
03/12/1998 |
Data da última atualização: |
01/04/2019 |
Autoria: |
LEE, D. L.; KIM, Y. M.; PATEL, G. |
Afiliação: |
DIK LUN LEE, Ohio State University; YOUNG MAN KIM, Mitsubishi Materials Corp.; GAURAV PATEL, Ohio State University. |
Título: |
Efficient signature file methods for text retrieval. |
Ano de publicação: |
1995 |
Fonte/Imprenta: |
IEEE Transactions on Knowledge and Data Engineering, v. 7, n. 3, p. 423-435, June 1995. |
DOI: |
10.1109/69.390248 |
Idioma: |
Inglês |
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 |
Palavras-Chave: |
Access methods; Codificação; Performance analysis; Recuperação de textos; Superimposed coding; Text retrieval. |
Categoria do assunto: |
-- |
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
Biblioteca(s): |
Embrapa Amazônia Oriental. |
Data corrente: |
29/11/1993 |
Data da última atualização: |
01/11/2023 |
Autoria: |
ALBUQUERQUE, M. de; GUIMARÃES, M. C. de F.; VIÉGAS, R. M. F. |
Afiliação: |
MILTON DE ALBUQUERQUE, CPATU; MÁRIO CARDOSO DE FREITAS GUIMARÃES, IPEAN; ROSEMARY MORAES FERREIRA VIÉGAS, CPATU. |
Título: |
Épocas de plantio e de colheita em zonas mandioqueiras do leste paraense. |
Ano de publicação: |
1974 |
Fonte/Imprenta: |
Boletim Técnico. IPEAN, n. 60, p. 193-221, 1974. |
Idioma: |
Português |
Palavras-Chave: |
Belém; Brasil; Cultivation; Cultivo; Pará. |
Thesagro: |
Mandioca. |
Thesaurus NAL: |
Amazonia; cassava. |
Categoria do assunto: |
F Plantas e Produtos de Origem Vegetal |
URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/doc/375631/1/Epocas-de-plantio-e-de-colheita...pdf
|
Marc: |
LEADER 00603naa a2200229 a 4500 001 1375631 005 2023-11-01 008 1974 bl uuuu u00u1 u #d 100 1 $aALBUQUERQUE, M. de 245 $aÉpocas de plantio e de colheita em zonas mandioqueiras do leste paraense. 260 $c1974 650 $aAmazonia 650 $acassava 650 $aMandioca 653 $aBelém 653 $aBrasil 653 $aCultivation 653 $aCultivo 653 $aPará 700 1 $aGUIMARÃES, M. C. de F. 700 1 $aVIÉGAS, R. M. F. 773 $tBoletim Técnico. IPEAN$gn. 60, p. 193-221, 1974.
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