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| Registros recuperados : 113 | |
| 5. |  | DALTRO, C. B.; ANDRADE, E. C. de. Estudo da similaridade existente entre a rdrp do vírus da meleira do mamoeiro ("PAPAYA MELEIRA VIRUS") e a rdrp de diferentes micovírus. In: REUNIÃO ANUAL DE CIÊNCIA, TECNOLOGIA, INOVAÇÃO E CULTURA NO RECÔNCAVO DA BAHIA - RECONCITEC, 2., 2012, Cruz das Almas. Energias Renováveis, Educação, Tecnologia e Sociedade. Cruz das Almas, BA: UFRB, 2012.| Biblioteca(s): Embrapa Mandioca e Fruticultura. |
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| 20. | | CALEGARIO, R. F.; FERREIRA, S. de S.; ANDRADE, E. C. de; ZERBINI, F. M. Characterization of Tomato yellow spot virus, a novel tomato-infecting begomovirus in Brazil Pesquisa Agropecuária Brasileira, Brasília, DF, v. 42, n. 9, p. 1335-1343, set. 2007 Título em português: Caracterização do Tomato yellow spot virus, um novo begomovírus isolado de tomateiro no Brasil.| Biblioteca(s): Embrapa Hortaliças; Embrapa Unidades Centrais. |
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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. |
Registro Completo
|
Biblioteca(s): |
Embrapa Agricultura Digital. |
|
Data corrente: |
08/04/1998 |
|
Data da última atualização: |
21/02/2011 |
|
Autoria: |
NASCIMENTO, M. A.; DUNHAM, M. H. |
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Afiliação: |
MARIO A. NASCIMENTO, CNPTIA; MARGARET H. DUNHAM, Southern Methodist University. |
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Título: |
Using B+-trees in a two disk-single processor architecture to efficiently process inclus'ion spatial queries. |
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Ano de publicação: |
1997 |
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Fonte/Imprenta: |
Campinas: UNICAMP-IC, 1997. |
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Páginas: |
16 p. |
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Série: |
(Relatório Técnico IC-97-23). |
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Idioma: |
Inglês |
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Conteúdo: |
In this paper we address the problem of indexing spatial data, in particular two dimensional rectangles. We propose an approach which uses two B+-trees, each of them indexing the project sides of the given rectangles. The approach, which we name 2dMAP21, can also be easily parallelized using two disks - but still a single processor - each holding the trees indexing the projected sides on either axes. We focus on queries of the type "find all rectangles included within another (reference) rectangle". Nevertheless, 2dMAP21 can processe other types of queries as well. We compare our approach to the R*-tree, known as the most efficient R-tree derivative. Our investigation shows that, if the queries have the same spatial distribution of the data, the non-parallel 2dMAP21 may be a competitive alternative to the R*-tree in some cases, whereas the parallelized version of 2dMAP21 outperforms that structure virtually always. 2dMAP21 may consume a little more or less storage space than the R*-tree, depending primarily on the spatial distribution on the indexed MBRs. The use of B+-trees renders our approach to be actually implementable using commercial DBMSs. |
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Palavras-Chave: |
Algoritmos; Árvores B+-; Indexação de dados espaciais. |
|
Thesaurus NAL: |
Algorithms; Spatial data. |
|
Categoria do assunto: |
X Pesquisa, Tecnologia e Engenharia |
|
Marc: |
LEADER 01766nam a2200205 a 4500
001 1006281
005 2011-02-21
008 1997 bl uuuu t 00u1 u #d
100 1 $aNASCIMENTO, M. A.
245 $aUsing B+-trees in a two disk-single processor architecture to efficiently process inclus'ion spatial queries.
260 $aCampinas: UNICAMP-IC$c1997
300 $a16 p.
490 $a(Relatório Técnico IC-97-23).
520 $aIn this paper we address the problem of indexing spatial data, in particular two dimensional rectangles. We propose an approach which uses two B+-trees, each of them indexing the project sides of the given rectangles. The approach, which we name 2dMAP21, can also be easily parallelized using two disks - but still a single processor - each holding the trees indexing the projected sides on either axes. We focus on queries of the type "find all rectangles included within another (reference) rectangle". Nevertheless, 2dMAP21 can processe other types of queries as well. We compare our approach to the R*-tree, known as the most efficient R-tree derivative. Our investigation shows that, if the queries have the same spatial distribution of the data, the non-parallel 2dMAP21 may be a competitive alternative to the R*-tree in some cases, whereas the parallelized version of 2dMAP21 outperforms that structure virtually always. 2dMAP21 may consume a little more or less storage space than the R*-tree, depending primarily on the spatial distribution on the indexed MBRs. The use of B+-trees renders our approach to be actually implementable using commercial DBMSs.
650 $aAlgorithms
650 $aSpatial data
653 $aAlgoritmos
653 $aÁrvores B+-
653 $aIndexação de dados espaciais
700 1 $aDUNHAM, M. H.
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Embrapa Agricultura Digital (CNPTIA) |
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