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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: |
23/12/1998 |
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Data da última atualização: |
20/01/2020 |
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Autoria: |
NASCIMENTO, M. A.; CUNHA, A. C. R. da. |
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Afiliação: |
MARIO A. NASCIMENTO, CNPTIA; ADRIANO C. R. DA CUNHA, IC/UNICAMP. |
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Título: |
An experiment stemming non-traditional text. |
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Ano de publicação: |
1998 |
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Fonte/Imprenta: |
In: STRING PROCESSING AND INFORMATION RETRIEVAL: A SOUTH AMERICAN SYMPOSIUM, 1998, Santa Cruz de la Sierra. Proceedings... Los Alamitos: IEEE Computer Society, 1998. |
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Páginas: |
p. 75-80. |
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DOI: |
10.1109/SPIRE.1998.712985 |
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Idioma: |
Inglês |
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Conteúdo: |
Stemming is a technique which aims to extract common suffixes of words. Thus, words which are literally different but have a commom stem, may be abstracted by their common stem. The underlying goal when using a stemming techniques is to improve recall, at the possible expense of precision loss. A well known technique for stemming text is Porter's algorithm, which is based on a set of rules extracted from the English language. In this paper, we argue that such an algorithm it is not efficient for non-traditional texts, e.g., one made up mainly of medical terms. We thus investigate the use of a technique, called Peak-and-Plateau, which is based on tries, and compare it to Porter's algorithm. Our experiments have shown that using Porter's algorithm or none at all makes no difference as far as precision and recall goes. On the other hand, using the Peak-and Plateau technique we improved recall by about 15% and decreased precision by an average of 40%. Moreover, it compressed the original text by 40% and the inverted file by 45%. |
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Palavras-Chave: |
Recuperação de informação; Stemming. |
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Thesaurus Nal: |
Information retrieval. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 01695nam a2200181 a 4500
001 1006876
005 2020-01-20
008 1998 bl uuuu u00u1 u #d
024 7 $a10.1109/SPIRE.1998.712985$2DOI
100 1 $aNASCIMENTO, M. A.
245 $aAn experiment stemming non-traditional text.$h[electronic resource]
260 $aIn: STRING PROCESSING AND INFORMATION RETRIEVAL: A SOUTH AMERICAN SYMPOSIUM, 1998, Santa Cruz de la Sierra. Proceedings... Los Alamitos: IEEE Computer Society$c1998
300 $ap. 75-80.
520 $aStemming is a technique which aims to extract common suffixes of words. Thus, words which are literally different but have a commom stem, may be abstracted by their common stem. The underlying goal when using a stemming techniques is to improve recall, at the possible expense of precision loss. A well known technique for stemming text is Porter's algorithm, which is based on a set of rules extracted from the English language. In this paper, we argue that such an algorithm it is not efficient for non-traditional texts, e.g., one made up mainly of medical terms. We thus investigate the use of a technique, called Peak-and-Plateau, which is based on tries, and compare it to Porter's algorithm. Our experiments have shown that using Porter's algorithm or none at all makes no difference as far as precision and recall goes. On the other hand, using the Peak-and Plateau technique we improved recall by about 15% and decreased precision by an average of 40%. Moreover, it compressed the original text by 40% and the inverted file by 45%.
650 $aInformation retrieval
653 $aRecuperação de informação
653 $aStemming
700 1 $aCUNHA, A. C. R. da
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Embrapa Agricultura Digital (CNPTIA) |
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Registro Completo
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Biblioteca(s): |
Embrapa Florestas. |
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Data corrente: |
09/03/2022 |
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Data da última atualização: |
09/03/2022 |
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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: |
RAMALHO, B.; DIECKOW, J.; MELO, V. de F.; BROWN, G. G.; SIMON, P. L.; IBARR, M. A.; CUNHA, L.; KILLE, P.; TPI NETWORK. |
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Afiliação: |
BRUNA RAMALHO, UFPR; JEFERSON DIECKOW, UFPR; VANDER DE FREITAS MELO, UFPR; GEORGE GARDNER BROWN, CNPF; PRISCILA LUZIA SIMON, UFPR; MARIANA ALVES IBARR, UFPR; LUIS CUNHA, University of Coimbra; PETER KILLE, Cardiff University; TPI NETWORK, Cardiff University. |
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Título: |
Carbon and nitrogen storage and stability by mineral-organic association in physical fractions of anthropogenic dark earth and of reference soils in Amazonia. |
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Ano de publicação: |
2022 |
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Fonte/Imprenta: |
Catena, v. 213, 106185, June 2022. 10 p. |
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DOI: |
https://doi.org/10.1016/j.catena.2022.106185 |
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Idioma: |
Inglês |
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Conteúdo: |
The anthropogenic dark earths (ADEs) are being assumed in recent years as a model representing the result of sustainable soil management practices carried out by Pre-Columbian peoples. However, little is known about the role of mineral-organic associations in organic matter storage in those soils compared to the emphasis generally given to the role of pyrogenic structures. We quantified the changes of carbon and nitrogen and their distribution in physical fractions of ADEs in relation to the reference (adjacent) soil. Four ADEs sites having the different soil textural classes of sandy clay loam, sandy clay, clayey, and very clayey were selected in the Amazon region of Brazil. Soil samples were collected from the 0?10 cm layer and a subset of the sample was separated into large aggregates (>500 micrômetro) and small aggregates (<500 micrômetro). The ADEs stored on average 45% more total organic carbon (TOC) and 44% more total nitrogen (TN) than the reference soils. Of the incremental TOC and TN in ADE relative to the reference soil, the silt size fraction stored on average 92% of this TOC and 37% of this TN and had C:N ratios as high as 25, which may indicate the presence of pyrogenic material. The clay fraction stored a substantial share of 27-46% of the incremental TOC and 27-66% of the incremental TN. The C:N ratio in the clay size fraction of ADEs, on average 10.5, was lower or not different than in the clay fraction of reference soil (average of 11.1), indicating that the organic matter in the clay fraction even of ADEs was predominantly of microbial origin, and not pyrogenic. We therefore conclude that the clay fraction proved to be an important location to the accumulation and stabilization of TOC and TN in these Anthrosols, possibly by mineral-organic association mechanisms. MenosThe anthropogenic dark earths (ADEs) are being assumed in recent years as a model representing the result of sustainable soil management practices carried out by Pre-Columbian peoples. However, little is known about the role of mineral-organic associations in organic matter storage in those soils compared to the emphasis generally given to the role of pyrogenic structures. We quantified the changes of carbon and nitrogen and their distribution in physical fractions of ADEs in relation to the reference (adjacent) soil. Four ADEs sites having the different soil textural classes of sandy clay loam, sandy clay, clayey, and very clayey were selected in the Amazon region of Brazil. Soil samples were collected from the 0?10 cm layer and a subset of the sample was separated into large aggregates (>500 micrômetro) and small aggregates (<500 micrômetro). The ADEs stored on average 45% more total organic carbon (TOC) and 44% more total nitrogen (TN) than the reference soils. Of the incremental TOC and TN in ADE relative to the reference soil, the silt size fraction stored on average 92% of this TOC and 37% of this TN and had C:N ratios as high as 25, which may indicate the presence of pyrogenic material. The clay fraction stored a substantial share of 27-46% of the incremental TOC and 27-66% of the incremental TN. The C:N ratio in the clay size fraction of ADEs, on average 10.5, was lower or not different than in the clay fraction of reference soil (average of 11.1), indicating that th... Mostrar Tudo |
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Palavras-Chave: |
Physical fractionation; Protection mechanisms. |
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Thesaurus NAL: |
Anthrosols; Clay fraction; Organic matter. |
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Categoria do assunto: |
P Recursos Naturais, Ciências Ambientais e da Terra |
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Marc: |
LEADER 02718naa a2200289 a 4500
001 2140681
005 2022-03-09
008 2022 bl uuuu u00u1 u #d
024 7 $ahttps://doi.org/10.1016/j.catena.2022.106185$2DOI
100 1 $aRAMALHO, B.
245 $aCarbon and nitrogen storage and stability by mineral-organic association in physical fractions of anthropogenic dark earth and of reference soils in Amazonia.$h[electronic resource]
260 $c2022
520 $aThe anthropogenic dark earths (ADEs) are being assumed in recent years as a model representing the result of sustainable soil management practices carried out by Pre-Columbian peoples. However, little is known about the role of mineral-organic associations in organic matter storage in those soils compared to the emphasis generally given to the role of pyrogenic structures. We quantified the changes of carbon and nitrogen and their distribution in physical fractions of ADEs in relation to the reference (adjacent) soil. Four ADEs sites having the different soil textural classes of sandy clay loam, sandy clay, clayey, and very clayey were selected in the Amazon region of Brazil. Soil samples were collected from the 0?10 cm layer and a subset of the sample was separated into large aggregates (>500 micrômetro) and small aggregates (<500 micrômetro). The ADEs stored on average 45% more total organic carbon (TOC) and 44% more total nitrogen (TN) than the reference soils. Of the incremental TOC and TN in ADE relative to the reference soil, the silt size fraction stored on average 92% of this TOC and 37% of this TN and had C:N ratios as high as 25, which may indicate the presence of pyrogenic material. The clay fraction stored a substantial share of 27-46% of the incremental TOC and 27-66% of the incremental TN. The C:N ratio in the clay size fraction of ADEs, on average 10.5, was lower or not different than in the clay fraction of reference soil (average of 11.1), indicating that the organic matter in the clay fraction even of ADEs was predominantly of microbial origin, and not pyrogenic. We therefore conclude that the clay fraction proved to be an important location to the accumulation and stabilization of TOC and TN in these Anthrosols, possibly by mineral-organic association mechanisms.
650 $aAnthrosols
650 $aClay fraction
650 $aOrganic matter
653 $aPhysical fractionation
653 $aProtection mechanisms
700 1 $aDIECKOW, J.
700 1 $aMELO, V. de F.
700 1 $aBROWN, G. G.
700 1 $aSIMON, P. L.
700 1 $aIBARR, M. A.
700 1 $aCUNHA, L.
700 1 $aKILLE, P.
700 1 $aTPI NETWORK
773 $tCatena$gv. 213, 106185, June 2022. 10 p.
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