Central composite design with two stars
Autor(a) principal: | |
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Data de Publicação: | 2014 |
Tipo de documento: | Artigo |
Idioma: | por |
Título da fonte: | Pesquisa Agropecuária Brasileira (Online) |
Texto Completo: | https://seer.sct.embrapa.br/index.php/pab/article/view/16263 |
Resumo: | This paper deals with the type of design known as “Central Composite, with Two Stars", a symmetric type, composed of a factorial (or fractional factorial) at the level ±W, two stars at levels ± α and ± ɣ α for each factor (at zero level of the remaining factors) and central points, presenting, normally, five or seven levels for each factor. In Agriculture, differently from technological experiments, principally in fertilizer research, due to soil and climatic variability, the experiments should be performed with all treatments allocated at the same time. In experiments with NPK, the responses obtained may be higher and enlarged in the good years smaller in the unfavourable years. These designs fit better these situations, because if the year was good, the complete design takes care of the situation; if the year was bad and the surface response presents a "plateau area", the elimination of the external star allows the determination of "unbiased estimate" of the coefficients of the model on the crescent part of the response surface. This article presents six Tables, Three of them present the orthogonal designs randonized for factors varying from two to seven; the last three tables present designs that are not only orthogonal, but divisible in blocks. |
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Central composite design with two starsDelineamento composto central com duas estrelassymmetric type; central point; plateau and surface response; unbiased estimateThis paper deals with the type of design known as “Central Composite, with Two Stars", a symmetric type, composed of a factorial (or fractional factorial) at the level ±W, two stars at levels ± α and ± ɣ α for each factor (at zero level of the remaining factors) and central points, presenting, normally, five or seven levels for each factor. In Agriculture, differently from technological experiments, principally in fertilizer research, due to soil and climatic variability, the experiments should be performed with all treatments allocated at the same time. In experiments with NPK, the responses obtained may be higher and enlarged in the good years smaller in the unfavourable years. These designs fit better these situations, because if the year was good, the complete design takes care of the situation; if the year was bad and the surface response presents a "plateau area", the elimination of the external star allows the determination of "unbiased estimate" of the coefficients of the model on the crescent part of the response surface. This article presents six Tables, Three of them present the orthogonal designs randonized for factors varying from two to seven; the last three tables present designs that are not only orthogonal, but divisible in blocks.Trata-se de um delineamento simétrico, da "Família do Composto Central", caracterizado, pela presença de duas estrelas. É composto por um fatorial ao nível de ± W, duas estrelas aos níveis ± α e ± ɣ α para cada fator (a nível zero dos fatores remanescentes) e pontos centrais, apresentando, cinco ou sete níveis para cada fator. Na Agricultura, os experimentos, diversamente dos tecnológicos, principalmente em pesquisas de fertilizantes, em face do solo e da variabilidade do clima, devem ser montados com todos os tratamentos do delineamento colocados no campo, de uma só vez. No caso de experimentos de adubação do tipo NPK, as respostas podem ser mais amplas nos anos bons e menos amplas nos anos ruins. Esse delineamento possibilita, a avaliação da resposta sobre toda a amplitude pesquisada, nos anos bons; nos anos ruins, com “resposta em platô", pode-se, pela eliminação da estrela exterior, analisa-lo como um composto central. Obtêm-se estimativas, "não-enviesadas" para os coeficientes do modelo, possibilitando fazer a análise estatística, e também a econômica. Apresentam-se seis Tabelas; em três delas se encontram os delineamentos ortogonais, casualizados para número de fatores variando de dois a sete; as outras três apresentam delineamentos não ortogonais, mais também divisíveis em blocos.Pesquisa Agropecuaria BrasileiraPesquisa Agropecuária BrasileiraConagin, Armando2014-04-16info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://seer.sct.embrapa.br/index.php/pab/article/view/16263Pesquisa Agropecuaria Brasileira; v.17, n.9, set. 1982; 1261-1269Pesquisa Agropecuária Brasileira; v.17, n.9, set. 1982; 1261-12691678-39210100-104xreponame:Pesquisa Agropecuária Brasileira (Online)instname:Empresa Brasileira de Pesquisa Agropecuária (Embrapa)instacron:EMBRAPAporhttps://seer.sct.embrapa.br/index.php/pab/article/view/16263/10453info:eu-repo/semantics/openAccess2014-04-16T16:39:47Zoai:ojs.seer.sct.embrapa.br:article/16263Revistahttp://seer.sct.embrapa.br/index.php/pabPRIhttps://old.scielo.br/oai/scielo-oai.phppab@sct.embrapa.br || sct.pab@embrapa.br1678-39210100-204Xopendoar:2014-04-16T16:39:47Pesquisa Agropecuária Brasileira (Online) - Empresa Brasileira de Pesquisa Agropecuária (Embrapa)false |
dc.title.none.fl_str_mv |
Central composite design with two stars Delineamento composto central com duas estrelas |
title |
Central composite design with two stars |
spellingShingle |
Central composite design with two stars Conagin, Armando symmetric type; central point; plateau and surface response; unbiased estimate |
title_short |
Central composite design with two stars |
title_full |
Central composite design with two stars |
title_fullStr |
Central composite design with two stars |
title_full_unstemmed |
Central composite design with two stars |
title_sort |
Central composite design with two stars |
author |
Conagin, Armando |
author_facet |
Conagin, Armando |
author_role |
author |
dc.contributor.none.fl_str_mv |
|
dc.contributor.author.fl_str_mv |
Conagin, Armando |
dc.subject.none.fl_str_mv |
|
dc.subject.por.fl_str_mv |
symmetric type; central point; plateau and surface response; unbiased estimate |
topic |
symmetric type; central point; plateau and surface response; unbiased estimate |
description |
This paper deals with the type of design known as “Central Composite, with Two Stars", a symmetric type, composed of a factorial (or fractional factorial) at the level ±W, two stars at levels ± α and ± ɣ α for each factor (at zero level of the remaining factors) and central points, presenting, normally, five or seven levels for each factor. In Agriculture, differently from technological experiments, principally in fertilizer research, due to soil and climatic variability, the experiments should be performed with all treatments allocated at the same time. In experiments with NPK, the responses obtained may be higher and enlarged in the good years smaller in the unfavourable years. These designs fit better these situations, because if the year was good, the complete design takes care of the situation; if the year was bad and the surface response presents a "plateau area", the elimination of the external star allows the determination of "unbiased estimate" of the coefficients of the model on the crescent part of the response surface. This article presents six Tables, Three of them present the orthogonal designs randonized for factors varying from two to seven; the last three tables present designs that are not only orthogonal, but divisible in blocks. |
publishDate |
2014 |
dc.date.none.fl_str_mv |
2014-04-16 |
dc.type.none.fl_str_mv |
|
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
https://seer.sct.embrapa.br/index.php/pab/article/view/16263 |
url |
https://seer.sct.embrapa.br/index.php/pab/article/view/16263 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.relation.none.fl_str_mv |
https://seer.sct.embrapa.br/index.php/pab/article/view/16263/10453 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Pesquisa Agropecuaria Brasileira Pesquisa Agropecuária Brasileira |
publisher.none.fl_str_mv |
Pesquisa Agropecuaria Brasileira Pesquisa Agropecuária Brasileira |
dc.source.none.fl_str_mv |
Pesquisa Agropecuaria Brasileira; v.17, n.9, set. 1982; 1261-1269 Pesquisa Agropecuária Brasileira; v.17, n.9, set. 1982; 1261-1269 1678-3921 0100-104x reponame:Pesquisa Agropecuária Brasileira (Online) instname:Empresa Brasileira de Pesquisa Agropecuária (Embrapa) instacron:EMBRAPA |
instname_str |
Empresa Brasileira de Pesquisa Agropecuária (Embrapa) |
instacron_str |
EMBRAPA |
institution |
EMBRAPA |
reponame_str |
Pesquisa Agropecuária Brasileira (Online) |
collection |
Pesquisa Agropecuária Brasileira (Online) |
repository.name.fl_str_mv |
Pesquisa Agropecuária Brasileira (Online) - Empresa Brasileira de Pesquisa Agropecuária (Embrapa) |
repository.mail.fl_str_mv |
pab@sct.embrapa.br || sct.pab@embrapa.br |
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1793416668135817216 |