Covariance Structure
Mostrando 1-12 de 56 artigos, teses e dissertações.
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1. MULTILEVEL NONLINEAR MIXED-EFFECTS MODEL AND MACHINE LEARNING FOR PREDICTING THE VOLUME OF Eucalyptus SPP. TREES
ABSTRACT Volumetric equations is one of the main tools for quantifying forest stand production, and is the basis for sustainable management of forest plantations. This study aimed to assess the quality of the volumetric estimation of Eucalyptus spp. trees using a mixed-effects model, artificial neural network (ANN) and support-vector machine (SVM). The datab
CERNE. Publicado em: 2020-03
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2. SITE INDEX FOR PROSOPIS ALBA PLANTATIONS IN THE SEMI-ARID CHACO THROUGH MIXED MODELS
ABSTRACT The classification of sites through curves of Site Index allows to predict the yield of the planted forests at a certain age of the stand and to plan cultural treatments. The goal of this research was to compare linear and non-linear models of fixed effects vs. mixed non-linear models to estimate the site index in plantations of Prosopis alba var Gr
CERNE. Publicado em: 09/09/2019
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3. Spatial and multivariate analysis of soybean productivity and soil physical-chemical attributes
RESUMO O objetivo deste trabalho foi avaliar a variabilidade espacial da produtividade de soja, do estoque de carbono e de atributos físicos do solo por meio de técnicas multivariadas e de geoestatística. Os atributos foram determinados em um Latossolo Vermelho textura argilosa e coeso no município de Mata Roma (Maranhão, Brasil). Na área de estudo for
Rev. bras. eng. agríc. ambient.. Publicado em: 01/07/2019
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4. Population structure correction for genomic selection through eigenvector covariates
Abstract We proposed a population structure correction for genome-wide selection based on covariance analysis via eigenvector (EVG) decomposition. The agreement between the predicted and true breeding values was evaluated by independent cross-validation data sets. Other correction methods such as correction via principal components, best linear unbiased pred
Crop Breed. Appl. Biotechnol.. Publicado em: 2017-12
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5. Variabilidad de Baja Frecuencia de la Persistencia de la Temperatura en el Sudeste de Sudamérica
Abstract Eight reference stations in south-eastern South America are analysed to derive the auto-covariance and auto-correlations of maximum and minimum temperature. Through the analysis are observed oscillations of periods between 18 and 25 years in the series studied. These periodicities show changes over time, especially in the 1950-1970 period. The excep
Rev. bras. meteorol.. Publicado em: 2017-03
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6. Use of tree species by White-throated treerunner (Pygarrhichas albogularis King) in a secondary native forest of southern Chile
ABSTRACT In forest ecosystems, numerous species of insectivorous birds use certain tree species as feeding and nesting substrates. Between 2009 and 2010, the use of different floristic components as feeding substrate by the Pygarrhichas albogularis King, 1831 was evaluated in a southern Chilean secondary native forest. From a total of 13 trees and bush speci
Iheringia, Sér. Zool.. Publicado em: 2015-06
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7. ON HYPOTHESIS TESTS FOR COVARIANCE MATRICES UNDER MULTIVARIATE NORMALITY
In this paper we proposed a new statistical test for testing the covariance matrix in one population under multivariate normal assumption. In general, the proposed and the likelihood-ratio tests resulted in larger values of estimated powers than VMAX for bivariate and trivariate cases. VMAX was not sensitive to general changes in the covariance (correlation)
Pesqui. Oper.. Publicado em: 2015-04
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8. Medindo valores com parcelas de itens: contribuições à teoria funcionalista dos valores / MEASURING VALUES WITH ITEM PARCELS: CONTRIBUTIONS TO FUNCTIONAL THEORY OF VALUES
ABSTRACT - The current thesis aimed to create a new instrument for measurement of human values, based on the functionalist theory of human values, for diagnosis and screening. To this end, it took out three studies. Study 1 aimed to build up a database of items that would meet an essential criterion: to represent the subfunctions recommended by the functiona
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 27/02/2012
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9. Tabapuã breed in Northeastern Brazil: genetic progress and population structure
The objective of this study was to evaluate the history of the Tabapuã breed in Northeastern Brazil by determining its population structure and genetic progress. Pedigree information from animals born in the period between 1965 and 2006 and weight-adjusted data at 205 (W205), 365 (W365) and 550 (W550) days of age for bovines born between 1975 and 2006 were
R. Bras. Zootec.. Publicado em: 2012-08
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10. Estimates of genetic parameters for visual scores and their correlation with production and reproductive traits in Brahman cattle
The objective of this study was to evaluate the association of visual scores of body structure, precocity and muscularity with production (body weight at 18 months and average daily gain) and reproductive (scrotal circumference) traits in Brahman cattle in order to determine the possible use of these scores as selection criteria to improve carcass quality. C
Revista Brasileira de Zootecnia. Publicado em: 2012-06
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11. Regeneração de espécies arbóreas em floresta impactada
This study aimed to investigate aspects of population ecology of six tree species in two areas with different historical preservation: Mata São Francisco State Park (MSFSP), Santa Mariana-Cornelio Procópio, PR, Brazil (23º 15 S and 50º 45 W, central point of fragment), who suffered exploration anthropogenic, and Mata dos Godoy State Park (MGSP) (23º 27
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 22/06/2011
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12. RESOURCE SHARING AND DISTRIBUTION OF RISK IN ANNUAL SPECIES OF TROPICAL ZONE Semiarid / Partilha de recurso e distribuiÃÃo de riscos em espÃcies anuais da zona tropical semiÃrida
Theoretical and empirical inferences about resources sharing and risk spreading based on seed germination and plants phenodynamics are concentrated in studies of annual desert species. These mechanisms should be standard for species that coexist in any environment where the risk of reproductive failure is high, as in Brazilian tropical semiarid. This study
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 21/03/2011