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	Provedor de dados Scientia Agricola (3) Rev. Ciênc. Agron. (2) AgEcon (2) REA (2) CIGR Journal (1) ArchiMer (1) Ciência e Agrotecnologia (1) Ciência Rural (1) Horticultura Brasileira (1) Mais... Autor Christoforo,André L. (2) Lahr,Francisco A. R. (2) Nogueira,Maria Cristina Stolf (2) Akbarnia, Abbas (1) Alimardani, Reza (1) Almeida,Diego H. de (1) Almeida,João P. B. (1) Aquino,Vinicius B. de M. (1) Barbosa,Thaina Q. (1) Campos,Katia Alves (1) Cavalcanti,Pórtya Piscitelli (1) Coimbra,Jefferson Luís Meirelles (1) Couto,Natalia G. (1) Cox, Nicholas J. (1) Farhani, Foad (1) Ferreira,Daniel Furtado (1) Ferreira,Eric Batista (1) Guidolin,Altamir Frederico (1) Kozak,Marcin (1) Legendre, P (1) Mais... Palavra-chave Analysis of variance (14) Multiple comparisons (2) Regression (2) Regression models (2) Agricultural experimentation (1) Anovaplot (1) Applied statistics (1) Assumptions (1) Back propagation (1) Coffea arabica (1) Comparison of surfaces (1) Completely randomized design (1) Crop breeding (1) D81 (1) Data transformation (1) Diagnostics (1) Experimental designs (1) Experimental error (1) Experimental precision (1) Experimental statistics (1) Mais... Tipo do documento Info:eu-repo/semantics/article (10) Journal Article (2) Info:eu-repo/semantics/other (1) Text (1) Ano 2020 (3) 2017 (1) 2016 (1) 2015 (1) 2014 (1) 2011 (2) 2010 (1) 2009 (1) 2004 (2) 1997 (1) Mais... País Brazil (10) United States (2) China (1) France (1) Idioma Inglês (14)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 14 Primeira ... 1 ... Última Alternative for the evaluation of coffee seedlings using Fisher's discriminant analysis Rev. Ciênc. Agron. Campos,Katia Alves; Morais,Augusto Ramalho de; Paixão,Crysttian Arantes. ABSTRACT One of the applications of Fisher's linear discriminant function (FDF) is its use in transforming multivariate data into a new univariate variable. This then makes possible a new option for the variance analysis of multivariate data, in addition to the multivariate analysis of variance (MANOVA). The aim of this work was to select groups of seven characteristics of quality in coffee seedlings using six criteria for selection, to use the FDF to transform such groupings of characteristics into a new variable, and then to compare interpretation of the results obtained from the univariate and multivariate analyses of variance of the characteristics and this new variable, with a view to its use in evaluating coffee seedlings. A randomised block design... Tipo: Info:eu-repo/semantics/article Palavras-chave: Variable selection; Multivariate analysis; Data transformation; Analysis of variance; Coffea arabica. Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902016000200299 Analyzing one-way experiments: a piece of cake of a pain in the neck? Scientia Agricola Kozak,Marcin. Statistics may be intricate. In practical data analysis many researchers stick to the most common methods, not even trying to find out whether these methods are appropriate for their data and whether other methods might be more useful. In this paper I attempt to show that when analyzing even simple one-way factorial experiments, a lot of issues need to be considered. A classical method to analyze such data is the analysis of variance, quite likely the most often used statistical method in agricultural, biological, ecological and environmental studies. I suspect this is why this method is quite often applied inappropriately: since the method is that common, it does not require too much consideration-this is how some may think. An incorrect analysis may... Tipo: Info:eu-repo/semantics/article Palavras-chave: Analysis of variance; Assumptions; Graphical statistics; Multiple comparisons; Normal distribution; Non-parametric statistics; One-way designs; Statistical analysis. Ano: 2009 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000400020 APPARENT DENSITY AS AN ESTIMATOR OF WOOD PROPERTIES OBTAINED IN TESTS WHERE FAILURE IS FRAGILE REA Christoforo,André L.; Couto,Natalia G.; Almeida,João P. B.; Aquino,Vinicius B. de M.; Lahr,Francisco A. R.. ABSTRACT The use of new wood species in construction requires knowledge of their properties for safer and more economical structural sizing. In Brazil, structural projects are carried out according to the standard document ABNT NBR 7190:1997. Tests required by this standard for the complete characterization of species require large machines with high costs, which are present only in large research centers. Considering the lack of experimental determination, this study aimed, with the help of analysis of variance of regression models, to investigate the possibility of estimating, through apparent density, wood properties obtained in tests where failure is considered fragile, allowing the estimation of properties of species still little used. Ten wood... Tipo: Info:eu-repo/semantics/article Palavras-chave: Hardwoods; Fragile failure; Regression models; Analysis of variance. Ano: 2020 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000100105 Comparison of surfaces ArchiMer Legendre, P; Mcardle, Bh. Values of a variable observed over a delimited geographic area are called a ''surface''. The problem we investigate is how to compare measures of the same area observed at two or more Sampling times. It is important to recognise that two different null hypotheses can be tested about the surface. The first is that the corresponding values in the surfaces differ only because of measurement or sampling error. The second is that the underlying process that generated the surfaces is the same. In the first case, the surfaces should have the same shape and values, while in the second case the surfaces might have different values, but if they still have the same means, variances and autocorrelation structures, the null hypothesis cannot be rejected. To prove the... Tipo: Text Palavras-chave: Analysis of variance; Comparison of surfaces; Log-linear model; Sampling strategy; Trend surface analysis. Ano: 1997 URL: http://archimer.ifremer.fr/doc/00093/20397/18064.pdf Hedging Effectiveness Around U.S. Department of Agriculture Crop Reports AgEcon McKenzie, Andrew M.; Singh, Navinderpal. It is well documented that ‘‘unanticipated’’ information contained in United States Department of Agriculture (USDA) crop reports induces large price reactions in corn and soybean markets. Thus, a natural question that arises from this literature is: To what extent are futures hedges able to remove or reduce increased price risk around report release dates? This paper addresses this question by simulating daily futures returns, daily cash returns, and daily hedged returns around report release dates for two storable commodities (corn and soybeans) in two market settings (North Central Illinois and Memphis, Tennessee). Various risk measures, including ‘‘Value at Risk,’’ are used to determine hedging effectiveness, and ‘‘Analysis of Variance’’ is used to... Tipo: Journal Article Palavras-chave: Analysis of variance; Storage hedging; United States Department of Agriculture Crop Reports; Value at risk; Marketing; Risk and Uncertainty; Q13; D81. Ano: 2011 URL: http://purl.umn.edu/100635 INFLUENCE OF FATIGUE ON BENDING OF Pinus caribaea WOOD REA Christoforo,André L.; Barbosa,Thaina Q.; Almeida,Diego H. de; Panzera,Tulio H.; Lahr,Francisco A. R.. ABSTRACT This research aimed to evaluate the effect of the number of fatigue cycles (NC, 0 – reference, 450, 4500, 45000, and 90000) for frequencies (Fr) of oscillation equal to 0.5 and 1.0 Hz on the modulus of elasticity (Em) and operating stress (σm) in the static bending of Pinus caribaea wood. Em and σm were determined taking into account three specimens (SPEC) manufactured for reference condition and another three for each of the four NC levels and each Fr level, resulting in 27 SPEC. Sixty experimental determinations were obtained, being the approximate total time of sample exposure to fatigue of 350 hours. The same specimens used to determine Em and σm for the reference condition were also used (via non-destructive tests) to obtain these properties... Tipo: Info:eu-repo/semantics/article Palavras-chave: Fatigue; Pinus caribaea; Static bending; Analysis of variance; Regression models. Ano: 2020 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000200238 Orthogonal contrasts: definitions and concepts Scientia Agricola Nogueira,Maria Cristina Stolf. The single degree of freedom of orthogonal contrasts is a useful technique for the analysis of experimental data and helpful in obtaining estimates of main, nested and interaction effects, for mean comparisons between groups of data and in obtaining specific residuals. Furthermore, the application of orthogonal contrasts is an alternative way of doing statistical analysis on data from non-conventional experiments, whithout a definite structure. To justify its application, an extensive review is made on the definitions and concepts involving contrasts. Tipo: Info:eu-repo/semantics/article Palavras-chave: Analysis of variance; Partition of sum of squares; Experiments with additional treatments. Ano: 2004 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162004000100020 Planning and implementing experiments and analyzing experimental data in vegetable crops: problems and solutions Horticultura Brasileira Lúcio,Alessandro Dal’Col; Sari,Bruno Giacomini. ABSTRACT The statistical interpretation of experimental results is inherent to the research process. Therefore, every researcher is expected to have basic understanding on the subject. In vegetable crops, the planning, implementing and data gathering is more complex due to specific aspects related to this group of plants, such as intensive management and high labor requirement to carry out the experiments, uneven fruit maturation and heterogeneity of the experimental area. Since all these factors are sources of variability within the experiment, circumventing them in the experiment planning and implementing phases is fundamental to reduce the experimental error. Furthermore, the knowledge of statistical tests and the assumptions for their use is equally... Tipo: Info:eu-repo/semantics/article Palavras-chave: Agricultural experimentation; Experimental precision; Experimental error; Experimental designs; Applied statistics; Analysis of variance; Horticulture.. Ano: 2017 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-05362017000300316 Simulation of draft force of winged share tillage tool using artificial neural network model CIGR Journal Akbarnia, Abbas; Mohammadi, Asghar; Alimardani, Reza; Farhani, Foad. An artificial neural network (ANN) model, with a back propagation learning algorithm, was developed to predict draft requirements of two winged share tillage tools in a loam soil. The input parameters to the 3–7–1 ANN model were; share width, working depth and operating speed. The output from the network was the draft requirement of each tillage tool. The developed model predicted the draft requirements of the winged share tillage tools with a mean relative error of less than 7% and mean square errors of less than 0.05, when compared to measured draft values. This result indicates that the ANN model had successfully learnt from the training data set to enable correct interpolation and could be used as an alternative tool for modeling soil-tool interaction... Tipo: Info:eu-repo/semantics/article Palavras-chave: Analysis of variance; Back propagation; Force evaluation; Multi layer perceptron; Prediction. Ano: 2014 URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3022 Sisvar: a computer statistical analysis system Ciência e Agrotecnologia Ferreira,Daniel Furtado. Sisvar is a statistical analysis system, first released in 1996 although its development began in 1994. The first version was done in the programming language Pascal and compiled with Borland Turbo Pascal 3. Sisvar was developed to achieve some specific goals. The first objective was to obtain software that could be used directly on the statistical experimental course of the Department of Exact Science at the Federal University of Lavras. The second objective was to initiate the development of a genuinely Brazilian free software program that met the demands and peculiarities of research conducted in the country. The third goal was to present statistical analysis software for the Brazilian scientific community that would allow research results to be... Tipo: Info:eu-repo/semantics/article Palavras-chave: Multiple comparisons; Analysis of variance; Regression; Hypothesis tests. Ano: 2011 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542011000600001 Speaking Stata: Graphing model diagnostics AgEcon Cox, Nicholas J.. Plotting diagnostic information calculated from residuals and fitted values is a long-standard method for assessing models and seeking ways of improving them. This column focuses on the statistical mainstream defined by regression models for continuous responses, treated in a broad sense to include (for example) generalized linear models. After some comments on the history of such ideas (and even their anthropology and psychology), the commands available in official Stata are reviewed, and a modeldiag package is introduced. A detailed example on fuelwood yield from fallow areas in Nigeria illustrates a variety of general points and specific tips. Tipo: Journal Article Palavras-chave: Modeldiag; Anovaplot; Indexplot; Ofrtplot; Ovfplot; Qfrplot; Racplot; Rdplot; Regplot; Rhetplot; Rvfplot2; Rvlrplot; Rvpplot2; Graphics; Diagnostics; Regression; Generalized linear models; Analysis of variance; Research Methods/ Statistical Methods. Ano: 2004 URL: http://purl.umn.edu/116273 Specific residue: application of orthogonal contrasts when heteroscedasticity is present Scientia Agricola Nogueira,Maria Cristina Stolf. When experimental data are submitted to analysis of variance, the assumption of data homoscedasticity (variance homogeneity among treatments), associated to the adopted mathematical model must be satisfied. This verification is necessary to ensure the correct test for the analysis. In some cases, when data homoscedascity is not observed, errors may invalidate the analysis. An alternative to overcome this difficulty is the application of the specific residue analysis, which consists of the decomposition of the residual sum of squares in its components, in order to adequately test the correspondent orthogonal contrasts of interest between treatment means. Although the decomposition of the residual sum of squares is a seldom used procedure, it is useful for a... Tipo: Info:eu-repo/semantics/other Palavras-chave: Analysis of variance; Completely randomized design; Randomized complete block design. Ano: 2010 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162010000100016 Split double factorial with additional treatment and the post-harvest of Niagara grapes Ciência Rural Cavalcanti,Pórtya Piscitelli; Ferreira,Eric Batista; Storti,Laís Brambilla. ABSTRACTThis study aims to discuss and explain how to deal with the analysis of experiments conducted in completely randomized design (CRD) and subdivided into double factorial with additional treatment in the plot. In addition it was illustrate the discussion by analyzing data from an experiment on post-harvest of Niagara grapes. The sums of squares for each source of variation are presented, while discussing how the additional treatment affects the whole variation. Niagara grapes were treated in the pre-harvest with three preservatives (calcium chloride, calcium nitrate and calcium lactate) at 0%, 0.5%, 1% and 2% and stored for 0, 10, 20 and 30 days.All the preservatives evaluated at 0% represented the control (additional) treatment. Tipo: Info:eu-repo/semantics/article Palavras-chave: Analysis of variance; Software R; Experimental statistics. Ano: 2015 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782015000901538 Statistical model assumptions achieved by linear models: classics and generalized mixed Rev. Ciênc. Agron. Melo,Rita Carolina de; Trevisani,Nicole; Santos,Marcio dos; Guidolin,Altamir Frederico; Coimbra,Jefferson Luís Meirelles. ABSTRACT When an agricultural experiment is completed and the data about the response variable is available, it is necessary to perform an analysis of variance. However, the hypothesis testing of this analysis shows validity only if the assumptions of the statistical model are ensured. When such assumptions are violated, procedures must be applied to remedy the problem. The present study aimed to compare and investigate how the assumptions of the statistical model can be achieved by classical linear model and generalized linear mixed model, as well as their impact on the hypothesis test of the analysis of variance. The data used in this study was obtained from a genetic breeding program on the cooking time of segregating populations. The following... Tipo: Info:eu-repo/semantics/article Palavras-chave: Analysis of variance; Homogeneity of variance; Normality of errors; Crop breeding; Generalized linear mixed models. Ano: 2020 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902020000100415 Registros recuperados: 14 Primeira ... 1 ... Última

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