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Registros recuperados: 69 | |
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COSTA, J. A. da; AZEVEDO, C. F.; NASCIMENTO, M.; SILVA, F. F. e; RESENDE, M. D. V. de; NASCIMENTO, A. C. C.. |
multicollinearity and high dimensionality problems, making it impossible to obtain stable estimates through the traditional method of estimation based on ordinary least squares. To overcome such challenges, dimensionality reduction methods have been proposed, because of their simple theory and easy application. We compared three dimensionality reduction methods: Principal Components Regression (PCR), Partial Least Squares (PLS), and Independent Components Regression (ICR). An important step for dimensionality reduction and prediction is selecting the number of components, as it affects the linear combinations of the explanatory variables. The linear combinations are inserted into the model to predict the response based on a reduced number of parameters. We... |
Tipo: Artigo de periódico |
Palavras-chave: Regression analysis; Genomics. |
Ano: 2021 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1139234 |
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Galeano-Vasco,Luis Fernando; Cerón-Muñoz,Mario Fernando; Narváez-Solarte,William. |
In this study, the Von Bertalanffy, Richards, Gompertz, Brody, and Logistics non-linear mixed regression models were compared for their ability to estimate the growth curve in commercial laying hens. Data were obtained from 100 Lohmann LSL layers. The animals were identified and then weighed weekly from day 20 after hatch until they were 553 days of age. All the nonlinear models used were transformed into mixed models by the inclusion of random parameters. Accuracy of the models was determined by the Akaike and Bayesian information criteria (AIC and BIC, respectively), and the correlation values. According to AIC, BIC, and correlation values, the best fit for modeling the growth curve of the birds was obtained with Gompertz, followed by Richards, and then... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chickens; Mathematical models; Poultry; Regression analysis; Weight gain. |
Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982014001100573 |
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Berck, Peter. |
This paper tests the hypothesis that the net of extraction cost price of a natural resource does not change with volume. The hypothesis is shown to he a consequence of Hotelling’s theory. The tests are performed on equations estimated by a nonparametric regression (ACE), and we show that the usual least squares estimation techniques are not general enough to successfully perform the test. The test rejects the pure form of the Hotelling theory and shows that it is necessary to adjust sale prices for volume sold. |
Tipo: Working or Discussion Paper |
Palavras-chave: Natural resources; Prices; Regression analysis. |
Ano: 1988 |
URL: http://purl.umn.edu/43665 |
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AKIN,Ahmet Cumhur; CEVGER,Yavuz. |
Abstract White cheese, kashar cheese, yogurt, and ayran are among the most common products produced by the dairy industry in Turkey. The present study determined the production cost of 1 kg of these packaged products as well as the financial implications on their distribution and the total cost. The study also estimated the cost factors affecting the profitability of the products by identifying the cost differences between production regions and scales, using a mean regression model for each product. The study used the data collected through a survey involving 15 dairy plants of three different sizes located in five different regions and involved in raw milk production. The study found a 2-year average capacity utilization rate of the businesses to be... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dairy industry; Economic; Cost; Husbandry; Regression analysis. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612019000300781 |
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Gao, Wen; Luo, Min. |
By selecting the data from 1989 to 2009 in China, we conduct regression analysis on the total out value of agriculture, the usage amount of chemical fertilizer, total power of agricultural machinery, effective irrigation area, and the damage area. The results show that the usage amount of chemical fertilizer and the damage area, the great obstacle to the construction of resource-saving and environment-friendly agriculture, have significant impact on the output value of agriculture; total power of agricultural machinery and effective irrigation area have insignificant impact on the output value of agriculture. Based on these, the suggestions for promoting the development of resource-saving and environment-friendly agriculture are put forward as follows:... |
Tipo: Article |
Palavras-chave: Resource-saving and environment-friendly agriculture; Influencing factors; Regression analysis; China; Agribusiness. |
Ano: 2011 |
URL: http://purl.umn.edu/119687 |
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Nunes, Luís; Monteiro, Maria do Loreto; Patrício, Maria do Sameiro; Alpuim, Teresa; Martins, Lucílio. |
Growing sweet chestnut (Castanea sativa) in high forest stands is a lucrative investment. Wood with medium and large dimensions can attain interesting profitability levels. Furthermore, forest producers are interested of new on this species and decision criteria for the best management are needed for landowners. So, accuracy is very important when evaluating volume in standing trees. Based on regression theory, it is developed predicting equations of wood volume as a function of tree variables easily measured (fast and cheap), such as diameter at breast height (DBH) and tree total height (h). Variable selection in volume equations was based on a stepwise modified procedure (linear models) and using generalized-F tests (nonlinear models). The resulting... |
Tipo: Article |
Palavras-chave: Castanea sativa Mill; High forest; Regression analysis; Volume equations. |
Ano: 2005 |
URL: http://hdl.handle.net/10198/2845 |
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Ilayperuma,I. |
Cranial capacity exerts a close correlation with the volume of the brain. A large body of evidence shows a clear racial variation in cranial dimensions. Therefore detailed knowledge of the population specific data on biometric features of the cranial cavity is important in the study and comparison of the crania of populations from different racial backgrounds, assessing growth and development of an individual and in the diagnosis of any abnormalities of cranial size and shape. Despite its significance, little is known concerning the cranial capacity in Sri Lankans. Hence, the present study was undertaken to establish the cranial capacity in an adult Sri Lankan population. A total of 210 subjects with an age span of 20-23 years were included in the study.... |
Tipo: Journal article |
Palavras-chave: Cranial capacity; Linear dimensions; Regression analysis; Sri Lanka. |
Ano: 2011 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022011000200029 |
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Silva,Édipo Menezes da; Tadeu,Maraísa Hellen; Silva,Victor Ferreira da; Pio,Rafael; Fernandes,Tales Jesus; Muniz,Joel Augusto. |
Abstract Blackberry is a small fruit with several properties beneficial to human health and its cultivation is an alternative for small producers due to its fast and high financial return. Studying the growth of fruits over time is extremely important to understand their development, helping in the most appropriate crop management, avoiding post-harvest losses, which is one of the aggravating factors of blackberry cultivation, being a short shelf life fruit. Thus, growth curves are highlighted in this type of study and modeling through statistical models helps understanding how such growth occurs. Data from this study were obtained from an experiment conducted at the Federal University of Lavras in 2015. The aim of this study was to adjust nonlinear,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Regression analysis; Model Selection; Fit quality; Sigmoid; Small fruits; Fruit development. |
Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452020000200701 |
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YENICE,HAYATI. |
Abstract: Drillability is influenced by many factors, including machine parameters and rock properties. The main machine parameters for drilling include rotational speed, thrust force, torque and flush pressure. The specific rock characteristics that affect penetration rate comprise uniaxial compressive strength (UCS), tensile strength, Young’s modulus, hardness and brittleness. In this study, drilling rate index (DRI) is attempted to predict based on UCS and Brazilian tensile strength (BTS) of rocks. Simple and multiple regression analyses have been carried out to determine the best measure of the relation between DRI and two geomechanical properties. The DRI value is strongly related to the uniaxial compressive strength and indirect tensile strength.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Drillability; Uniaxial compressive strength; Tensile strength; Regression analysis. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652019000500906 |
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Soto,Alonso; Solari,Lely; Agapito,Juan; Acuna-Villaorduna,Carlos; Lambert,Marie-Laurence; Gotuzzo,Eduardo; Stuyft,Patrick Van der. |
This study developed a clinical score based on clinical and radiographic data for the diagnosis of smear-negative pulmonary tuberculosis (SNPT). SNPT was defined as a positive culture in Ogawa in a patient with two negative sputum smears. Data from patients admitted to the emergency ward with respiratory symptoms and negative acid-fast bacilli (AFB) smears was analyzed by means of logistic regression to develop the predictive score.Two hundred and sixty two patients were included. Twenty patients had SNPT. The variables included in the final model were hemoptysis, weight loss, age > 45 years old, productive cough, upper-lobe infiltrate, and miliary infiltrate. With those, a score was constructed. The score values ranged from -2 to 6. The area under the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Tuberculosis; Pulmonary; Regression analysis; Scoring methods. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702008000200006 |
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Duarte,Karina Ferreira; Junqueira,Otto Mack; Filardi,Rosemeire da Silva; Siqueira,Jefferson Costa de; Puzotti,Maíra Mangili; Garcia,Edivaldo Antônio; Molino,Andrea de Britto; Laurentiz,Antonio Carlos de. |
The objective of this experiment was to establish different criteria to evaluate the requirements of digestible tryptophan for broilers from 22 to 42 d of age, using different regression models (quadratic, exponential and Linear Response Plateau) and in case of statistical significance the comparison of means by Duncan test at 5% probability was also adopted. A total of 1,920 Cobb 500 male broilers were distributed in a completely randomized experimental design, with 6 treatments (6 digestible tryptophan levels: 0.1395, 0.1610, 0.1825, 0.2040, 0.2255 and 0.2470%) and 8 replications containing 40 broilers each. Performance and carcass characteristics were evaluated. The level of 0.2255% of digestible tryptophan numerically improves feed conversion, and the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Digestible amino acids; Ideal protein; Performance; Regression analysis. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982013001000006 |
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Registros recuperados: 69 | |
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