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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Estudo da forma do fuste de ?rvores de eucaliptos em diferentes espa?amentos / Study of stem form of Eucalyptus sp. trees in different planting densities

Souza, Rafael Ribeiro 09 August 2013 (has links)
Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-01-07T11:19:58Z No. of bitstreams: 2 rafael_ribeiro_souza.pdf: 2710502 bytes, checksum: 2b3967310df95d3b8ec1f8cbff51c07b (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-01-07T11:20:20Z (GMT) No. of bitstreams: 2 rafael_ribeiro_souza.pdf: 2710502 bytes, checksum: 2b3967310df95d3b8ec1f8cbff51c07b (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-01-07T11:20:38Z (GMT) No. of bitstreams: 2 rafael_ribeiro_souza.pdf: 2710502 bytes, checksum: 2b3967310df95d3b8ec1f8cbff51c07b (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Made available in DSpace on 2015-01-07T11:20:39Z (GMT). No. of bitstreams: 2 rafael_ribeiro_souza.pdf: 2710502 bytes, checksum: 2b3967310df95d3b8ec1f8cbff51c07b (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 2013 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Os objetivos deste estudo foram: avaliar o efeito do arranjo espacial de plantio na forma do fuste de ?rvores de eucalipto; avaliar se as redes neurais artificiais estimam com precis?o o afilamento, os di?metros ao a qualquer altura especificada e as alturas a qualquer di?metro especificado em fustes de eucalipto; estudar a forma dos fustes em arvores de eucalipto em diferentes arranjos espaciais e idades, e de maneira espec?fica, determinar as formas geom?tricas aproximadas, que ocorrem ao longo destes fustes e as suas propor??es em rela??o ? altura total. Foram utilizados dados de um experimento implantado em dezembro de 2002, no delineamento em blocos (tr?s blocos), sendo testados os arranjos espaciais de 3,0 x 0,5; 3,0 x 1,0; 3,0 x 1,5; 3,0 x 2,0 e 3,0 x 3,0 m. Foram utilizados tamb?m, dados de ?rvores provenientes de um sistema agroflorestal-SAF, plantio com 6,03 hectares, implantado em dezembro de 1993, no arranjo espacial de 10,0 x 4,0 m. Para analisar a forma m?dia dos fustes foram utilizados modelos de Kozak, Sch?epfer, Garay, Demaerschalk e Ormerod. Os modelos selecionados foram de Garay e de Sh?epfer. A escolha foi feita com base nas estat?sticas, coeficiente de correla??o, erro-padr?o residual, Bias e da an?lise gr?fica dos res?duos. Testes de identidade de modelos foram aplicados nos modelos selecionados com a finalidade de verificar a igualdade entre a forma dos fustes. Foram utilizadas redes neurais artificiais feed-forward, do tipo Multilayer Perceptrons, treinadas por meio do algoritmo error-backpropagation. Para os ajustes das redes foi utilizada uma aplica??o computacional em linguagem Java, e para as fun??es destinadas ao treinamento e aplica??o foi utilizada a biblioteca Weka. As estat?sticas de acur?cia utilizadas para avaliar as melhores redes foram a raiz quadrada do erro m?dio e as correla??es entre os valores observados e os valores estimados. Utilizando a equa??o geral das curvas, buscou-se determinar a forma aproximada do s?lido geom?trico m?dio dos fustes e descrever as formas geom?tricas aproximadas que os fustes assumem ao longo de seu comprimento, determinar os seus pontos aproximados de inflex?o e a propor??o de cada forma em rela??o ? altura total. O modelo de Garay ? o mais indicado para descrever o taper de eucaliptos nos arranjos espaciais avaliados. Foi aceita a hip?tese de nulidade no teste de identidade de modelos n?o linear, indicando a igualdade entre as equa??es nos arranjos de 3,0 x 0,5 e 3,0 x 1,0 m. Para uma dist?ncia de 3,0 metros entre fileiras, quanto maior a dist?ncia entre plantas, mais c?nica ? a forma do fuste. A rede neural artificial estimou com precis?o o afilamento dos fustes, distinguindo as varia??es na forma dos fustes em virtude dos diferentes arranjos espaciais. A rede neural artificial estimou com precis?o os di?metros a qualquer altura especificada. As estimativas das alturas a qualquer di?metro especificado, obtidas pela RNA e pelo modelo de taper de Garay, apresentaram valores de erros percentuais acentuados na base dos fustes, em todos os arranjos espaciais. Os fustes nos arranjos de 3,0 x 0,5 e 3,0 x 3,0 m, apresentaram a forma m?dia de um parabol?ide, j? os fustes no arranjo de 10,0 x 4,0 m, a forma m?dia de um tronco de cone. Os fustes nos arranjos espaciais 3,0 x 0,5 e 3,0 x 3,0 m, assumem as formas de um tronco de neil?ide, um tronco de cone e um parabol?ide, nas propor??es de 10,96; 43,81 e 45,14 %, e de 14,58; 37,76 e 47,66 %, respectivamente. Os fustes referentes ao arranjo espacial 10,0 x 4,0 m, assumem as formas de um tronco de neil?ide e de um tronco de cone, nas propor??es de 20,78 e 79,30 %, respectivamente, em rela??o ? altura total. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2013. / ABSTRACT The objectives of this study were: assess the effect of the planting?s spatial arrangement in the bole form of eucalypt trees; evaluate whether artificial neural networks estimate the tapering with accuracy, the diameters at any specified height and the heights at any specified diameter in eucalypt boles; study the boles? form in eucalypt trees in different spatial arrangements and ages, and in a specific manner, determine the approximate geometric shapes that occur along these boles and their proportions in relation to the total height. There were utilized data from an experiment established in December 2002, in blocks design (three blocks), being tested the spatial arrangements of 3,0 x 0,5; 3,0 x 1,0; 3,0 x 1,5; 3,0 x 2,0 and 3,0 x 3,0 m. There were also used, tree data from an agroforestry system-AFS, with 6,03 hectares of planting, established in December 1993, with spatial arrangement of 10,0 x 4,0 m. To analyze the average forms of the boles, there were used Kozak, Sch?epfer, Garay, Demaerschalk and Ormerod models. The selected models were Garay and Sh?epfer. The selection was made based on the statistics, correlation coefficient, residual standard error, Bias and graphical analysis of the residuals. Models identity tests were applied on the selected models in order to verify the equivalence between the shape of the boles. There were used feed-forward artificial neural networks, Multilayer Perceptron type, trained by the error-backpropagation algorithm. To adjust the networks it was utilized a computational application in Java language, and for the functions intended for training and application it was used the Weka library. The accuracy statistics used to evaluate the best networks were the root mean square error and the correlations between the observed and estimated values?. Using the general equation of the curves, it aimed to determine the approximate shape of the mean geometric solid for the boles and describe the approximate geometric shapes that the boles assume along their length, determine their approximate inflection points and the proportion of each form in relation to the total height. The Garay model is the most suitable to describe the taper of eucalypts in the evaluated spatial arrangements. It was accepted the null hypothesis in the identity test of nonlinear models, indicating equality between the equations in the arrangements of 3,0 x 0,5 and 3,0 x 1,0 m. For a distance of 3,0 m between the rows, the greater the distance between plants is, more conical shaped is the bole. The artificial neural network estimated with accuracy the tapering of the boles, distinguishing variations in the form of the boles due to the different spatial arrangements. The artificial neural network estimated with accuracy the diameters at any specified height. The estimates heights at any specified diameter, obtained by the ANN and taper model of Garay, presented values of percentage errors accented at the base of the boles, in all spatial arrangements. The boles in the arrangements of 3,0 x 0,5 and 3,0 x 3,0 m, presented the mean form of a paraboloid, while the boles in the arrangement of 10,0 x 4,0 m, the mean form of a conic trunk. The boles in the spatial arrangements 3,0 x 0,5 and 3,0 x 3,0 m, assume the forms of a neiloid trunk, a conic trunk and a paraboloid, in the proportions of 10,96; 43.81 and 45,14 %, and of 14,58; 37,76 and 47,66 %, respectively. The boles for the spatial arrangement of 10,0 x 4,0 m, assume the forms of a neiloid trunk and a conic trunk, in the proportions of 20,78 and 79,30 %, respectively, in relation to the total height.

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