Penggunaan Analisis Regresi Terboboti dalam Penyusunan Model Pertumbuhan Peninggi Acacia mangium Willd.

The compilation of growth stand model usually uses the regression analysis. Homoscedasticity or residual kind homogeneity is one assumption which underlying the use of this regression analysis.  Breaking this assumption causes the low of model accuracy which is shown by the low of determination coef...

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Main Authors: M Muhdin, Endang Suhendang
Format: Article
Language:English
Published: Bogor Agricultural University 2011-05-01
Series:Jurnal Manajemen Hutan Tropika
Subjects:
Online Access:https://journal.ipb.ac.id/index.php/jmht/article/view/3233
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author M Muhdin
Endang Suhendang
author_facet M Muhdin
Endang Suhendang
author_sort M Muhdin
collection DOAJ
description The compilation of growth stand model usually uses the regression analysis. Homoscedasticity or residual kind homogeneity is one assumption which underlying the use of this regression analysis.  Breaking this assumption causes the low of model accuracy which is shown by the low of determination coefficient and the height of error standard. The problem of heteroscedasticity can be solved by using weighted regression analysis.The Selected Raiser Growth Model equation in this research was transformed into a model equation: ln P = a + b/A, where there was a significant correlation between the growth and the age (R2  = 55.04%, sb0 = 0.041, and sb1 = 0.171).  From the use of weighted regression analysis with weightier wi = 1/”Xi, it can be concluded that there was no real correlation between the growth and the age (R2 = 0.55%, sb0 = 0.572, and sb1 = 2.560).  The use of weightier shows much lower accuracy than without weightier.  However, from the use of weighted regression analysis with weightier: wi = 1/si2, where si2 = residual kinds at free variable group to I (X1) shows that there was significant correlation between the growth and the age (R2 = 45.46%; sb0 = 0.084, and sb1 = 0.205).  There fore it can be said that the accuracy was much better than regression without weightier.  Furthermore,  the use of weighted regression analysis with weightier wi = 1/si2, where  si2 is residual kind at free variable to i (X) which is estimated through second orde polynomial regression model shows a very significant correlation between the growth and the age (where R2 = 87.22%, sb0 = 0.029, and sb1 = 0.072). The last result shows a better accuracy than the preceding treatments.  From this research, it can be concluded that by using a suitable weightier, the use of weighted regression analysis in compiling raiser growth model can improve the model accuracy.
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spelling doaj.art-5c53263402294c648aac7631a60c99132022-12-22T02:35:19ZengBogor Agricultural UniversityJurnal Manajemen Hutan Tropika2087-04692089-20632011-05-011512970Penggunaan Analisis Regresi Terboboti dalam Penyusunan Model Pertumbuhan Peninggi Acacia mangium Willd.M MuhdinEndang SuhendangThe compilation of growth stand model usually uses the regression analysis. Homoscedasticity or residual kind homogeneity is one assumption which underlying the use of this regression analysis.  Breaking this assumption causes the low of model accuracy which is shown by the low of determination coefficient and the height of error standard. The problem of heteroscedasticity can be solved by using weighted regression analysis.The Selected Raiser Growth Model equation in this research was transformed into a model equation: ln P = a + b/A, where there was a significant correlation between the growth and the age (R2  = 55.04%, sb0 = 0.041, and sb1 = 0.171).  From the use of weighted regression analysis with weightier wi = 1/”Xi, it can be concluded that there was no real correlation between the growth and the age (R2 = 0.55%, sb0 = 0.572, and sb1 = 2.560).  The use of weightier shows much lower accuracy than without weightier.  However, from the use of weighted regression analysis with weightier: wi = 1/si2, where si2 = residual kinds at free variable group to I (X1) shows that there was significant correlation between the growth and the age (R2 = 45.46%; sb0 = 0.084, and sb1 = 0.205).  There fore it can be said that the accuracy was much better than regression without weightier.  Furthermore,  the use of weighted regression analysis with weightier wi = 1/si2, where  si2 is residual kind at free variable to i (X) which is estimated through second orde polynomial regression model shows a very significant correlation between the growth and the age (where R2 = 87.22%, sb0 = 0.029, and sb1 = 0.072). The last result shows a better accuracy than the preceding treatments.  From this research, it can be concluded that by using a suitable weightier, the use of weighted regression analysis in compiling raiser growth model can improve the model accuracy. https://journal.ipb.ac.id/index.php/jmht/article/view/3233growth modelweighted regressionacacia mangiumregression analysis
spellingShingle M Muhdin
Endang Suhendang
Penggunaan Analisis Regresi Terboboti dalam Penyusunan Model Pertumbuhan Peninggi Acacia mangium Willd.
Jurnal Manajemen Hutan Tropika
growth model
weighted regression
acacia mangium
regression analysis
title Penggunaan Analisis Regresi Terboboti dalam Penyusunan Model Pertumbuhan Peninggi Acacia mangium Willd.
title_full Penggunaan Analisis Regresi Terboboti dalam Penyusunan Model Pertumbuhan Peninggi Acacia mangium Willd.
title_fullStr Penggunaan Analisis Regresi Terboboti dalam Penyusunan Model Pertumbuhan Peninggi Acacia mangium Willd.
title_full_unstemmed Penggunaan Analisis Regresi Terboboti dalam Penyusunan Model Pertumbuhan Peninggi Acacia mangium Willd.
title_short Penggunaan Analisis Regresi Terboboti dalam Penyusunan Model Pertumbuhan Peninggi Acacia mangium Willd.
title_sort penggunaan analisis regresi terboboti dalam penyusunan model pertumbuhan peninggi acacia mangium willd
topic growth model
weighted regression
acacia mangium
regression analysis
url https://journal.ipb.ac.id/index.php/jmht/article/view/3233
work_keys_str_mv AT mmuhdin penggunaananalisisregresiterbobotidalampenyusunanmodelpertumbuhanpeninggiacaciamangiumwilld
AT endangsuhendang penggunaananalisisregresiterbobotidalampenyusunanmodelpertumbuhanpeninggiacaciamangiumwilld