Modelling a system of nonlinear additive crown width models applying seemingly unrelated regression for Prince Rupprecht larch in northern China

2017 ◽  
Vol 386 ◽  
pp. 71-80 ◽  
Author(s):  
Liyong Fu ◽  
Ram P. Sharma ◽  
Guangxing Wang ◽  
Shouzheng Tang
Keyword(s):  
Northern China ◽  
Seemingly Unrelated Regression ◽  
Crown Width ◽  
Unrelated Regression

scholarly journals Generic Additive Allometric Models and Biomass Allocation for Two Natural Oak Species in Northeastern China

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 715
Author(s):  
Shengwang Meng ◽  
Fan Yang ◽  
Sheng Hu ◽  
Haibin Wang ◽  
Huimin Wang
Keyword(s):  
Biomass Allocation ◽  
Tree Height ◽  
Northeastern China ◽  
Seemingly Unrelated Regression ◽  
Biomass Estimation ◽  
Model Parameters ◽  
Stem Biomass ◽  
Crown Width ◽  
Biomass Models ◽  
Mongolian Oak

Current models for oak species could not accurately estimate biomass in northeastern China, since they are usually restricted to Mongolian oak (Quercus mongolica Fisch. ex Ledeb.) on local sites, and specifically, no biomass models are available for Liaodong oak (Quercuswutaishanica Mayr). The goal of this study was, therefore, to develop generic biomass models for both oak species on a large scale and evaluate the biomass allocation patterns within tree components. A total of 159 sample trees consisting of 120 Mongolian oak and 39 Liaodong oak were harvested and measured for wood (inside bark), bark, branch and foliage biomass. To account for the belowground biomass, 53 root systems were excavated following the aboveground harvest. The share of biomass allocated to different components was assessed by calculating the ratios. An aboveground additive system of biomass models and belowground equations were fitted based on predictors considering diameter (D), tree height (H), crown width (CW) and crown length (CL). Model parameters were estimated by jointly fitting the total and the components’ equations using the weighted nonlinear seemingly unrelated regression method. A leave-one-out cross-validation procedure was used to evaluate the predictive ability. The results revealed that stem biomass accounts for about two-thirds of the aboveground biomass. The ratio of wood biomass holds constant and that of branches increases with increasing D, H, CW and CL, while a reverse trend was found for bark and foliage. The root-to-shoot ratio nonlinearly decreased with D, ranging from 1.06 to 0.11. Tree diameter proved to be a good predictor, especially for root biomass. Tree height is more prominent than crown size for improving stem biomass models, yet it puts negative effects on crown biomass models with non-significant coefficients. Crown width could help improve the fitting results of the branch and foliage biomass models. We conclude that the selected generic biomass models for Mongolian oak and Liaodong oak will vigorously promote the accuracy of biomass estimation.

A Note on the Efficiency of Seemingly Unrelated Regression

1988 ◽  
Vol 42 (2) ◽  
pp. 137-139 ◽  
Author(s):  
James K. Binkley ◽  
Carl H. Nelson
Keyword(s):  
Seemingly Unrelated Regression ◽  
Unrelated Regression

Workplace disability and job satisfaction in Britain: A co-worker test?

2021 ◽  
pp. 0143831X2110142
Author(s):  
Getinet Astatike Haile
Keyword(s):  
Job Satisfaction ◽  
Negative Relationship ◽  
Organisational Culture ◽  
Seemingly Unrelated Regression ◽  
Unrelated Regression ◽  
Significant Negative Relationship ◽  
Using Data

The article examines the link between workplace disability (WD) and workplace job satisfaction (JS) using data from WERS2011. Controlling for a rich set of workplace characteristics including organisational culture, the study finds a significant negative relationship between JS and the share of disabled respondents within workplaces. Notably, Seemingly Unrelated Regression (SUR)-based analysis distinguishing between disabled and non-disabled respondents reveals that the negative relationship found is specific to non-disabled respondents. Moreover, disability equality policies are found to be significantly positively related with disabled respondents’ JS while they are negatively related with the JS of their non-disabled counterparts. The article ponders if there is a co-worker aspect to the WD–JS link and whether HR policies may need to take heed of co-worker dynamics in this respect.

Determinan Kelaparan di Indonesia Tahun 2015-2019

2021 ◽  
Vol 2021 (1) ◽  
pp. 547-556
Author(s):  
Daniel M V Mone ◽  
Efri Diah Utami
Keyword(s):  
Sustainable Development ◽  
Sustainable Development Goals ◽  
Fixed Effect Model ◽  
Fixed Effect ◽  
Seemingly Unrelated Regression ◽  
Unrelated Regression ◽  
Effect Model ◽  
Development Goals

Sustainable Development Goals (SDGs) adalah sebuah perencana aksi berskala global yang disepakati oleh para pemimpin dunia, termasuk Indonesia dengan tujuan mendorong pembangunan sosial, ekonomi dan lingkungan hidup. Salah satu dari 17 tujuan SDGs adalah mengakhiri kelaparan. Berdasarkan data yang dirilis Badan Pusat Statistik, salah satu pendekatan untuk mengukur tingkat kelaparan adalah proporsi penduduk dengan asupan kalori minimum di bawah 1400 kkal/kapita/hari.  Proporsi penduduk dengan asupan kalori minimum di bawah 1400 kkal/kapita/hari di Indonesia masih cukup tinggi dan terus mengalami peningkatan dari tahun 2017 hingga 2019. Penelitian ini bertujuan untuk menganalisis bagaimana gambaran umum dari tingkat kelaparan dan variabel-variabel yang diduga mempengaruhinya, serta  bagaimana pengaruh variabel-variabel tersebut terhadap tingkat kelaparan di Indonesia tahun 2015-2019. Hasil dari penelitian ini dapat digunakan untuk merumuskan kebijakan-kebijakan guna penuntasan kelaparan di Indonesia. Metode analisis yang digunakan adalah regresi data panel dengan menggunakan  fixed effect model yang diestimasi dengan metode Seemingly Unrelated Regression (SUR). Hasil dari penelitian ini menunjukkan bahwa variabel yang berpengaruh signifikan terhadap tingkat kelaparan adalah pengeluaran makanan dan harga beras, sedangkan jumlah penduduk miskin dan pendapatan perkapita tidak berpengaruh signifikan.

scholarly journals Robust Bayesian seemingly unrelated regression model

2018 ◽  
Vol 34 (3) ◽  
pp. 1135-1157
Author(s):  
Chamberlain Mbah ◽  
Kris Peremans ◽  
Stefan Van Aelst ◽  
Dries F. Benoit
Keyword(s):  
Regression Model ◽  
Seemingly Unrelated Regression ◽  
Unrelated Regression ◽  
Seemingly Unrelated Regression Model

Additive crown width models comprising nonlinear simultaneous equations for Prince Rupprecht larch (Larix principis-rupprechtii) in northern China

Trees ◽  
2017 ◽  
Vol 31 (6) ◽  
pp. 1959-1971 ◽  
Author(s):  
Liyong Fu ◽  
Wei Xiang ◽  
Guangxing Wang ◽  
Kaijie Hao ◽  
Shouzheng Tang
Keyword(s):  
Northern China ◽  
Simultaneous Equations ◽  
Crown Width ◽  
Nonlinear Simultaneous Equations

scholarly journals ELASTISITAS HARGA TERHADAP PENAWARAN OUTPUT DAN PERMINTAAN INPUT USAHATANI JAGUNG DI KABUPATEN GROBOGAN, JAWA TENGAH

2020 ◽  
Vol 22 (2) ◽  
pp. 213
Author(s):  
Dewi Sahara ◽  
Tota Suhendrata
Keyword(s):  
Seemingly Unrelated Regression ◽  
Unrelated Regression

Permintaan jagung cenderung meningkat, namun harganya juga relatif berfluktuasi. Penelitian ini bertujuan untuk mengetahui pengaruh perubahan harga output dan harga input terhadap penawaran jagung dan permintaan input produksi. Kegiatan dilaksanakan pada bulan September – Nopember 2016 dengan metode survey terhadap 30 petani jagung di Desa Boloh, Kecamatan Toroh, Kabupaten Grobogan.  Data yang dikumpulkan meliputi data karakteristik rumah tangga, jumlah dan harga input, jumlah dan harga jagung. Data dianalisis dalam bentuk pangsa biaya menggunakan metode <em>Seemingly Unrelated Regression</em> (SUR). Hasil penelitian menunjukkan bahwa penawaran output terhadap harga sendiri bersifat elastis dengan tanda positif, sedangkan terhadap harga input bertanda negatif dan bersifat inelastis, kecuali terhadap permintaan pupuk Urea.  Elastisitas permintaan input terhadap harga sendiri bertanda negatif dan inelastis kecuali terhadap permintaan pupuk Urea dan tenaga kerja bersifat elastis, sedangkan terhadap harga input lainnya besaran dan tandanya bervariasi.  Luas areal tanam bersifat inelastis terhadap permintaan input produksi. Demikian pula dengan pendidikan dan pengalaman usahatani bersifat inelastis kecuali terhadap permintaan tenaga kerja bersifat elastis. Oleh karena itu untuk meningkatkan produksi jagung dapat dilakukan dengan meningkatkan harga jagung, memperluas areal tanam dan meningkatkan kapabilitas sumberdaya petani.

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