Judul: Evaluasi Kemitraan antara PG Pagottan dengan Petani Tebu di Kabupaten Madiun
Abstrak: Sugar necessary will be increased every year for industry or household necessary. But, the increasing of sugar necessary is not balanced with national production of sugar. One of the alternative to full fill the national sugar needs is business partner. One of the business partner that tied in between Pagottan sugar factory with sugar cane farmer in Madiun regency, East Java. A method of analysis data on this research using farm income analysis, R/C analysis and t-test analysis. Sugar cane farm income analysis showed that revenue over total cost partner farmers more than non-partner farmers. According to R/C ratio showed that with business partner, sugar cane farmer can get profits than farmer non business partner. Whereas, based on the result of t-test show that revenue over total costs per hectare have a significant difference between farmer in business partner and non business partner.
Keyword: t-test, sugarcane, R/C ratio, farm income analysis, business partner

Judul: The Influence of Land Size and Performance of Partnership Assistance on Sugarcane Farming Income (Case Study of PG Jatitujuh Partner Farmers).
Abstrak: Pabrik Gula Jatitujuh menjalin kemitraan dengan petani di Desa Sumber Kulon. Petani mengelola lahan dengan berbagai luasan. Adanya ketentuan dan pendampingan kemitraan menyebabkan perbedaan pendapatan pada pendapatan petani tebu. Oleh karena itu, penelitian ini bertujuan untuk menganalisis pengaruh luas lahan dan kinerja pendampingan kemitraan terhadap pendapatan. Data yang digunakan adalah data sekunder tahun 2022. Metode analisis yang digunakan yaitu analisis pendapatan, uji anova, analisis regresi linear berganda, analisis standar deviasi, dan koefisien variasi. Hasil penelitian menunjukan bahwa terdapat perbedaan pendapatan pada kelompok luas lahan. Selain itu, kemitraan yang dijalankan oleh PG belum sesuai dengan SOP (Standard Operating Procedure) dari kementrian pertanian., Jatitujuh Sugar Factory has established partnerships with farmers in Sumber Kulon Village. Farmers manage lands of various sizes. The existence of partnership provisions and assistance results in differences in income for sugarcane farmers. Therefore, this study aims to analyze the effect of land area and partnership assistance performance on income. The data used are secondary data from 2022. The analysis methods used are income analysis, ANOVA test, multiple linear regression analysis, standard deviation, and coefficient of variation. The results of the study show that there are differences in income among different land area groups. In addition, the partnerships run by the sugar factory are not in accordance with the Standard Operating Procedure (SOP) of the Ministry of Agriculture.
Keyword: anova, Kinerja, pendapatan, regresi berganda, tebu

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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