Judul: Income Analysis and Factors Influencing Sugar Cane Farmers Decisions to Participate in the Candi Smart Farming Program (Case Study: Candi Baru Sugar Factory, Sidoarjo Regency)
Abstrak: Pabrik Gula Candi Baru menciptakan program candi smart farming sebagai usaha menghadapi produktivitas tebu yang menurun di Kabupaten Sidoarjo, dengan memanfaatkan drone dan aplikasi smartphone. Namun, program candi smart farming belum berjalan secara optimal karena keterbatasan kemampuan teknologi dan jumlah anggota yang masih sedikit. Tujuan penelitian ini adalah: (1) Mengetahui persepsi petani tebu terhadap program candi smart farming di Kabupaten Sidoarjo, Jawa Timur; (2) Membandingkan pendapatan antara petani tebu yang mengikuti program candi smart farming dengan yang tidak mengikuti program candi smart farming; (3) Menganalisis faktor-faktor yang memengaruhi keputusan petani tebu untuk mengikuti program candi smart farming. Metode analisis yang digunakan adalah analisis skala likert, analisis R/C ratio, dan analisis regresi logistik biner. Hasil penelitian menunjukkan bahwa persepsi petani smart farming terkait alasan mengikuti program candi smart farming karena adanya akses peminjaman modal, sedangkan persepsi petani non smart farming terkait alasan tidak mengikuti program karena tidak mengetahui fitur-fitur layanan yang ditawarkan oleh program secara detail. Nilai R/C ratio atas biaya tunai dan biaya total pada petani smart farming lebih tinggi dibandingkan dengan petani non smart farming. Faktor-faktor yang berpengaruh signifikan terhadap keputusan petani tebu untuk mengikuti program candi smart farming adalah lama pendidikan petani dan lama pengalaman usahatani tebu., Candi Baru Sugar Factory created a candi smart farming program as an effort to deal with declining sugarcane productivity in Sidoarjo Regency, by utilizing drones and smartphone applications. However, the program has not run optimally due to limited technological capabilities and and few members. The objectives of this study were: (1) to determine the perception of sugarcane farmers towards the candi smart farming program; (2) Comparing the income between smart farmers and non-smart farmers; (3) Analyzing the factors that influence sugarcane farmers' decisions to participate in the candi smart farming program. The analytical methods used are Likert scale, R/C ratio analysis, and binary logistic regression. The results showed that the perception of smart farmers regarding the reason for participating in the program was due to access to loan capital, while non-smart farmers did not participate in the program because they did not know the features of the services offered by the program in detail. The value of the R/C ratio for smart farmers is higher than for non-smart farmers. The factors that significantly influence the sugarcane farmer's decision to participate in the candi smart farming program are the length of farmer's education and experience in sugarcane farming.
Keyword: adopsi teknologi, bagi hasil tebu, persepsi petani, smart farming

Judul: Analysis of Factors Affecting Production an Income of Sugarcane in East Java Province
Abstrak: Meningkatnya konsumsi gula di Indonesia meningkatkan permintaan gula, sehingga diperlukan peningkatan produksi tebu nasional. Namun produksi tebu setiap tahunnya cenderung menurun sehingga Indonesia masih perlu mengimpor gula, terutama gula mentah. Penelitian ini bertujuan untuk mengetahui faktor-faktor yang memengaruhi produksi dan menganalisis pendapatan petani tebu di Jawa Timur. Penelitian ini menggunakan data 2909 petani pada Sensus Pertanian 2013 Badan Pusat Statistika. Pendapatan usahatani dianalisis dengan R/C yang dibedakan menurut luas lahan arealnya. Faktor-faktor yang memengaruhi produksi tebu dianalisis menggunakan fungsi produksi Cobb Douglass. Hasil penelitian menunjukan bahwa luas lahan, bibit, pupuk unsur N, dan tenaga kerja memengaruhi produksi tebu. Rasio R/C menunjukan bahwa usahatani tebu dengan lahan sempit lebih efisien. Biaya tenaga kerja merupakan biaya terbesar untuk pertanian tebu lahan besar. Hasil penelitian menunjukan bahwa pemberian kredit produksi diperlukan untuk usahatani tebu skala besar., The increasing consumption of sugar in Indonesia increases the demand for sugar, so it is necessary to increase national sugarcane production. However, sugarcane's annual production tends to decline. Therefore Indonesia still needs to import sugar, especially raw sugar. The research aims to determine the factors that affect the production and analyze sugarcane farmers' income in East Java Province. This study used 2909 farmer’s data of Agricultural Census 2013, Central Bureau of Statistics. Farm income was analyzed using R/C analysis, which is differentiated according to its area. The factors affecting sugarcane production were analyzed using the Cobb-Douglas production function. The results showed that area, seeds, nitrogen unsure fertilizer, and labor affected sugar cane production. The R/C ratio indicated that small-size sugarcane farming was more efficient. The cost of hired labor was the highest cost for large-size sugarcane farming. This finding implies that production credit provision is needed for extensive sugarcane farming.
Keyword: agriculture, cost structure, land area, sugar cane

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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