Judul: Analisis Pendapatan Usahatani Sayuran Organik pada Yayasan Bina Sarana Bakti Kecamatan Cisarua Kabupaten Bogor
Abstrak: The high demand of organic vegetables and government’s program concerned in ‘Go Organic’ is an opportunity for the producers to develop organic vegetables in Indonesia, whereas Yayasan Bina Sarana Bakti (YBSB) is one of them. Until present, YBSB is not able to fulfill the consumer’s demand of certain organic vegetables, such as carrot, green spinach, caisin, cos lettuce, and broccoli; therefore YBSB plan to increase its bussiness scale to increase the production. YBSB has not been able to calculate the income levels of those vegetables, which is needed to analyze whether the bussiness is feasible to increase or not. Hence the purpose of this research is to analyze the feasibility of YBSB’s plan to increase its bussiness scale through farm income and R-C ratio analysis. The results of this research concluded that the plan to increase the bussiness scale of carrot, green spinach, and cos lettuce is feasible to run because they are profitable, meanwhile YBSB has to consider the plan to increase the bussiness scale of caisin and broccoli because they are less profitable.
Keyword: organic vegetables, Farm income

Judul: Analisis Pendapatan Usahatani Wortel Organik dan Anorganik di Kecamatan Cisarua, Kabupaten Bogor, Jawa Barat
Abstrak: Dewasa ini masyarakat semakin peduli terhadap kemananan dan kesehatan pangan serta bahaya yang ditimbulkan oleh penggunaan obat-obatan kimia dalam pertanian. Kini masyarakat mulai beralih kepada gaya hidup sehat atau “back to nature” yang mengutamakan pangan sehat tanpa kandungan obat-obatan yang dapat diperoleh dari produk pertanian organik. Preferensi konsumen yang seperti ini menyebabkan peningkatan permintaan terhadap produk organik. Salah satu sayuran yang dapat dikembangkan menggunakan sistem pertanian organik adalah wortel. Penelitian ini bertujuan untuk mengetahui tingkat produktivitas, pendapatan, serta tingkat efisiensi pada usahatani wortel organik dan anorganik di Kecamatan Cisarua. Hasil penelitian menunjukkan bahwa wortel organik memiliki tingkat produktivitas yang lebih rendah dibandingkan wortel anorganik. Pendapatan atas biaya tunai dan biaya total petani wortel organik lebih besar daripada petani wortel anorganik. Nilai R/C pada kedua usahatani ini memiliki nilai yang kurang dari satu yang menunjukkan kedua usahatani belum berjalan secara efisien.
Keyword: organic farm, productivity, R/C, revenue

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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