Judul: Kelayakan Pengusahaan Buah Tin (Ficus carica) Kebun Jogja Ara Garden di Yogyakarta.
Abstrak: Tin merupakan tanaman asal Mediterania yang saat ini mulai diusahakan di Indonesia. Salah satunya berada di Jogja Ara Garden, Provinsi Yogyakarta. Tujuan dari penelitian ini adalah menganalisis kelayakan pengusahaan tin Jogja Ara Garden berdasarkan aspek nonfinansial, aspek finansial, tingkat sensitivitas, dan switching value. Analisis kelayakan pengusahaan tin terdiri atas tiga skenario, yaitu skenario I (pembibitan), skenario II (produksi buah), dan skenario III (pembibitan dan produksi buah). Berdasarkan aspek nonfinansial (aspek pasar, aspek teknis, aspek manajemen dan hukum, aspek sosial, ekonomi, dan budaya, serta aspek lingkungan) dan aspek finansial (NPV, Net B/C, IRR, dan payback period) bahwa usaha tin Jogja Ara Garden layak untuk dijalankan. Tingkat sensitivitas usaha dilihat berdasarkan penurunan produksi tin dan peningkatan harga pupuk NPK mutiara.
Keyword: nonfinansial, finansial, sensitivitas, switching value

Judul: Analisis Kelayakan Usaha Jaboticaba (Myrciaria cauliflora) di Kecamatan Lembang, Jawa Barat
Abstrak: Indonesia has a high diversity of fruits. The original fruits can be come from Indonesia or from other countries. Jaboticaba is one of the fruit plants from the other country that can be growth in Indonesia. Jaboticaba farm at Lembang, West Java is the biggest Jaboticaba farm in Indonesia. This research will analyze the business if the farm is reliable. The analyze aspects are financial analyze and non financial analyze. The financial analylze shown that earn after tax is Rp.5.494.373.101, NPV Rp.120.580.103, IRR 6,641% (discount rate is 6%), Net B/C 1,07 and PP is 19 years. The non-financial analyze shown the farm are reliable included market aspect, technical aspect, management aspect, social and environment aspect. The conclusion after the writer took observation that Jaboticaba Cherry Brazil farm is reliable to agribusiness.
Keyword: PP, Net B/C, IRR, NPV, financial aspect, non-financial aspect, Jaboticaba

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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