Judul: Analisis Keuntungan Usahaternak Sapi Perah (Kasus di Kelurahan Kebon Pedes, Kota Bogor
Abstrak: Indonesia’s milk production in 2012 equal 959.732 litre. Most of dairy cattle farmers in Indonesia run their business in small and medium scale. Productivity of dairy milk is closely related to the location of the farm. One of the location dairy farm in Bogor city is in Kebon Pedes sub-district. Dairy farm activities in Kebon Pedes sub-district been going on for decades. This area has an average temperature of 36o – 40o C and the unavailability of land as source of green feed making dairy milk productivity is not good. The results of this research showed milk productivity average by 10,51 litres per day. Cost of concentrate feed contributed the highest percentage of the total costs that equals to 49,33% of the total cost. Profit of dairy farm average by Rp.2.296,30 per litre and R/C ratio obtained 1,39. Feed cost factor and health cost factor significantly affect profitability of dairy farm business.
Keyword: profitability, dairy farm, dairy milk

Judul: Faktor-faktor pendukung dan penghambat pengembangan usaha ternak sapi perah (studi kasus di Kelurahan Kebon Pedes Kecamatan tanah Sareal Kota Bogor)
Abstrak: Dairy farms have a high opportunity to be developed, but the farmers faced constraint those can be threat the sustainability of the dairy farms. During 1999- 2003, the average milk consumption per capita in Indonesia increased as much as 1.05% per year. A case study was carried out to understand the supporting and constraint factors for dairy farms development in Kebon Pedes, Bogor during May to June 2005. Thirty farmers by census and 30 people live around the farm by purposive were used as sample. Descriptive analysis, financial and milk demand forecast were used to analyze data. The farmer's average income per year was Rp 30,465,334.16 and R/C ratio was 1.93. It indicated that the dairy farm in Kebon Pedes was feasible. The supporting factors for dairy farm's development in Kebon Pedes were farmer knowledge, milk price, financial, institution, dairy cattle populatio~i and demand of milk in Bogor, which increase every year. The constraint factors are climate, land, and the environment pollution.
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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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