Judul: Analisis Efisiensi Produksi dan Tingkat Pendapatan Peternak Sapi Perah di Desa Cibodas, Kecamatan Cikajang, Kabupaten Garut
Abstrak: There are two dairy farmer groups in Cibodas area which are also joined theKoperasiPeternakGarut Selatan (KPGS) Cikajang. The dairy farmers are mostly smallholders, thus the dairy farms are still being maintained traditionally. Therefore, to achieve the maximum profit, the farmers should arrange the production factor allocation efficiently. Therefore, it is interesting to see as also analyzed by the writer, the farmers’ characteristics, production efficiency analysis, and the degree of income analysis. This study uses the descriptive analysis to identify the farmers’ characteristics, the double linier regression which further is being transformed into the natural logarithm form, the farmers’ degree of income analysis, and the optimum input usage analysis. The study is resulting evidences that the dairy farmers in KPGS are dominated by men, with the average age is 41-50 years old, farmers are typically finished their elementary school, with the dairy farming experiences are 11-20 on average, and the owned dairy cows are 1,8 ST. The degree of income analysis shows that with 1,8 ST owned cows per farmer, the dairy business has already profitable. The regression analysis shows that the usage of feed, concentrate, and water are significantly influenced the model with 5 percent alpha, while the worker factor is not significantly proven to influence the model. The optimum input usage analysis shows that input usage has not been optimally used in Cibodas Area, it is showed by the NPM/BKM ratio of each input is not equal with one.
Keyword: Bogor Agricultural University (IPB), optimum input, production factor, milk production, cooperative

Judul: Analisis efisiensi produksi dan peran koperasi terhadap usaha ternak Sapi Perah di Kecamatan Cibungbulang Kabupaten Bogor
Abstrak: Indonesia has a potency to develops the dairy industry in the future, however Indonesia still imports about 73% of its dairy need and produces the 27% remaining domestically (Kementerian Pertanian, 2013). Kawasan Usaha Ternak (KUNAK) Cibungbulang, Bogor District is purposively established by the Koperasi Peternak Susu (KPS) Bogor as a national pilot area of an environmentally friendly dairy farm. Further, it is also expected that its milk production can support national milk supply. However, as the milk production in KUNAK Cibungbulang still highly depends on the input usage, therefore the influencing factors of milk production analyses are interesting to be examined. Moreover, this study also analyses the farmer’s income level, the optimum input usage, and also the dairy cooperative’s role in supporting the farmer’s activity. This study applies the double linear regression which has been transformed into the natural logarithm form, the farm management income analysis, the efficiency analysis of production factor, and the descriptive analysis. The result of the study indicates that the significant production factors which influence the milk production are: the amount of the feed, concentrate, tofu dregs, and workers. The analysis is resulting an evidence of profitable dairy farm. However, it is also important to increase the usage of optimum input and the cooperative roles, thus the KUNAK Cibungbulang can reach its optimum profit. The research found that inputs farm have not been used optimally, even the dairy cooperatives have supported the farms well.
Keyword: Bogor Agricultural University (IPB), optimum input, production factor, milk production, cooperative

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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