Judul: Production efficiency analysis of dairy farm in pondok ranggon cipayung sub-district east jakarta
Abstrak: Permintaan susu sapi perah di Indonesia meningkat setiap tahunnya, namun produksinya belum memenuhi kebutuhan nasional. Peternakan sapi perah Pondok Ranggon merupakan tempat penyedia susu sapi untuk warga DKI Jakarta. Peternakan sapi perah Pondok Ranggon memiliki peranan penting dalam peningkatan produksi susu di Indonesia. Tujuan penelitian ini adalah untuk: (1) menganalisis faktor-faktor yang mempengaruhi produksi susu sapi perah, (2) menganalisis efisiensi produksi susu sapi perah, (3) menganalisis pendapatan usaha peternakan sapi perah di Pondok Ranggon. Faktor produksi susu sapi perah dianalisis menggunakan fungsi produksi Cobb-Douglas dan parameter diestimasi dengan metode Ordinary Least Squares (OLS), analisis efisiensi produksi dilakukan dengan menggunakan Nilai Produk Marginal (NPM) sama dengan harga faktor produksi, dan pendapatan usaha peternakan dilakukan dengan analisis pendapatan. Faktor-faktor yang mempengaruhi produksi susu sapi perah adalah pakan hijauan, ampas tahu, dan tenaga kerja. Nilai efisiensi masing-masing faktor produksi tidak sama dengan satu, berarti bahwa penggunanaan faktor produksi belum efisien. Nilai R/C ratio yang lebih besar dari satu, sehingga analisis pendapatan menunjukkan bahwa usaha peternakan sapi perah menguntungkan., The demand for milk of dairy cattle in Indonesia increasing every year, but the production has not fulfill the national needs. Pondok Ranggon dairy farm is a supplier milk to DKI Jakarta people. Pondok Ranggon dairy farm has an important role in improvement milk production in Indonesia. The purposes of the study were to: (1) analyze the affecting factors for the production milk of dairy cattle, (2) analyze the production efficiency of milk of dairy cattle, (3) analyze the income of Pondok Ranggon dairy farm. The production factor of milk of dairy cattle was using the production function of Cobb-Douglas analysis and estimated parameter was using Ordinary Least Squares (OLS) method, analysis production efficiency was using Value of Marginal Product (VMP) equal to production factor prices, and income of dairy farm analyze using income analysis. The affecting factors of production milk of dairy cattle is grass, tofu waste, and labors. The value of efficiency of each production factor is not equal to one, means that the use of production function have not been efficient. The value of R/C ratio is greater than one, so that the income analysis shows for dairy farm is profitable.
Keyword: analisis pendapatan, efisiensi produksi, Pondok Ranggon, susu sapi, usaha peternakan

Judul: Hubungan antara Produksi dan Kualitas Susu Sapi Perah dengan Faktor yang Mempengaruhi (Studi Kasus di Pondok Ranggon, Jakarta Timur)
Abstrak: Dairy cows are the large ruminants that mostly kept by Indonesian dairy farmers. The dairy farms of Indonesia located not only in the villages, but also in the urban areas, such as Pondok Ranggon in East Jakarta. Recent study was done to observe effect of technical factors on milk production and quality of dairy farms in Pondok Ranggon in East Jakarta. The parameters were environmental conditions, feeding patterns, animal conditions, lactation performance, and milk quality. The data were analyzed using multiple regression analysis. To overcome less of roughage supply, farmers used agro-industry by products such as tofu waste, soybean waste, and rice bran. The averages of roughage, concentrate, tofu waste, soybean waste and rice bran that offered to the animals were 20,85±4,27; 0,67±0,73; 28,94±7,62; 2,26±4,51; and 0,01±0,09 kg/h/d, respectively. Under this feeding regime, the average milk produced was 9,28±3,22 kg/h/d. The averages of fat, lactose, protein, solid non fat, density of milk quality were 4,44%; 4,20%; 3,91%; 8,83%; and 1,032 g/ml. The relationship of milk production(Y) on roughage (X1), concentrate (X2), tofu waste (X3), soybean waste (X4) and rice bran (X5) was Y1=2,672X10,256 X20,014 X30,018 X4-0,008 X5-0,055. The influenced of age, number of lactation, lactation days, pregnancy and body weight on milk production and quality were also confirmed. It was concluded that maximum milk production in Pondok Ranggon was produced by the cows at 2,5 years age, in the first lactation, at the second months of lactation, from heavier cows, or in the non pregnant cows.
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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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