Judul: Production, Farm Income and Postharvest Technology of Corn in Cibatu sub-district, Garut Regency, West Java.
Abstrak: Kecamatan Cibatu merupakan salah satu wilayah penghasil jagung di Kabupaten Garut yang produktivitasnya belum optimal dan produksinya mengalami penurunan. Penurunan produksi disebabkan oleh penurunan luas lahan jagung yang diduga dipengaruhi rendahnya penerimaan petani. Tujuan dari penelitian ini adalah menganalisis faktor-faktor yang memengaruhi produksi, menganalisis pendapatan usahatani serta pengaruh penanganan pascapanen terhadap pendapatan petani jagung hibrida di Kecamatan Cibatu. Penelitian ini menggunakan fungsi produksi Cobb-Douglas, analisis pendapatan dan anggaran parsial. Hasil penelitian menunjukkan bahwa benih, pupuk organik, pupuk urea, pupuk phonska serta varietas benih non-subsidi berpengaruh positif dan signifikan terhadap produksi jagung. Usahatani jagung dengan penanganan pascapanen memberikan penerimaan yang lebih tinggi dibanding tanpa penanganan pascapanen. Penanganan pascapanen yang dikaji adalah proses pemipilan. Beberapa teknologi pemipilan yang dikaji yaitu pemipilan manual, parut ban, sepeda, alat sederhana dan mesin. Alternatif terbaik dalam penanganan pascapanen baik dari tambahan penerimaan, kualitas biji, waktu pemipilan dan nilai tambah adalah menggunakan alat sederhana.
Keyword: Corn hybrid, Income, Partial budget, Post-harvest, Production function, Income analysis, Revenue, Cobb-Douglass

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: 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.
Keyword: