Judul: Analisis Keunggulan Komparatif dan Kompetitif Usahatani Padi Semiorganik di Desa Ciburuy, Kecamatan Cigombong,Kabupaten Bogor
Abstrak: If the views of potential resources and condition of agricultural markets organic products is increasing, then Indonesia has a great opportunity to be producers of organic food. It was realized by the government to make the program “Go Organic 2010”, where one of the purpose is to encourage the development of organic farming who have the competitiveness and sustainability. This research wanted to see rice farming semiorganic run by farmers in the village Ciburuy have comparative and competitive advantages or not. The results of this research are: 1). Semiorganic rice farming run by each farmer characteristics have comparative and competitive advantages, as indicated by PCR and DRC values smaller than one. The land sharecroppers farmers value is 0.851 and 0.826. The land tenant farmers value is 0.532 and 0.632. The farmers owner land value is 0.608 and 0.616; 2). Based on the sensitivity analysis, the most sensitive indicator of the decline occurred in the conditions of the selling price of output, and decrease the amount of output. For indicators the increase of anorganic fertilizer price is not overly sensitive, due to the use of anorganic fertilizers is not too much in rice farming semiorganic.
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Judul: Technical Efficiency Analysis of Semi-Organic Rice Farming in Cigombong Sub-District Bogor District
Abstrak: The development of semi-organic rice in Cigombong Sub-district is quite prospected. Cigombong Sub-district has the largest land area of organic rice in Bogor District and semi-organic rice production has been conducted since 2002. However, semi-organic rice productivity in Cigombong Sub-district is still relatively low due to the inefficiencies in the use of inputs or production factors (such as: land, seed, compost, etc) in farming and inefficiencies that come from internal factors farmers (such as: age, education, experience and so on). The aims of this study are 1) to analyze the factors that influence the production of semi-organic rice farming in Cigombong Sub-district, Bogor District; 2) to analyze the technical efficiency of semi-organic rice farming in Cigombong Sub-district, Bogor District; and 3) to analyze the income of semiorganic rice farming in Cigombong Sub-district, Bogor District. Stochastic Frontier Production function with Maximum Likelihood Estimation (MLE) method was used to analyze the problems in this research. The research was done in Cigombong Sub-district Bogor District from January 2013 until December 2013. Respondents in this research were selected by purposive sampling method. This research used cross section data and it was gotten by direct interview to the sample farmers. The research findings showed that land (X1), seed (X2), compost (X3), urea (X4), and labour (X5) had positive significant effect on semi-organic rice production. Land, compost, and urea were significant at 95% level, seed was significant at 90% level, and labour was significant at 85% level. The result also showed that the semi-organic rice farming was technically efficient (mean efficiency was 0.78). Land ownership status was an important factor in technical inefficiency and it significantly increased technical efficiency. Besides, the research also showed that the semi-organic rice farming was profitable (the benefit was Rp3 233 498.09) and feasible to be developed (R/C ratio by cash cost was 1.42 and R/C ratio by total cost was 1.24).
Keyword: farmers income, production factors, stochastic frontier

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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