Judul: Analisis Risiko Diversifikasi Sayuran Indigenous (Kasus: Usahatani Anggota Kelompok Tani Mitra Tani Parahyangan, Kabupaten Cianjur)
Abstrak: Indigenous vegetable is a vegetable local which one of Indonesia's biodiversity. Farmer groups in agribusiness, particularly vegetables in Cianjur one of which is the Mitra Tani Parahyangan Farmers Group. Productivity fluctuations indicates a risk in farming. The purpose of this research is to analyze the activity of specialization and diversification undertaken by the farmer members Group Mitra Tani Parahyangan by looking at the extent of the risks faced by and devise an alternative strategy of diversification by providing the right combination of commodities to reduce the risk of farming on the specialization activities carried out by farmers Group members Mitra Tani Tani Parahyangan. A methods of collecting data done by means observation, interviews, discussions and filled out the questionnaire to 25 respondents. Respondents were selected consisting of 10 tomato farmers, 10 cabbage farmers, and 5 leunca farmers. The process of sampling respondents conducted by purposive sampling method . Data processing was performed using Microsoft Excel 2007. While the measure of risk used cover opportunities, expected return, variance, standard deviation, and coefficient of variation. Sources of risk faced by farmers Farmers Group members of Mitra Tani Parahyangan is precipitation, fog, and pests and diseases. Results of the analysis indicate that the specialization of activities leunca is a commodity with the lowest coefficient of variation is equal to 0.27. The combination of these two commodities namely leunca and cabbage is the most diversified activities namely lower risk of 0.29 compared to a combination of two other commodities as well as the tomatoes and tomato and cabbage leunca. Alternative strategies that can be run by farmers group members of Mitra Tani Parahyangan to decrease the risk of production is the timing and the right commodity diversification activities and the control of pests and diseases .
Keyword: diversification, specialization, risk, indigenous vegetables

Judul: Analisis Risiko Usaha Diversifikasi Sayuran pada Petani Gapoktan Rukun Tani di Kecamatan Ciawi Kabupaten Bogor Jawa Barat
Abstrak: Vegetables diversification is one of the best form solution to applied by farmer to reduce existing risk. Form of diversification that can applied by vegetable farmer generally consist of combination cultivation among the various of vegetables such as peas, beans, tomatoes, curly chili and mustard. Gapoktan Rukun Tani is one gapoktan that have farmers at most cultivation the vegetables. The purpose of this research are risk identification that faced by farmers, to iii analyze diversification business died by farmer in solution reduce of risk, to know magnitude of the risk decline after to do diversification business, and to analyze alternative strategy that can farmer doing to handle of risk vegetable business. Taking sample from farmer in this research use purpossive method. Furthermore, techniques of data collection include interview with farmer that appropriate with questions in questionnaire, discussions, and observation on farmer’s field. its processing have done by using Microsoft Excel 2007. Whereas, risk measure used consists of opportunities, expected return, variance, standard deviation, and coefficien variation. There are two activities that calculated measure of risk are spesialisation and diversification activities. The result show curly chili the best cultivated spesialisation because the smallest coefficient variation earned by 0.259. However, for commodity beans, chickpeas, tomatoes, and mustard are the best if cultivated with diversification activities. Because result value coefficient variation on the spesialisation activity can be reduced through diversification activities.
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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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