Judul: Dampak Kenaikan Harga Kedelai Terhadap Tiga Usaha Kecil dan Menengah Tahu Kota Bogor
Abstrak: Inability to meet the needs of domestic soybeans make Indonesia dependence on imports. Consequently there is no certainty of domestic supply availability and price stability of soybean. The increased price of soybeans in the country influenced by the world soybean prices often occur and cannot be avoided by tofu industries that are consumers of imported soybeans. With the diversity of tofu business scale existing in Indonesia, the impact of rising soybean prices will vary from one tofu business to others. Therefore, this study uses three samples with different scale business to compare the impact of rising soybean prices. Classification of used business scale is based on the amount of daily production capacity, that is the scale of households with a daily production capacity of ≤ 100 kg, small scale with a daily production capacity of 101-200 kg, and medium scale with a daily production capacity of 201-300 kg. The indicators used in this study is the profitability value, value-added and sensitivity. The results obtained are that v medium-sized tofu businesses generate the highest profitability value and valueadded, and are the most resistant tofu business in encountering the increased soybean prices. However, the results obtained by medium-sized tofu businesses are not much different from the value obtained by small-sized tofu businesses. Thus, in this study, small and medium-sized tofu business generate insignificantly different profitability value, value-added, and the sensitivity.
Keyword: Bogor Agricultural University (IPB), tofu, profitability, value added, soybean price fluctuations

Judul: Analisis Pengaruh Kenaikan Harga Kedelai Terhadap Kinerja Usaha Industri Tempe di Desa Citeureup Kabupaten Bogor
Abstrak: Soybean demand continues to increase but does not meet sufficient domestic production resulting in higher price shock. An increase in soybean prices caused a major influence on tempeh industry in Indonesia, since soybean is the main input of tempeh,. The aims of this research were to analyze the effects of the increasing soybean price on business performance in terms of cost structure, revenue, profit, and efforts to deal with adjustments made under these conditions. This research was conducted from December 2012 to Februari 2013. This research used primary data from direct interviews with respondents and secondary data from relevant institutions and literature. The analysis tools used are quantitative and qualitative analysis. The results indicated that an increase in soybean prices affected rising of the total cost significantly because 70 percent of the cost was used for the purchase of soybeans. The condition led to decrease the amount of profit earned. Based on the comparison of the cost structure of the three production-scale showed there was a trend that an increasing of business scale will decrease the cost per kg of soybeans. It is concluded that an adjustment has to be undertaken in order to get high profit by reducing the size and increasing the price of tempeh
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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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