Judul: Analisis Tataniaga Tebu (Studi kasus: Kecamatan Trangkil, Kabupaten Pati, Jawa Tengah)
Abstrak: Sugarcane can be used as raw material for the manufacture sugar. Cane farmers crops can be sold to sugar factories to meet the market demand for sugar. Therefore, research is needed to find out about business administration cane sugar in a comprehensive overview of business administration. The purpose of this study is to identify the channel, function, organization, and structure of the market in sugar cane business administration systems, and analyze operational efficiency with a cane trading system trading system margin approach, the farmer's share, and the ratio of benefits to costs. Observations and interviews were conducted to farmers in Sub Trangkil with purposive sampling method, while the method of follow the flow of commodity is done to institutions trading system. The results showed that there is a 4 channel trading system with institutions, functions, and different market structures on each channel. Under margin trading system, the farmer's share, and the ratio of benefits to costs shows one channel trading system is the most efficient channels.
Keyword: sugarcane marketing, Trangkil district, farmer’s share, efficient, efficiency

Judul: Analisis Tataniaga Tebu, Desa Pintu, Kecamatan Jenangan, Kabupaten Ponorogo, Jawa Timur
Abstrak: Sugarcane is one of the 15 national main commodities to support plantation development goals from 2010 to 2014. The purpose of this study are to identify the marketing channel, function, institution, market structure and market behavior, and to analyze the operational efficiency of trading sugarcane system with margin trading system approach, the farmer's share, and the ratio of benefit to cost. Observation and interview were performed with the purposive method for farmers in the Pintu Village, while the snowball method was performed for institution trading system. The result showed that there were four trading channels system. Based on margin trading system, the farmer's share, and the ratio of benefit to cost trading system shows that the channel one is the efficient channel to direct sales from farmers to sugar factory and channel four is an efficient channel sales through middlemen.
Keyword: sugarcane marketing, Pintu Village, farmer's share, Efficiency

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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