Judul: Kuriak  kususik  rice  variety  marketing  analysis  in  agam  regency Sumatera Barat province
Abstrak: Beras varietas Kuriak Kususik adalah salah satu komoditi pangan unggulan di Kabupaten Agam yang memilki nilai ekonomis. Tujuan penelitian ini terdiri dari: 1) mengidentifikasi lembaga, saluran, dan fungsi tataniaga beras kuriak kusuik, 2) mengidentifikasi struktur dan perilaku pasar tataniaga beras kuriak kusuik, dan 3) menganalisis efisiensi saluran tataniaga berdasarkan indikator marjin tataniaga, farmer`s share dan rasio keuntungan terhadap biaya. Pengamatan dilakukan dengan cara observasi dan wawancara menggunakan metode snowball sampling dengan empat puluh orang responden petani dan lima belas responden pedagang. Penelitian ini menggunakan analisis kualitatif dan kuantitatif. Hasil penelitian ini menunjukkan adanya delapan saluran tataniaga beras Kuriak Kusuik yang dikelompokkan menjadi dua, pertama kelompok saluran yang petaninya menjual hasil panen berupa gabah dan kedua petani yang menjual hasil panen berupa beras. Pada kelompok saluran pertama, saluran yang relatif lebih efisien yaitu saluran IV yang melibatkan petani dan pedagang pengumpul. Pada kelompok saluran kedua, saluran yang relatif lebih efisien yaitu saluran VII yang melibatkan petani dan pedagang pengecer lokal., Kuriak Kususik rice variety is one of the primary commodities in Agam Regency that has economic value. This research is aimed to: 1) identify the institutions, functions and marketing channels, 2) identify the market`s structures and conducts, and 3) analyze the marketing channels’ efficiency of Kuriak Kusuik rice based on certain indicators such as marketing margin, farmer’s share, and revenue per cost ratio. Observations and interviews were conducted to 40 farmers and 15 merchant middlemen as respondents, using the snowball sampling method. Quantitative and qualitative analysis were both used in this research where the quantitative one was used to analyse marketing margin, farmer’s share, and revenue per cost ratio. The result showed that totally there were 8 marketing channels of Kuriak Kusuik rice, which could be divided to 2 types of marketing channels based on their final product: first, the farmers that sell their product in unhulled paddy form and second, in rice form. At the first type of marketing channel, the relative efficient channel is the fourth channel that involved the farmers and the middlemen. On the other hand, the relative efficient channel in the second type is the seventh channel that involved farmers and local retailers.
Keyword: Pemasaran, beras, efisiensi

Judul: Analisis Sistem Pemasaran Beras Ciherang di Kecamatan Cibeber, Kabupaten Cianjur
Abstrak: Rice is the basic commodity that became the staple food for the Indonesian. The purposes of this research were analyzing marketing channels, function, structure and marketing institutions of farmer Ciherang Variety in Cibeber Subdistrict. Beside that, the purposes of this research were analyzing the marketing efficiency by marketing margin, farmer’s share and benefit cost ratio approaching. The research was conducted in 3 villages that are Cisalak, Karangnunggal, Salamnunggal with 30 farmers as the respondents and there are 7 marketing institutions in the subdistrict. Generally, the market structure in this subdistrict is oligopsonistic . Based on the marketing function and the profitable ratio about marketing cost, the channels that through farmers-middlemen-major collector and rice mills in village-retailer-consumer rice in Jakarta is the most efficient channels. The farmer should have made farmer groups or cooperation as part of the marketing system to improve the bargaining position and easier capitalization like through the warehouse system in Cianjur.
Keyword: Rice, Marketing Margin, Farmer’ 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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