Judul: Keragaan farming of bakalancattle (case study:  farmer and  breeder group of tanjung lurah, nagari salimpauang, kabupaten Tanah Datar)
Abstrak: Nagari Salimpauang merupakan salah satu wilayah di Kecamatan Salimpauang, Kabupaten Tanah Datar, Provinsi Sumatera Barat dimana penduduknya banyak mengusahakan penggemukan sapi. Namun untuk mengembangkan usahanya, para peternak memiliki permasalahan seperti lahan, pengolahan limbah, ketersediaan input, dan tenaga kerja. Salah satu solusi untuk mengatasi permasalahan tersebut yaitu melalui pengelolaan dengan Kelompok Tani Ternak Tanjung Lurah. Tujuan dari penelitian ini yaitu (1) Menganalisis biaya dan penerimaan, dan (2) Menganalisis pendapatan dan rasio penerimaan dan biaya. Hasil perhitungan pendapatan atas biaya tunai per ST per tahun dan nilai R/C rasio yang paling besar diperoleh peternak skala besar. Sementara itu perhitungan pendapatan atas biaya total per ST per tahun menghasilkan nilai positif dan nilai R/C rasio lebih dari satu untuk semua skala, sehingga usaha ternak menguntungkan. Usaha pada peternak skala besar yang lebih baik dibandingkan skala kecil karena keuntungan yang diperoleh paling besar dan nilai R/C rasio nya yang paling besar., Nagari Salimpauang is located at Kecamatan Salimpauang, Kabupaten Tanah Datar, West Sumatera Province where the majority of people do fattening cattle husbandry for living. Meanwhile to develop the business, the breeders face through several obstacles such as area availability, waste management, input availability and labor. One of solution to solve those problems is by implementing supervision with farmer and breeder group of Tanjung Lurah. This study was aimed to (1) analyze cost and revenue, and (2) analyze profit and ratio of revenue and cost. Measurement result of profit based on cash cost per livestock unit (satuan ternak, ST) per year and biggest R/C ratio value were gained by wide– scale breeder. Otherwise, calculation of profit based on cash cost per ST per year indicated positive value and R/C ratio values which were more than 1 for every scales, therefore the business is considered profitable. Business by wide–scale breeder was better compared to small–scale one because of the most profit obtained and biggest R/C ratio value.
Keyword: analisis pendapatan, R/C rasio, usaha penggemukan sapi

Judul: Analysis of Beef Cattle Farming Business for Members and Non-Members of Sentra Peternakan Rakyat in Bojonegoro District
Abstrak: Populasi sapi potong di Indonesia terus meningkat setiap tahunnya, hal tersebut menjadikan usahaternak sapi potong berpeluang besar untuk dikembangkan terutama pada peternakan rakyat yang saat ini masih didominasi oleh usahaternak berskala kecil. Salah satu program yang dicanangkan pemerintah untuk pemberdayaan peternak yaitu Sentra Peternakan Rakyat (SPR). SPR Mega Jaya merupakan SPR percontohan dan terbaik di Indonesia tahun 2017. Namun tidak semua peternak tergabung dalam SPR, sehingga penelitian ini bertujuan untuk menganalisis struktur biaya, penerimaan, serta pendapatan peternak anggota dan non anggota SPR Mega Jaya. Metode analisis yang digunakan adalah analisis pendapatan usahaternak sapi potong, R/C ratio, dan uji beda. Hasil penelitian menunjukkan pendapatan atas biaya total usahaternak anggota SPR dan non anggota berturut-turut sebesar Rp8.561.126,06 dan -Rp3.928.392,91. Nilai R/C rasio total sebesar 1,37 persen dan 0,76 persen, hal ini menunjukkan bahwa usahaternak anggota layak dijalankan sedangkan non anggota tidak layak untuk dijalankan., The beef cattle population in Indonesia continues to increase every year, making beef cattle farming a great opportunity to be developed, especially on smallholder farms which are currently still dominated by small-scale farming. One of the programs launched by the government to empower farmers is the People's Livestock Center (SPR). SPR Mega Jaya is a pilot SPR and the best in Indonesia in 2017. However, not all farmers are members of SPR, so this study aims to analyze the cost structure, revenue, and income of farmer members and non-members of SPR Mega Jaya. The analytical methods used were beef cattle farming income analysis, R/C ratio, and difference test. The results showed that the income over the total cost of farming of SPR members and non-members amounted to Rp8.561.126,06 and -Rp3.928.392,91, respectively. The total R/C ratio value is 1,37 percent and 0,76 percent, this indicates that the livestock business of members is feasible to run while non-members are not feasible to run.
Keyword: pendapatan, R/C ratio, sapi potong, Sentra Peternakan Rakyat, Uji beda

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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