Judul: Cooperative entrepreneurship business plan for yard-based ginger cultivation in Bubulan Village, Bubulan District, Bojonegoro Regency
Abstrak: Kabupaten Bojonegoro merupakan salah satu daerah yang mayoritas penduduknya bekerja dibidang pertanian dengan tingkat pendapatan yang rendah. Untuk itu, diperlukan sebuah strategi yang dapat meningkatkan pendapatan para pekerja sektor pertanian dengan memanfaatkan sumberdaya yang ada. Pemanfaatan pekarangan untuk budidaya tanaman bernilai ekonomi seperti jahe merupakan salah satu alternatif yang dapat dilakukan penduduk untuk memperoleh tambahan pendapatan. Agar kegiatan pemanfaatan ini dapat dikembangkan secara terstruktur, perlu dilakukan penerapan konsep wirakoperasi. Tujuan penelitian ini adalah rancangan bisnis wirakoperasi jahe berbasis lahan pekarangan. Metode analisis aspek non finansial meliputi rencana pemasaran, rencana teknis, dan rencana manajemen sedangkan analisis aspek finansial meliputi rencana keuangan. Hasil penelitian menunjukkan bahwa produk jahe dari usaha ini akan dipasarkan untuk kebutuhan konsumsi masyarakat dengan target produksi 5,5 ton per bulan dalam waktu 5 tahun dibawah lembaga koperasi sebagai badan usaha. Nilai NPV usaha terhitung layak dan mencapai Rp170.770.105 selama 5 tahun dengan nilai gross B/C sebesar 1.12. Pada tahun pertama dengan skema pembagian hasil sebesar 50% untuk petani, 5% wirakoperasi dan 45% sebagai laba tertahan, usaha ini dapat memberikan pembagian hasil sebesar Rp1.616.200 kepada setiap petani yang melakukan panen. Pada tahun kedua dengan skema pembagian hasil 70% terhadap petani, 10% terhadap wirakoperasi dan 20% sebagai laba ditahan, usaha ini memberikan pembagian hasil sebesar Rp4.487.560 kepada setiap petani yang melakukan panen., Bojonegoro Regency is one of the areas where the majority of the population works in agriculture with a low level of income. For this reason, a strategy is needed that can increase the income of agricultural sector workers by utilizing existing resources. The utilization of yards for cultivating economically valuable plants such as ginger is an alternative that residents can do to obtain additional income. In order for this utilization activity to be developed in a structured manner, it is necessary to apply the concept of cooperative entrepreneurship. The purpose of this study is the design of a yard-based ginger cooperative entrepreneurship. Non-financial aspect analysis methods include marketing plans, technical plans, and management plans while the analysis of financial aspects includes financial plans. The results of the study show that ginger products from this business will be marketed for public consumption with a production target of 5.5 tons per month within 5 years under the cooperative as a business entity. The NPV value of the business is considered feasible and reaches IDR 170,770,105 for 5 years with a gross B/C value of 1.12. In the first year, with a profit sharing scheme of 50% for farmers, 5% as a cooperative entrepreneurship and 45% as retained profit, this business can provide a profit sharing of IDR 1,616,200 for each farmer who harvests. In the second year, with a profit sharing scheme of 70% for farmers, 10% for cooperative entrepreneurship and 20% as retained earnings, this business provides a profit sharing of IDR 4,487,560 for each farmer who harvests.
Keyword: Bojonegoro, business plan, cooperative entrepreneur, ginger  cultivation, yard cultivation

Judul: Factors Affecting Production and Income of Ginger in Center Java
Abstrak: Jahe merupakan komoditas biofarmaka unggulan sebagai bahan baku Industri Obat Tradisional. Namun perkembangan produktivitas jahe pada enam tahun terakhir cenderung menurun. Penelitian ini bertujuan untuk mengetahui faktor-faktor yang memengaruhi produksi dan pendapatan usahatani jahe. Analisis faktor produksi akan dianalisis menggunakan model fungsi produksi Cobb-Douglas dan pendapatan usahatani menggunakan analisis pendapatan dan R/C ratio . Hasil penelitian menunjukkan bahwa faktor yang berpengaruh nyata meningkatkan produksi jahe adalah benih, pupuk kimia, pupuk organik, tenaga kerja dan dummy pola tanam monokultur-tumpang sari. Usahatani jahe yang dijalankan oleh petani di Jawa Tengah menguntungkan karena memperoleh pendapatan yang bernilai positif. Apabila dilihat berdasarkan luas lahan, usahatani yang dijalankan pada lahan sempit memperoleh pendapatan lebih tinggi dibandingkan dengan usahatani lahan luas, namun memberikan R/C ratio lebih rendah. Apabila dilihat berdasarkan pola tanam, usahatani monokultur memperoleh pendapatan lebih tinggi dibandingkan dengan usahatani tumpang sari., Ginger is a leading biopharmaceutical commodity as a raw material for the Traditional Medicine Industry. However, the development of ginger productivity in the last six years tends to decline. This study aims to determine the factors that affect the production, and income of ginger farming. Production factor analysis was analyzed using the Cobb-Douglas production function model. Farm income is analyzed using income analysis, and the R/C ratio is differentiated according to plant area and cropping pattern. The analysis showed that the factors that significantly affected ginger production were seeds, chemical fertilizers, organic fertilizers, labor, and dummy cropping patterns of monoculture-double cropping. Ginger farming, which farmers run in Central Java is profitable because it gets a positive income. When viewed based on the plan area, farms run on narrow learn higher income compared to large land farming, but provide a lower R/C ratio. When viewed based on cropping patterns, monoculture farming earns higher income compared to double cropping farming.
Keyword: ginger, income, production

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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