Judul: Analisis Efisiensi Penggunaan Input Usahatani Bawang Merah di Sumatera Barat
Abstrak: Bawang merah merupakan salah satu komoditas pangan strategis Indonesia. Penyebaran daerah penghasil bawnag merah di Indonesia cukup luas tetapi sentra produksi bawang merah di Indonesia masih terkonsentrasi di Pulau Jawa. Sedangkan Kebutuhan bawang merah di luar Pulau Jawa juga cukup tinggi sehingga Pemerintah memilih daerah Sumatera Barat untuk dijadikan sebagai daerah pengembangan budidaya bawang merah yang ada di luar Pulau Jawa. Tujuan dari penelitian ini adalah menganalisis efisiensi penggunaan input usahatani bawang merah di Sumatera Barat dan faktor yang memengaruhinya. Data yang digunakan adalah data sekunder yang bersumber dari Survei Rumah Tangga Usaha Tanaman Hortikultura Tahun 2014 yang dilakukan oleh Badan Pusat Statistik (BPS). Jumlah sampel petani dalam penelitian ini sebanyak 367 orang petani. Metode analisis yang digunakan yaitu Data Envelopment Analysis (DEA) dan regresi Tobit. Hasil penelitian menunjukkan bahwa petani belum efisien dalam mengunakan input. Hal ini dapat diatasi dengan melakukan pengurangan input. Pendidikan dan jenis lahan berpengaruh signifikan terhadap efisiensi penggunaan input usahatani bawang merah di Sumatera Barat., Shallots are one of Indonesia's strategic food commodities. The distribution of shallot-producing areas in Indonesia is quite wide, but the center of shallot production in Indonesia is still concentrated on the island of Java. Meanwhile, the need for shallots outside Java is also quite high, so the Government has chosen West Sumatra as the area for the development of shallot cultivation outside Java. The purpose of this study was to analyze the efficiency of using shallot farming inputs in West Sumatra and the factors that influence it. The data used is secondary data sourced from the 2014 Horticultural Crops Business Household Survey conducted by the Central Statistics Agency (BPS). The number of samples of farmers in this study were 367 farmers. The analytical methods used are Data Envelopment Analysis (DEA) and Tobit regression. The results showed that farmers have not been efficient in using inputs. This can be overcome by reducing the input. Education and land type have a significant effect on the efficiency of the use of shallot farming inputs in West Sumatera.
Keyword: DEA, Shallots, Tobit Regression

Judul: Farming Income Analysis Shallots in the province of East Java
Abstrak: Bawang merah merupakan komoditas hortikultura dengan laju konsumsi tertinggi di Indonesia. Terdapat beberapa daerah yang menghasilkan produksi yang tinggi salah satunya adalah Jawa Timur yang menduduki posisi tertinggi kedua setelah Jawa Tengah. Tujuan penelitian ini adalah untuk menganalisis pendapatan dan struktur biaya usahatani bawang merah di Provinsi Jawa Timur. Data yang digunakan adalah data sekunder yang bersumber dari Sensus Pertanian 2013: Survei Rumah Tangga Usaha Tanaman Hortikultura Tahun 2014 yang dilakukan oleh Badan Pusat Statistik (BPS). Jumlah sampel petani bawang merah sebanyak 1.571 petani. Metode analisis yang digunakan yaitu analisis struktur biaya, penerimaan, pendapatan, dan R/C rasio usahatani bawang merah pada musim kemarau dan musim penghujan. Proporsi biaya produksi terbesar adalah biaya benih yakni mencapai 38,95 persen saat musim kemarau dan 39,60 persen saat musim penghujan. Pendapatan petani bawang merah, baik atas biaya tunai maupun atas biaya total, pada musim kemarau dan musim hujan bernilai positif. Pendapatan atas biaya tunai usahatani bawang merah di Jawa Timur pada musim kemarau (Rp47.467.450 per hektare) lebih besar dibandingkan pada musim penghujan (Rp29.817.750 per hektare). Begitu juga dengan return to total capital saat musim kemarau lebih besar (82,62%) dibandingkan saat musim penghujan (61,40%). Hal ini menunjukkan bahwa usahatani bawang merah mampu memberikan imbalan bagi petani. Hasil analisis R/C rasio menunjukkan bahwa usahatani saat musim kemarau lebih efisien dibandingkan musim penghujan., Shallots is horticultural commodities with the highest consumption rate in Indonesia. There are several areas that produce high production, one of which is East Java which occupies the second highest position after Central Java. The purpose of this study was to analyze the revenue and cost structure of shallot farming in the province of East Java. The data is secondary data from Sensus Pertanian 2013: Survei Rumah Tangga Usaha Tanaman Hortikultura Tahun 2014 has been done by Badan Pusat Statistik (BPS). There are 1.571 farmers who are the sample in this study. The analytical method consists of cost structure analysis, revenues, income, and the R/C ratio of shallot farming in two seasons (dry season and rainy season). The largest cost in shallot farming is the cost of seeds, reaching 38,95 percent in the dry season and 39,60 percent during the rainy season. The income of shallot farmers (both cash and total costs) in the both seasons is positive. The cash income of shallot farming in East Java in the dry season (Rp47.467.450/hectare) is greater than in the rainy season (Rp29.817.750/hectare). Likewise, the return to total capital in the dry season is greater (82,62%) than in the rainy season (61,40%). This means that shallot farming is able to provide rewards for farmers. The last point, R/C ratio shows that shallot farming in the dry season is more efficient than the rainy season.
Keyword: Cost Structure, Income, R/C Ratio, Shallot Farming

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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