Judul: Analisis Persediaan Bahan Baku Kedelai di Rumah Tempe Indonesia
Abstrak: Rumah Tempe Indonesia (RTI) memerlukan bahan baku utama kedelai Genetically Modified Organism (GMO) dan Non-GMO dalam memproduksi tempe. Namun, persediaan kedelai saat ini cenderung menumpuk sehingga dapat meningkatkan biaya. Bila tidak dikendalikan dengan baik, maka bahan baku akan mengalami kekurangan atau kelebihan yang berdampak pada perusahaan. Tujuan penelitian ini adalah untuk menganalisis sistem persediaan bahan baku di RTI, menganalisis optimalisasi persediaan bahan baku kedelai dan menganalisis perbandingan biaya persediaan di perusahaan dengan biaya Economic Order Quantity (EOQ), meramalkan persediaan bahan baku kedelai sebaiknya dilakukan RTI. Jenis data terdiri dari data primer dan data sekunder. Metode penelitian yang digunakan ialah EOQ dan metode peramalan deret berkala. Sistem persediaan bahan baku pada RTI tidak menggunakan teori secara khusus. Analisis metode EOQ menghasilkan pemesanan optimal bahan baku kedelai GMO sebanyak 897,91 kg dan kedelai Non-GMO sebanyak 1.087,38 kg dengan penghematan biaya persediaan sebesar Rp. 1.879.378 pertahun. Berdasarkan peramalan di tahun 2016, EOQ cenderung menurun 1 persen dari tahun sebelumnya sebesar 887,82 kedelai GMO dan 1.082,21 untuk kedelai Non-GMO.
Keyword: kedelai, metode EOQ, persediaan bahan baku

Judul: Pengaruh Kenaikan Harga Kedelai Terhadap Struktur Biaya dan Keuntungan Usaha Tempe (Studi Kasus: Rumah Tempe Indonesia di Bogor)
Abstrak: Tempe is a processed product which has a high nutritional value. Tempe businesses are generally run by household and small industries. Tempe produced by RTI consist of genetic modifier organism and Non-genetic modifier organism soybean. This research had only analyzed GMO tempe produced of 450gr and 700gr package. The increase in soybean prices are expected to give effect to the business craftsmen tempe in this case the business RTI. This study aims to analyze the cost structure of the soybean business in RTI before rising soybean prices and the impact of price rise of soybean in terms of the feasibility analysis (R/C ratio and break-even point (BEP). The results showed that the increase in soybean prices affect revenue of RTI. But R/C ratio was rising after the price rise of soybean. Based on these conditions, RTI is advised to improve the amount of their market because of RTI’s market which are segmented.
Keyword: the break-even, R/C ratio, sales revenue, GMO

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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