Judul: Analisis Faktor-faktor yang Mempengaruhi Risiko Produksi Benih Ikan Neon Tetra di Kecamatan Bojongsari, Kota Depok.
Abstrak: Petani pembenihan ikan hias neon tetra di Kecamatan Bojongsari menghadapi risiko yang berasal dari penggunaan faktor-faktor produksi. Tujuan penelitian ini adalah menganalisis pengaruh faktor produksi terhadap risiko produksi yang dihadapi petani pembenihan ikan neon tetra di Kecamatan Bojongsari. Penelitian ini mengambil 33 sampel petani di Kecamatan Bojongsari dengan menggunakan purposive sampling sebagai metode penentuan sampel sedangkan metode analisis data menggunakan model Just and Pope. Hasil perhitungan menunjukkan bahwa artemia, kutu air saring, dan tenaga kerja meningkatkan produktivitas secara nyata, sedangkan obat-obatan menurunkan produktivitas secara nyata. Peningkatan penggunaan artemia dan tenaga kerja meningkatkan risiko produksi secara nyata (risk inducing factors), sedangkan indukan dan obat-obatan menurunkan risiko produksi secara nyata (risk reducing factors).
Keyword: Just dan Pope, neon tetra, risiko produksi

Judul: Analisis Risiko Produksi Pembesaran Ikan Hias Neon Tetra (Studi Kasus di Pengusaha Bapak Rodi, Kecamatan Bojongsari, Kota Depok)
Abstrak: Indonesia is the archipelago country and well-known in the world, So it supports the fisheries sector and has the potential for economics development as maritime country and nation. One of these, is the non-consumption of fishery products business in Indonesia, in particulary is a commodity of ornamental fish. It has developed quite rapidly besides having promising prospects economically. The Objective of this study is to identify a source of risk production and to analyze probability and impact of risk production in the rearing operational business of ornamental fish neon tetra owned by Mr. Rodi. The analytical method used is the analysis of risk management and risk analysis based on the size of the Expected Return approach, variance, standard deviation, and coefficient of variation. The result Based on the risk assessment on the production of ornamental fish rearing business neon tetra obtained the expected return value is 84.77 for a single period. That Means is Mr. Rodi can expect as much the result of the acquisition of 84.77 per cent survival rate in this enlargement effort for each harvest period. The coefficient of variation values obtained results of 0.20. In other words, for every one percent success rate ornamental fish neon tetra obtained will have a risk of 0.20 percent at the time of production risk. Some things that can be done is to make investments in the form of a purchase thermometers and pH meters tool that checks the temperature and pH can be done routinely.
Keyword: coefficient variation, standard deviation, variance, Expected Return, Survival rate, Neon Tetra

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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