Judul: Analisis Total Factor Productivity (Tfp) Tanaman Perkebunan Di Indonesia Periode 1990-2010
Abstrak: Tujuan penelitian ini adalah untuk menganalis Total Factor Productivity (TFP) tanaman perkebunan di Indonesia periode 1990-2010 dengan menggunakan Indeks Tornqvist-Theil. Selain itu untuk melihat pengaruh input produksi terhadap output produksi tanaman perkebunan di Indonesia, metode yang digunakan adalah OLS (Ordinary Least Square) dengan model fungsi Cobb-Douglass. Hasil penelitian menunjukan bahwa Indeks TFP pada tanaman perkebunan di Indonesia periode 1990-2010 bernilai positif. Hal ini menandakan bahwa penggunaan input dan output dapat dihasilkan secara maksimal. Hasil estimasi dari fungsi Cobb- Douglass untuk melihat pengaruh input terhadap output produksi menunjukan bahwa seluruh penggunaan input seperti kapital, tenaga kerja, dan luas panen berpengaruh secara positif dan signifikan terhadap output produksi.
Keyword: Indeks Tornqvist-Theil, Tanaman perkebunan Indonesia, Total Factor Productivity.

Judul: Faktor-faktor yang Memengaruhi Total Factor Productivity Industri Pertanian Indonesia Periode 1981-2010
Abstrak: Industry has a big role in Indonesia’s economy as the main driver of development, which it gives the largest contribution to the Gross National Product (GNP). Indonesia is an agrarian country which has a big potency in developing agriculture products because of the abundant resources it has, supporting climate, and fertile soil. This study aims to analyze Total Factor Productivity (TFP) of Indonesia’s agriculture industry through a Cobb-Douglas production function approach and analyze factors influencing it using Error Correction Model (ECM), along with a descriptive method to explain an overview of agriculture industry in Indonesia. Time series data are used for period 1980-2010. The estimation result shows that variables significantly influencing TFP are Gross National Product, domestic investment, export of industry output (X), and investment import (M).
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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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