Judul: Dayasaing dan Permintaan Ekspor Sayuran Indonesia di Negara Tujuan Utama
Abstrak: The export commodities competitiveness is one of many indicators used for measuring the economic growth of a country. This research analyzed the export competitiveness of the five Indonesian vegetables, including potatoes, tomatoes, onions, cabbage, and chili which are delivered to five major destination countries and compared with competitor countries by looking at the comparative and competitive advantages as well as the factors that influence it. The period of analysis from 2008 to 2012 using Releaved Comparative Advantage (RCA), Export Product Dynamic (EPD), and the Gravity Model which used the data panel regression approach E-views 6. The result of this study indicates that the Indonesian commodities of vegetables do not have a comparative advantage better than its competitors, namely Netherland and China to the world. On the other hand, Indonesia has the best competitive advantage compared to its competitors. The factors that affect is Economic Distance, GDP, Exchange Rate, Population, and the Price of the Export with different results on each of the commodities.
Keyword: gravity model, competitive advantage, comparative advantage, Bogor Agricultural University (IPB)

Judul: Trade Competitiveness Diagnostic and Export Determinants of Indonesian Vegetable Commodities
Abstrak: Komoditas sayuran merupakan salah satu komoditas ekspor hortikultura Indonesia memilki tren positif selama lima tahun terakhir. Penelitian ini menganalisis daya saing dan determinan ekspor sayuran Indonesia menggunakan metode Trade Competitiveness Diagnostics (TCD) yang terdiri dari beberapa indikator, di antaranya: Revealed Comparative Symmetric Advantage (RSCA), Trade Balance Index (TBI), Intra Industry Trade Index (IIT), Trade Complementarity Index (TCI), dan Index of Export Market Penetration (IEMP). Determinan ekspor dianalisis menggunakan metode regresi data panel. Hasil analisis TCD menunjukkan sebagian besar sayuran Indonesia belum memilki keunggulan komparatif, indeks penetrasi lemah, dan perdagangan hanya bersifat satu arah. Namun sayuran Indonesia menunjukkan posisi sebagai net-exporter dan memiliki share yang bersifat complementary dengan negara tujuan. Determinan yang berpengaruh terhadap nilai ekspor komoditas sayuran Indonesia di negara tujuan utama adalah harga ekspor, RSCA, dan TBI., Vegetable commodity is one of Indonesia's horticultural export commodities which has a positive trend over the last five years. This study analyzes the competitiveness and determinants of Indonesian vegetable exports using the Trade Competitiveness Diagnostics (TCD) method which consists of several indicators, including: Revealed Comparative Symmetric Advantage (RSCA), Trade Balance Index (TBI), Intra Industry Trade Index (IIT), Trade Complementarity Index (TCI), and Index of Export Market Penetration (IEMP). Export determinants were analyzed using panel data regression method. The results of the TCD analysis show that most Indonesian vegetables do not yet have a comparative advantage, the penetration index is weak, and trade is only one-way. However, Indonesian vegetables show a position as a net-exporter and have a share that is complementary to the destination country. The determinants that affect the export value of Indonesian vegetable commodities in the main destination countries are export prices, RSCA, and TBI.
Keyword: Panel Data Analysis, Trade Competitiveness Diagnostic, Vegetable

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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