Judul: Trade Competitiveness Diagnostic and Export Determinants of Indonesian Fruit Commodities
Abstrak: Ekspor buah-buahan Indonesia ditentukan oleh daya saing komoditas buahbuahan Indonesia dan faktor lainnya. Pada penelitian ini daya saing buah-buahan Indonesia dianalisis dengan metode Trade Competitiveness Diagnostic (TCD) yang meliputi Revealed Symmetric Comparative Advantage, Trade Balance Index, Intra Industry Trade Index, Trade Complementarity Index, serta Index of Export Market Penetration. Analisis data panel digunakan untuk menganalisis determinan yang memengaruhi nilai ekspor buah-buahan Indonesia ke negara tujuan. Hasil analisis TCD menunjukkan secara umum komoditas buah-buahan belum berdaya saing secara komparatif, bersifat net importir, memiliki penetrasi pasar yang rendah, serta masih bersifat inter industri (one way trade). Kendati demikian, buah-buahan Indonesia memiliki komplementaritas perdagangan yang tinggi. Selanjutnya, hasil analisis data panel menunjukkan determinan yang memengaruhi nilai ekspor buahbuahan Indonesia ke negara tujuan meliputi GDP riil negara tujuan, jarak ekonomi, kurs riil, harga ekspor dan RSCA., Indonesian fruit exports are determined by the competitiveness of the fruits among other factors. In this research, Indonesian fruit competitiveness is analyzed using the Trade Competitiveness Diagnostic (TCD) method which involves: Revealed Symmetric Comparative Advantage, Trade Balance Index, Intra Industry Trade Index, Trade Complementary Index, and the Index of Export Market Penetration. Panel data analysis is used to analyze the determinants that influence the export of fruits to the destination countries. TCD results show that in general fruits are not yet comparatively competitive, are net importers, have low market penetration power, and are still inter-industrialized (one way trade). Nevertheless, Indonesian fruits have high trade complementarity. Furthermore, panel analysis results show that the determinants that influence the export value of Indonesian fruits to destination countries include the destination country’s real GDP, economic distance, real exchange rate, export value, and RSCA.
Keyword: Buah-buahan, Data Panel, Trade Competitiveness Diagnostic

Judul: The  position  of  competitiveness  and  the  factors  which  affect the Indonesian fruits export  in the world and the destination countries
Abstrak: Keberhasilan dayasaing ekspor buah Indonesia di negara tujuan ditentukan oleh keunggulan komparatif dan kompetitif serta faktor lainnya. Revealed Comparative Advantage (RCA) dan Export Product Dynamic (EPD) digunakan untuk menganalisis posisi dayasaing ekspor buah-buahan Indonesia. Pada penelitian ini digunakan analisis data panel gravity model untuk menganalisis faktor-faktor yang memengaruhi aliran volume ekspor buah-buahan Indonesia (mangga, manggis, rambutan, pisang, dan melon). Pada metode Export Product Dynamic (EPD) dan Revealed Comparative Advantage (RCA) menunjukkan bahwa buah yang memiliki keunggulan komparatif dan kompetitif tertinggi di negara tujuan dan dunia adalah buah manggis, mangga, dan jambu. Ekspor buah Indonesia yang kehilangan kesempatan dalam bersaing di negara tujuan adalah stroberi. Hasil penelitian menunjukkan bahwa faktor yang memengaruhi aliran ekspor buah Indonesia ke negara tujuan meliputi harga ekspor, populasi, jarak ekonomi, GDP riil dan per kapita, nilai tukar riil, indeks harga konsumen Indonesia, dan variabel dummy krisis yang terjadi di Eropa., The success of competitiveness of Indonesian fruits export in the destination countries is determined by comparative and competitive advantage and other factors. Revealed Comparative Advatege (RCA) and Export Product Dynamic (EPD) are used in this research to analyze the position of competitiveness of Indonesian fruits export. This research also uses panel gravity model to analyze the factors which affect the export volume of Indonesia fruits (mango, mangosteen, rambutan, banana, and melon). The results from EPD and RCA method show that fruits which have the highest comparative and competitive advantage in destination countries and the world are mangoesteen, mango, and guava. Indonesian fruits which its export experiences a lost opportunity for competing in the destination countries is strawberry. The results of this research shows that the factors which influence the export of Indonesian fruits the destination conutries are export price, population, economic distance, real GDP and GDP per capita, real exchange rate, Indonesian consumer price index, and dummy variable of crisis which happened in Europe.
Keyword: Dayasaing, EPD, gravity model, RCA

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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