Judul: Analisis Daya Saing dan Faktor-Faktor yang Memengaruhi Aliran Ekspor Mangga Indonesia ke Negara Tujuan
Abstrak: Mangoes are Indonesian local fruit which have value and volume of export that increase from 2001 to 2011. The aim of this research is to analyze the competitiveness of Indonesian local mango in global market and to determine factors which affect it to be exported to target countries. RCA method shows Indonesian mango comparative strength, comparing to some countries which are UEA, Kuwait, Saudi Arabia, Hongkong, Malaysia and Singapore. IIT method shows bilateral economic relationship between Indonesia with Malaysia and Singapore. EPD method shows comparative strength of Indonesian mangoes, “Rising Star” in Malaysian and Singaporean market, “Falling star” in UEA, Kuwait and Hongkong, “Retreat” in Saudi Arabian market. Based on estimation of Gravity Model, the factor of GDP per capita riil of target countries, economical distance, and the price of mangoes in the global market could affect significantly to the demand of export of Indonesian local mango and the factor of exchange rate of rupiah to target countries is not affecting significantly
Keyword: mangoes, gravity model, competitiveness

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.
Keyword: