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: Posisi Daya Saing dan Faktor-Faktor yang Memengaruhi Ekspor Manggis, Mangga, dan Jambu Indonesia ke Negara Tujuan Ekspor
Abstrak: Penelitian ini bertujuan untuk menganalisis daya saing dan faktor-faktor yang memengaruhi aliran ekspor manggis, mangga, dan jambu Indonesia ke negara tujuan ekspor. Penelitian ini menggunakan data time series tahun 2012 sampai 2016 pada 20 negara tujuan ekspor. Hasil analisis RCA menunjukkan bahwa manggis, mangga, dan jambu Indonesia memiliki daya saing di 11 negara tujuan ekspor yaitu Bahrain, Denmark, Perancis, Hong Kong, Kuwait, Malaysia, Oman, Qatar, Thailand, Uni Emirat Arab dan Vietnam. Hasil analisis EPD manggis, mangga, dan jambu Indonesia di pasar Bahrain dan Swiss berada pada posisi Rising Star. Di negara Amerika Serikat dan Uni Emirat Arab manggis Indonesia berada di posisi Lost Opportunity. Posisi dayasaing Falling Star di Cina, Denmark, Perancis, Jerman, Hong Kong, Italia, Kuwait, Malaysia, Oman, Qatar, Saudi Arabia, Spanyol, Thailand, dan Vietnam. Sedangkan pasar manggis, mangga, dan jambu Indonesia di negara Singapura berada pada posisi Retreat. Hasil analisis gravity model menunjukkan bahwa variabel yang berpengaruh signifikan terhadap permintaan ekspor manggis, mangga, dan jambu adalah GDP riil, nilai tukar riil, jarak ekonomi, dan harga ekspor manggis Indonesia.
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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