Judul: Analysis of the Export Competitiveness of Indonesian Canned Tuna in International Market and the Factors of Affecting It
Abstrak: Indonesia merupakan salah satu negara produsen dan tuna kaleng terbesar di dunia. Akan tetapi, nilai ekspor tuna kaleng Indonesia cenderung lebih kecil dibandingkan nilai ekspor tuna segar. Hal tersebut tentunya dapat menjadi peluang bagi Indonesia untuk mengekspor tuna dalam bentuk kaleng karena dapat meningkatkan devisa negara dan menyerap lebih banyak tenaga kerja. Penelitian ini bertujuan untuk (1) menganalisis daya saing komparatif dan kompetitif komoditas tuna kaleng Indonesia di negara tujuan utama; (2) menganalisis faktor-faktor yang memengaruhi nilai ekspor tuna kaleng Indonesia. Metode analisis yang digunakan adalah Revealed Symetric Comparative Advantage (RSCA), Export Product Dynamic (EPD), X-Model Potential Export Product dan gravity model. Hasil analisis RSCA menunjukkan tuna kaleng Indonesia memiliki keunggulan komparatif di tiga negara tujuan utama. Hasil analisis EPD menunjukkan bahwa Indonesia memiliki daya saing kompetitif di Jepang dan Arab Saudi. Hasil X- Mddel Potential Export Product menunjukkan bahwa Amerika Serikat, Jepang, dan Arab Saudi masih menjadi pasar potensial tuna kaleng Indonesia. Faktor-faktor yang memengaruhi volume ekspor tuna kaleng Indonesia secara signifikan di Amerika Serikat adalah harga ekspor dan jarak ekonomi, di Jepang adalah harga ekspor, dan di Arab Saudi adalah harga ekspor dan GDP riil per kapita Indonesia., Indonesia is one of the largest canned tuna producing countries in the world. However, the export value of Indonesian canned tuna tends to be smaller than the export value of fresh tuna. This of course can be an opportunity for Indonesia to export canned tuna because it can increase the country's foreign exchange and absorb more workers. This study aims to (1) analyze the comparative and competitive competitiveness of Indonesian canned tuna in the main destination countries; (2) analyze the factors that influence the export value of Indonesian canned tuna. The analytical method used is Revealed Symetric Comparative Advantage (RSCA), Export Product Dynamic (EPD), X-Model Potential Export Product andgravity model. RSCA analysis results show that Indonesian canned tuna has a comparative advantage in the three main destination countries. The results of the EPD analysis show that Indonesia has competitive competitiveness in Japan and Saudi Arabia. ResultsX- Model Potential Export Product shows that the United States, Japan, and Saudi Arabia are still potential markets for Indonesian canned tuna. Factors that significantly affect the volume of exports of Indonesian canned tuna in the United States are export prices and economic distance, in Japan are export prices, and in Saudi Arabia are export prices and Indonesia's real GDP per capita. Keywords: HACCP, international trade, regression, SPS, time series
Keyword: HACCP, international trade, regression, SPS, time series

Judul: Competitiveness Analysis of Indonesia’s Tuna Export in International Market
Abstrak: Ikan tuna merupakan salah satu komoditas ekspor unggulan Indonesia dan memiliki potensi yang besar di Indonesia. Meskipun memiliki potensi yang besar, Indonesia hanya menempati urutan kedua sebagai negara produsen ikan tuna di ASEAN. Penelitian ini bertujuan untuk (1) mengkaji struktur pasar tuna Indonesia di pasar internasional, (2) menganalisis daya saing ekspor tuna Indonesia di pasar internasional, serta (3) menganalisis faktor-faktor yang memengaruhi ekspor tuna Indonesia di pasar internasional. Metode penelitian yang digunakan adalah metode analisis data sekunder, sedangkan metode analisis data yang digunakan yaitu Herfindahl Hirschman Index (HHI) dan Concentration Ratio (CR4), Revealed Comparative Advantage (RCA) dan Export Product Dynamic (EPD) serta regresi data panel. Hasil analisis HHI dan CR4 menyatakan bahwa stuktur pasar komoditas tuna segar dan tuna beku adalah pasar persaingan sempurna, sementara struktur pasar pada tuna olahan adalah pasar oligopoli. Analisis RCA menunjukkan bahwa tuna segar, beku dan olahan Indonesia memiliki daya saing kuat di negara tujuan ekspor Amerika dan Jepang. Analisis EPD menerangkan bahwa Indonesia berada pada posisi rising star di pasar Amerika, Perancis dan Bulgaria pada komoditas ikan tuna olahan. Analisis regresi data panel membuktikan bahwa variabel yang memengaruhi nilai ekspor ikan tuna Indonesia di pasar tujuan ekspor adalah harga ekspor ikan tuna.
Keyword: competitiveness, exports, market structure, panel data regression, tuna fish

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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