Judul: Analisis Dampak Non-Tariff Measures dan Faktor-Faktor yang Memengaruhi Ekspor Buah-Buahan Indonesia ke Negara Tujuan
Abstrak: Buah-buahan merupakan salah satu komoditas yang menjadi unggulan dalam ekspor sektor hortikultura Indonesia. Adanya hambatan non tarif (non tariff measures/NTMs) dalam perdagangan internasional produk pertanian, khususnya pada buah-buahan Indonesia dapat membuat volume ekspor buah-buahan Indonesia ke negara tujuan mengalami penurunan. Lebih lanjut, hambatan non tarif yang sering diberlakukan adalah kebijakan Sanitary and Phytosanitary (SPS) dan Technical Barries to Trade (TBT). Pada penelitian ini dianalisis dampak NTMs serta faktor-faktor yang memengaruhi ekspor buah-buahan Indonesia pada periode 2010 hingga 2019 ke negara tujuan. Metode yang digunakan pada penelitan ini terdiri dari analisis deskriptif dengan menggunakan pendekatan inventory dan analisis data panel dengan menggunakan model gravity. Hasil analisis inventory menunjukkan bahwa komoditas buah-buahan Indonesia paling banyak dikenakan kebijakan SPS dengan jenis testing requirement. Selanjutnya, hasil estimasi model gravity menunjukkan GDP riil negara pengimpor, GDP riil Indonesia, populasi negara pengimpor, populasi Indonesia, jarak ekonomi, nilai tukar riil, dan coverage ratio SPS berpengaruh signifikan terhadap volume ekspor buah-buahan Indonesia., Fruits are one of the leading commodities in Indonesia's horticultural sector exports. The existence of non-tariff barriers (non-tariff measures/NTMs) in the international trade of agricultural products, especially Indonesian fruit has reduced the volume of Indonesian fruit exports to the destination countries. Furthermore, non-tariff barriers that are often applied are the Sanitary and Phytosanitary (SPS) and Technical Barriers to Trade (TBT) policies. This study analyzes the impact of NTMs and the factors that affect the Indonesian fruits exports in the period 2010 to 2019 to destination countries. The method used in this research consists of descriptive analysis using an inventory approach and panel data analysis using a gravity model. The results of the inventory analysis show that the most Indonesian fruit commodities are subject to the SPS policy with the type of testing requirement. Furthermore, the estimation results of the gravity model show that the real GDP of the importing country, the real GDP of Indonesia, the population of the importing country, the population of Indonesia, the economic distance, the real exchange rate, and the SPS coverage ratio have a significant effect on the volume of Indonesian fruit exports.
Keyword: export, fruits, gravity model, inventory approach, NTMs

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: 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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