Judul: Diversification of Indonesian Export Markets to SICA: Competitiveness and Export Determinants of Main Commodities
Abstrak: Pandemi Covid-19 yang melanda seluruh negara membuat perekonomian negara Indonesia terkontaksi sebesar 2,07 % pada tahun 2020 kemudian tumbuh positif pada tahun 2021, pertumbuhan tertinggi disumbang dari sisi pengeluaran yang dicapai oleh komponen ekspor barang dan jasa. Central American Integration System (SICA) merupakan organisasi yang terdiri dari 8 negara di Kawasan Amerika Tengah yang memiliki populasi dan GDP per kapita yang cukup tinggi. Tingginya GDP per kapita menunjukkan daya beli yang tinggi sehingga dapat menjadi peluang bagi Indonesia untuk terus meningkatkan ekspor ke pasar SICA. Penelitian ini bertujuan untuk mengetahui daya saing dan determinan komoditas unggulan. Metode penelitian yang digunakan RCA, EPD, X-Model dan regresi data panel. Analisis regresi menunjukkan variabel yang berpengaruh positif dan signifikan yaitu GDP dan populasi negara importir pada komoditas HS 40, HS 48, dan HS 87, populasi Indonesia pada komoditas HS 48, FDI pada komoditas HS 87, RCA pada semua komoditas. Variabel yang berpengaruh negatif dan signifikan yaitu dummy Covid pada komoditas HS 48 dan 87. Adapun nilai tukar tidak berpengaruh signifikan., The Covid-19 pandemic that hit all countries caused the Indonesian economy to contract by 2,07% in 2020 and then expand in 2021. The highest growth was contributed by the expenditure side which was achieved by the component of exports of goods and services. The Central American Integration System (SICA) is an organization consisting of 8 countries in the region of Central America, which has a fairly high population and level of GDP per capita. The high level of GDP per capita shows high purchasing power, which indicates an opportunity for Indonesia to continue to increase exports to the SICA market. This study aims to determine the competitiveness and determinants of superior commodities. The research method used is RCA, EPD, X-Model and panel data regression. Regression analysis shows that the variables that have a positive and significant effect are GDP and the population of the destination country on HS 40, HS 48, and HS 87 commodities, the Indonesian population on HS 48 commodities, FDI on HS 87 commodities, and RCA on all commodities. The variable that has a negative and significant effect is the Covid dummy on HS 48 and 87 commodities. The exchange rate has no significant effect.
Keyword: dummy Covid, export, panel data regression, RCA, SICA

Judul: Analisis Daya Saing dan Dampak Ekspor Perabotan Indonesia ke CARICOM
Abstrak: Indonesia tidak luput dari dampak guncangan ekonomi akibat pandemi. Perabotan adalah salah satu produk unggulan komoditas hasil industri di Indonesia. Ketergantungan pasar ekspor pada negara tujuan utama (tradisional) mendorong Indonesia melakukan diversifikasi pasar. Salah satu upaya diversifikasi adalah dengan menjajaki kemungkinan perundingan perdagangan dengan CARICOM. Penelitian ini bertujuan untuk menganalisis daya saing, dinamika dan determinan ekspor perabotan Indonesia ke CARICOM. Metode penelitian yang digunakan dalam penelitian ini adalah RCA, EPD, X-Model, dan regresi data panel. Hasil analisis RCA menunjukkan perabotan Indonesia berdaya saing tinggi. Hasil analisis EPD menunjukkan pengembangan pasar rising star dan lost opportunity. Hasil analisis X-Model menunjukkan pengembangan pangsa pasar optimis dan potensial. Hasil analisis regresi data panel menunjukkan bahwa variabel yang berpengaruh positif dan signifikan yaitu GDP riil negara tujuan, nilai tukar dan RCA. Variabel yang berpengaruh negatif dan signifikan yaitu populasi dan dummy Covid-19. Sementara variabel yang tidak signifikan yakni harga ekspor., Indonesia has not escaped the impact of the pandemic. Furniture is one of top commodity products in Indonesia. The dependence of the export market on the main (traditional) destination countries encourages Indonesia to diversify its markets. One of Indonesia’s efforts to diversify the export market is by exploring the possibility of trade negotiations with CARICOM. This study aims to analyze the competitiveness, dynamics, and determinants of furniture from Indonesia to CARICOM. The research methods used in this study are RCA, EPD, X-Model, and panel data regression. The results of RCA analysis show that Indonesian furniture is highly competitive. The results of the EPD analysis show the development of the rising star market and lost opportunity. The results of the X-Model analysis show the development of optimistic market share and potential market share. Panel data regression analysis results show that the positive and significant influential variables are the real GDP of the target country, exchange rate, and RCA. The negative and significant influencing variables are population and dummy Covid-19. While the non-significant variables are export prices.
Keyword: CARICOM, diversification, export, furniture, panel data regression

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: