Judul: Analysis of Competitiveness, Potential,  and Factors Affecting Indonesian Whole Pepper Exports to Main Destination  Countries
Abstrak: Salah satu komoditas unggulan ekspor perkebunan yang menjadi sumber pendapatan negara yang bernilai tinggi adalah lada utuh. Penelitian ini bertujuan untuk menganalisis daya saing dan pasar potensial untuk ekspor lada utuh yang bisa dikembangkan, serta mengetahui faktor-faktor yang memengaruhi ekspor komoditas lada utuh. Periode yang digunakan pada penelitian ini yaitu 2010-2020 dengan menggunakan metode RCA, EPD, X-Model, dan regresi data panel. Hasil penelitian menunjukkan bahwa lada utuh memiliki keunggulan komparatif yang kuat di seluruh negara tujuan ekspor yang diteliti, sementara pangsa pasar lada utuh Indonesia sebagian besar menempati posisi falling star dengan pengembangan pasar potensial. Hasil analisis dengan regresi data panel menunjukkan bahwa PDB per kapita negara tujuan, harga ekspor, nilai tukar riil, jarak ekonomi, dummy Covid-19, dan dummy kebijakan TBT berpengaruh signfikan terhadap volume ekspor lada utuh Indonesia sedangkan variabel dummy kebijakan SPS tidak berpengaruh signfikan terhadap ekspor lada utuh Indonesia ke negara tujuan utama., One of the leading export commodities of plantations which is a source of high-value state income is whole pepper. This study aims to analyze the competitiveness and potential market for whole pepper exports that can be developed, as well as to determine the factors that affect the export of whole pepper commodities. The period used in this study is 2010-2020 using the RCA, EPD, X-Model, and panel data regression methods. The results showed that whole pepper has a strong comparative advantage in all export destination countries studied, while the market share of Indonesian whole pepper mostly occupies a falling star position with potential market development. The results of the analysis with panel data regression showed that the GDP per capita of the destination country, export prices, real exchange rates, economic distance, the Covid-19 dummy, and the TBT policy dummy had a significant effect on the volume of Indonesian whole pepper exports, while the SPS policy dummy variable had no significant effect on Indonesian whole pepper exports to main destination countries.
Keyword: panel data, EPD, RCA, whole pepper, X-Model

Judul: Competitiveness Analysis and Factors Affecting of Indonesian Ground Pepper Export
Abstrak: Lada bubuk merupakan salah satu produk turunan dari lada yang mengalami proses pengolahan lebih lanjut dengan dihancurkan atau ditumbuk. Ekspor lada bubuk masih kurang diminati oleh negara-negara pengimpor bila dibandingkan dengan lada utuh. Hal ini dapat dilihat dari nilai ekspornya yang hanya mencapai seperempatnya yaitu sebesar 4.645.621.000 US dollar. Sedangkan ekspor lada utuh mencapai 16.264.857.000 US dollar. Lada bubuk Indonesia mulai meningkat volume dan nilai ekspornya pada tahun 2012. Tujuan penelitian ini untuk menganalisis daya saing dan faktor-faktor yang memengaruhi ekspor lada bubuk Indonesia ke enam negara tujuan utama yang meliputi Jepang, Belanda, Australia, USA, Inggris, dan Belgia. Analisis dilakukan dengan metode Revealed Comparative Advantage (RCA) dan gravity model. Hasil analisis menunjukkan bahwa lada bubuk Indonesia memiliki keunggulan komparatif di Jepang, Belanda, Inggris dan Belgia. Variabel yang berpengaruh signifikan terhadap ekspor lada bubuk Indonesia adalah nilai tukar. Sedangkan variabel yang tidak berpengaruh signifikan adalah harga lada bubuk, GDP per kapita negara tujuan, populasi negara tujuan, dan jarak ekonomi., Ground Pepper is one of the derivative products of pepper that undergoes further processing by finishing or grinding. Exports of Indonesian ground pepper are still less attractive to importing countries than whole pepper. This can be seen from the export value which only reached a quarter of US dollar 4,645.621,000. Meanwhile, whole pepper exports reached US dollar 16,264,857,000. Indonesian ground pepper began to increase in volume and value of exports in 2012. The purpose of this study is to analyze the competitiveness and factors that influence exports of Indonesian pepper powder to six central destination countries which include Japan, the Netherlands, Australia, the USA, the UK, and Belgium. The analysis was carried out using the Revealed Comparative Advantage (RCA) method and the gravity model. The results of the analysis show that Indonesian ground pepper has a comparative advantage in Japan, the Netherlands, the UK, and Belgium. The variable that has a significant effect on the export of Indonesian pepper powder is the exchange rate. While the variables that do not have a significant effect are the price of ground pepper, GDP per capita of the destination country, the population of the destination country, and economic distance.
Keyword: daya saing, gravity model, lada bubuk

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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