Judul: Analisis daya saing ekspor komoditas kakao Indonesia di bandingkan dengan Malaysia di pasar Singapura tahun 2003-2013
Abstrak: Cocoa plantation sector has the potential to contribute greatly to the development of Indonesian exports. Since the implementation of tax policy on cocoa beans 1 April 2010 led to the Indonesia's cocoa export into a significant decline. On the other hand, tax policy for the export of cocoa beans in April 2010 to make Indonesian cocoa processing industry shows growth. The objective of this study is to analyze the Indonesia's cocoa export competitiveness than malaysia's in Singapore as one of the cocoa export destinations in ASEAN. Data used in this study is secondary data in the form of time series data trade Indonesia, Malaysia and the world with Singapore in the period 2003-2013. The method used in this study is Revealed Compare Analysis (RCA) to determine Indonesia and Malaysia cocoa competitiveness. Constant Market Share (CMS) method is for decomposing the growth determinants of Indonesia and Malaysia cocoa exports to singapore. Based on the comparison of the value of cocoa RCA Indonesia and Malaysia in the Singapore market over the period 2003-2013 is seen that the value of RCA Indonesia is still higher compared to Malaysia for cocoa beans, while the value of Indonesia's RCA on processed cocoa products is lower than Malaysia. Based on the results of the CMS in Indonesia, the average growth of Indonesian cocoa exports to Singapore in the period 2003-2009 is more influenced by the effects of the commodity composition effect, while the growth rate in 2010-2013 CMS Indonesia is more influenced competitiveness effect.
Keyword: Bogor Agricultural University (IPB), RCA, export tax, CMS, competitiveness, cocoa

Judul: Competitiveness of Indonesian Cocoa  Beans and Processed Cocoa Products in the International Market
Abstrak: Kakao memberikan kontribusi pendapatan nasional ketiga tertinggi setelah karet dan kelapa sawit. Sebagian besar kakao Indonesia diekspor dalam bentuk biji. Namun, setelah adanya kebijakan bea keluar terhadap biji kakao terjadi perubahan struktur ekspor yang semula didominasi biji bergeser menjadi produk olahan. Penelitian ini bertujuan untuk mengevaluasi perkembangan dan struktur ekspor kakao setelah adanya kebijakan bea keluar dan menganalisis daya saing biji kakao Indonesia dan beberapa produk olahannya. Metode yang digunakan adalah indeks Revealed Comparative Advantage (RCA), Indeks Spesialisasi Perdagangan (ISP), dan Export Product Dynamics (EPD). Hasil penelitian menunjukkan bahwa daya saing biji kakao Indonesia setelah adanya kebijakan bea keluar diukur dengan metode RCA mengalami penurunan signifikan bahkan pada tahun 2016 sampai 2018 nilai RCA biji kakao Indonesia kurang dari satu yang artinya biji kakao Indonesia tidak memiliki keunggulan komparatif. Sedangkan daya saing produk olahan kakao Indonesia kecuali coklat mengalami peningkatan, nilai RCA pasta kakao, lemak kakao, dan bubuk kakao menunjukkan ketiga produk tersebut memiliki keunggulan komparatif., Cocoa provides the third highest contribution to national income after rubber and palm oil. Most of Indonesia's cocoa is exported in the form of beans. However, after the export tax policy for cocoa beans, there was a change in the export structure, which was originally dominated by cocoa beans, shifted to processed products. This study aims to evaluate the development and structure of cocoa exports after the export tax policy and to analyze the competitiveness of Indonesian cocoa beans and some of their processed products. The methods used are Revealed Comparative Advantage (RCA), Trade Specialization Index (ISP), and Export Product Dynamics (EPD). The results showed that the competitiveness of Indonesian cocoa beans after the export tax policy measured by the RCA method decreased significantly, even 2016 to 2018 the RCA value of Indonesian cocoa beans was less than one, meaning that Indonesian’s cocoa beans did not have a comparative advantage. While the competitiveness of processed Indonesian cocoa products except chocolate has increased, the RCA value of cocoa paste, cocoa butter, and cocoa powder shows that these three products have a comparative advantage.
Keyword: Cocoa Beans, Cocoa Processed Products, Exports, 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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