Judul: Competitivenes of Indonesian Gum Rosin in Global Market in the Period 2004-2020
Abstrak: Indonesia merupakan negara produsen terbesar ketiga setelah China dan Brazil yang menyumbangkan lebih dari 10% produksi gondorukem dunia pada tahun 2019. Indonesia juga menduduki urutan kedua setelah Brazil sebagai negara pengekspor komoditas gondorukem terbesar di dunia. Sejak tahun 2015 perkembangan ekspor gondorukem Indonesia menunjukkan tren yang menurun meskipun masih tetap merupakan negara utama di pasar gondorukem internasional. Penelitian ini bertujuan untuk menganalisis daya saing komparatif dan kompetitif serta faktor-faktor yang mempengaruhi pertumbuhan ekspor gondorukem Indonesia pada periode 2004-2020. Metode analisis yang digunakan berturut-turut adalah Revealed Comparative Advantage, Indeks Spesialisasi Perdagangan, dan Constant Market Share. Hasil penelitian menunjukkan bahwa komoditas gondorukem Indonesia selama periode 2004-2020 memiliki daya saing komparatif yang kuat seperti yang ditunjukkan oleh nilai indeks RCA berkisar 5,5-19,4 dan juga daya saing kompetitif kuat seperti yang ditunjukkan oleh nilai indeks ISP berkisar 0,78-0,97. Indonesia telah mencapai tahap kematangan di pasar internasional pada periode 2004-2020. Di samping faktor daya saing, faktor pertumbuhan standar dan faktor distribusi pasar berpengaruh positif terhadap pertumbuhan ekspor gondorukem Indonesia pada periode 2004-2020., Indonesia was the third largest producer country after China and Brazil that contributed more than 10% of the world's gum rosin production in 2019. Indonesia was also ranked second after Brazil as the largest gum rosin commodity exporter in the world. Since 2015 Indonesian’s gum rosin exports had a declining trend even though Indonesia was still the main exporter country in the international gum rosin market. The purpose of this study were to analyze the comparative and competitive advantages as well as factors influencing the growth of Indonesia's gum rosin exports in the period 2004-2020. The analytical methods used were Revealed Comparative Advantage, Trade Specialization Index, and Constant Market Share, respectively. The results showed that the Indonesian gum rosin commodity during the period 2004-2020 had a strong comparative advantage as indicated by RCA index value ranging from 5,5-19,4 and also a strong competitive advantage as indicated by the ISP index value ranging from 0,78-0,97. Indonesian reached the maturity stage in the international market for the 2004-2020 period. In addition to competitiveness factor, market growth and market distribution factors had a positive influence on Indonesia's gum rosin export growth for the period 2004-2020.
Keyword: Constant market share, export, gum rosin, trade specialization index, revealed comparative advantage

Judul: Competitiveness Analysis of Indonesian Lac,  Gums, and Resins Commodities in Global Market on 2018-2021 period
Abstrak: Permintaan komoditas lak, gum, dan resin terus meningkat di pasar dunia. Sebagai produk HHBK yang dibutuhkan pada berbagai sektor industri, hal ini menjadi peluang bagi Indonesia untuk terus meningkatkan daya saingnya. Penelitian ini bertujuan menganalisis daya saing komparatif dan kompetitif serta faktor-faktor yang mempengaruhi ekspor komoditas lak, gum, dan resin Indonesia di pasar dunia periode 2018-2021. Komoditas lak, gum, dan resin yang dianalisis meliputi Gum arabic (HS 130120) serta Lac; natural gums, resins, gum-resins, balsams and other natural oleoresins (exclude Gum arabic) (HS 130190). Penelitian ini menggunakan tiga metode analisis yaitu RCA untuk mengukur keunggulan komparatif, ISP untuk mengukur keunggulan kompetitif, dan CMS untuk mengetahui faktor-faktor yang mempengaruhi nilai ekspor produk. Hasil penelitian menunjukkan bahwa produk HS 130190 memiliki daya saing yang kuat dan berada pada tahap kematangan di pasar dunia. Produk HS 130120 memiliki daya saing yang lemah dan masih dalam tahap pengenalan ekspor di pasar dunia. Faktor yang memberikan kontribusi positif terhadap analisis CMS adalah komposisi komoditas, pertumbuhan standar, dan daya saing, sedangkan distribusi pasar memberikan nilai negatif., Demand for lac, gums, and resins commodities continues to increase in the world market. As part of NTFP products needed in various industrial sectors, this is an opportunity for Indonesia to continue to improve its competitiveness. The purpose of this study is to analyze the comparative and competitive competitiveness and factors influencing the export of Indonesian lac, gums, and resins commodities in the world market on 2018-2021 period. Lac, gums, and resins commodities analyzed included Gum arabic (HS 130120) and Lac; natural gums, resins, gum- resins, balsams and other natural oleoresins (exclude Gum arabic) (HS 130190). This study uses three analysis methods that is Revealed Comparative Advantage (RCA) to measure product comparative advantage, Trade Specialization Index (ISP) to measure product competitive advantage, and Constant Market Share (CMS) to find out the factors that influence the value of product exports. The results show that HS 130190 products have a strong level of competitiveness and already classified on the maturity stages of exports in the world market. Besides, HS 130120 products is less competitive and are still in the introduction stages of exports in the world market. Factors that contributed positively to the CMS analysis were commodity composition, standard growth, and competitiveness, while market distribution give a negative value.
Keyword: Constant Market Share, competitiveness, lac, gums, and resins commodities, Revealed Comparative Advantage, Trade Specialization Index

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: