Judul: Comparative Competitiveness And Determinants Of Indonesia-Australia Coal-Derived Product Exports to Asian Markets
Abstrak: Batubara merupakan salah satu komoditas unggulan ekspor bagi Indonesia dan Australia. Kedua negara, sebagai salah satu produsen dan eksportir batubara terbesar dunia, kini fokus pada ekspor batubara olahan seperti batubara bitumen (HS 270112) untuk meningkatkan daya saing. Metode yang digunakan meliputi Revealed Comparative Advantage (RCA), Export Product Dynamic (EPD), X- Model, dan regresi data panel. Hasil RCA menunjukkan produk turunan batubara Indonesia dan Australia memiliki daya saing tinggi di sepuluh negara Asia. EPD mengungkapkan posisi Indonesia di China dan Hongkong berada pada posisi rising star. Sementara Australia berada pada posisi rising star di Hongkong, India, Jepang, dan Vietnam. X-Model menunjukkan prospek pasar optimis bagi Australia di lima negara dan Indonesia di dua negara kawasan Asia. Regresi data panel menunjukkan bahwa GDP per kapita, RCA, dan harga ekspor berpengaruh positif dan signifikan, sedangkan inflasi, REER, dan dummy Covid-19 berpengaruh negatif dan signifikan. Variabel LPI tidak berpengaruh signifikan terhadap nilai ekspor produk turunan batubara.
Keyword: daya saing, ekspor, batubara

Judul: Comparative Analysis of Export Competitiveness of Coconut Shell Charcoal Products from ASEAN Countries in the Japanese Market
Abstrak: Jepang menempati posisi utama sebagai negara pengimpor terbesar untuk produk arang tempurung kelapa dunia (HS 440290) yang sebagian besar diimpor dari wilayah ASEAN. Sebagai negara eksportir terbesar arang tempurung kelapa dunia, nilai ekspor arang tempurung kelapa Indonesia di pasar Jepang masih menunjukkan kondisi yang fluktuatif. Hal ini menunjukkan bahwa praktik ekspor arang tempurung kelapa Indonesia di pasar Jepang belum optimal dan terdapat potensi nilai ekspor yang belum dimanfaatkan (untapped potential). Penelitian ini bertujuan untuk menganalisis posisi dan potensi daya saing ekspor arang tempurung kelapa Indonesia di pasar Jepang dikomparasikan dengan negara ASEAN lainnya. Penelitian ini menggunakan metode TBI, RCA, RSCA, EPD, Product Mapping, dan X-Model. Hasil analisis TBI menunjukkan bahwa Indonesia cenderung berperan sebagai net-exporter pada tahap kematangan ekspor bersamaan dengan Malaysia, Vietnam, dan Laos. Hasil analisis RCA dan Product Mapping menunjukkan bahwa Indonesia memiliki daya saing komparatif di pasar Jepang bersamaan dengan Laos dan Malaysia. Sementara itu, dilihat dari sisi EPD dan X-Model, arang tempurung kelapa Indonesia didominasi posisi retreat dan pasar kurang potensial., Japan occupies the main position as the largest importing country for the world's coconut shell charcoal products (HS 440290), most of which are imported from the ASEAN region. As the world's largest exporter of coconut shell charcoal, the value of Indonesia's coconut shell charcoal exports to the Japanese market is still fluctuating. This shows that the practice of exporting Indonesian coconut shell charcoal in the Japanese market is not optimal and there is an untapped potential for export value. This study aims to analyze the position and potential competitiveness of Indonesia's coconut shell charcoal exports in the Japanese market compared to other ASEAN countries. This study used TBI, RCA, RSCA, EPD, Product Mapping, and X-Model methods. The results of the TBI analysis show that Indonesia tends to act as a net-exporter at the export maturity stage along with Malaysia, Vietnam and Laos. The results of RCA and Product Mapping analysis show that Indonesia has comparative competitiveness in the Japanese market along with Laos and Malaysia. Meanwhile, from the perspective of EPD and X-Model, Indonesian coconut shell charcoal is dominated by retreat positions and a less potential market.
Keyword: posisi ekspor, potensi ekspor, produk turunan kelapa, spesialisasi ekspor

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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