Judul: Competitiveness and Factors Affecting Indonesian Seaweed and Carrageenan Exports to Major Destination Countries
Abstrak: Indonesia merupakan eksportir rumput laut kedua di dunia. Sedangkan Indonesia sebagai eksportir karagenan ketiga di dunia tahun 2019. Penelitian ini bertujuan untuk menganalisis daya saing dan mengetahui faktor-faktor yang memengaruhi ekspor rumput laut dan karagenan Indonesia ke negara tujuan utama masing-masing. Periode waktu yang dianalisis, yaitu tahun 2015 hingga 2019 dengan metode analisis RCA, EPD, dan regresi data panel. Hasil perhitungan RCA menunjukkan bahwa ekspor rumput laut dan karagenan Indonesia berdaya saing kuat ke negara tujuan utamanya masing-masing. Hasil perhitungan EPD menunjukkan posisi pasar rumput laut Indonesia menempati posisi pasar Rising Star di lima negara tujuan ekspor, yaitu China, Denmark, Vietnam, Chili, dan Korea Selatan. Sedangkan Prancis dan Spanyol menempati posisi pasar Falling Star. Hasil perhitungan menggunakan metode EPD menunjukkan posisi pasar karagenan Indonesia menempati posisi pasar Rising Star di empat negara tujuan ekspor, yaitu China, Belanda, Amerika Serikat, dan Rusia. Kemudian Australia dan Jepang menempati posisi pasar Falling Star. Sedangkan Jerman menempati posisi pasar Retreat. Hasil analisis regresi data panel menunjukkan variabel harga ekspor, populasi, serta nilai tukar riil berpengaruh secara signifikan terhadap volume ekspor rumput laut dan karagenan Indonesia, sedangkan PDB riil tidak berpengaruh secara signifikan., Indonesia is the second exporter of seaweed in the world. Meanwhile, Indonesia is the third carrageenan exporter in the world in 2019. This study aims to analyze competitiveness and determine the factors that influence the export of Indonesian seaweed and carrageenan to their respective main destination countries. The time period analyzed is 2015 to 2019 using the RCA, EPD, and panel data regression analysis methods. The results of the RCA calculation show that Indonesia's seaweed and carrageenan exports are highly competitive to their respective main destination countries. The results of the EPD calculation show that the Indonesian seaweed market is in the Rising Star market position in five export destination countries, namely China, Denmark, Vietnam, Chile, and South Korea. Meanwhile, France and Spain occupy the position of the Falling Star market. The results of calculations using the EPD method show that Indonesia's carrageenan market position occupies the Rising Star market position in four export destination countries, namely China, the Netherlands, the United States, and Russia. Then Australia and Japan occupy the position of the Falling Star market. Meanwhile, Germany occupies the position of the Retreat market. The results of panel data regression analysis show that the variables of export prices, population, and real exchange rates have a significant effect on the export volume of Indonesian seaweed and carrageenan, while real GDP has no significant effect.
Keyword: Carrageenan, EPD, Panel Data, RCA, Seaweed

Judul: Analisis Daya Saing Ekspor Rumput Laut Indonesia ke Negara Tujuan
Abstrak: Indonesia merupakan pemasok utama rumput laut (raw material) di dunia, namun dalam mengembangkan ekspornya masih menghadapi berbagai masalah sehingga menuntut Indonesia untuk dapat meningkatkan daya saing rumput laut supaya dapat bertahan dan bersaing di pasar internasional. Penelitian ini bertujuan untuk 1) menganalisis faktor-faktor yang memengaruhi nilai ekspor rumput laut (raw material) Indonesia ke negara tujuan dan 2) Menganalisis daya saing komoditas rumput laut (raw material) Indonesia melalui pendekatan keunggulan komparatif dan kompetitif. Metode yang digunakan dalam penelitian ini adalah Gravity Model, RCA, EPD, dan Porter’s Diamond. Hasil estimasi gravity model menunjukkan bahwa variabel harga ekspor rumput laut Indonesia ke negara tujuan dan populasi negara tujuan memengaruhi nilai ekspor rumput laut Indonesia ke negara tujuan. Hasil analisis RCA menunjukkan bahwa Indonesia memiliki daya saing kuat di negara tujuan Cina, Chili, Korea Selatan, Vietnam, Filipina, Hongkong, Perancis, Spanyol, dan Denmark. Hasil analisis EPD menunjukkan bahwa ekspor rumput laut Indonesia berada di posisi rising star, lost opportunity, falling star dan retreat. Hasil Porter’s Diamond menunjukkan bahwa komponen faktor, kondisi permintaan, peran pemerintah, dan peran kesempatan merupakan kekuatan yang di butuhkan untuk ekspor rumput laut Indonesia, sedangkan industri terkait dan pendukung, dan struktur, strategi, dan persaingan perusahaan merupakan kelemahan dalam hal penunjang ekspor., Indonesia is the main supplier of seaweed (raw material) in the world, but in developing its exports it still faces various problems, thus demanding Indonesia to increase the competitiveness of seaweed so that it can survive and compete in the international market. This study aims to 1) analyze the factors that affect the export value of Indonesian seaweed to the destination country, and 2) analyze the competitiveness of Indonesian seaweed commodities (raw material) through a comparative and competitive advantage approach. The method used in this research is Gravity Model, RCA, EPD, and Porter’s Diamond. The estimation results of the gravity model show that the variable price of Indonesian seaweed exports to the destination country and the population of the destination country affect the export value of Indonesian seaweed to the destination country. The results of the RCA analysis show that Indonesia has strong competitiveness in the destination countries of China, Chile, South Korea, Vietnam, the Philippines, Hong Kong, France, Spain, and Denmark. The results of the EPD analysis show that Indonesia's seaweed exports are in the position of the rising star, lost opportunity, falling star, and retreat. Porter's Diamond results show that the component factors, demand conditions, the role of government, and the role of opportunity are the strengths needed for Indonesian seaweed exports, while the related and supporting industries, and the structure, strategy, and company competition are weaknesses in terms of supporting exports.
Keyword: EPD, export value, gravity model, porter's diamond, RCA

Judul: Penyelesaian model infeksi HIV pada sel darah Putih (T CD4+) dengan menggunakan metode perturbasi homotopi
Abstrak: Acquired immunodefficiency syndrome (AIDS) is defined as symptoms of human immune system deterioration caused by human immunodefficiency virus (HIV). The virus damages the leucocytes; therefore, once a person is infected by the HIV, his/her immune system will be paralyzed and eventually he/she will not be able to survive from any disease. HIV is transmitted in many ways, such as having unsafe sex, using unsterilized syringe and blood transfusion. Homotopy perturbation method is implemented to give approximate and analytical solutions of nonlinear ordinary differential equation systems as a model for HIV infection of CD4+ T cells. A modification of the homotopy perturbation method (HPM), based on the use of numerical solution, is proposed. Some plots are presented to show the reliability and simplycity of the homotopy perturbation method. The results obtained in this study indicate that the homotopy perturbation method is highly efficient to solve models of HIV infection of cells (T CD4+). Errors resulting from this method is so small that the solution obtained by is very close to the exact solution.
Keyword: