Judul: Overview of agribusiness and factors that influence the Indonesian Seaweed
Abstrak: The development of seaweed cultivation in Indonesia in the last decade has grown very fast. Since 2007 Indonesia has become the largest seaweed producer in the world. Fifty percent of seaweed from the tropical regions in the world are produced in Indonesia. In the period of 2005-2010, the export of Indonesian seaweed continued to increase with an average of seventeen percent growth per year. While the value of exports FOB Indonesia increased by fifty-one percent over six years. The average growth of seaweed production in six years increased by forty percent. Indonesia's exports are mostly in the form of dried seaweeds with the major destination countries: China, the Philippines, Hong Kong, South Korea, Denmark, and Italy. The objectives of this study are (1) to analyze the factors that affect the production, demand and price of domestic seaweed (2) analyze the factors that affect the Indonesian seaweed exports to China, Hong Kong and the Philippines (3) to analyze policy alternatives in order to increase Indonesian seaweed production. The secondary data (time series) in was collected from 1989 until 2011. The model in this study was analyzed using the SAS program 2SLS method. The factors that affect the production of Indonesian seaweed significantly were budget of the Ministry of Marine Affairs Fisheries MMAF, the world price of seaweed and trends. Factors that affect the domestic demand of seaweed significantly were the population of Indonesia and carageenan price. The price of domestic seaweed was significantly influenced by the price of domestic seaweed in the previous year. Factor that significantly affects seaweed exports to the Philippines was the seaweed domestic price in the previous year. While the factor affecting exports to China was the Chinese national income and the factors that affect the seaweed exports to Hong Kong were the domestic price of seaweed in the previous year, import tariffs imposed by Hong Kong and the world price of seaweed. Production, demand and price of domestic seaweed is influenced by the Indonesian government policy. Policies pursued by MMAF in increasing domestic seaweed production and exports are needed to be implemented, where concrete step is by increasing with increased government budget.
Keyword: agribusiness, export, price, seaweed.

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: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular