Judul: The strategy to achieve sugar self-sufficiency program in central java
Abstrak: Gula merupakan komoditas pangan yang sampai saat ini belum tergantikan dengan bahan pangan lain sebagai pemanis buatan. Tujuan dari penelitian ini adalah mengestimasi konsumsi dan produksi gula di Jawa Tengah dan merumuskan alternatif strategi yang sesuai untuk mencapai target swasembada. Penelitian ini menggunakan metode ARIMA untuk menghasilkan peramalan jangka pendek yang akurat dan metode AHP untuk menentukan strategi yang tepat dan efektif. Hasil dari penelitian ini adalah Jawa Tengah belum mampu mencapai swasembada sesuai target 2014-2018 terkait dengan permasalahan baik dalam on-farm maupun offfarm. Kriteria yang perlu ditingkatkan adalah rendemen dan produktivitas (29,5%), revitalisasi pabrik gula (27,1%) dan teknologi atau alat ukur rendemen (19,3%) . Untuk mendukung tiga kriteria tersebut perlu adanya kerjasama antara pabrik gula dan petani yaitu dalam sistem bagi hasil, kredit murah dan mudah, dan kerjasama maupun kemitraan supaya program swasembada dapat dicapai secara berkelanjutan., Sugar is a food commodities that until now has not been replaced by other foodstuffs as sweetener. The aim of this research was to estimate the consumption and production of sugar in Central Java and to formulate the alternative strategy which is suitable to obtain the self-sufficiency target. This research used ARIMA method to produce an accurate short-term forecasting and AHP method to determine the right and effective strategy. The results showed that Central Java had not been able to reach self-suffiency as targeted 2014-1018 related to both problems, on-farm or off-farm. The criteria that must be increased were the yield and productivity (29%), revilatization of sugar plant (27,1%) and technology and yield measuring instrument (19,3%). To support those three criteria, the cooperation between sugar plant and farmer is needed. The cooperation could be in the forms of income sharing system, cheap and easy credit, and cooperation or partherships so that the self-sufficiency program could be obtained continously.
Keyword: AHP, ARIMA, gula, strategi, swasembada

Judul: The Affecting Factors of Sugar Production in Indonesia due to National Sugar Self Sufficiency
Abstrak: Untuk memenuhi peningkatan konsumsi gula, pemerintah sedang gencar mendorong peningkatan produksi gula dengan target dapat berswasembada gula nasional. Akan tetapi, produktivitas gula saat ini tergolong rendah, dan produksi gula pun mengalami tren penurunan setiap tahunnya. Tujuan penelitian ini yaitu mendeskripsikan perkembangan agribisnis gula, menganalisis faktor-faktor yang memengaruhi produksi gula di Indonesia, dan meramalkan pencapaian swasembada gula Indonesia tahun 2025. Data yang digunakan berupa data runtun waktu dari tahun 1966-2019 dan dianalisis menggunakan metode VECM. Hasil analisis menunjukkan bahwa pada jangka pendek, produksi gula dipengaruhi oleh luas areal panen tebu dan konsumsi gula, sedangkan pada jangka panjang produksi gula dipengaruhi oleh konsumsi gula, impor gula, dan harga GKG. Peramalan hingga tahun 2025 menunjukkan bahwa ketergantungan Indonesia terhadap gula impor cenderung meningkat, sehingga Indonesia tidak dapat memenuhi target swasembada gula tahun 2025., In order to fulfill the increasing of sugar consumprtion, government is aggressively encouraging an increase in sugar production to achieve sugar selfsufficiency. However, the sugar production still has low productivity, and decreasing trend each year. This study aims to describe the growth of sugar agribusiness, analyze the affecting factors of sugar production, and forecast the achievement of sugar self-sufficiency in 2025. The data has been used in this study is time series data from 1966 until 2019, and analyzed by VECM method. The result of the analysis shows that, in the short term sugar production are affected by sugarcane harvest area and sugar consumption, while in long term, sugar production are affected by sugar consumption, sugar import, and price of paddy. Forecasting until 2025 shows that Indonesia's dependence on imported sugar tends to increase, so that Indonesia cannot achieve the sugar self-sufficiency target in 2025.
Keyword: production, self sufficiency, sugar, VECM

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: