Judul: The Influence of farm Inputs on the Productivity and Risk of Clove Production in East Java Province
Abstrak: Permintaan cengkeh di pasar nasional dan internasional diprediksikan akan terus meningkat setiap tahunnya. Namun selama tahun 2015-2021, tingkat produktivitas cengkeh di Provinsi Jawa Timur sebagai salah satu produsen terbesar cengkeh di Indonesia terus mengalami fluktuasi dan cenderung menurun. Penelitian ini bertujuan untuk menganalisis faktor yang mempengaruhi produktivitas dan risiko produksi cengkeh di Jawa Timur. Data yang digunakan pada penelitian ini adalah data sekunder berjumlah 937 petani yang dianalisis menggunakan model Just and Pope. Hasil analisis menunjukkan bahwa tingkat risiko produksi cengkeh di Jawa Timur tergolong tinggi karena nilai CV > 0,5. Adapun faktor yang berpengaruh meningkatkan produktivitas cengkeh adalah tenaga kerja dalam keluarga, tenaga kerja luar keluarga, pupuk organik, pestisida, dan populasi tanaman. Sedangkan faktor yang dapat menurunkan produktivitas adalah pupuk TSP. Pada faktor yang mempengaruhi risiko produksi, input produksi yang dapat meningkatkan risiko meliputi pupuk ZA. Sedangkan faktor input yang mampu menurunkan risiko produksi adalah tenaga kerja dalam keluarga., The demand for cloves in the national and international markets is predicted to increase every year. However, during the period of 2015-2021, the productivity rate of cloves in East Java Province, as one of the largest producers of cloves in Indonesia, has been fluctuating and tends to decline. This research aims to analyze the factors influencing the productivity and production risk of cloves in East Java. The data used in this study consist of 937 secondary data from farmers, analyzed using the Just and Pope model. The analysis results indicate that the production risk level of cloves in East Java is considered high, as the CV value is greater than 0.5. The factors that positively influence the productivity of cloves include family labor, external labor, organic fertilizer, pesticides, and plant population. On the other hand, the use of TSP fertilizer can decrease productivity. Regarding the factors influencing production risk, inputs that can increase the risk is ZA fertilizer. Conversely, family labor is an input factor that can reduce production risk.
Keyword: Cloves, Productivity, Production risk

Judul: Analisis Faktor-Faktor yang Memengaruhi Impor Cengkih Indonesia
Abstrak: Salah satu komoditas perkebunan yang berpotensi menjadi sumber devisa Indonesia adalah cengkih (Syzigium aromaticum L. Marr. and Perr.). Produksi cengkih nasional sering mengalami fluktuasi, sehingga dikenal panen raya, panen sedang, dan panen kecil. Industri rokok kretek merupakan konsumen utama cengkih karena menyerap 95% produksi cengkih nasional yang digunakan sebagai bahan baku utama dalam berproduksi. Indonesia merupakan negara pengekspor dan pengimpor cengkih. Cengkih dalam penelitian ini menggunakan cengkih dengan kode (HS) 0907(Whole fruit, cloves, and stems). Indonesia melakukan impor cengkih untuk memenuhi permintaan domestik. Kebijakan pemerintah yang tepat terkait impor cengkih sangat penting agar persediaan cengkih baik di pasar domestik maupun pasar dunia terpenuhi. Oleh karena itu, penelitian ini bertujuan untuk (1) menganalisis perkembangan produksi, konsumsi, harga, dan impor cengkih Indonesia, (2) menganalisis perkembangan kebijakan impor cengkih Indonesia dan implikasinya terhadap volume dan nilai impor cengkih, dan (3) menganalisis faktor-faktor yang memengaruhi volume impor cengkih Indonesia. Hasil penelitian menunjukkan bahwa bahwa variabel-variabel yang berpengaruh signifikan terhadap volume impor cengkih Indonesia periode 1977-2019 adalah variabel harga cengkih impor, harga cengkih domestik, produksi cengkih domestik, dan variabel inflasi Indonesia. Perubahan kebijakan impor cengkih Indonesia juga sudah mengalami perubahan dari kebijakan pembatasan impor menjadi kebijakan yang mendukung impor cengkih Indonesia., One of the plantation commodities that has the potential to become a source of foreign exchange for Indonesia is cloves (Syzigium aromaticum L. Marr. and Perr.). National cloves production fluctuates, so that in cloves production it is known as the big harvest, medium harvest and small harvest. The clove cigarette industry is the main consumer of cloves because it absorbs 95% of the national clove production which is used as the main raw material in producing. This causes the volume of cloves to exported reduced. Apart from being a clove exporting country, Indonesia also imports cloves. Cloves used in this study are cloves with the (HS) code 0907 (Whole fruit, cloves, and stems). Indonesia imports cloves to meet domestic demand, especially from the kretek cigarette industry. Appropriate government policies related to cloves import are very important so that the supply of cloves in both the domestic and world markets is met. Therefore, this study aims to (1) analyze the development of Indonesian clove production, consumption, price, and imports, (2) analyze the development of Indonesia's clove commodity trade policy and its implications for the volume and value of clove imports, and (3) analyze the factors that affect the volume of clove imports in Indonesia. The results showed that the variables that have a significant effect on the volume of Indonesian clove imports for the period 1977-2019 are the imported clove price, the domestic clove price, the domestic clove production, and the Indonesian inflation variable. Changes in Indonesia's clove import policy have also undergone a change from the import restriction policy become a policy that supports the import of Indonesian cloves.
Keyword: Cloves import, Cloves import policy, Cochrane-Orcutt method, Ordinary Least Squares (OLS)

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: