Judul: Potensi Ekonomi Manggis dan Durian Terhadap Pendapatan Petani KTH Rimba Lestari Desa Karacak Kecamatan Leuwiliang Kabupaten Bogor
Abstrak: Manggis dan durian menjadi komoditas Desa Karacak yang hasilnya cukup menguntungkan dan menjadikan desa ini sebagai salah satu sentra produksi buah-buahan tersebut. Mengetahui potensi hasil hutan bukan kayu (HHBK) penting dilakukan untuk diperhitungkan nilai ekonomi dalam pemanfaatannya. Penelitian ini bertujuan mengidentifikasi keberadaan dan potensi manggis dan durian beserta nilai ekonomi manggis dan durian terhadap pendapatan petani KTH Rimba Lestari, dan peranannya dalam mendukung keberadaan hutan rakyat di Desa Karacak. Penelitian dilakukan melalui wawancara kepada petani KTH Rimba Lestari sebagai informan dalam mencari data produktivitas manggis dan durian, serta pengukuran di lapangan melalui pembuatan plot contoh. Hasil penelitian menunjukkan nilai ekonomi manggis dan durian memiliki kontribusi dominan dengan rata-rata pendapatan bersih Rp 51.679.000 per tahun atau persentase rata-rata 72,03% terhadap pendapatan rata-rata petani Rp 70.956.522 per tahun. Manggis memiliki kontribusi pendapatan lebih besar yaitu rata-rata pendapatan bersih Rp 33.802.500 per tahun atau persentase 47,35% dibandingkan durian dengan rata-rata pendapatan bersih Rp 17.876.500 per tahun atau persentase 24,68%. Nilai tersebut membuat keberadaan manggis dan durian di lahan petani lebih dominan dari tanaman lain sehingga banyak dibudidayakan dan petani berencana memperbanyak komoditas ini. Rata-rata umur pohon manggis dan durian milik petani sudah berumur tua sehingga dimungkinkan terjadi penurunan produksi yang akan berdampak pada pendapatan petani, sementara rencana petani untuk memperbanyak komoditas ini belum dilakukan. Kondisi tersebut menjadi alasan kuat untuk segera melakukan upaya permudaan guna mempertahankan keberlanjutan tanaman manggis dan durian., Mangosteen and durian have become important commodities in Karacak Village, providing considerable profit and making this village a major production center for these fruits. Assessing the potential of non-timber forest products (NTFPs) is essential to evaluate their economic value. This study aims to identify the presence and potential of mangosteen and durian, as well as their economic value to the income of KTH Rimba Lestari farmers, and their role in supporting community forests in Karacak Village. The research was conducted through interviews with KTH Rimba Lestari farmers to collect data on mangosteen and durian productivity, and field measurements by making sample plots. The results of the study show that the economic value of mangosteen and durian has a dominant contribution with an average net income of Rp 51.679.000 per year or an average percentage of 72,03% to the average farmers income of Rp 70.956.522 per year. Mangosteen has a greater revenue contribution, namely an average net income of Rp 33.802.500 per year or a percentage of 47,35% compared to durian with an average net income of Rp 17.876.500 per year or a percentage of 24,68%. This value makes the existence of mangosteen and durian on farmers land more dominant than other crops so that it is widely cultivated and farmers plan to multiply this commodity. The average age of mangosteen and durian trees owned by farmers is old, so it is possible that there will be a decrease in production that will have an impact on farmers income, while farmers plans to multiply this commodity have not been carried out. This condition is a strong reason to immediately make rejuvenation efforts to maintain the sustainability of mangosteen and durian plants.
Keyword: durian, economic potential, income contribution, mangosteen

Judul: Pengaruh Kemitraan Terhadap Pendapatan Petani Manggis Di Desa Karacak Kecamatan Leuwiliang Kabupaten Bogor
Abstrak: Mangosteen is a fruit tree crop that comes from a shady tropical forests in Southeast Asia. Mostly comes from Malaysian and Indonesian jungle. Mangosteen fruits one of Indonesia'sleading commodities for agribussiness. And therefore mangosteen have the potential to be exported to foreign countries. But the limitations of mangosteen farmers towards price information and market assurance are recognized as the greatest obstacle to developing the potential of the mangosteen fruit. One effort to resolve that problems is by using the partnership. Mangosteen farmers in Karacak Village, Leuwiliang, Bogor, has already made a partnership with PT. Agung Mustika Selaras. The aim of this research is to describes the implementation of partnership mechanism between PT. Agung Mustika Selaras with mangosteen farmers in Karacak Village, Leuwiliang, Bogor and also to analyzes the influence of partnership toward mangosteen farmer’s income in the Karacak village, Leuwiliang, Bogor. Data for this research was taken from October 2012 to November 2012. The respondent of this research is all partners farmer in Karacak village with the amount 23 farmers and non partner farmers with the amount 25 farmers This research is analyzed by using descriptive analysis, descriptive statistical , analysis of farming income, and the ratios (R/C).
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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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