Judul: Marketing Value Chain of Non-Timber Forest Products in Private Forests of Karacak Village Bogor Regency
Abstrak: Salah satu isu penting dalam pengelolaan hutan rakyat di Kabupaten Bogor adalah lemahnya posisi tawar para petani hutan rakyat dalam hal pemasaran. Identifikasi rantai nilai pemasaran penting dilakukan dengan menganalisis margin keuntungan dan farmer’s share dari setiap rantai pemasaran, sehingga bisa digunakan sebagai salah satu referensi dalam menemukan strategi pemasaran yang efisien. Penelitian ini menggunakan metode snowball sampling dengan megikuti alur pemasaran hasil hutan bukan kayu melalui instrumen wawancara kepada pelaku pemasaran yang terlibat. Desa Karacak di Kabupaten Bogor dengan potensi hutan rakyat yang besar memiliki komoditas unggulan berupa manggis, durian, dan duku. Pelaku pemasaran tersebut adalah petani, pedagang pengumpul, pedagang ecer, dan eksportir. Komoditi manggis terdiri dari tiga saluran dengan urutan perolehan keuntungan tertinggi untuk manggis kualitas super adalah: 1) eksportir (35,67%); 2) pedagang pengumpul (32,38%); 3) petani (31,95%), dan untuk manggis kualitas lokal adalah: 1) pedagang ecer (60,67%); 2) petani (39,33%). Sementara komoditi durian dan duku hanya terdiri dari dua saluran pemasaran. Urutan perolehan keuntungan tertinggi untuk komoditi durian adalah: 1) petani (69,70%); 2) pedagang ecer (30,30%), sedangkan pada komoditi duku adalah: 1) pedagang ecer (56,76%); 2) petani (43,24%)., One important issue in the management of private forests in Bogor Regency is the weak bargaining position of private forest farmers in terms of marketing. Identifying the marketing value chain is crucial by analyzing profit margins and the farmer’s share in each marketing chain to provide a reerence for developing efficient marketing strategies. This study uses a snowball sampling method, following the marketing flow of non-timber forest products through interviews with the marketing actors involved. Karacak Village in Bogor Regency, with its large potential for privat forests, has leading commodities such as mangosteen, durian, and langsat. The marketing actors include farmers, collectors, retailers, and exporters. Mangosteen commodities consist of three channels, with the highest profit acquisition order for super-quality mangosteen being: 1) exporters (35.67%); 2) collectors (32.38%); 3) farmers (31.95%), and for local-quality mangosteen: 1) retailers (60.67%); 2) farmers (39.33%). Meanwhile, durian and langsat commodities only have two marketing channels. The highest profit acquisition order for durian commodities is: 1) farmers (69.70%); 2) retailers (30.30%), while for langsat commodities: 1) retailers (56.76%); 2) farmers (43.24%).
Keyword: value chain, marketing margin, marketing efficiency, farmer's share

Judul: Wood Marketing from Community Forests in Karacak Village, Leuwiliang Subdistrict, Bogor Regency
Abstrak: Kecamatan Leuwiliang memiliki potensi hutan rakyat yang cukup besar di Kabupaten Bogor, salah satunya adalah Desa Karacak. Tujuan dari penelitian ini adalah mengidentifikasi pelaku yang terlibat dalam proses pemasaran kayu hutan rakyat, dan menjelaskan alur serta efisiensi pemasaran kayu dari hutan rakyat di Kecamatan Leuwiliang. Pengambilan data penelitian dilaksanakan pada Juni-Agustus 2022 dengan metode wawancara. Analisis yang digunakan dalam penelitian ini adalah margin pemasaran, farmer’s share, rasio keuntungan, dan efisiensi pemasaran. Hasil penelitian ini menunjukkan bahwa terdapat dua saluran pemasaran kayu dari hutan rakyat Kecamatan Leuwiliang. Pelaku pemasaran pada saluran pertama terdiri dari petani hutan rakyat dan industri sawmill, sedangkan pada saluran pemasaran kedua terdiri dari petani hutan rakyat, pedagang pengumpul, dan industri sawmill. Nilai margin dan farmer’s share pada saluran pemasaran pertama berturut turut sebesar 68,18% dan 31,82%; sedangkan pada saluran pemasaran kedua sebesar 82,64 % dan 17,36%. Rasio keuntungan K/B pemasaran hanya menguntungkan pada tingkat industri sawmill di kedua saluran pemasaran. Nilai efisiensi pemasaran pada saluran pemasaran pertama sebesar 50,17%; sedangkan saluran pemasaran kedua sebesar 70,42%. Kedua saluran pemasaran kayu hasil hutan rakyat memiliki nilai efisiensi pemasaran lebih dari 50% sehingga dikategorikan tidak memiliki efisiensi pemasaran yang baik., Leuwiliang Subdistrict has a significant potential for community forests in Bogor Regency, and one of these areas is karacak Village. The aim of this research was to identify the stakeholders involved in the marketing process of wood from community forests and explain the flow and efficiency of wood marketing from community forests in Leuwiliang Subdistrict. Data collection for this research was conducted from June to August 2022 using interview methods. The analysis employed in this study included marketing margin, farmer’s share, profit ratio, and marketing efficiency. The results of this research showed that two channel for marketing wood from community forests in Leuwiliang Subdistrict. The first channel involves community forest farmers and sawmill industries, while the second channel comprises community forest farmers, collecting traders, and sawmill industries. The margin and farmer’s share in the first marketing channel were 68.18% and 31.82%; respectively, while in the second marketing channel, they were 82.64% and 17.36%. The profit ratio (K/B) in marketing was only profitable at the sawmill industry level in both channels. The marketing efficiency in the first channel was 50.17%; whereas in the second channel, it was 70.42%. Both marketing channels for wood from community forests had a marketing efficiency values exceeding 50%, categorizing them as not having good marketing efficiency
Keyword: community forests, marketing channel, marketing efficiency, marketing stakeholders

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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