Judul: Kajian Pengambilan Keputusan Pemilihan Jenis Pohon dalam Pengelolaan Hutan Rakyat (Kasus di Desa Bojonggedang, Kecamatan Rancah, Kabupaten Ciamis)
Abstrak: The development and management of community forests in fact now is facing some problems. One of them is related to the selection of seed. The seeds that farmers can get, have modest quality. On the other hand, the choice of good quality tree is determined by the quality of the good seed. In addition to seed selection in community forest management, we should also consider how the farmers run their community forests, therefore this study aims are: 1) to explain the conditions of community forest management at the study site, and 2) to describe the considerations of the tree species which planted by farmers. This study takes place at Bojonggedang Village, Rancah Sub District, Ciamis Regency. The method for selecting respondents is purposive sampling method, with total respondents are 30 peoples. The results of this study indicate that the process of forest management by farmers are: 1) preparation of land, 2) planting, and 3) maintenance with undetermined frequency. Farmers are not doing harvesting activities by themself, they submitted on middlemen for both logging and timber transportation. Processing of forest products by farmers only for personal consumption, not for sale. Economic consideration is a primary consideration in determining the type of tree seed that will be planted. It can be seen from the factor type of seed that produce faster; easier access to markets; and the stability of the selling price of these types.
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Judul: Pemilihan Jenis  Tanaman Hutan Rakyat Di Desa Hegarmanah, Kec. Cicantayan, Kab. Sukabumi
Abstrak: Pemilihan jenis tanaman berkaitan dengan pengetahuan dan keterampilan petani dalam pengelolaan hutan rakyat. Pemilihan jenis tanaman harus melibatkan aspek ekonomi, ekologi, dan sosial-budaya. Penelitian ini menggunakan metode penelitian deskriptif kualitatif. Pengumpulan data dilakukan dengan wawancara mendalam, observasi dan dokumentasi. Petani mengelola hutan rakyat berdasarkan pengetahuan yang diperoleh dari pengetahuan lokal, penyuluh kehutanan, penyuluh pertanian, perguruan tinggi, pihak swasta, dan interaksi antar petani. Petani pada umumnya menanam sengon, suren, puspa, mahoni, kayu afrika, jati, jabon, sonokeling, gmelina, aren, bambu, manggis, durian, rambutan, duku, jambu jamaika, jengkol, dan petai. Petani memilih jenis tanaman berdasarkan faktor ekonomi sebagai faktor dominan yaitu pemilihan jenis yang cepat menghasilkan, kemudahan akses pengadaan bibit, kemudahan akses pemasaran hasil, dan kestabilan harga jual. Sub faktor sosial-budaya yang mempengaruhi yaitu pengetahuan lokal dan interaksi antar petani. Sub faktor ekologi yang mempengaruhi yaitu kesesuaian tempat tumbuh, dan kemampuan tanaman beradaptasi.
Keyword: the selections of plant, private forest, forest farmer

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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