Judul: Analysis of Candlenut Tree Management in Tanah Pinem District, Dairi Regency, North Sumatera Province
Abstrak: One orientation in the long-term development of forest by the Indonesian government is the resulted welfare and active role of the people in forest management by expanding the people’s forest acreage. The type of plants selected for the community’s forest that will be developed must be suited to the local environmental conditions in terms of technical, economic, ecological, social and cultural aspects so that economically the activities of community’s forest can become the people’s choice of productive and sustainable business activities. Candlenut is one of the trees growing in the community environment. Economically the plants are very beneficial as their income sources and ecologically can serve to improve the functions of environment. The objectives of this study were (1) to determine the influential factors in the management candlenut trees and (2) to examine the sustainability of the people’s candlenut tree management for the ecological, economic and social aspects. The data was analyzed with a binary logistic regression and the sustainability analysis includes ecological, economic and social aspects. The factors that affect the candlenut management are age, land size, income, land origin, and land accessibility. The sustainability of candlenut management falls into the category of “sustainable with some considerations” based on “Lembaga Ekolabel Indonesia” standard because the community’s management of candlenut has not indicated a continuous or sustainable management.
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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: 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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