Judul: Faktor-Faktor yang Mempengaruhi Pemilihan Pola Tanam Tahunan Hutan Rakyat Pangan di Desa Barengkok dan Desa Purasari
Abstrak: Hutan rakyat sebagai penunjang bagi kebutuhan hidup manusia memiliki pengaruh terhadap ketahanan pangan di perdesaan. Setiap daerah mengembangkan pola tanam hutan rakyat yang beragam sebagai landasan untuk meningkatkan produktivitas. Penelitian ini bertujuan untuk mengetahui faktor-faktor yang mempengaruhi pemilihan pola tanam di lokasi penelitian. Metode yang digunakan adalah purposive sampling dan analisis regresi linier berganda dengan jumlah responden 60 orang dari Desa Barengkok dan Desa Purasari. Hasil penelitian menunjukan bahwa dominasi petani di kedua desa menggunakan pola tanam agroforestri dengan kombinasi campuran dari jenis tanaman kehutanan dan pertanian. Faktor-faktor yang berpengaruh secara signifikan terhadap pemilihan pola tanam di Desa Barengkok dengan selang kepercayaan 95% adalah modal usaha tani dan pengalaman bertani dengan arah hubungan negatif. Pada Desa Purasari faktor-faktor yang berpengaruh secara signifikan dengan tingkat ketelitian yang sama adalah luas lahan, jarak antara tempat tinggal dengan lokasi usaha tani, pendapatan total, dan pengalaman bertani dengan arah hubungan positif dengan pemilihan pola tanam., Community forest as a support for human life needs has an influence on food security in rural areas. Each region develops various community forest crops pattern as a basis for increasing productivity. This study was to determine the factors that influence the selection of crops pattern in the research location. The method used was purposive sampling and multiple linear regression analysis with 60 respondents from Barengkok Village and Purasari Village. The results of this research is the dominance of farmers in both villages used agroforestry cropping patterns with a mixture of forestry and agricultural plant species. Factors that significantly Affect the selection of crops pattern in Barengkok Village with a 95% accuracy are farming capital and farming experience with a negative direction. In Purasari Village, the factors that significant affect with the same level of accuracy are land area, distance between residence and location of farming, total income, and farming experience with a positive relationship with the choice of cropping patterns.
Keyword: affect, crops pattern, factors, food community forest

Judul: Pengambilan Keputusan Pemilihan Jenis Tanaman dan Pola Tanam di Lahan Hutan Negara dan Lahan Milik (Studi Kasus di Desa Sungai Langka Kecamatan Gedong Tataan Kabupaten Pesawaran Propinsi Lampung)
Abstrak: Agroferestry adoption studies about farmer’s decision making on tree planting have been conducted for many cases, but there was an important aspect that still had less concern about farmer views especially how they choose the plant species and planting pattern and why they do that. The aim of this study was to explain the farmer’s reasons when they choose a plant species and planting pattern with different land tenure systems, state forest and private land. Method used in this study was case study through analyzing plant species and planting pattern selection, financial flow, household revenue structure, and portfolio diversification. The results showed that: the farmer’s reasons were (1) cash income, (2) production continuity, (3) gestation period, (4) easy maintenance and harvest, (5) easy post harvest process, (6) tolerance to be planted with other plants, and (7) land tenure security (especially in state forest land); most farmers chose cacao species, with the main combination of planting pattern that consist of cacao and banana in state forest land, cacao and petai, cacao and durian in private land; all the planting pattern were financially feasible; the largest contribution was given by cacao at all planting patterns based on farmer household revenue structure, and portfolio diversification was not conducted by the farmers.
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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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