Judul: Sistem pengelolaan hutan rakyat jenis sengon [Paraserianthes falcataria (L) Nielsen] di Desa Burat, Kecamatan Kepil, Kabupaten Wonosobo, Provinsi Jawa Tengah
Abstrak: Hutan merupakan sumberdaya alam yang dalam penggunaannya dapat dipulihkan kembali (renewable). Pemanfaatan dan pengelolaan hutan bertujuan untuk meningkatkan kesejahteraan masyarakat tanpa mengabaikan aspek kelestariannya. Dalam prakteknya di lapangan masih didapatkan beberapa hal yang dirasa kurang maksimal dalam pengelolaan hutan, khususnya hutan rakyat. Karena pengelolaannya masih sederhana dan sangat bervariasi berdasarkan letak geografis dan perlakuan dari pemilik lahan. Dengan adanya beberapa cara pengembangan hutan rakyat dan dengan lebih intensifnya pengelolaan dengan cara yang lebih sustainable dengan daya dukung potensi sumberdaya hutan rakyat, kinerja pengusahaan, dinamika lingkungan dan faktor-faktor lainnya diharapkan hutan rakyat dapat menjadi suatu unit bisnis startegis yang mampu mempertahankan keberlangsungan produksi dan pengusahaanya dengan tetap memprioritaskan kelestarian hutannya. Tujuan utama dari penelitian ini, adalah untuk mempelajari sistem pengelolaan hutan rakyat dan menyusun rencana pengaturan kelestarian produksi hutan rakyat sengon di Desa Burat, Kecamatan Kepil, Kabupaten Wonosobo, Propinsi Jawa Tengah. Sumber data yang digunakan adalah data primer dan data sekunder. Data primer diperoleh dari wawancara kepada responden yang menangani produsen, pedagang, pengrajin industri dan industri pengolahan kayu. Data sekunder diperoleh dari Dinas Kehutanan Kabupaten Wonosobo, Kantor Kecamatan Kepil, Kantor Desa Burat dan browsing internet. Metode analisis yang digunakan adalah analisis kualitatif untuk data sekunder melalui hasil wawancara berdasarkan hasil kuisioner dan analisis kuantitatif untuk data primer yang berupa data potensi jenis sengon melalui pendugaan berdasarkan teknik sampling sederhana. Sistem pengelolaan hutan rakyat di Desa Burat sifatnya masih sederhana, dalam hal ini dapat dibuktikan dari tahapan kegiatan pengelolaannya seperti penanaman, pemeliharaan, pemanenan serta pemasaran masih belum mengikuti pola yang sama. Hal ini disebabkan karena sistem informasi manajemen belum efektif untuk dapat diterima oleh masyarakat petani hutan Desa Burat. Faktor-faktor penunjang dalam pengelolaan hutan rakyat seperti sarana dan prasarana masih belum merata. Sistem kelembagaan serta kebijakan yang ada belum mendukung sepenuhnya kegiatan usaha pengembangan di bidang hutan rakyat sengon di Desa Burat.
Keyword: Forest, Forest people, The concept of sustainability, Peoples forest management system, Sustainable

Judul: Sistem Pengelolaan Hutan Rakyat Jenis Sengon (Paraserianthes falcataria (L) Nielsen) di Desa Burat, Kecamatan Kepil, Kabupaten Wonosobo
Abstrak: Forest is one of renewable resources. The goal of forest management and forest utilization is to increase society welfare without aside it’s sustainable aspect. In fact, there are several things that supposed to be maximal on forest management, especially in community forest. Community forest has simple management it also has diversity on geographical place and treatment from its land holder. With several ways on developing community forest and also more intensive community forest management with sustainable ways together with support capability from community forest resources potency, exertion activity , environmental dynamics and the other factors are expected to form community forest as a certain business strategic that capable to maintain sustainable production and utilization that also put forest sustainable as priority. This research main objective is to learn community forest management and tabulate systemization of sustainable production planning of community forest at Burat Village, Kepil Sub-District, Wonosobo Regency, Central Java. Data taken in this research includes primary data from direct interview to land holder as producer, merchant, craftsman industry and timber industry. Secondary data taken from Forestry Department of Wonosobo Regency, Kepil Sub-District office, Burat Village office and internet browsing. Analysis method that use in this research are qualitative analysis for secondary data based on interview result and quantitative analysis for sengon species potency as primary data that taken based on simple sampling technique. Burat Village community forest has a simple management; it is proven by phases of utilization activity including planting, cultivation, harvesting, and marketing that haven’t follow the same pattern of management activity. This is occurring by ineffective management information that implement to all land holders at Burat community forest. There’s also misdistribution on supporting factors such as facility and infrastructure in Burat Village community forest. Institutional system and policy also cannot deliver utmost support for development of Burat Village sengon community forest management. Rotation on every sub-village is determined by range of rotation on existing condition; there are two different rotations which is 6 years rotation (Geger Jeruk and Krungsung sub village) and 7 years rotation (Burat, Kalibarong, Kalinongko, Kaliwang and Krajan sub village). Sustainability concept for every sub village that implemented 6 years rotation is range 1069 – 1118 trees/ha that can be harvest or replant, 3 years period 535 – 559 trees/ha, 1 year period 1178 – 186 trees/ha, 6 months period 89 – 93 trees/ha and for 3 months period 45 – 47 trees/ha. Sustainability concept for every sub village that implemented 7 years rotation is range 226 – 893 trees/ha that can be harvest or replant, 3 years period 97 – 383 trees/ha, 1 year period 32 – 128 trees/ha, 6 months period 16 – 64 trees/ha and for 3 months period 8 – 32 trees/ha.
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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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