Judul: Studi Penyebaran Jenis Tumbuhan Eksotik dan Persepsi Masyarakat terhadap Penggantiannya di Taman Nasional Gunung Halimun Salak (Studi Kasus di Stasiun Penelitian Cikaniki)
Abstrak: Gunung Halimun Salak National Park (TNGHS) surrounded by the area of rural district, agricultural and plantation. So that this area becomes susceptible one of them is the attack of strange species (eksotik) which came to the area. The coming of eksotik plan to the TNGHS has a negative impact to the existence of genuine plant. So that, it has to manage the eksotik plan. The first step to manage is the needed of the data of spread, benefit and the perception of society toward the eksotik plan. This research has three purpose, they are: (1) spread of eksotik plant at Cikaniki research station (TNGHS), (2) the benefit of eksotik plant at Cikaniki research station (TNGHS), and (3) society perception on eksotik plan substitution in Cikaniki research station (TNGHS). This research carrying out at Cikaniki research station (TNGHS) Malasari village, Nanggung Sub district, Bogor regency on July until August 2009. Primary data and secondary data are use in they research. Primary data obtained from the analysis of vegetation using compartmentalized stripe and result of interview which using snowball method toward 30 respondents. Secondary data obtained from house of TNGHS, the government of Malasari village and literature study. Forest vegetation data obtained analyze by calculate: type frequency, the density of type, type domination, emphatic value index, varied type, dominate index and spread pattern. Tabulation and scoring of interview result then describe in descriptive. To measure relationship closeness between respondent characteristic and level perception, used correlation spearman test. The eksotik plant which found in research location are: harendong bulu (Clidemia hirta), ki rinyuh (Eupatorium pallescens), kecubung (Brugmansia suaveolens), kaliandra (Calliandra calothyrsus), and seuseureuhan (Piper aduncum). It growth at 1.000-1.077 m dpl, and has grouping spreaded pattern. The kind of eksotik plant which used by the society are kaliandra (Calliandra calothyrsus), sesuseureuhan (Piper aduncum), pinus (Pinus merkusii), ki rinyuh (Eupatorium pallescens), teh (Camellia sinensis), sengon (Paraserianthes falcataria), and kayu afrika (Maesopsis eminii). It used for firewood, medicine and cattle food. Society perception toward eksotik plan spread justify; low (0-2), medium (3-5), and high (6-8) they are 33,33%. A lot of society (53,33%) states that they are agree with tes subtition of eksotik plant.
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Judul: Studi Etnobotani Tumbuhan Eksotik di Desa Penyangga Resort Bodogol, Taman Nasional Gunung Gede Pangrango
Abstrak: Taman Nasional Gunung Gede Pangrango menjadi salah satu kawasan konservasi yang menghadapi permasalahan adanya keberadaan tumbuhan eksotik yang mengancam kelestarian ekosistem. Namun di sisi lain masyarakat di sekitar kawasan secara turun temurun sudah memanfaatkan spesies eksotik tersebut. Tujuan penelitian ini yaitu mendokumentasikan pengetahuan etnobotani dan mengidentifikasi spesies tumbuhan eksotik yang memiliki nilai budaya penting bagi masyarakat di desa penyangga Resort Bodogol. Kegiatan penelitian dilaksanakan pada November 2022 - Januari 2023 di Kampung Babakan Kencana, Desa Benda, Kecamatan Cicurug, Kabupaten Sukabumi, Jawa Barat. Penelitian ini menggunakan metode studi pustaka, observasi lapang, dan wawancara. Analisis data menggunakan metode ICS, UV dan ICI. Terdapat 60 spesies tumbuhan eksotik dari 26 famili yang dimanfaatkan dengan kegunaan tertinggi sebagai tumbuhan obat. Spesies eksotik yang memiliki nilai budaya penting diantaranya yaitu; M. eminii, C. hirta, O. barrelieri, S. torvum, A. inulifolium, dan C. calothyrsus. Penelitian ini diharapkan dapat menjadi salah satu pertimbangan dalam mendukung keberhasilan pengelolaan spesies eksotik di kawasan TNGGP melalui pendekatan sosial budaya masyarakat dalam pemanfaatan spesies eksotik., Gunung Gede Pangrango National Park is one of the conservation areas that faces the problem of the existence of exotic plants that threaten the sustainability of the ecosystem. But on the other hand, the people around the area have been using these exotic species for generations. The purpose of this study was to document ethnobotanical knowledge and identify exotic plant species that have important cultural alues for the buffer village communities around Bodogol Resort. Research activities were carried out in November 2022 - Januari 2023 in Babakan Kencana Village, Benda Village, Cicurug District, Sukabumi Regency, West Java. This study used the method of literature study, field observation, and interviews. Data analysis using ICS, UV and ICI methods. There are 60 species of exotic plants from 26 families which are utilized with the highest use as medicinal plants. Exotic species that have important cultural values include; M. eminii, C. hirta, O. barrelieri, S. torvum, A. inulifolium, and C. calothyrsus. This research is expected to be one of the considerations in supporting the successful management of exotic species in the TNGGP area through a socio-cultural approach to the community in the utilization of exotic species.
Keyword: tumbuhan eksotik, sosial budaya, TNGGP

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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