Judul: Welfare Management and Economic Benefit Value of Deer in Lembah Paniisan Deer Captivity Subang
Abstrak: Rusa timor (Cervus timorensis) dan rusa totol (Axis axis) termasuk spesies rusa yang dikembangbiakkan di Indonesia. Jumlah populasi rusa di alam semakin terancam akibat perusakan habitat dan perburuan liar sehingga perlu adanya upaya konservasi ex-situ, salah satunya yaitu Penangkaran Rusa Lembah Paniisan. Penelitian ini bertujuan mendeskripsikan pengelolaan kesejahteraan dan menilai tingkat kesejahteraan rusa, menganalisis tingkat keberhasilan penangkaran, serta menghitung nilai manfaat ekonomi rusa dan dampak sosial ekonominya bagi masyarakat. Metode yang digunakan yaitu observasi lapang, wawancara, dan studi pustaka. Hasil penelitian menunjukkan bahwa pengelolaan kesejahteraan rusa tergolong sangat baik dengan capaian implementasi sebesar 85,10. Tingkat keberhasilan penangkaran tergolong ke dalam kategori tinggi. Nilai manfaat ekonomi rusa dihitung berdasarkan biaya pemeliharaan sebesar Rp5.650.196,08/ekor/tahun, berdasarkan harga pasar sebesar Rp28.800.000– Rp67.500.000/pasang. Nilai keuntungan usaha penangkaran untuk penjualan individu rusa tahun 2022 sebesar Rp45.903.529,41 dan tahun 2023 sebesar Rp61.204.705,88, serta keuntungan penjualan produk turunan rusa sebesar Rp50.900.000/tahun. Nilai manfaat ekonomi penangkaran bagi masyarakat yang terlibat sebagai pekerja dihitung berdasarkan nilai share and covering. Nilai share terhadap total pendapatan rumah tangga sebagai perawat satwa tergolong rendah (47,08%) dan sangat rendah (20,03%) bagi tenaga kerja. Covering pendapatan penangkaran perawat satwa (66,10%) dan tenaga kerja (24,93%) tidak dapat menutupi total pengeluaran rumah tangga., The timor deer (Cervus timorensis) and the spotted deer (Axis axis) are species of deer bred in Indonesia. The number of deer populations in the wild is increasingly threatened by habitat destruction and wild hunting that requires ex-situ conservation effort, one of which is Lembah Paniisan Deer Captivity. The study aims to describe the welfare management and assess the level of welfare of deer, analyze the success rate of captivity, and calculate the value of the economic benefits of the deer and its socio-economic impact on community. The methods used are literature study, field observation, and interview. The results show that animal welfare management was rated as very good with an implementation reach of 85,10. The success rate of captivity belongs to the high category. The economic benefit value of the deer is calculated based on maintenance costs of Rp5,650,196.08/acre/year, based on the market price of Rp28,800,000–Rp67,500,000/pair. Profit value for individual deer sales of Rp45,903,529.41 in 2023 and Rp61,204,705.88 in 2022 and sales of deer-derived products of Rp50,900,00/year. The economic benefits of incarceration for the community involved as a worker are calculated based on share and covering. The share of total household income as a animal keeper is low (47.08%) and very low (20.03%) for the labor force. Covering the captivity income of animal keeper (66.10%) and labor (24.93%) could not cover the total household expenditure.
Keyword: Ekonomi, keberhasilan, kesejahteraan, penangkaran, rusa

Judul: Management and Level of Welfare and Economic Valuation of Timor Deer (Rusa timorensis) in Ragunan Wildlife Park Jakarta
Abstrak: Rusa timor (Rusa timorensis) merupakan salah satu satwa liar yang memiliki nilai ekonomi cukup tinggi, sehingga terus berkembang usaha konservasi eksitu dan penangkarannya. Penelitian ini bertujuan menganalisis pengelolaan dan tingkat kesejahteraan, pengelolaan reproduksi dan tingkat keberhasilannya, dan menghitung besarnya nilai ekonomi berdasarkan biaya pemeliharaan dan kesediaan membayar pengunjung (willingnes to pay) guna mendukung upaya konservasi rusa timor di Taman Margasatwa Ragunan Jakarta. Metode yang digunakan berupa observasi lapang, wawancara, dan studi literatur. Data yang terkumpul dianalisis secara deskriptif kualitatif dan kuantitatif. Hasil penelitian menunjukkan bahwa pengelolaan kesejahteraan rusa timor sudah baik dengan capaian tingkat kesejahteraan satwa termasuk kategori sangat baik dengan nilai terbobot 80,15. Pengelolaan reproduksi belum dilakukan secara optimal dengan tingkat keberhasilan reproduksi rusa timor tergolong sedang sebesar 36,1%. Nilai ekonomi rusa timor berdasarkan biaya pemeliharaan sebesar Rp1.664.259,5/ekor/bulan dan rata-rata nilai WTP sebesar Rp127.150,00/individu dengan perkiraan nilai ekonomi total sebesar Rp12.715.000,00., The timor deer (Rusa timorensis) is one of the wild animals that has quite a high economic value, so that its ex-situ conservation and captive breeding efforts continue to develop. This research aimed to analyze management and welfare levels, reproductive management and success rates, and calculate the amount of economic value based on maintenance costs and willingness to pay for visitors to support timor deer conservation efforts in the Ragunan Wildlife Park Jakarta. The methods used were field observations, interviews, and literature studies. The collected data were analyzed descriptively qualitatively and quantitatively. The results of the research showed that the welfare management of timor deer was good with the level of animal welfare achieved a very good category with a weighted value of 80,15. Reproductive management had not been carried out optimally with the reproductive success rate of timor deer being classified as moderate at 36,1%. The economic value of timor deer was based on maintenance costs of IDR 1.664.259,5/head/month and an average WTP value of IDR 127.150,00/individual with an estimated total economic value of IDR 12.715.000,00.
Keyword: Kesejahteraan satwa, nilai ekonomi, pengelolaan, rusa timor, taman margasatwa ragunan, animal welfare, economic value, management, ragunan wildlife park jakarta

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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