Judul: Management and Visitor Perceptions of Timor Deer  (Rusa timorensis) as a Tourism Object in Deer Breeding at IPB Campus Darmaga Bogor.
Abstrak: Keterancaman dari kelestarian populasi dan habitat menjadi pemicu utama dilakukannya upaya konservasi Rusa Timor (Rusa timorensis), salah satunya melalui upaya penangkaran yang dilakukan di Penangkaran Rusa Kampus IPB Darmaga. Penelitian ini bertujuan mendeskripsikan pengelolaan Rusa Timor dan menganalisis persepsi pengunjung terhadap pemanfaatan Rusa Timor sebagai objek wisata. Pengumpulan data dilakukan pada Juni hingga Oktober 2023, melalui observasi lapang dan wawancara dengan pengelola, serta penyebaran dan pengisian kuisioner oleh responden. Hasil penelitian menunjukan bahwa perlu dipertimbangkan mengenai adanya pengaturan reproduksi untuk menghasilkan populasi dan produktivitas rusa di penangkaran yang sejahtera. Pengunjung memberikan persepsi positif terhadap pemanfaatan rusa sebagai objek wisata dan dapat disimpulkan bahwa responden memiliki daya tarik dan mendukung pengembangan penangkaran. Hubungan tersebut perlu dilakukan perbaikan pengelolaan kesejahteraan terhadap rusa, pengelolaan penangkaran, maupun terhadap pengayaan fasilitas penangkaran dan penambahan sarana dan prasarana di lokasi penangkaran.
Keyword: utilization, captive breeding, Timor deer

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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