Judul: Management of Sumatran Elephant Welfare and Utilization as a Tourism Object in Serulingmas Wildlife Recreation Park, Banjarnegara
Abstrak: Gajah Sumatra merupakan satwa kategori kritis terancam punah. Kondisi tersebut menyebabkan perlu peran lembaga konservasi eksitu, salah satunya adalah Taman Rekreasi Margasatwa Serulingmas. Penelitian bertujuan menganalisis pengelolaan dan tingkat kesejahteraan Gajah Sumatra, mengidentifikasi bentuk pemanfaatan Gajah Sumatra, menganalisis persepsi dan preferensi pengunjung terhadap pemanfaatan Gajah Sumatra, serta merumuskan strategi pengembangan pemanfaatan Gajah Sumatra. Data didapatkan dari observasi lapang, studi literatur, wawancara dengan animal keeper dan pengunjung. Penilaian implementasi kesejahteraan Gajah Sumatra dalam kategori sangat baik dengan nilai rata-rata 89,96. Bentuk pemanfaatan Gajah Sumatra di TRM Serulingmas meliputi kegiatan pemberian pakan, berfoto, menyentuh gajah dan display gajah. Secara keseluruhan pengunjung memiliki persepsi yang baik, dengan nilai rata-rata TCR 82,94% untuk pengelolaan kesejahteraan Gajah Sumatra dan TCR untuk pemanfaatan gajah sebagai objek wisata sebesar 79,22%. Mayoritas pengunjung tertarik dengan keberadaan Gajah Sumatra di TRM Serulingmas. Strategi pengembangan pemanfaatan Gajah Sumatra dapat dilakukan dengan penetapan harga biaya tambahan, pengembangan program wisata dan peningkatan sarana dan prasarana wisata., Sumatran elephants are critically endangered. This condition calls for the role of exsitu conservation institutions, one of which is Taman Rekreasi Margasatwa Serulingmas. The study aimed to analyze the management and welfare level of sumatran elephants, identify the form of utilization of sumatran elephants, analyze visitor perceptions and preferences for the use of sumatran elephants, and formulate a development strategy for the use of sumatran elephants. Data were obtained from field observations, literature studies, interviews with animal keepers and visitors. The assessment on sumatran elephants welfare management resulted in a score of 89.96, or in good category. Sumatran elephants were used in tourism activities, which included feeding, taking pictures, touching elephants and elephant displays. Overall, visitors had good perception of welfare management of sumatran elephants with TCR score of 82.94% and the use of sumatran elephant as a tourist attraction with TCR score of 79.22%. The majority of visitors were interested in the presence of sumatran elephants in TRM Serulingmas. The strategy propose for developing the use of sumatran elephants include setting surcharge prices, special member promotions, developing tourism programs and improving tourist facilities and infrastructure.
Keyword: gajah sumatra, kesejahteraan satwa, pemanfaatan, wisata

Judul: Spatial Distribution of Traces of Sumatran Elephant (Elephas maximus sumatranus Temminck, 1847) Activity in Pemerihan Resort Bukit Barisan Selatan National Park
Abstrak: Penurunan populasi gajah Sumatra mengindikasikan pentingnya kajian penelitian terkait jejak aktivitas gajah Sumatra. Penelitian ini bertujuan untuk mengidentifikasi jenis jejak aktivitas, menduga bentuk sebaran spasial jejak aktivitas, dan menganalisis hubungan jejak aktivitas dengan karakteristik habitat gajah Sumatra di Resort Pemerihan. Metode yang digunakan adalah pengamatan langsung pada jalur transek sepanjang 1 km dan studi literatur. Hasil penelitian menunjukkan bahwa jenis jejak aktivitas gajah Sumatra terdiri dari feses dan tapak. Jejak aktivitas yang paling banyak ditemukan adalah feses di hutan sekunder. Bentuk sebaran spasial jejak aktivitas gajah Sumatra adalah mengelompok dengan nilai IM=2,61. Sebaran spasial jejak aktivitas gajah Sumatra hubungan dengan karakteristik habitat yaitu tipe tutupan lahan (hutan sekunder), kelas topografi (datar), jarak dari sumber air (<1000 m), dan jarak dari permukiman (1000-2000 m). Pengelolaan habitat dan populasi gajah Sumatra melalui pengayaan pakan dan kegiatan penangkaran diperlukan sebagai bentuk upaya konservasi gajah Sumatra., The decline in the sumatran elephant population indicates the importance of research studies related to the traces of Sumatran elephant activities. This study aims to identify the types of activity traces, estimate the shape of the spatial distribution of activity traces, and analyze the relationship between activity traces and the characteristics of the Sumatran elephant habitat at Pemerihan Resort. The method used is direct observation on a 1 km transect line and literature study. The results showed that the types of traces of Sumatran elephant activity consisted of feces and footprints. The most traces of activity found were feces in secondary forest. The form of the spatial distribution of the Sumatran elephant's activity traces is clustered with a value of IM=2,61. The spatial distribution of Sumatran elephant activity traces is related to habitat characteristics, namely land cover type (secondary forest), topographic class (flat), distance from water sources (<1000 m), and distance from settlements (1000-2000 m). Management of the habitat and population of Sumatran elephants through enrichment of feed and captive activities is needed as a form of Sumatran elephant conservation efforts.
Keyword: activity traces, Pemerihan Resort, spatial distribution shape, Sumatran elephant

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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