Judul: Economic Valuation of Non-Use Value and The Management Strategy of Tebet Eco Park, South Jakarta
Abstrak: Keberadaan ruang terbuka hijau di Daerah Khusus Ibukota Jakarta sangat penting karena memiliki berbagai macam fungsi, terutama di wilayah dengan aktivitas masyarakat yang banyak polusi. Besarnya potensi yang dimiliki RTH Tebet Eco Park menjadikan keberadaannya sangat dibutuhkan ditengah permasalahan wilayah perkotaan, oleh karena itu penelitian ini dilakukan dengan tujuan (1) menganalisis persepsi masyarakat terhadap pengelolaan Tebet Eco Park, (2) mengestimasi besaran nilai ekonomi keberadaan dan nilai ekonomi warisan Tebet Eco Park, (3) menganalisis strategi pengelolaan Tebet Eco Park. Metode yang digunakan dalam penelitian ini adalah skala likert, Contingent Valuation Method (CVM), dan PROMETHEE. Hasil penelitian ini menunjukkan bahwa pengunjung memiliki penilaian sangat baik terhadap Tebet Eco Park. Nilai ekonomi non-guna Tebet Eco Park adalah sebesar Rp6.584.116.974 per tahun dengan rincian untuk nilai ekonomi keberadaan sebesar Rp1.182.210.355 per tahun dan untuk nilai ekonomi warisan sebesar Rp5.401.906.619 per tahun. Alternatif kebijakan yang dapat dijadikan prioritas dalam membuat strategi pengelolaan Tebet Eco Park adalah revitalisasi sungai kemudian peningkatan pemeliharaan vegetasi yang ada di Tebet Eco Park., The existence of green open space in DKI Jakarta is very important because it has various functions, especially in areas with high pollution level. The large potential of the Tebet Eco Park makes its existence very much needed to overcome theproblems in urban areas. These research aims are to(1) Analyze public perceptions of Tebet Eco Park management, (2) Estimate the economic value of existence and the economic value of inheritance of Tebet Eco Park, (3) Analyze the management strategy of Tebet Eco Park. The methods used in this study are the Likert scale, Contingent Valuation Method (CVM), and PROMETHEE. The results of this study indicate that visitors have a very good assessment of Tebet Eco Park. The non-use economic value of Tebet Eco Park is IDR 6.584.116.974 per year, with details of the existence economic value of IDR 1.182.210.355 per year and the bequest economic value of IDR 5.401.906.619 per year. Alternative policy that can be prioritized in Tebet Eco Park are river revitalization and then increasing the maintenance of existing vegetation in Tebet Eco Park.
Keyword: CVM, PROMETHEE, persepsi pengunjung, ruang terbuka hijau, willingness to pay

Judul: Analysis of the Economic and Environmental Impact of Tebet Eco Park, South Jakarta
Abstrak: Ruang Terbuka Hijau (RTH) di DKI Jakarta pada tahun 2023 mengalami peningkatan sebesar 1,08% dari tahun 2018. Tebet Eco Park merupakan salah satu RTH yang dikelola oleh Dinas Pertamanan dan Hutan Kota DKI Jakarta yang memiliki luas lahan sebesar 7,3 hektare. Tebet Eco Park merupakan taman interaktif yang pada tahun 2023 jumlah wisatawannya mencapai 555.853 kunjungan. Tujuan dari penelitian ini, yaitu: (1) Mengestimasi nilai ekonomi Tebet Eco Park menggunakan pendekatan Individual Travel Cost Method, (2) Mengestimasi dampak ekonomi yang ditimbulkan akibat adanya kegiatan wisata di Tebet Eco Park bagi masyarakat sekitar. (3) Menganalisis dampak lingkungan yang ditimbulkan akibat adanya kegiatan wisata di Tebet Eco Park dengan pendekatan persepsi kepada masyarakat. Metode yang digunakan adalah model regresi linear berganda, analisis pendapatan, dan statistika deskriptif. Hasil dari penelitian ini yaitu: (1) Faktor-faktor yang berpengaruh dalam fungsi permintaan wisata di wisata Tebet Eco Park adalah biaya perjalanan, pendidikan, pendapatan, dan lama berkunjung. Adapun nilai ekonomi wisata dari Tebet Eco Park adalah Rp. 153.004.832.753. (2) Dampak ekonomi yang dihasilkan masih relatif rendah disebabkan karena pengeluaran wisatawan masih ada yang dikeluarkan di luar kawasan Tebet Eco Park. (3) Dampak lingkungan berdasarkan persepsi masyarakat sekitar berada di kriteria sangat baik., Green Open Space (RTH) in DKI Jakarta in 2023 increased by 1.08% from 2018. Tebet Eco Park is one of the RTH managed by the DKI Jakarta Parks and City Forest Service, with a land area of 7.3 hectares. Tebet Eco Park is an interactive park that recorded 555,853 visits in 2023. The objectives of this study are: (1) To estimate the economic value of Tebet Eco Park using the Individual Travel Cost Method, (2) To estimate the economic impact of tourism activities in Tebet Eco Park on the surrounding community, (3) To analyze the environmental impact of tourism activities in Tebet Eco Park based on community perceptions. The methods used are multiple linear regression models, income analysis, and descriptive statistics. The results of this study are: (1) Factors influencing the demand function for tourism in Tebet Eco Park include travel costs, education, income, and length of visit. The economic value of tourism in Tebet Eco Park is Rp. 153,004,832,753. (2) The economic impact generated is still relatively low because some tourist expenditures are made outside the Tebet Eco Park area. (3) The environmental impact based on the perceptions of the surrounding community falls into the very good category.
Keyword: analisis pendapatan, Individual Travel Cost Method, persepsi masyarakat, RTH

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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