Judul: Manajemen Pelestarian Penyu Sisik di Taman Nasional Kepulauan Seribu dan Taman Nasional Karimunjawa
Abstrak: Hawksbills turtle are one type of rare and protected animals found in the waters of Indonesia because it population had sharply decreased. Conservation efforts that need to be performed such as arranging a turtle captive breeding program in Kepulauan Seribu National Park and Karimunjawa National Park which aimed at keeping the turtles population. This research aims to measure the success of hawksbills preservation management, identify the technical aspects of hatching and maintenance management, and find out the utilization that can be performed based on perception of visitors. The results showed that success rate in TNKpS an TNKJ are in the low category, which are valued on 52.5% and 37.5%. Technical aspects of turtle preservation management consist of hatching and maintenance management. The utilization that can be made against the turtles preservation was limited tourism which emphasize on education aspect and minimize physical contact with turtles.
Keyword: TNKJ, TNKpS, maintenance management, hawksbill turtle, hatching management

Judul: Utilisation Management and Perception of  Community and Visitors in Turtle Conservation in Karimunjawa National Park
Abstrak: Karimunjawa merupakan habitat penyu sisik dan penyu hijau sebagai satwa yang dinyatakan hampir punah. Penelitian bertujuan mengidentifikasi dan mendeskripsikan manajemen pemanfaatan, persepsi, serta menganalisis kesediaan membayar masyarakat dan pengunjung dalam mendukung konservasi penyu hijau dan penyu sisik. Data dikumpulkan dengan metode observasi lapang, wawancara, dan pengisian kuesioner. Hasil penelitian menunjukkan bahwa bentuk manajemen pemanfaatan penyu di TNKJ adalah melalui program Penetasan Semi Alami (PSA) Penyu, yakni penetasan telur dan pemeliharaan untuk dilepasliarkan guna menjaga kelestarian penyu di alam, serta penunjang ilmu pengetahuan dan teknologi konservasi, pendidikan, penelitian dan wisata. Terdapat empat kategori responden yang diwawancarai, yakni 1) masyarakat nelayan, 2) masyarakat non-nelayan, 3) pengunjung PSA, dan 4) pengunjung non-PSA yang secara keseluruhan memiliki persepsi positif dengan kategori sangat baik terkait konservasi, pemanfaatan, dan upaya pelestarian penyu melalui program PSA di TNKJ serta memiliki nilai rata rata Willingness to Pay (WTP) dalam mendukung konservasi penyu sebesar Rp 14.924., Karimunjawa is the habitat of hawksbill and green turtles, which are endangered species. The study aims to identify and describe the use management, perception, and analyse the willingness to pay of the community and visitors in supporting the conservation of green and hawksbill turtles. Data were collected using field observation, interviews, and questionnaires. The results showed that the management of sea turtle utilisation in TNKJ is through the Turtle Semi-Natural Hatchery (PSA) programme, which is the hatching of eggs and rearing for release to preserve sea turtles in nature, as well as supporting science and technology conservation, education, research and tourism. There are four categories of respondents interviewed, namely 1) fishing communities, 2) non-fishing communities, 3) PSA visitors, and 4) non-PSA visitors who overall have positive perceptions with very good categories related to sea turtle conservation, utilisation, and conservation efforts through the PSA programme in TNKJ and have an average Willingness to Pay (WTP) value in supporting sea turtle conservation of Rp 14.924.
Keyword: Karimunjawa, Kesediaan membayar, Pemanfaatan, Penyu, Persepsi

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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