Judul: Habitat characteristic of green turtle (Chelonia Mydas) nesting population at Pangumbahan Beach, Sukabumi, West Java.
Abstrak: Pangumbahan beach is one of green turtle (Chelonia mydas) nesting beach which still exist in West Java. Conservation strategy for green turtle in Pangumbahan beach include relocating eggs into hatchery sites. Accessibility and disturbance level at beach is important for seaturtle to choose preferable nesting sites. Most of Green Turtle in Pangumbahan preferred to nest at the centre part of the beach, especially at Pos 2. Natural nest temperature characteristic was different with the artificial ones (hatchery). Natural nest temperature ranged 26.0-29.6 (28.2±0.8)°C at the upper rim and 28.0-29.5 °C with mean of (28.6±0.8) °C at the bottom, while artificial nests temperature ranged 25.7- 28.3°C with mean of (27.2±0.8)°C at the upper rim and 28.3-33.2 °C with mean of (29.6±1.5)°C at the bottom. Characteristic of natural nests and artificial nests were dissimilar. According to the bathymetry, Pangumbahan Beach is quite accessible for seaturtle to land. Pangumbahan beach line is close to reef crest and directly connected with Indian Ocean. Sea surface temperature at high nesting abundance period was contrary to the period of low nesting abundance. The sea surface temperature during the high nesting period was cooler than at the low nesting abundance period. There was temperature gradient signature at high nesting abundance period whereas even temperature distribution occurred during low nesting abundance period. Keywords: green turtle (Chelonia mydas), nesting habitat, near shore habitat natural nest, artificial nest, sand temperature, Pangumbahan beach
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Judul: Status Populasi Penyu Hijau (Chelonia mydas, Linnaeus 1758) di Taman Pesisir Pantai Penyu Pangumbahan, Kabupaten Sukabumi, Jawa Barat.
Abstrak: The populations of green turtles in Indonesia tend to decline in linearly over the time that affects the sustainability of green turtle. The turtles beach of Pangumbahan consist of productive area for green turtles landing and nesting habitat. Research to assess the status of sea turtle population from the past few years was carried out using data from management and from field survey on the coast of Pangumbahan beach in March until April 2014. The purpose of this research is to study green turtles population change and the production of eggs from 2007-2013, and to assess threat to green turtles (biophysical properties of habitat, number of tourist, villas and the number of building), and to recommends management strategy for green turtles conservation. Social data was taken using purposive sampling methods and length of green turtles was taken using curve carapace line method. The frequency of green turtle landing in 2009 to 2013 is dominated un nested. There is a declining trend of number of green turtles that nest in 2007-2013. This has an impact to production of eggs and hatchlings which showed a decline. A decrease in the frequency of green turtles that landed in the beach might be caused by variation of nesting activity, the number of eggs, and hatching success. Another threat to the population of nesting green turtles changes in turtles habitat at Pangumbahan beach, the level of lighting of the beach, the increasing number of buildings villa, and social condition.
Keyword: Bogor Agricultural University (IPB), status population green turtles, Pangumbahan, frequency egg laying green turtles, change habitats

Judul: Aproksimasi Fungsi Sinus dan Kosinus sebagai Kombinasi Linear dari Fungsi Eksponensial
Abstrak: Salah satu gagasan yang menarik dalam matematika adalah aproksimasi suatu fungsi oleh fungsi lain. Sebagai contoh, fungsi polinom dapat diaproksimasi menggunakan deret Taylor atau fungsi persamaan diferensial dapat diaproksimasi menggunakan deret Fourier. Adapun fungsi yang dapat mengaproksimasi fungsi lain salah satunya adalah fungsi eksponensial. Kemungkinan mengaproksimasi fungsi dengan kombinasi linear dari fungsi eksponensial dari bentuk eˣ, e²ˣ, ... dianggap sebagai perkembangan sejajar dengan gagasan Deret Taylor yang mengaproksimasi fungsi dengan kombinasi linear dari segi fungsi kuadrat. Fungsi sin x dan cos x digunakan sebagai target untuk menilai seberapa baik aproksimasi yang dilakukan oleh fungsi yang diberikan. Aproksimasi fungsi sinus dan kosinus menggunakan hampiran Taylor lebih akurat dibandingkan dengan aproksimasi menggunakan fungsi eksponensial.
Keyword: Aprosimaksi eksponensial, aproksimasi fungsi, aprosimaksi Taylor, fungsi eksponensial