Judul: Successful Hatching of Hawksbill Turtle (Eretmochelys imbricata) Eggs in Semi-Natural Nests on Harapan Island, Thousand Islands
Abstrak: Penyu sisik (Eretmochelys imbricata) merupakan jenis penyu yang tersebar di wilayah Indonesia, salah satunya di Kepulauan Seribu. Penelitian ini bertujuan menganalisis teknik penetasan telur penyu sisik yang dapat mempersingkat masa inkubasi dan meningkatkan keberhasilan penetasan telur penyu sisik di kawasan konservasi penyu Pulau Harapan. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) dengan tiga perlakuan, yaitu ember tanam dalam pasir, ember di permukaan pasir, dan pasir tanpa ember. Parameter yang diukur adalah suhu, kelembaban, substrat sarang, masa inkubasi, dan Jumlah telur yang menetas dan gagal menetas. Hasil menunjukkan suhu rata-rata di semua perlakuan memiliki rentang nilai 30,12 - 30,98℃. Kelembaban rata-rata pada rentang nilai 84,67 - 86,38%. Rata-rata masa inkubasi paling rendah terjadi pada perlakuan ember tanam dalam pasir yaitu selama 48 hari. Keberhasilan penetasan telur tertinggi terdapat pada perlakuan ember tanam dalam pasir, yaitu 70%. persentase keberhasilan penetasan cenderung lebih tinggi dengan masa inkubasi paling singkat pada teknik dengan ember ditanam dalam pasir. Namun demikian, perlakuan teknik penetasan memiliki pengaruh yang tidak signifikan terhadap lama masa inkubasi dan keberhasilan penetasan telur penyu sisik., Hawksbill turtle (Eretmochelys imbricata) is a type of sea turtle that is spread across Indonesia coral reef, one of the area is the Thousand Islands. This study aims to analyze hawksbill turtle egg hatching techniques that can shorten the incubation period and increase the hatching success of hawksbill turtle eggs in the Harapan Island turtle conservation area. This study used a completely randomized design (CRD) with three treatments. Parameters measured were temperature, humidity, nest substrate, incubation period, and number of eggs hatched and failed to hatch. The results showed that the average temperature in all treatments had a value range of 30.12 - 30.98℃. Average humidity in the value range of 84.67 - 86.38%. The lowest average incubation period occurred in the treatment of planting buckets in sand, which was 48 days. The highest egg hatching success was found in the treatment of planting buckets in sand, which was 70%. The percentage of hatching success tends to be higher with the shortest incubation period in the technique with buckets planted in sand. However, the treatment of hatching techniques had a non-significant effect on the length of the incubation period and the hatching success of hawksbill turtle eggs. However, the hatching technique treatment had a non-significant effect on the length of the incubation period and the success of hatching hawksbill turtle eggs.
Keyword: hatching success, incubation period, hawksbill turtle

Judul: Characteristics of the Hawksbill Turtle (Eretmochelys imbricata) Nesting Beach on Kepayang Island, Bangka Belitung.
Abstrak: Populasi penyu sisik di alam saat ini mengalami penurunan, terutama dikarenakan oleh faktor alami dan faktor antropogenik. Penelitian ini bertujuan mengetahui karakteristik habitat peneluran penyu sisik (Eretmochelys imbricata) di Pulau Kepayang pada tahun 2019. Parameter yang diukur kemudian dianalisis menggunakan metode Principal Components Analysis (PCA) dan Correspondence Analysis (CA). Jumlah telur terbanyak terdapat di lokasi 3 yaitu 507 butir, sementara jumlah terendah berada di lokasi 2 sejumlah 355 butir. Karakteristik habitat peneluran penyu sisik yaitu tipe pantai dengan kemiringan berkisar 2.16-3.81°, lebar pantai berkisar 8.4-10.52 m, panjang pantai berkisar 460-515 m. Fraksi sedimen didominasi oleh pasir sedang dan pasir sangat kasar. Kerapatan vegetasi termasuk dalam kategori baik. Sarang 4, 5 dan 6 dipengaruhi oleh lebar pantai dan pasir sangat halus sedangkan sarang 7,8,9 dan 10 dipengaruhi panjang pantai, kemiringan pantai dan pasir sangat kasar. Hasil analisis CA menunjukkan bahwa vegetasi Pcem, Pbut, Paka, Tbut dan Tsim memiliki hubungan yang erat dengan jumlah telur yang banyak 3(133-145). Sementara vegetasi lainnya memiliki korelasi yang erat dengan telur yang berjumlah sedang 2(121-132). Kata kunci: karakteristik lingkungan, penyu sisik, Pulau Kepayang, vegetasi, The hawksbill population in the wild is currently declining, mainly due to natural factors and anthropogenic factors. This study aims to determine the characteristics of the hawksbill nesting habitat (Eretmochelys imbricata) in Kepayang Island in 2019. The parameters measured then analyzed by Principal Components Analysis (PCA) and Correspondence Analysis (CA) methods. The highest number of turtle eggs was found in location 3 with a total of 507 eggs, while the lowest number was in location 2 with 355 eggs. The characteristics of the hawksbill nesting habitat include a sloping type of beach with 2.16-3.81°, a beach width ranging from 8.4-10.52 m, a beach length ranging from 460-515 m. The sediment fraction is dominated by medium and very coarse sand. The vegetation density is in the good category. Whereas nests 4, 5 and 6 are influenced by the characteristics of beach width, very fine sand and nests 7,8,9 and 10 are affected by beach length, beach slope and very coarse sand. The results of the CA analysis showed that the Pcem, Pbut, Paka, Tbut and Tsim vegetation had a close relationship with a large number of eggs 3(133-145). Meanwhile, the other vegetations had a close correlation with the medium number of eggs 2(121-132). Keywords: environmental characteristics, hawksbill turtle, Kepayang Island, vegetation
Keyword: environmental characteristics, hawksbill turtle, Kepayang Island, vegetation

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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