Judul: Kontribusi Ekowisata dalam Upaya Konservasi Ekosistem Mangrove di Pulau Pramuka, Kepulauan Seribu
Abstrak: Ekosistem mangrove Pulau Pramuka saat ini dimanfaatkan sebagai kawasan wisata. Kegiatan wisata dapat meningkatkan kegiatan manusia sehingga dapat mempengaruhi kegiatan konservasi dan akivitas wisata. Penelitian ini bertujuan untuk menganalisis kontribusi ekowisata dalam upaya konservasi ekosistem mangrove di Pulau Pramuka. Penelitian dilakukan di Pulau Pramuka pada Maret hingga April 2019. Pengambilan data mencakup data ekologi mangrove dan sistem manajemen yang telah dilaksanakan terhadap ekosistem mangrove dan kawasan wisata. Kontribusi ekowisata untuk konservasi masih perlu ditingkatkan agar upaya pemanfaatan dan konservasi mangrove dapat dioptimalkan. Sumberdaya mangrove saat ini belum sesuai untuk pemanfaatan kegiatan wisata dan belum diterapkannya sistem daya dukung dapat mengancam kelestarian lingkungan. Variabel K5, E1, dan E1 menunjukan bahwa masyarakat Pulau Pramuka mengerti bila perlindungan terhadap ekosistem mangrove dapat mendatangkan manfaat salah satunya yaitu pemanfaatan sebagai wisata mangrove. Terdapat tujuh rekomendasi pengelolaan agar kegiatan ekowisata untuk konservasi mangrove di Pulau Pramuka dapat berjalan lebih efektif.
Keyword: ekowisata, mangrove, pengelolaan, Pulau Pramuka

Judul: Karakteristik dan Dampak Pengelolaan Ekosistem Mangrove Rehabilitasi di Kawasan Konservasi dan Wisata: Studi Kasus Pulau Pramuka dan Pulau Pari
Abstrak: Ekosistem mangrove memiliki manfaat ekologi maupun ekonomi. Namun, rentan terhadap kerusakan dan penurunan biodiversitas. Oleh sebab itu, pemahaman mengenai pengelolaan dan strategi rehabilitasi mangrove penting. Penelitian ini bertujuan menganalisis karakteristik pengelolaan ekosistem mangrove di kawasan konservasi dan wisata di Pulau Pramuka dan Pulau Pari, Kepulauan Seribu, pada November 2023–Februari 2024. Metode yang digunakan, yaitu melakukan wawancara secara purposive sampling, pengambilan data vegetasi mangrove, dan sampel makrozoobentos. Variabel yang dianalisis meliputi karakteristik pengelolaan (tata kelola, aturan lokal, strategi rehabilitasi, dan pengelolaan pasca tanam) dan dampak pengelolaan (cakupan mangrove rehabilitasi, kerapatan mangrove, dan keanekaragaman makrozoobentos). Hasil penelitian menunjukkan dua jenis mangrove di Pulau Pramuka (Rhizophora stylosa dan Rhizophora mucronata) dan empat jenis mangrove di Pulau Pari (Rhizophora stylosa, Rhizophora apiculata, Soneratia alba, dan Bruguiera cylinndrica). Tingkat kerapatan mangrove pada kedua pulau tergolong sangat padat (31.714-128.500 ind/ha). Kepadatan makrozoobentos di Pulau Pramuka dan Pulau Pari masing-masing sebesar 121 ind/m2 dan 189 ind/m2 dengan keanekaragaman sedang. Kerapatan mangrove berkorelasi positif dengan kepadatan makrozoobentos (r>0.9). Terdapat perbedaan pengelolaan mangrove di kedua pulau dari segi tata kelola, aturan lokal, pengawasan dan pemeliharaan pasca tanam., The mangrove ecosystem has both ecological and economic benefits. However, it is vulnerable to damage and biodiversity loss. Therefore, understanding mangrove management and rehabilitation strategies is crucial. This research aims to analyze the characteristics of mangrove ecosystem management in conservation and tourism areas on Pramuka Island and Pari Island, Kepulauan Seribu, from November 2023 to February 2024. The methods used include purposive sampling interviews, mangrove vegetation data collection, and macrozoobenthos sampling. The variables analyzed include management characteristics (governance, local regulations, rehabilitation strategies, and post-planting management) and management impact (rehabilitated mangrove coverage, mangrove density, and macrozoobenthos diversity). The research results show two types of mangroves on Pramuka Island (Rhizophora stylosa and Rhizophora mucronata) and four types on Pari Island (Rhizophora stylosa, Rhizophora apiculata, Soneratia alba, and Bruguiera cylindrica). The mangrove density on both islands is classified as very dense (31,714-128,500 ind/ha). The macrozoobenthos density on Pramuka Island and Pari Island is 121 ind/m2 and 189 ind/m2, respectively, with moderate diversity. Mangrove density positively correlates with macrozoobenthos density (r>0.9). There are differences in mangrove management between the two islands in terms of governance, local regulations, post-planting monitoring, and maintenance.
Keyword: mangroves, macrozoobenthos, management, rehabilitation

Judul: Algorithm Construction of HLI Hash Function
Abstrak: Cryptography is a study of mathematical techniques related to aspects of information security regarding on confidentiality, data integrity, entity authentication, and data origin authentication. Data integrity is a service, which is associated with the conversion of data carried out by unauthorized parties. To maintain data integrity, one can use hash functions. An hash function is a computationally efficient function to map an arbitrary length bitstring to a fixed length bitstring called as hash value. The use of hash function in maintaining the information integrity and authentication is in digital signatures, virus protection, and software distribution. Illustration of the hash function in the integrity and authentication of information that is emailed as follow. The sender sends the information and hash value to the recipient. If the hash value of the information is equal to the hash value that is sent by the sender, then information has not been changed. Otherwise the information has been changed. An hash function has two properties, one way and collision resistance. An hash function is called one way if it is computationally infeasible to find any input such that when given any hash value . Meanwhile an hash function is called collision resistant if it is computationally infeasible to find any two inputs where such that . The purpose of this study is to construct a HLI hash function algorithm, to analyze the speed and security of the hash functions as a results of construction. Furthermore, it is to compare it with SWIFFT. Hash function is constructed based on the result of algebraic operations on modular polynomial ringwith . Modular polynomial ring noted as is a set of all polynomials of degree at most with coefficients in . can be represented as a set of integer vector of modulo in dimension . So, it is simple to implement in a computer. In vector operations, is lattice . Furthermore, alattice that is defined from certain polynomial ring is called ideal lattice. HLI hash function is consists of addition and multiplication algorithm in the ring. Addition algorithm consists of sumation operations of modulo and multiplication consists of multiplication operations of modulo . Generally, algorithm of HLI hash function consists of multiplication operations of modulo and addition operations of modulo . However, if the input is binary number then multiplication algorithm only consists of multiplication operation of modulo , so algorithm of HLI hash function consists of multiplication operations of modulo and addtion operations of modulo . An hash function is secured if it has two properties, i.e., one way and collision resistance. HLI hash function hash is one way, it is following the proof of Micciancio. It is has collision resistant because of polynomial is irreducible over and monic. Moreover, it is proved that for every unit vector , the vector is small vector. If the input of hash function is a binary number then HLI hash function only involves addition operations of modulo . So the time that used almost same with SWIFFT. The excellence of HLI hash function is the key size smaller than SWIFFT. This effect on
Keyword: hash function, modular polynomial ring, lattice