Judul: Preferensi Habitat Spons di Pesisir Pulau Pramuka, Kepulauan Seribu, DKI Jakarta
Abstrak: Marine sponges live at several habitats, such as sand, dead coral, rock and any media which has hard structure. The purposes of this study were to study sponges community structure and determine the habitat preferences of sponges’ at Pramuka Island coast, Kepulauan Seribu. This study was conducted in August to November 2014 at three sites representing each habitats; in The east of Pramuka Island for seagrass (SL1) and mangrove (SM1), Southeast (SL2 and SM2), and South (SL3 and SM3). Sponge observation and sample collection were done by 30 m belt transect method placed along the coastline with the radius of 1 m, while to calculate the density and type of seagrass and mangrove closure using quadratic transect size of 0.5 x 0.5 m2 and 5 x 5 m2. The result of this study showed that sponges had a variety of 16 species of 9 orders, 14 families, and 16 genera. Seven species of sponge was observed at seagrass habitat, while four species at mangrove and five at both habitats. Plakinastrella onkodes was the most common species observed in seagrass, Callyspongia pallida was the most common species observed in mangrove.
Keyword: Bogor Agricultural University (IPB), Pramuka Island, mangrove, seagrass, sponges, community structure

Judul: Analysis of the Relationship between  Aquatic Parameters and Sponge Abundance in Pramuka Island, Kepulauan Seribu  and Its Surroundings
Abstrak: Spons adalah hewan yang hidup sesil di bentik dengan mengandalkan arus serta oksigen yang cukup untuk memperoleh makanan (filter feeder). Informasi mengenai spons meliputi kelimpahan, kekayaan, dan habitat masih tergolong rendah di Indonesia sehingga dapat menjadi penghalang untuk studi lanjutan. Penelitian bertujuan untuk mengetahui kondisi perairan, kelimpahan, dan distribusi spons di Kepulauan Seribu dengan metode transect belt. Penelitian dilakukan di Pulau Pramuka, Pulau Panggang, Pulau Air, dan Pulau Sekati pada tanggal 5 – 13 Agustus 2023. Parameter perairan (suhu, DO, pH, salinitas, dan kecerahan) di lokasi penelitian tergolong baik. Kelimpahan dan kekayaan spons tertinggi adalah Aaptos Suberitoides. Parameter perairan (suhu, derajat keasaman, oksigen terlarut, salinitas, kecerahan) dari tujuh lokasi penelitian tergolong layak untuk kehidupan spons laut dikarenakan semua parameter perairan masih berada dalam ambang batas. Pada penelitian ini, tidak ditemukan hubungan antara kelimpahan dan kekayaan spons dengan parameter perairan. Hasil uji two – way ANOVA menunjukkan kekayaan spons diduga dipengaruhi oleh kedalaman, kedalaman 10 meter memiliki kelimpahan spons lebih tinggi daripada kedalaman 3 meter. Hasil Principle Component Analysis (PCA) memberikan pengelompokkan parameter kecerahan dan DO terhadap stasiun SPG 1, SPG 2, BPR 2, BAI 1, dan BAI 2; pH dengan SPR 1, SPR 2, dan BPR 1; suhu dengan stasiun DMG 1, DMG 2, BSK 1, dan BSK 2; salinitas dengan stasiun APL
Keyword: Parameter Perairan, Kedalaman, Kelimpahan spons, Parameter perairan, Pengelompokkan

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