Judul: Keanekaragaman Makroavertebrata Air pada Empat Habitat Berbeda di Teluk Madong, Pulau Bintan
Abstrak: Teluk Madong berlokasi di Pulau Bintan yang faunanya tergolong kelompok asiatis karena berada pada wilayah Wallace. Keanekaragaman makroavertebrata air di Teluk Madong menghadapi resiko dari kegiatan pemanfaatan perairan. Penelitian dilakukan untuk membandingkan keanekaragaman makroavertebrata air, menguji pengaruh lama penyimpanan dan lokasi penempatan substrat buatan terhadap kepadatan makroavertebrata air. Penelitian dilakukan pada bulan Agustus 2018 hingga Desember 2018 di keramba jaring apung, hutan mangrove, bagan tancap, dan padang lamun di Teluk Madong, Pulau Bintan. Data yang digunakan adalah data primer yang berupa kepadatan jenis makroavertebrata air, dan data sekunder yang berupa gelombang pasang surut. Analisis data yang digunakan yaitu indeks diversitas, uji statistik analisis ragam digunakan untuk uji hipotesis, dan klasterisasi stasiun. Sebanyak 56 spesies dari lima filum ditemukan selama penelitian. Keramba jaring apung dan bagan tancap memiliki indeks diversitas yang rendah dibandingkan hutan mangrove dan padang lamun. Lama penyimpanan dan lokasi penempatan substrat tidak berpengaruh nyata terhadap kepadatan makroavertebrata air.
Keyword: diversitas, makroavertebrata air, substrat buatan

Judul: Keanekaragaman Makrozoobentos dan Keterkaitannya dengan Ekosistem Padang Lamun di Perairan Sekitar Pulau Bintan.
Abstrak: Salah satu fungsi lamun adalah tempat hidup bagi organisme-organisme laut, khususnya makrozoobentos. Penelitian ini bertujuan mencari hubungan kerapatan lamun dengan keanekaragaman makrozoobentos di Pulau Bintan. Pengambilan sampel dilakukan di 3 stasiun menggunakan pendekatan Purpossive Sampling Method dengan transek garis. Transek garis dibentangkan sepanjang 100 m sebanyak tiga substasiun dengan beda jarak 25 m setiap substasiunnya. Pada setiap transek garis diletakkan transek kuadrat berukuran 0.5 m x 0.5 m. Pada lokasi penelitian ditemukan sebanyak 7 jenis lamun, yaitu Cymodocea rotundata, Cymodocea serrulata, Syringodium isoetifolium, Halodule uninervis, Halophyla minor dan Enhalus acoroides, serta Thalassia hemprici dengan kerapatan berkisar antara 18 – 636 ind/m2. Makrozoobentos yang ditemukan diantaranya kelas Gastropoda, Bivalvia, dan Crustacea dengan kepadatan berkisar antara 4-1600 ind/m2. Kenakaragaman tinggi pada dua stasiun dan sangat tinggi pada satu stasiun dengan nilai indeks 3.16 – 4.25. Distribusi spasial makrozoobentos di tiap stasiun berbeda-beda.
Keyword: lamun, Pulau Bintan, makrozoobentos, gastropoda, bivalvia

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