Judul: Struktur Komunitas Makrozoobentos di Perairan Kali Baru Kodya Bengkulu
Abstrak: Penelitian bertujuan untuk mengetahui struktur kornunitas makrozoobentos akibat beban rnasukan bahan organik dari kegiatan yang berbeda. Penelitian dilaksanakan bulan Maret sarnpai Mei 1998, di perairan Kali Baru Kodya Bengkulu. Penentuan stasiun pengarnatan di dasarkan atas perbedaan beban rnasukan dari aktivitas rnanusia. Stasiun A (aktivitas: industri periknan, pernukirnan, dan pelabuhan perikanan), stasiun B (aktivitas: di tarnbak), dan stasiun C (tidak ada aktivitas manusia yang menonjol). Pengarnbilan sarnpel rnakrozoobentos, air dan substrat dilakukan sebanyak 7 (tujuh) kali, pada waktu surut.
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Judul: Struktur komunitas makrozoobenthos di Perairan Kanal Duri, Duri Kabupaten Bengkalis, Propinsi Riau
Abstrak: Penelitian ini bertujuan untuk melihat struktur komunitas makrozoobenthos di perairan kanal Duri, di daerah pemboran minyak bumi dengan mengkaji: 1. Faktor-faktor lingkungan yang banyak mempengaruhi keberadaan makrozoobenthos yang meliputi kualitas air dan substrat. University 2 . Komposisi jenis, Kepadatan jenis, Keanekaragaman jenis, Keseragaman jenis, Dominansi dan pola penyebaran jenis makrozoobenthos. 3. Penggunaan analisa Nodul untuk mengetahui preferensi makrozoobenthos terhadap habitatnya. Penelitian ini dilakukan pada bulan Juli 1998. Stasiun penelitian ditentukan berdasarkan metode pengambilan contoh sistematik (melihat daerah-daerah khusus). Lokasi penelitian terdiri dari empat stasiun, dan di tiap stasiun ditentukan tiga sub stasiun. Analisa struktur komunitas makrozoobenthos meliputi kepadatan jenis, keanekaragaman, keseragaman, dominansi, pola sebaran jenis dan analisa Nodul untuk melihat keberadaan makrozoobenthos di perairan. Parameter fisika-kimia kualitas air yang diukur adalah suhu, kecerahan, kedalaman, padatan tersuspensi (TSS), kecepatan arus, kekeruhan, oksigen terlarut (DO), pH, BOD, COD. Sedangkan parameter fisika-kimia substrat yang diukur adalah tekstur substrat, kandungan C-organik dan kandungan minyak. Suhu yang terukur selama penelitian antara 27-31°C, kecerahan perairan antara 30-57 cm, padatan tersuspensi antara 1,68-363,2 mg/l, kecepatan arus antara 0,179-0,514 m/dt, kandungan oksigen terlarut antara 2,4-6,30 mg/l, nilai kekeruhan antara 7-61 NTU, nilai pH yang terukur antara 4,45-6,03, nilai BOD antara 15,25-31,28 mg/l dan nilai COD-nya antara 48,77-98,78 mg/l. Secara umum kualitas air di daerah penelitian sudah terganggu. Sedangkan tipe substrat pada daerah penelitian adalah lempung, lempung berdebu, liat berdebu. ...
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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