Judul: Kondisi terumbu karang di perairan kabupaten Sumenep, Madura - Jawa Timur
Abstrak: Informasi mengenai kondisi terumbu karang merupakan langkah awal dalam pengelolaan dan pemanfaatan sumber daya alam yang berguna, khususnya bagi masyarakat Kabupaten Sumenep, Madura-Jawa Timur. Penelitian ini menggunakan data primer dan data sekunder. Data sekunder diambil pada tanggal 01-20 Agustus 2006 di daerah kepulauan kabupaten Sumenep, sedangkan data primer diambil pada tanggal 27 Desember 2007 Noveember 2006 di daerah pesisir kabupaten Sumenep.
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Judul: Kondisi terumbu karang di daerah sekitar pelabuhan dan non pelabuhan di perairan Pulau Kelapa  dan Pulau Harapan, Kepulauan Seribu, Jakarta
Abstrak: Penelitian ini bertujuan untuk mengetahui dan membandingkan kondisi terumbu karang yang berada pada daerah pelabuhan dan non pelabuhan. Kegiatan penelitian ini dilakukan pada tanggal 23 hingga 28 April 2007 bertempat di perairan Pulau Kelapa dan Pulau Harapan, Kepulauan Seribu Jakarta. Pengamatan terumbu karang dan ikan karang menggunakan metode LIT (Line Intercept Transect) dan metode visual sensus. Data yang didapatkan dianalisis berdasarkan persentase penutupan karang keras (HC), indeks mortalitas karang (IMK), serta indeks keanekaragaman (H'), keseragaman (E) dan dominasi (C) ikan karang. Parameter kualitas air yang diukur diantaranya suhu, kedalaman, kecepatan arus, kecerahan, salinitas, derajat keasaman (pH), oksigen terlarut (DO), fosfat dan nitrat perairan
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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