Judul: Estimasi daya dukung terumbu karang berdasarkan biomasa ikan kerapu macan di perairan Sulamadaha, Maluku Utara (suatu pendekatan pengelolaan ekologis):
Abstrak: Terumbu karang merupakan kumpulan endapan massive karbonat (C2CO3) yang dihasilkan berdasrakn hubungan simbiosis mutualisme antara hewan kurang dengan algae (zooxanthelae). Terumbu karang sangat sensitif terhadap pengaruh kegiatan manusia, pada umunya ekosistem terumbu karang sudah mengalami tekanan karena adanya pemanfaatan sumberdaya yang berlebihan, sehingga kondisi terumbu karang telah banyak mengalami penurunan. Persentase terumbu karang yang dikelompokan dalam katagori sangat baik sebesar 6.83%, baik 25.72%,sedang 36,87%, dan rusak 30,58%.
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Judul: Kondisi ekosistem terumbu karang ditinjau dari persentase penutupan karang di Zona Inti III Taman Nasional Laut Kepulauan Seribu Jakarta Utara
Abstrak: Ekosistem Terumbu Karang merupakan salah satu komponen yang sangat unik dan penting dalam lingkungan laut tropis. Keunikan ekosistem tersebut telah banyak mendapat perhatian, baik dalam hal pemanfaatan maupun pengelolaannya. Strategi pengelolaan ekosistem terumbu karang dapat direncanakan dengan melihat kondisinya. B nivers Tujuan penelitian ini adalah menelaah dan menduga kondisi ekosistem terumbu karang ditinjau dari persentase penutupannya. Data yang diperoleh, dianalisis berdasarkan persentase penutupan karang (De Silva, 1982), indeks struktur komunitas (Odum, 1971), indeks similaritas Bray- Curtis (Clifford dan Stephenson, 1975) dan Analisis Frontier (1985). Pengukuran yang dilakukan terhadap suhu (27.67 28.83) dan salinitas (32.67% - 33.67%) di permukaan air berada pada kondisi optimum untuk kehidupan karang. Kecepatan arus permukaan air pada saat pengamatan berkisar antara 5.79 cm/detik - 15.41 cm/detik. Kecerahan perairan pada semua stasiun pengamatan sebesar 3 meter dan 10 meter, artinya kecerahan 100%. Persentase penutupan biota karang berkisar antara 55.47% 85.01% pada kedalaman 3 meter, dan 65.58% 89.98% pada kedalaman 10 meter Kisaran penutupan biota karang tersebut berada pada kategori bagus sampai memuaskan. Secara keseluruhan persentase penutupan biota karang pada kedalaman 10 meter lebih tinggi daripada di kedalaman 3 meter. Biota yang ditemukan pada setiap stasiun kedalaman 3 meter adalah tipe karang ACB, CF dan CS. Di kedalaman 10 meter, terdiri dari: ACB, CF, CS, SP dan CM Persentase penutupan total karang mati di kedalaman 3 meter berkisar antara 15.00% 44.46%, yang terdiri dari: DCA (13.83%- 41.77%), DC (1.00% - 13.66%) dan R (1.83%). Persentase penutupan total karang mati di kedalaman 10 meter berkisar antara 8.33% 31.27%, terdiri dari: DCA (3.67% 31.27%), DC (2.00% - - 5.00%)...dst
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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