Judul: Kajian komunitas terumbu karang daerah perlindungan laut perairan Sitardas Kabupaten Tapanuli Tengah Propinsi Sumatera Utara:
Abstrak: Terumbu karang merupakan ekosistem perairan dangkal yang banyak dijumpai di sepanjang garis pantai daerah tropis yang terbentuk dari endapan massif kalsium karbonat (CaCO3), dihasilkan oleh karang hermatifik yang bersimbiosis dengan alga zooxantella (Nybakken, 1992). Secara ekologis terumbu karang merupakan tempat hidup biota laut sebagai tempat berlindung, mencari makan, bertelur dan daerah pembesaran. Kerusakan ekosistem terumbu karang tidak hanya menyebabkan turunnya kualitas dan kuantitas terumbu karang tetapi juga menurunkan kualitas dan kuantitas biota yang berinteraksi terhadap terumbu karang, seperti halnya ikan dan hewan benthic lainnya. Adanya kerusakan ekosistem terumbu karang di Perairan Sitardas mengakibatkan turunnya kualitas dan kuantitas terumbu karang serta turunnya hasil perikanan masyarakat nelayan Desa Sitardas. Oleh karena itu, maka penelitian ini dilakukan untuk memberikan saran dan rekomendasi bagi perbaikan upaya pengelolaan ekosistem terumbu karang di Perairan Sitardas agar kerusakan yang lebih besar dapat dihindarkan. Penelitian ini bertujuan, untuk mengkaji kondisi terumbu karang yang ada di Perairan Sitardas, kemudian mengkaji kerusakan terumbu karang di Perairan Sitardas, selanjutnya memberikan rekomendasi strategi pengelolaan terumbu karang dalam upaya pengembangan Daerah Perlindungan Laut Sitardas.
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Judul: Kajian Keberlanjutan Pengelolaan Daerah Perlindungan Laut Berbasis Masyarakat Pulau Sebesi Kabupaten lampung selatan.
Abstrak: Terumbu karang merupakan ekosistem khas perairan tropik Yang dapat memberikan berbagai manfaat langsung maupun tidak langsung. Cesar (2000) menyebutkan bahwa ekosistem terumbu karang banyak menyumbangkan berbagai biota laut seperti ikan karang, mollusca, crustacean bagi kehidupan masyarakat yang tinggal di kawasan pesisir. Sementara Supriharyono (2000) menyatakan bahwa tingginya produktivitas primer di perairan terumbu karang memungkinkan ekosistem ini dijadikan tempat pemijahan, pengasuhan dan pencarian makan bagi banyak biota laut.
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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