Judul: Pemanfaatan Penginderaan Jauh Untuk Kajian Distribusi dan Kondisi Karakteristik Dasar Perairan Pada Ekosistem Terumbu Karang di Kepulauan Spermonde (Sangkarang) Selat Makassar
Abstrak: Penelitian ini bertujuan untuk mengetahui kondisi dan distribusi karakteristik dasar perairan pada ekosistem terumbu karang, memetakan dan mempelajari perubahan serta penyebabnya selama kurun waktu 3 tahun melalui citra sateli Landsat TM 29 Agustus 1994 dan 2 Juni 1997 yang didukung oleh pengamatan lapangan di Pulau Kondongbali dan Pulau Bontosua. Pengolahan citra dilakukan di Laboratorium lnderaja Program Studi llmu Kelautan lnstiiut Pertanian Bogor dengan menggunakan perangkat lunak IDRlSl versi 4.1 pada bulan Juli - Desember 1997. Pengamatan lapangan dilaksanakan di Pulau Kondongbali dan Bontosua Kepulauan Spermonde (Sangkarang), Selat Makassar tanggal 21 - 27 Juli 1997 dengan menggunakan metode transek garis.
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Judul: Pemanfaatan Data SateHt Landsat-TM untuk Inventarisasi Ekosistem Terumbu Karang Di Perairan Sibolga Kabupaten Tapanuli Tengah Sumatera Utara
Abstrak: Ekosistem terumbu karang merupakan salah satu sumberdaya alam laut yang mempunyai nilai dan arti yang sangat penting baik dari segi ekologi laut maupun sosial, ekonomi dan budaya. Karena itu diperlukan adanya upaya pengelolaan sumberdaya tersebut yang berdasarkan prinsip pengembangan yang berkelanjutan untuk mencegah pengrusakan dan penurunan sumberdaya yang dikandungnya. Data dan informasi mengenai distribusi dan kondisi ekosistem terumbu karang sebagai langkah awal dari pengelolaan dan pengembangan sumberdaya ekosistem terumbu karang. Dimana teknologi penginderaan jauh merupakan alternatif yang tepat dalam mendukung penyediaan data dan informasi tersebut. Penelitian dengan tujuan menganalisis data inderaja untuk memperoleh informasi tentang kondisi dan perubahan yang terjadi di kawasan ekosistem terumbu karang dari tahun 1995 sampai dengan tahun 1997 ini dilakukan di perairan Sibolga, Kabupaten Tapanuli Tengah Sumatera Utara. Metode yang digunakan untuk pengolahan data citra dalam penelitian ini adalah metode yang dikembangkan oleh Siregar et a/. 1995 yang didasarkan pada persamaan Lyzenga, 1978, yaitu "Exponential Attenuation Moder atau yang lebih dikenal dengan sebutan Algoritma Lyzenga. Data citra yang digunakan adalah data citra Landsat-TM multi temporal tahun 1995 dan tahun 1997.
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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