Judul: Studi tentang Keadaan Sedimen Dasar dan Makrobentos di Sekitar Delta Muara Jaya, Sungai Citarum, Teluk Jakarta
Abstrak: Salah satu dampak dari kegiatan industri ialah makin banyaknya sisa produksi atau limbah yang harus dibuang dan akhirnya dapat menurunkan kualitas ligkungan. yang lebih merasakan dampak tersebut ialah perairan sungai, karena umumnya industri-industri sungai untuk membuang limbah. Daerah muara memanfaatkan Daerah Bekasi dipersiapkan sebagai kawasan industri. Sebagai konsekuensinya, jumlah limbah dan segala macam sisa produksi bertambah banyak, sehingga diperkirakan Sungai Citarum dan sungai-sungai lain yang berada di sekitarnya akan mengalami tekanan ekologis yang lebih berat. Penelitian ini bertujuan untuk mengetahui kualitas perairan, kondisi sedimen dasar dan komunitas makrobentos di sekitar delta Muara Jaya sungai Citarum, Teluk Jakarta. Penelitian dilakukan selama tiga kali periode pengamatan, yaitu 15 Februari, 5 April dan 8 Nopember 1990. Lokasi penelitian termasuk ke dalam wilayah Kecamatan Muara Gembong, Kabupaten Bekasi, Propinsi Jawa Barat. Parameter yang diukur terdiri dari parameter fisik-kimia air (kejelukkan, suhu, salinitas, kecerahan, arus, DO, PH, BOD5 dan COD), kemudian fraksi sedimen, redokspotensial, kandungan logam berat (Hg dan Cd) serta kepadatan dan biomas makrobentos. ...
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Judul: Karakteristik Komunitas Makrozoobenthos di Muara Sungai Citarum dalam Hubungannya dengan Pendugaan Pencemaran Perairan di Teluk Jakarta
Abstrak: Penelitian ini dilaksanakan pada bulan Pebruari 1990 hingga April 1990 di Muara Sungai Muara Jaya, Kec. Muara Gembong, Kab. Bekasi, Jabar. Lokasi penelitian ini merupakan salah satu dari 3 Muara Sungai Citarum. Penelitian bertujuan untuk menilai kondisi perairan Muara Sungai Muara Jaya dengan melihat karakteristik komunitas makrozoobenthos seperti kelimpahan jenis, keragaman, keseragaman, dominansi dan penyebarannya. Metode yang digunakan dalam mengambil contoh adalah metode transek dengan posisi menyebar ke arah laut dari titik pusat, yang terletak di depan muara. Lokasi penelitian terdiri dari 11 stasiun dan masing-masing stasiun berjarak sekitar 2 km. Makrozoobenthos diambil dengan menggunakan Ekman Dredge. Contoh benthos diambil sebanyak 3 kali dengan interval waktu 1 bulan. Contoh air diambil dengan menggunakan Botol Nansen pada pengambilan contoh pertama dan ketiga. Parameter fisika, kimia dan substrat yang diukur meliputi : suhu air, salinitas, kecerahan, kedalaman, kec.arus, D0,BOD5, COD, it rat, Fosfat, pH air, tekstur substrat, Logam berat Hg dan Cd dalam lumpur, total bahan organik substrat dan p~ substrat.
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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