Judul: Kondisi sedimen dan kehidupan makrozoobenthos di Perairan Donan dan sekitarnya, Cilacap-Jawa Tengah
Abstrak: Penelitian ini dilakukan di perairan Donan dan Sekitarnya yang mencakup perairan di selat Nusa Kambangan, Cilacap propinsi Jawa Tengah. Penelitian dilakukan pada bulan Juli 1992, bertujuan untuk mempelajari karakteristik fisika kimiawi sedimen dan keragaman makrozoobentos dilihat dari struktur komunitasnya, serta kemungkinan adanya pengaruh yang ditimbulkan oleh aktivitas di sekitarnya. Hasil penelitian menunjukkan perairan Donan dan sekitarnya (Selat Nusa Kambangan) yang memiliki profil "perairan estuari" memiliki salinitas antara 26,7 29,900 dan termasuk dalam perairan estuari polyhaline (Gosner, 1971). Dengan demikian perairan Donan menunjukkan bukan merupakan suatu perairan sungai yang membawa massa air tawar. Suhu perairan tergolong normal, berkisar antara 28,0 31,0°C. Batimetri lokasi pengamatan cukup beragam, bagian tepi timur mempunyai kedalaman sekitar 3 meter, tepi barat kurang dari 3 meter, dan pada alur pelayaran (lebar sekitar 80 meter) mempunyai kedalaman terdangkal antara 7,5 8,0 meter.
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Judul: Tipologi Komunitas Makrozoobentos Sebagai Bioindikator Pencemaran .Perairan Di Muara Sungai Donan, Cilacap, Jawatengah
Abstrak: Muara sungai merupakan daerah pertemuan dua massa air yaitu massa air sungai dan mass a air laut sehingga mempunyai potensi dan peranan dalam berbagai bidang kehidupan serta merupakan ekosistem untuk kehidupan organisme perairan dan makhluk hid up sekitamya. Muara Sungai Donan merupakan pertemuan aliran Sungai Donan dengan Selat Nusa Kambangan. Melihat kecenderungan peningkatan pencemaran yang terjadi di perairan ini, maka pengkajian kualitas perairan baik kualitas fisika-kimia maupun biologi perairan perlu dilakukan. Menurut Wilhm (1975) komponen biologi yang sering digunakan sebagai indikator terjadinya perubahan kualitas perairan adalah bentos karena mempunyai tiga sifat yang sangat membantu dalam mengindikasikan tingkat pencemaran suatu perairan, yaitu: I. Mempunyai tingkat kepekaan yang berbeda-beda terhadap berbagai jenis bahan pencemar dan memberikan reaksi yang cepat terhadap perubahan yang terjadi, 2. Mempunyai mobilitas yang rendah, sehingga sangat mudah dipengaruhi oleh keadaan lingkungan di sekitamya, 3. Mudah ditangkap dan diidentifikasi. Penelitian ini bertujuan untuk mengetahui struktur komunitas makrozoobentos sebagai spesies indikator dan interaksinya dengan karakteristik fisika dan kimia lingkungan di Muara Sungai Donan, Cilacap dalam pendugaan kualitas 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