Judul: Penilaian Keadaan Fisik Dan Potensi Air Tanah Dangkal Dengan Pengamatan Recovery Pada Beberapa Pertjobaan Pemompaan Di Daerah Tangerang, Djawa Barat
Abstrak: Penelitian untuk keperluan penilaian keadaan fisik dan potensi air tanah dangkal pada tudjuh desa jang dikelompokkan mendjadi dua Areal Penelitian telah diadakan dengan pengumpulan data melalui pengukuran pengukuran dan pengamatan dilapang mengenai: a) kedalaman muka air, b) pengisian kembali serta analisa tjontoh air dilaboratorium. Pengamatan dilapang dilakukan dalam bulan Maret dan April 1970 didesa-desa Tjikupa, Pousar dan Tjiakar (Areal Penelitian Tjikupa), Tjurug Kulon, Tjurug Wetan, Djatake dan Gembor (Areal Penelitian Tjurug), sedangkari analisa tjontoh air dilakukan di Laboratorium Teknik Ponjehatan I.T.B., Bandung. Metode penelitian jang dipergunakan, ialah "Case Study" dengan pengambilan tjontoh setjara atjak setelah distratifikasi berdasarkan djumlah desa pada masing-masing Areal Penelitian. Pongamatan dan pengukuran kedalaman muka air dilakukan terhadap 30 buah sumur untuk masing-masing Areal Penelitian, sedangkan pengamatan dan pengukuran pengisian kembali dilakukan dengan mengadakan pertjobaan pemompaan pada lima buah sumur dari masing-masing Areal. Penelitian. Untuk keperluan penentuan kwalitas air telah dilakukan pengambilan 10 tjontoh air, jaitu 3 dari Areal Penelitian Tjikupa dan 7 dari Areal Penelitian Tjurug. Pe- nilaian dilakukan terhadap kedalaman muka air dari permukaan tanah, besarnja debit pengisian kembali air tanah dalam sumur dan kwalitas air jang didasarkan pada persen Na, nilai SAR, daja hantar listrik (DHL), kadar Cl dan SO, serta deradjat kemasaman (pH) air. ...
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Judul: Kualitas air tanah dangkal daerah pemukiman di kecamatan Bekasi Barat, Timur dan Selatan Kabupaten Bekasi
Abstrak: Tujuan penelitian adalah untuk mengetahui kelayakan air tanah dangkal di daerah penelitian sebagai air minum ditinjau dari baku mutu yang telah ditetapkan dan mengkaji bagaimana pengaruh jenis tanah dan kepadatan permukiman terhadap kualitas air tanah. Disamping itu penelitian ini juga bertujuan mendapatkan luas dan sumber pencemaran di daerah penelitian. Diharapkan dari penelitian ini akan <lidapat gambaran tentang kualitas air tanah di daerah permukiman dan mendapatkan hubungan yang lebih jelas antara kepadatan permukiman, jenis tanah dan kualitas air tanah dangkal. Metode penelitian yang digunakan adalah metode survai untuk pengamatan lapangan, pengambilan oontoh air, pengamatan parameter fisik lingkungan, pengambilan kuesioner dan wawanoara. Pengambilan contoh air tanah mewakili kepadatan permukiman dan jenis tanah. Conteh air dianalisis untuk mengetahui parameter fisik (suhu, kekeruhan, DHL, padatan total, padatan terlarut total), kimia (pH, amonia, nitrit, nitrat, kesadahan total, kalsium, magnesium, sulfida, sulfat, besi, mangan, klorida, bahan organik total, oksigen terlarut, kebutuhan oksigen biokimia, kebutuhan oksigen kimiawi, total fosfat, orto/ fosfat, deterjen) dan mikrobilogi (koliform dan Escheri- .chi.a =li). Pengambilan parameter fisik lingkungan dimaksudkan agar dapat mengetahui hubungan antara kualitas air dan kondisi fisik lingkungan. Sedang kuesioner sosial ekonomi bertujuan untuk mengevaluasi sejauh mana hubungan antara kualitas air dan kondisi sosial ekonomi masyarakat yang tinggal di dekat lokasi pengambilan contoh air. ...
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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