Judul: Pengaruh Pemberian Bahan Organik terhadap Limpasan dan Erosi Tanah
Abstrak: Penelitian ini bertujuan untuk melihat pengaruh pemberian bahan organik terhadap erosi tanah dan limpasan permukiman, serta mengamati sifat fisik tanah. Penelitia dilakukan dengan petak kecil berukuran (22x2m) dengan kemiringan 9% di Cikabayan, Dramaga, Bogor. Masing-masing perlakuan yairu, petak tanah bahan organik, petak tanah denga bahan organik ayam dan petak tanah dengan bahan organik sapi, dilakukan dua kal ulangan. Dosis bahan organik yang dipakai adalah 10 ton/ha untuk bahan organik dari ayam dan 30 ton/ha untuk bahan organik dari sapi.
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Judul: Pengaruh pemberian bahan organik dan lintasan traktor terhadap pemadatan tanah
Abstrak: Pemadatan tanah merupakan masalah yang belum terpecahkan, yang disebabkan oleh penggunaan alat secara tradisional dan peningkatan penggunaan mekanisasi pertanian. Penelitian ini bertujuan untuk mengetahui pengaruh pemberian bahan organik kotoran sapi terhadap terjadinya pemadatan tanah akibat lintasan roda traktor. Penelitian ini dilaksanakan di lahan percobaan Leuwikopo dan Laboratorium Mekanika dan Fisika Tanah, Jurusan Teknik Pertanian, Institut Pertanian Bogor dan berlangsung dari bulan Mei sampai Juli 1997. Perlakuan penelitian ini terdiri dari 2 macam yaitu perlakuan terhadap dosis kotoran sapi (KS) dan perlakuan terhadap jumlah lintasan (L), masing-masing perlakuan dilakukan dalam 3 kali ulangan. Penelitian yang dilakukan dibagi 2 bagian yaitu penelitian yang dilakukan di lapangan dengan mengambil sampel tanah untuk pengukuran kadar air dan bulk density serta pengukuran tahanan penetrasi dan penelitian yang dilakukan di laboratorium adalah uji standar proctor. Penelitian dimulai dengan menimbang berat traktor beserta emplemennya dan pengukuran dimensi traktor. Kemudian areal penelitian diplot sesuai dengan ukuran tiap perlakuan yaitu 30 m² dengan panjang 10 m dan lebar 3 m sebanyak 10 plot dan dibagi menjadi 9 plot yang diberi perlakuan kotoran sapi dan lintasan dan I plot tanpa perlakuan. Tanah kemudian diolah dengan pengolahan pertama pada seluruh plot dengan menggunakan bajak singkal dan pengolahan tahap kedua menggunakan garu rotari yang dilakukan seminggu setelah pengolahan pertama agar terjadi pengomposan dan bahan organik benar-benar tercampur. ...
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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