Judul: Pengaruh Serbuk Briket Organik Dan Kadar Air Pada Beberapa Sifat Fisik Regosol Ciomas, Bogor Dan Pertumbuhan Tanaman Bayam (Amaranthus Tricolor L.)
Abstrak: Bayam merupakan salah satu komoditi sayuran yang ban yak dikonsumsi oleh masyarakat. Komoditi ini akan mencapai pertumbuhan dan produksi optimal apabila didukung oleh media tmnbuh tanaman yang cukup memadai terutama sifat fisik tanah dan kebutuhan akan air. Penggunaan serb uk briket organik dan pemberian air pada tanah Regosol diharapkan dapat memperbaiki sifat fisik tanah sehingga dapat meningkatkan efisiensi penggunaan air dan produksi bayam. Penelitian ini bertujuan untuk mengetahui pengaruh dari penggunaan serbuk briket organik dan beberapa perlakuan kadar air terhadap sifat -sifat fisik tanah, pertumbuhan dan produksi tanaman bayam pada Regosol Ciomas. Penelitian dilaksanakan di rumah kaca Cikabayan, Darmaga dan Laboratorium Fisika dan Konservasi Tanah, Departemen Tanah, Fakultas Pertanian, Institut Pertanian Bogor. Penelitian dilakukan sejak pertengahan bulan Maret sampai dengan Juni 2003.
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Judul: Pengaruh serbuk briket organik dan pemberian air terhadap beberapa sifat fisik tanah latosol merah Oxic Dystrudept Gunung Sindur, evapotranspirasi, pertumbuhan dan produksi tanaman selada Lactut a sativa
Abstrak: Selada merupakan komoditi sayuran yang banyak dikonsumsi masyarakat. Tanaman sayur ini telah banyak dibudidayakan di sentra-sentra perkebunan sayur. Selada dapat tumbuh pada tegalan maupun perladangan. Jenis tanah yang cocok untuk pertumbuhannya adalah tanah dengan tekstur liat berpasir seperti Latosol maupun Andosol, dengan bahan organik cukup dan tidak tergenang. Latosol merupakan tanah yang telah mengalami perkembangan lanjut. Tanah ini memiliki sifat-sifat fisik yang cukup baik tetapi kurang mendukung bagi pertumbuhan tanaman sayuran karena daya retensinya terhadap air rendah. Daya retensi terhadap air ini dapat diperbaiki dengan menambahkan bahan organik. Salah satu bahan organik yang dipergunakan adalah serbuk briket. Penelitian ini bertujuan untuk mengetahui pengaruh pemberian serbuk briket dan beberapa tingkat kadar air terhadap beberapa karakteristik fisik Latosol Merah Gunung Sindur dan pertumbuhan serta produksi tanaman selada (Lactuta sativa). Penelitian ini dilakukan di rumah kaca dan Laboratorium Fisika dan Konservasi Tanah, Departemen Tanah, Fakultas Pertanian, Institut Pertanian Bogor. ...
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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