Judul: Efisiensi air pada budidaya tanaman tebu Saccharum officinarum : Analisis kebutuhan air irigasi dan masa tanam optimal di areal PG Rejosari PTP XI Magetan Jawa Timu
Abstrak: Tanaman Tebu (Saccharum officinarum) memiliki karakteristik yang khas, pada umur 1-9 bulan dibutuhkan jumlah air yang banyak sedangkan pada umur 10-12 bulan menghendaki keadaan yang kering atau sedikit air. Areal PG Rejosari memiliki sumber daya air yang sangat terbatas, hal ini diperburuk lagi dengan adanya persaingan pemanfaatan air irigasi dengan tanaman lain khususnya tanaman padi sehingga diperlukan adanya pengelolaan air pengairan yang tepat dan penyesuaian masa tanam guna mengefisienkan sumber daya air yang ada dan meningkatkan produktifitas tanaman tebu. Tujuan penelitian ini untuk mengetahui jumlah kebutuhan air irigasi pada masa tanam optimal dan mengetahui pengaruh karakteristik lahan dalam menahan dan menyimpan air irigasi di Areal PG Rejosari. Penelitian ini dilakukan di PG Rejosari. Analisis sifat fisik tanah dilakukan di Laboratorium Fisika dan Konservasi Tanah; Laboratorium Genesis, Klasifikasi dam Mineralogi Tanah. Penelitian berlangsung mulai bulan Mei hingga bulan Juli 2004. ...
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Judul: Hubungan Antara Panjang Alur, Debit dan Lama Pemberian Air pada Sistem Irigasi Alur untuk Tanaman Tebu di PT. PG. Rajawali Unit PG. Subang, Jawa Barat
Abstrak: Peningkatan produksi gula dapat tercapai bila ditunjang oleh adanya penerapan i teknologi budidaya tanaman tebu yang tepat dengan memperhatikan sifat lahan dan kondisi pengairan. Teknik budidaya tebu lahan kering mengharuskan adanya pendayagunaan air secara optimal. Salah satu cara pengairan yang dapat diterapkan pada tanaman tebu adalah sistem irigasi alur. Dengan cara ini air diberiltan pada alur tanaman dengan jarak tertentu, dan air akan menyebar secara vertikal dan horisontal ke dalam tanah lalu membasahi daerah perakaran tanaman. Irigasi yang baik diantaranya dapat dilihat dari nilai keseragamatl penyebaran air, akibat erosi dan efisiensi pemberian air. Efisiensi irigasi alur dapat ditingkatkan melalui upaya pencegahan kehilangan air berupa limpasan dan perkolasi. Besarnya kehilangan air berupa limpasan dan perkolasi sangat dipengaruhi oleh dimensi dan panjang alur serta sistem operasi yang diterapkan. Untuk itu perlu dilakukan penentuan hubungan antara panjang alur, debit aliran dan lama pemberian air irigasi pada sifat fisik tanah tertentu, kebutuhan air tanaman, air tanah tersedia, dan kemiringan lahan tertentu
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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