Judul: Perbedaan keefisienan pemupukan nitrogen pada tanah tergenang dan kadar air kapasitas lapang pada tanaman padi varietas IR-42
Abstrak: Pada budidaya tanaman padi yang intensif pemberian pupuk merupakan salah satu syarat yang tidak dapat ditinggalkan untuk meningkatkan produkai gabah, terutama pada pemakaian varietas padi unggul yang tanggap terhadap pemberian pupuk. Kebanyakan lahan pertanian untuk tanaman padi, baik lahan sawah maupun lahan kering kekurangan nitrogen. Oleh karena itu pemakaian pupuk nitrogen paling banyak dilakukan. Dengan meningkatnya penggunaan pupuk nitrogen perlu dipikirkan keefisienannya dalam rangka penghematan energi. Lahan sawah merupakan area pertanaman padi yang utama, selain sebagian lahan kering untuk pertanaman padi gogo. Penelitian keefisienan pemakaian pupuk nitrogen lebih banyak dilakukan pada pertanaman padi sawah dibandingkan pada padi gogo. Pupuk nitrogen yang biasa digunakan adalah urea dan amonium sulfat. Kebanyakan petani menyukai pemakaian urea yang diproduksi PT Pupuk Sriwijaya karena telah terbukti dapat meningkatkan hasil gabah. Sedangkan urea yang diproduksi PT Pupuk Kujang pada permulaan berproduksi belum banyak dikenal petani, di samping bukti peningkatan hasil gabah belum meyakinkan petani.
Keyword: Oryza;, Rice production;, Fertilization;, Plant nutrition;, Bogor Agricultural University;

Judul: Efisiensi Penggunaan Nitrogen Pada Padi (Oryza sativa L.)
Abstrak: Nitrogen fertilizer in the form of urea has become a staple for farmers, especially in Indonesia. Consequently, applying such large quantities of urea cannot be avoided. The understanding of nutrient-use efficiency on paddy-field is needed to increase plant productivity and reduce environmental pollution because of the utilization of luxury urea fertilizer. The objective of this research was to quantify the nitrogen-use efficiency (NUE) on paddy-field. This study was conducted in field and green house. The experiments were carried out in the experimental field at the Indonesian Center For Rice Research (ICRR), Subang-West Java and farmer’s field at Bogor– West Java. The N fertilizer applied in ICRR and farmer field were 225 and 612.25 kg urea/ha, established in experimental plots of about 25 m2. The N fertilizer applied in the green house experiment were 200, 300, 400, 500 and 600 kg urea/ha, respectivelly. The result showed that the NUE and N resorption were higher in ICRR than that of in farmer’s field. The green house experiment showed that the NUE and N resorption were higher under 500 kg urea/ha than other treatments. The plant growth, plant biomass, grain yield, NUET, NUEES, ANUE, PNUE dan N resorption were declined with the high availability in nitrogen-pool and increasing in large quantities at certain doses of N fertilizer.
Keyword: 

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