Judul: Pengaruh waktu pemupukan nitrogen dan pemberian triakontanol terhadap pertumbuhan dan produksi tanaman jagung (Zea mays L.)
Abstrak: Mengingat sifat pupuk N mudah larut dan mudah hilang, sedangkan tanaman jagung menghendaki ketersediaan N yang cukup secara kontinu sepanjang hidupnya, maka pemberian bertahap merupakan alternatif untuk mengatasi masalah tersebut. Zat pengatur tumbuh juga akan efektif bila diberikan pada fase pertumbuhan tertentu. Tindakan yang diarahkan kepada memanipulasi faktor-faktor pertumbuhan dan perkembangan yang menunjang peningkatan hasil merupakan alternatif untuk meningkatkan tanggap tanaman terhadap zat pengatur tumbuh. Suatu penelitian yang berjudul seperti tersebut di atas telah dilakukan di Kebun Percobaan Balittan Sukarami Cabang Rambatan dari bulan Juli 1989 sampai dengan Januari 1990…dst
Keyword: Field crops, Nitrogen fertilizers, Triacontanol

Judul: Pengaruh macam dan waktu pemberian pupuk N terhadap efisiensi pengambilan nitrogen oleh tanaman jagung (Zea mays L.)
Abstrak: Penelitian ini bertujuan untuk mengetahui pengaruh mocam dan waktu pemberian pupuk N terhadap pengambilan nitrogen, efisiensi pengambilan nitrogen dan produksi tanaman jagung. Penelitian dilakukan di kebun percoba- an Balai Penelitian Tanaman Pangan Sukamandi. Pupuk nitrogen yang digunakan adalah urea, amonium nitrat ka- pur (ANK) dan SCU. Waktu pemberian pupuk adalah seka- ligus, 2/3 pada waktu tanam 1/3 pada 30 het, 1/3 pada waktu tanam + 2/3 pada 30 hst dan 1/3 pada waktu tanam +1/3 pada 30 hst+ 1/3 pada 45 hst. Percobaan disusun dalam faktorial dengan rancangan acak kelompok. Macam pupuk sebagai faktor pertama dan waktu pemberian seba- gai faktor kedua. Untuk mengetahui efifiensi pengam- bilan nitrogen digunakan pupuk urea dengan 4 persen ekses atom 15N. Ekses atom 15N dalam tanah dan tanaman dilacak dengan Spektrometer emisi. Pergerakan nitrogen di dalam tanah ke arah samping dan ke arah dalam tidak dapat dilacak dengan memakai..dst
Keyword: Zea mays, Nitrogen fixation, Nitrogen fertilizers

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