Judul: Percobaan pengadaan bahan tanaman Eucalyptus urophylla S. T. Blake melalui pertumbuhan plantlet pada beberapa media tumbuh
Abstrak: Tujuan penelitian ini adalah untuk mengamati pertumbuhan plantlet E. urophylla pada beberapa kombinasi media tumbuh pasir, tanah, kompos. Penelitian ini dilakukan di Laboratorium "Tissue Culture" dan rumah kaca Tropical Forest Biology BIOTROP selama sepuluh bulan.
Keyword: E. urophylla

Judul: Pengaruh kepadatan tanah, media tumbuh dan cendawan ektomikorhiza terhadap pertumbuhan semai encolyptus urophylla S.T.Blake
Abstrak: Sistem silvikultur Tebang Pilih Tanam Indonesia (TPTI) merupakan salah satu bentuk pengelolaan hutan alam tropika di Indonesia pada hutan tidak seumur. Salah satu pedoman TPTI adalah dengan melaksanakan penanaman pada areal terbuka, antara lain bekas jalan sarad, TPn dan TPК. Namun kegiatan tersebut masih banyak menemui kegagalan karena terjadinya pemadatan tanah oleh alat- alat berat. Pemadatan tanah berakibat buruk terhadap pertumbuhan tanaman karena sistem perakarannya tidak berkembang, laju pergerakan air terhambat, memburuknya sirkulasi udara tanah dan pengurangan porositas tanah. Untuk mengatasi permasalahan tersebut maka diperlukan usaha pemecahan masalah melalui pemilihan jenis tanaman yang cocok dan melalui pendekatan teknologi yang tepat. Pemanfaatan teknologi dilakukan dengan penambahan bahan organik untuk memperbaiki sifat-sifat tanah dan penggunaan mikorhiza untuk meningkatkan kualitas dan kemampuan hidup bibit di lapangan. Penelitian ini bertujuan untuk mengetahui pengaruh kepadatan tanah, media tumbuh dan cendawan ektomikorhiza terhadap pertumbuhan semai Eucalyptus urophylla S.T. Blake. Penggunaan tanah dan kompos sebagai media tumbuh dan cendawan ektomikorhiza diharapkan dapat mempengaruhi pertumbuhan semai dalam mengatasi efek pemadatan tanah. Penelitian ini dilaksanakan di Laboratorium Mekanika dan Fisika Tanah FATETA IPB, Rumah Kaca Silvikultur FAHUTAN IPB dan Laboratorium Bioteknologi dan Pemuliaan Pohon SEAMEO- BIOTROP Bogor pada bulan Mei 1998 sampai dengan Maret 1999. Bahan-bahan yang digunakan dalam penelitian ini terdiri dari benih Eucalyptus urophylla, spora cendawan ektomikorhiza Scleroderma dictyosporun dan Rhizopogon luteolus, tanah podsolik merah kuning, pasir, kompos, vapam, parafin, sodium alginate, kristal calsium clorit, alkohol, xylol, alcian blue 91%, safranin 1%, tissue dan aquadest. Sedangkan alat-alat yang digunakan bak kecambah, ayakan, autoklave, handspryer, pipa paralon dan tutup pipa (dop), gergaji, biji plastik, glue gun, bor kayu, plastik, proctor, dongkrak tanah, pisau plat baja, timbangan, gelas ukur, cawan petri, erlenmeyer, stirer magnetic, buret titrasi, sekop, mistar, jangka sorong, oven, kaca preparat, gelas penutup, mikroskop, kamera, mikrotom putar, benang, alat-alat tulis, kalkulator dan komputer.
Keyword: silvikultur

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