Judul: Rehabilitas tanah pasir-kuarsa eks-tambang-timah pulau bangka dengan bahan-bahan alamiah untuk budidaya tanaman jambu monyet
Abstrak: Penelitian bertujuan mengetahui tehnik-tehnik rehabilitasi tanah pasir-kuarsa bekas-pertambangan-timah Pulau Bangka dengan menggunakan bahan-bahan alamiah berupa kotoran hewan dan sekam, sehingga tanah tersebut dapat di budidayakan untuk tanaman jambu monyet. Kotoran hewan (K), sekam (S), dan pasir Bangka (P) sebagai variable perlakuan dicampur dengan perbandingan berat sebagai berikut: A (K:S:P 0:0:40), B (5:0:35), C (10:0:30), D (15:0:25), E (20:0:20), F (0:10:30), G (5:10:25), H (10:10:20), I (15:10:15), J (20:10:10), K (0:20:20), L (5:20:15), M (10:20:10), N (15:20:5), dan 0 (20:20:0). Semua perlakuan diatur dalam 4 kelompok (ulangan) untuk Rancangan Acak Kelompok. Tiap pot berisi 5 kg campuran (Berat Kering-Udara). Setelah inkubasi selama 1 bulan bibit tanaman jambu monyet yang telah berumur 18 hari ditanam. Tanaman dipanen setelah berumur + 3 bulan di dalam pot. Sebagai parameter pertumbuhan adalah tinggi tanaman, diameter batang, dan berat kering tanaman pada waktu panen. ...
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Judul: Rehabilitasi tanah pasir kuarsa dari bangka untuk budi daya tanaman jagung
Abstrak: Pulau Bangka yang berpetrografi dominan granitik dan sedikit yang bersifat ophioloitik dengan sendirinya meru- pakan daerah yang kurang produktif untuk pertanian. Ke- adaan alamiah ini menjadi lebih parah lagi oleh prosedur teknis pertambangan untuk memperoleh biji timah melalui pemindahan tanah bagian atas dan pencucian secara inten- sif. Budi daya tradisional penduduk setempat pada satu pihak berhasil menemukan teknik pengelolaan tanah yang baik untuk budi daya lada, pada lain pihak bagian lain dari penduduk seringkali secara sengaja hendak menguras habis kapasitas potensi produksi lahan melalui perladangan. Tujuan penelitian ini adalah penjajagan pendahuluan kemungkinan rehabilitasi tanah-tanah bekas pertambangan timah Bangka sebagai upaya peningkatan potensi produksi tanah-tanah pasir kuarsa (termasuk eks Spodosol).
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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