Judul: Pengaruh lamanya tahun pembukaan hutan terhadap beberapa sifat tanah podzolik merah kuning Sumatera Selatan dan kaitannya dengan proses degradasi tanah
Abstrak: Tujuan penelitian untuk mempelajari pengaruh lamanya tahun pembukaan hutan dan posisi lahan terhadap perubahan sifat-sifat tanah dan mencari upaya cara pengelolaan tanah podzolik merah kuning melalui percobaan rumah kaca. Metode penelitian terdiri dari pengamatan lapang (pemerian penampang profil tanah, pengumpulan data lingkungan dan pengambilan contoh tanah), penelitian laboratorium (analisis sifat mineralogi, fisik dan kimia tanah) dan percobaan rumah kaca (perlakuan pemberian kapur dan pupuk nitrogen, fosfor dan kalium pada tanah podzolik merah kuning) yang telah beberapa tahun terbuka dari vegetasi aslinya dan terletak pada dua posisi, yaitu puncak bukit dan lereng bukit, dengan tanaman jagung dan kedelai sebagai indikator. Dosis kapur 1.5 kali aluminium dapat ditukarkan dan pemupukan NPK dengan empat taraf: 1) tanpa pupuk 2) 1 ku Urea + 1/2 ku ZA, 1 ku TSP, 1 ku KCL 3) 2 ku Urea + 1 ku ZA, 2 ku TSP, 1 ku KCL 4) 4 ku Urea + 2 ku ZA, 4 ku TSP, 2 ku KCL per hektar. Hasilnya tanah podzolik merah kuning Batumarta cadangan mineralnya sudah langka (kurang dari .5 persen). Perubahan morfologi yang menonjol adalah hilangnya/berkurangnya lapisan permukaan tanah. Lima tahun setelah pembukaan hutan lapisan atas tanah podzolik merah kuning Batumarta berkurang tujuh cm di puncak bukit dan sembilan cm di lereng bukit. Per tahun kehilangan antara 1.4 cm dan 1.8 cm. Hampir semua sifat fisik tanah berubah secara tidak menguntungkan, terutama bobot isi yang meningkat dengan nyata. Sifat kimia tanah sebagian besar juga berubah secara tidak menguntungkan; kapasitas tukar kation dan kandungan C-organik menurun secara nyata. Dapat dikatakan tanah podzolik merah kuning mengalami degradasi tingkat tinggi. Pemberian kapur dan pupuk NPK memberikan pengaruh baik pada pertumbuhan jagung dan kedelai. Tetapi semakin lama tanah terbuka dari vegetasi aslinya pertumbuhan tanaman dengan pemberian NPK cenderung menurun.
Keyword: Podzols;, Afforestation;, Soil deterioration;, Soil Conservation;, Soil physics;

Judul: Pengaruh lamanya tahun pembukaan hutan terhadap beberapa sifat tanah podzolik merah kuning Sumatera Selatan dan kaitannya dengan proses degradasi tanah
Abstrak: Berdasarkan hal-hal tersebut di atas telah dilakukan penelitian lapang, laboratorium dan rumah kaca yang dimulai sejak tahun 1983 sampai dengan tahun 1986. Penelitian lapang dilakukan di daerah transmigrasi Batumarta, Baturaja, Sumatera Selatan yang tanahnya didominasi oleh jenis tanah Podzolik Merah Kuning. Tanah Podzolik Merah Kuning diteliti oleh karena jumlahnya yang luas tersebar di empat pulaupulau besar kepulauan Indonesia dan mempunyai potensi untuk dikembangkan menjadi lahan pertanian dalam rangka pembangunan daerah.
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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