Judul: Potensi Simpanan Karbon pada Tegakan Revegetasi Lahan Pasca Tambang PT Jorong Barutama Greston, Kalimantan Selatan.
Abstrak: Kegiatan pertambangan menimbulkan hilangnya vegetasi sehingga menyebabkan berkurangnya penyerapan CO2. Kegiatan reklamasi dan revegetasi diharapkan dapat meningkatkan penyerapan CO2. Penelitian ini bertujuan untuk menduga dan membandingkan simpanan karbon yang ada di tegakan revegetasi lahan pasca tambang tahun penanaman 2008, 2009 dan 2010 PT Jorong Barutama Greston. Pendugaan simpanan karbon Acacia mangium dan Paraserianthes falcataria dilakukan dengan menggunakan persamaan alometrik sedangkan untuk serasah dan tumbuhan bawah dengan metode destruktif. Simpanan total karbon tegakan tahun 2008 sebanyak 41.09 ton/ha, tegakan tahun 2009 sebanyak 27.43 ton/ha, dan tegakan tahun 2010 sebanyak 22.90 ton/ha. Hasil analisis vegetasi menunjukkan jumlah spesies tumbuhan bawah yang ada pada tahun 2008 sebanyak 20 spesies, pada tegakan tahun 2009 sebanyak 19 spesies, sedangkan pada tegakan tahun 2010 sebanyak 26 spesies. Hasil uji korelasi Pearson menunjukkan tingkat keanekaragaman jenis tumbuhan bawah tidak berpengaruh terhadap simpanan karbonnya.
Keyword: Acacia mangium, Paraserianthes falcaratia, simpanan karbon, tegakan revegetasi

Judul: Pendugaan Potensi Simpanan Karbon di Atas Permukaan Lahan Pasca Tambang PT. Antam UBPE pongkor, Jawa Barat
Abstrak: Post mining land reclamation is one of the effort to increase carbon stock. Reclamation activities will recover the post-mining degraded lands. The objectives of this study were create an allometric of some tree species, estimate and compare the carbon stock on the land of PT. Antam UBPE Pongkor, West Java in 2001, 2002, and 2003 planting years. Biomass measurement of tree, pole, and sapling was done with non destructive method, while understorey, litter, and necromass was done with destructive method. The allometric which used in this study has the highest R2 value, so that all of allometric can be used for estimate tree’s volume. The result of this study show the highest potential carbon found in 2001 planting years, the potential carbon of this planting year is 107.14 ton/ha, and then 2003 planting years is 101.44 ton/ha, and 2002 planting years is 94.18 ton/hnd a. Carbon potential differences caused by composition, structure, stand density, and canopy coverage
Keyword: Bogor Agricultural University (IPB), PT. Antam UBPE Pongkor, carbon, biomass

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