Judul: Ekologi Regenerasi Tumbuhan Berkayu pada Sistem Agroforest Karet
Abstrak: Penelitian ini bertujuan untuk mengkaji kemampuan agroforest karet dalam menampung jenis tumbuhan berkayu dari hutan yang ada di sekitarnya. Kajian difokuskan pada beberapa aspek ekologi regenerasi anakan tumbuhan berkayu pada tingkat lanskap. Penelitian ini dilakukan dari Agustus 2002 hingga Agustus 2005 di Kabupaten Bungo dan Tebo Provinsi Jambi. Survei jenis anakan tumbuhan berkayu (tinggi = 1 m, diameter = 3 cm) tidak termasuk liana, dilakukan dengan menggunakan metode transek sepanjang 60 m yang dikombinasikan dengan subplot berbentuk lingkaran berdiameter 6 m. Faktor lain yang diukur dan ditentukan adalah struktur tegakan berupa luas penampang batang (BA), kerapatan, cahaya, tanah, kelompok pemencar biji, umur, manajemen dan vegetasi asal agroforest karet.
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Judul: Pendugaan Potensi Karbon Jenis-Jenis Tanaman Berkayu Di Pekarangan Desa Tegalwaru, Kecamatan Ciampea, Kabupaten Bogor
Abstrak: Isu lingkungan yang terkait dengan kehutanan adalah terjadinya pemanasan global. Cara untuk mengurangi emisi gas rumah kaca adalah dengan adaptasi dan mitigasi. Salah satu contoh upaya mitigasi adalah agroforestri. Salah satu bentuk sistem agroforestri yang terdapat di masyarakat adalah pekarangan. Pekarangan merupakan suatu sistem penggunan lahan yang terletak di sekitar tempat tinggal. Penelitian ini bertujuan untuk menduga total potensi simpanan karbon yang terdapat pada seluruh jenis tanaman berkayu di pekarangan Desa Tegalwaru, Kecamatan Ciampea, Kabupaten Bogor. Penelitian ini adalah metode alometrik. Penelitian dilakukan di 30 pekarangan Desa Tegalwaru yang dipilih secara acak. Hasil penelitian menunjukkan terdapat 31 jenis tanaman berkayu. Tanaman yang mendominasi, yaitu: rambutan (Nephelium lappaceum), jambu air (Syzygium aqueum), mangga (Mangifera indica), dan nangka (Artocarpus heterophyllus). Jumlah total biomassa dan kandungan karbon untuk tanaman berkayu di pekarangan Desa Tegalwaru sebesar 14.98 ton ha-1 dan 7.04 ton ha-1. Stok karbon tersebut masuk dalam kategori stok karbon rendah.
Keyword: alometrik, Desa Tegalwaru, pekarangan, potensi karbon, tanaman berkayu

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