Judul: Pengamatan lapang jamur pelapuk kayu di areal bekas kebakaran hutan : Studi kasus di HPH PT Maandau Abadi, Propinsi Riau
Abstrak: Kebakaran hutan merupakan salah satu ancaman yang besar bagi kelestarian hutan bila hutan tidak dipelihara dan dilindungi secara benar. Bahaya kerusakan akibat kebakaran hutan terutama terhadap pohon atau tegakan, dapat mengakibatkan adanya pelukaan yang akan menyebabkan pertumbuhan pohon terganggu serta memudahkan hama dan penyakit berkembang. Hadi (1992) menyatakan bahwa jamur merupakan kelompok jasad paling utama yang menyebabkan pohon-pohon hutan menjadi sakit bila dibandingkan dengan bakteri, virus, mikoplasma atau nematoda. Penelitian ini bertujuan untuk mengetahui jenis-jenis jamur pelapuk kayu yang berkembang di areal bekas kebakaran hutan dan faktor-faktor fisik lingkungan yang mendukung pertumbuhan dan perkembangan jamur pelapuk kayu di lokasi penelitian. Penelitian dilaksanakan di areal bekas kebakaran hutan dan di areal hutan yang tidak terbakar pada bulan April sampai bulan Mei 1998. Pengumpulan jamur pelapuk kayu dilakukan dengan cara sensus yaitu mengambil setiap jenis jamur makrofungi yaitu jamur pelapuk kayu yang mempunyai tubuh buah yang dapat dilihat secara makroskopis di lapangan. Pengukuran kondisi fisik lingkungan (suhu udara, kelembaban relatif dan kadar air substrat) dilaksanakan di sekitar tempat tumbuh jamur baik di areal bekas kebakaran hutan maupun di areal hutan yang tidak terbakar.
Keyword: Fungicides

Judul: Jenis-Jenis Jamur Pelapuk Kayu Koleksi Laboratorium Perlindungan Hutan Fakultas Kehutanan Institut Pertanian Bogor
Abstrak: Salah satu permasalahan yang dihadapi dalam Pengelolaan Hutan adalah menurunnya kualitas tegakan sebagai akibat terjadinya pelapukan kayu teras oleh jamur pelapuk kayu. Dalam kaitan dengan masalah tersebut maka penerapan sistem silvikultur yang erat kaitannya dengan pelapukan kayu teras oleh jamur pelapuk kayu adalah penetapan daur patologis yang sesuai untuk jenis pohon hutan tertentu pada tempat tumbuh tertentu pula.
Keyword: 

Judul: The Construction of Greedy SVP LLL Algorithm
Abstrak: A lattice is a set of all integer linear combination of a set of linearly independent vectors in ℝ𝑛���. The independent vectors are called bases of lattice. Any lattice can be generated from many bases, and these bases have the same cardinality. In the lattice, the most fundamental and renowned problem is the Shortest Vector Problem (SVP). SVP is a tracking problem of the shortest nonzero vector in a lattice with equivalent bases. In two dimensions, SVP problem has resolved exactly by Gauss’ algorithm. When the lattice dimension is higher than two, A.K. Lenstra, H.W. Lenstra and L. Lovasz gave a LLL algorithm to compute approximation of nonzero shortest vector in the lattice. Reduced bases solution obtained from LLL algorithm still be an approximation and has polynomial running time of arbitrary dimension which large enough. In 1994, Schnoor and Euchner modified this LLL algorithm as a new variant which later was named deep insertion LLL algorithm. This algorithm is a modified version of the LLL algorithm to the terms of the exchange step to improve the accuracy of output of LLL reduced bases and applying it to the subset sum problem. The purpose of this research are: (1) Reconstruct the LLL algorithm and deep insertion LLL algorithm using a geometric approach. (2) Construct a greedy SVP LLL algorithm. (3) Implement the three algorithms in a symbolic programming language, and evaluate them experimentally. A bases ℬ=[𝐛���1,𝐛���2,…,𝐛���𝑛���] in ℝ𝑚��� is called reduced LLL with parameter 𝛿��� if satisfies: (a) |𝜇���𝑗���𝑖���|≤12, for every integer 𝑖���,𝑗��� with 1≤𝑖���<𝑗���<𝑛���. (b)𝛿���‖𝜋���𝑗���(𝐛���𝑗���)‖2≤‖𝜋���𝑗���(𝐛���𝑗���+1)‖2, for 𝑗���=1,2,…,𝑛���−1,where 𝛿��� is a reduced parameter of real numbers with 14<𝛿���<1. The first requirement is the reduced basis 𝛿��� must “nearly orthogonal” and in its computation case, this requirement can be reached out by using the Gram-Schmidt’s orthogonalization. While the second requirement is called exchange step, or used to called as Lovasz condition. By using both of these requirements, then they establish the LLL algorithm. Then, Schnoor and Euchner modify the LLL algorithm based on the requirements of the exchange step called the deep insertion LLL algorithm, where the exchange step is based on the comparison of the projected vector in orthogonal complement [𝐛���1,𝐛���2,…,𝐛���𝑘���−1]⊥ after j-th reduction. To construct greedy SVP LLL algorithm, the requirements of the exchange step is based on purely by comparing norm of lattice 𝐛���𝑗��� with norm lattice 𝐛���𝑖��� for 𝑖���=1,2,3…,𝑗���−1. The process of insertion reduced vector after the exchange step also has done greedily. Then, we calculate the number of arithmetic operation in greedy SVP LLL algorithm for further analysis. The result of our exprimentation for three algorithms on the certain matrix size shows that the running time of the three algorithms increases propotional to the size of the matrix. The result also shows that by using 𝛿���=34 for the LLL algorithm and the deep insertion LLL algorithm, and the greedy SVP LLL algorithm which is a new variant made by using no parameter of 𝛿���, outperform of the other of two previous algorithm in terms of speed with the same output.
Keyword: LLL algorithm, LLL deep insertion algorithm, greedy SVP LLL algorithm