Judul: Pengaruh pencemaran debu pabrik semen Cibinong terhadap sifat-sifat tanah pada arah selatan dan timur
Abstrak: Penelitian ini dilakukan untuk mengetahui pengaruh pencemaran debu pabrik semen Cibinong terhadap sifat-sifat tanah terutama kemantapan agregat dan beberapa sifat kimia tanah pada arah selatan dan timur. Penelitian dilakukan di lapang untuk pengambilan contoh tanah dan di laborato- rium untuk analisis sifat fisika dan kimia tanah. Labora- torium yang digunakan adalah laboratorium Jurusan Tanah, Fakulatas Pertanian, IPB, serta Laboratorium Sub Bagian Zat Hara Kelompok Fisiologi, BPTP Bogor. Untuk Pengamatan lapang dan pengambilan contoh tanah dilakukan melalui pemboran pada setiap 250 m sepanjang transek arah Selatan dan Timur dari Pabrik Semen Cibinong sebagai sumber pencemaran. Pada setiap pemboran diamati sifat-sifat morfologi tanah yang didasarkan pada Pedoman Pengamatan Tanah di Lapang (PPT, 1967). Untuk analisis di laboratorium, contoh tanah dikering udarakan terlebih dahulu, kemudian ditumbuk dan diayak dengan ukuran 2 mm untuk analisis kimia dan tekstur. Untuk analisis kemanta- pan agregat contoh tanah dibiarkan saja.
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Judul: Pengaruh Pencampuran Tanah Mineral Bersulfat Masam Pada Tanah Gambut Tebal serta Pencucian dan Pengapuran terhadap Perubahan Sifat Kimia Tanah
Abstrak: Tujuan penelitian ini ialah untuk mempelajari pengaruh pencampuran tanah mineral bersulfat masam pada tanah gambut tebal serta pencucian dan pengapuran terhadap perubahan sifat kimia tanah pada akhir pencucian dan selama pertumbuhan tananan. Penelitian in i dilakukan di rumah kaca Baranangsiang dan penetapan sifat fisik dan kimia tanah dilakukan di laboratorium Jurusan Tanah, Fakultas Pertanian, Institut Pertanian Bogor. Penelitian ini dimulai dari bulan Oktober 1986 sampai dengan bulan Juni 1987. Rancangan percobaan yang digunakan selarua pencucian adalah rancangan acak lengkap faktorial dengan dua perlakuan dm tiga ulangan, dan pada akhir inkubasi kapur digunakan rancangan acak lengkap faktorial dengan tiga perlakuan dan tiga ulangan.
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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