Judul: Pengaruh kelembaban tanah terhadap ketahanan hidup Corynospora cassiicola (Berk. dan Curt.) Wei penyebab penyakit gugur daun pada karet (Hevea brasillensis Muell. Arg.)
Abstrak: Penelitian dilakukan di laboratorium cendawan Jurusan Hama dan Penyakit Tumbuhan, Fakultas Pertanian, Institut Pertanian Bogor. Penelitian dilaksanakan sejak bulan Juni sampai November 1990. Tujuan dari penelitian ialah untuk mengetahui kemam- puan bertahan hidup C. cassiicola pada tiga tingkat kelem- baban tanah. Isolat C. cassiicola diperoleh dari daun karet yang terserang penyakit gugur daun Corynespora dengan cara isolasi "single spore", dan dibiakkan secara masal pada media PDA. Biakan patogen dirangsang memproduksi konidia dengan diberi perlakuan sinar NUV. Infestasi tanah dila- kukan dengan menambahkan suspensi konidia pada tanah dengan tiga tingkat kelembaban yaitu 15%, 30% dan keadaan tergenang...
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Judul: Kisaran tanaman inang Corynespora cassiicola (Berk. dan Curt.) Wei enyebab penyakit gugur daun karet (Hevea brasiliensis Muell. arg)
Abstrak: Penelitian mengenai kisaran Tanaman inang C. cassiicola dilaksanakan di laboratorium dan rumah kaca. Tujuh jenis tanaman yang diinokulasi dengan suspensi konidia C. cassiicola yaitu karet, ubi kayu, bogenvil, kalopogonium, cabai, kedelai dan pepaya. Inokulasi dilakukan dengan penyemprotan suspensi konidia pada permukaan daun yang dilukai dengan karborundum. Tiga konsentrasi suspensi konida yang digunakan untuk inokulasi yaitu 3.67 x 102/ml, 2.49 X 104/ml, dan 1.56 x 104/ml. Pengamatan yang dilakukan ialah masa inkubasi dan perkembangan gejala penyakit pada masing-masing tanaman, serta pengukuran panjang, lebar dan jumlah septa konidia yang diperoleh dari hasil reisolasi tujuh jenis tanaman yang diinokulasi. Masa inkubasi dan perkembangan gejala penyakit ternyata berbeda pada tujuh jenis tanaman yang diinokulasi dengan suspensi konidia. Masa inkubasi paling cepat berturut-turut yaitu karet (3 hari), ubi kayu (6 hari), bogenvil (6 hari), kedelai (5 hari), pepaya (8 hari), kalopogonium (8) hari). cabai (10 hari) Gejala yang ditimbulkan pada tanaman karet berbeda dengan keenam jenis tanaman uji lainnya. Intensitas serangan C.cassiicola pada tanaman karet menunjukkan angka tertinggi untuk perlakuan dengan konsentrasi suspensi konidia tinggi (3.67 x 104/ml).
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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