Judul: Pengaruh penghambatan ekstrak segar rempah-rempah tropis terhadap beberapa cendawan dan bakteri patogen tumbuhan
Abstrak: Aktivitas antimikrobe ekstrak segar rempahrempan menunjukkan pengaruh yang tidak sama terhadap ketiga cendawan dan kedua bakteri patogen tanaman padi. Aktivitas antimikrobe ekstrak segar bawang putih pada konsentrasi 2% dan 5% menunjukkan pengaruh penghambatan yang paling nyata terhadap ketiga cendawan patogen, diikuti kemudian oleh laos, bawang merah dan cabe rawit. Ekstrak segar kunyit pada kedua konsentrasi ini, menstimulir pertumbuhan ketiga cendawan patogen. Pada pengujian ekstrak segar rempahrempah tropis terhadap bakteri patogen, semua ekstrak segar rempah-rempah tidak menunjukkan pengaruh penghambatan atau stimulasi baik pada konsentrasi 2% maupun 5%...
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Judul: Pengujian tiga ekstrak tanaman obat tropis terhadap pertumbuhan enam kapang patogen tanaman
Abstrak: Dalam penelitian ini, tiga macam tanaman obat tropis yaitu daun cengkeh (Cyzigium aromaticum L.), daun jati (Tectona grandis L.) dan pelepah daun sereh dapur (Cymbopogon citratus (DC) Stapf) diekstraksi dengan etanol absolut. Sifat antimikrobe ketiga ekstrak tanaman tersebut diperiksa terhadap kapang patogen tumbuhan yang meliputi Rhizoctonia solani, Erysiphe polygoni, Sclerotium oryzae, Sclerotium rolfsii, Cochiobolus miyabeanus dan Pyricularia oryzae. Ekstrak daun cengkeh memberikan pengaruh penghambatan berkisar antara 0%-92,5%. Pada konsentrasi 1% penghambat- an di atas 50% terjadi pada kapang S. rolfsii (53%), R. solani (76%), S. oryzae (81%) dan E. polygoni (92%). Ekstrak daun jati memberikan penghambatan berkisar antara 0-100%. Pada konsentrasi 1% ekstrak ini menghambat dengan nyata pertumbuhan E. polygoni (54%) dan menyebabkan penghambatan total pada pertumbuhan R. solani. Ekstrak pelepah daun sereh dapur memberikan pengaruh penghambatan yang berkisar antara 0-100%. Konsentrasi 1% ekstrak ini menekan pertumbuhan C. miyabeanus (56%), S. oryzae (61%), R. solani (78%) dan P. oryzae (100%). Dari ekstrak yang diujikan, ekstrak daun cengkeh dan pelepah daun sereh dapur menunjukkan spektrum antifungi yang lebih luas dibandingkan dengan ekstrak daun jati. Secara umum, kapang yang paling rentan terhadap keti- ga ekstrak tersebut adalah R. solani, sedangkan yang pa- ling tahan adalah S. rolfsii.
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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