Judul: Penyebab Penyakit Kuning Pada Tanaman Bawang Merah (Allium cepa var. ascolonicum) dan Uji Potensi Trichoderma sp.
Abstrak: Tujuan percobaan ini adalah untuk mengidentifikasi penyebab penyakit kuning pada tanaman bawang merah dan mengetahui pengaruh agens antagonis Trichoderma sp. terhadap penyakit kuning tersebut. Percobaan dilakukan di Laboratorium Mikologi Tumbuhan dan Rumah Kaca, Jurusan Hama dan Penyakit Tumbuhan, Fakultas Pertanian, Institut Pertanian Bogor. Pelaksanaan ini dari bulan April - September 1999.
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Judul: Isolasi dan Karakterisasi Bakteri Pengendali Cendawan Patogen Colletotrichum sp. pada Tanaman Bawang Merah (Allium cepa L.).
Abstrak: Salah satu masalah dalam pertanian bawang merah (Allium cepa L.) ialah munculnya penyakit antraknosa, yang disebabkan oleh cendawan patogen Colletotrichum sp. Selama ini cendawan patogen dikendalikan dengan menyemprotkan fungisida sintetik. Penggunaan fungisida menimbulkan dampak negatif pada organisme lain dan lingkungan. Dampak negatif dari penggunaan fungisida yang berlebihan, dapat dikurangi dengan penggunaan agen biokontrol seperti bakteri endofit dan bakteri tanah yang mampu menghambat pertumbuhan cendawan patogen. Tujuan dari penelitian ini ialah mengisolasi bakteri endofit dan bakteri rizosfer dari tanaman bawang merah, serta menguji kemampuan bakteri dalam menghambat pertumbuhan cendawan patogen Colletotrichum sp. Sebanyak 40 isolat bakteri endofit dan 16 isolat bakteri rizosfer berhasil diisolasi dari tanaman bawang merah asal Brebes, Jawa Tengah. Hasil uji antagonis menunjukkan enam isolat mampu menghambat pertumbuhan cendawan Colletotrichum sp. dengan persentase daya hambat pada skala 3 (60-75 %). Sebanyak 4 dari 6 isolat potensial yaitu ABS4.1.2, ABP5.1.3, BBP5.2.1, dan ABP5.2.2, memiliki karakteristik morfologi dan mikroskopis yang berbeda. Hasil uji hipersensitivitas menunjukkan bahwa isolat bakteri endofit tidak bersifat patogen terhadap tanaman. Dua dari enam isolat bakteri endofit yaitu BBP5.2.1 dan DBP4.1.2, menunjukkan reaksi negatif dalam uji hemolisin. Hasil ini menunjukkan bahwa isolat bakteri BBP5.2.1 dan DBP4.1.2 tidak bersifat patogen pada mamalia termasuk manusia. Berdasarkan semua hasil pengujian, diperoleh satu isolat endofit BBP5.2.1 memiliki penghambatan pertumbuhan cendawan patogen terbaik dan tidak bersifat patogen pada tanaman dan mamalia.
Keyword: antagonis, cendawan patogen, persentase daya hambat, uji hemolisin, uji hipersensitivitas

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