Judul: Isolasi, Karakterisasi, dan Penentuan Konsentrasi Hambatan Minimum Senyawa Antibakteri dari Fraksi Heksana Bawang Putih
Abstrak: Timbulnya masalah resistensi beberapa mikrob patogen terhadap antibiotik menyebabkan tnntutan ditemukannya senyawa antimikrob bam yang dapat menghamhat atau membunuh mikroorganisme dan aman penggunaannya hagi penderita. Banyak tanaman yang berguna sebagai obat -obatan yang telah digunakan oleh orang secara empiris. Beberapa ekstrak tanaman menunjukkan adanya senyawa antimikroba di dalam jaringarmya. Dalam penelitian ini digunakan tanaman uji hawang pntih yang berfungsi sebagai antibakteri.
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Judul: Penapisan Fitokimia, Ekstraksi, Fraksionasi, dan Ulasan Potensi Temu Putih (Curcuma zedoaria) sebagai Antibakteri
Abstrak: Temu putih (Curcuma zedoaria) adalah tanaman obat yang dapat digunakan untuk mengobati penyakit akibat infeksi bakteri. Penelitian ini bertujuan menapis fitokimia, memfraksionasi fraksi n-heksana, dan mengulas potensi rimpang tanaman ini sebagai antibakteri. Sampel dimaserasi dengan metanol kemudian diekstraksi cair-cair berturut-turut dengan pelarut n-heksana dan etil asetat. Senyawa fitokimia ditapis pada ekstrak metanol dan fraksi n-heksana. Fraksi n-heksana difraksionasi menggunakan kromatografi radial (KR) dan kromatografi lapis tipis (KLT) preparatif. Potensi temu putih diulas berdasarkan studi pustaka. Metabolit sekunder yang terkandung dalam fraksi n-heksana adalah alkaloid dan triterpenoid. Dari fraksionasi fraksi n-heksana menggunakan KR diperoleh enam fraksi. Salah satu fraksi dilanjutkan pemurniannya menggunakan KLT preparatif, menghasilkan tiga fraksi dan salah satu fraksinya membentuk kristal. Penelusuran pustaka mengungkapkan bahwa ekstrak temu putih memiliki potensi lebih tinggi sebagai antibakteri terhadap bakteri Gram positif dibandingkan dengan tanaman satu genus atau berbeda genus dalam famili Zingiberaceae.
Keyword: antibakteri, fraksi n-heksana, Gram positif, temu putih

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