Judul: Potensi Ekstrak Sereh Wangi (Cymbopogon nardus L.) Sebagai Anti Streptoccus mutans.
Abstrak: Pengujian aktivitas anti Streptococcus mutans dilakukan untuk menentukan KHTM (Konsentrasi Hambat Tumbuh Minimum) dari daun dan batang sereh wangi (Cymbopogon nardus L.). Daun dan batang sereh wangi dikeringkan kemudian diekstrak dengan menggunakan pelarut etanol dan air. Filtrat yang dikeringkan digunakan untuk menguji aktivitas anti S. mutans dan menentukan KHTM. Hasil penelitian menunjukkan bahwa ekstrak etanol daun dan batang sereh wangi memiliki aktivitas anti S. Mutans lebih tinggi dibandingkan dengan ekstrak air daun dan batang sereh wangi. KHTM yang diperoleh dari ekstrak etanol daun dan batang dan ekstrak air batang sereh wangi sebesar 6% (b/v), sedangkan ekstrak air daun sereh wangi memiliki KHTM sebesar 11% (b/v). Konsentrasi 14% (b/v) merupakan konsentrasi maksimal ekstrak etanol dan ekstrak air daun dan batang sereh wangi dalam menghambat pertumbuhan bakteri S. mutans.
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Judul: Penapisan Ekstrak Daun Zingiberaceae Sebagai Antibakteri Streptococcus Mutans Dan Pendegradasi Biofilm Pada Gigi
Abstrak: Penelitian ini dilakukan untuk mengevaluasi kandungan fitokimia dari ekstrak n-heksana, etil asetat, dan metanol dari daun 10 spesies dalam famili Zingiberaceae, baik secara kualitatif dan kuantitatif. Aktivitas antibakteri Streptococcus mutans dan pendegradasi biofilm dari setiap ekstrak dievaluasi menggunakan metode mikrodilusi. Ekstrak diperoleh dari daun kering menggunakan maserasi bertingkat. Rendemen tertinggi diperoleh dari ekstrak metanol daun kapulaga (10.14%). Berdasarkan uji kualitatif, ekstrak etil asetat dan metanol untuk semua daun positif mengandung golongan flavonoid dan triterpenoid. Sementara itu, uji kuantitatif menunjukkan ekstrak etil asetat daun kapulaga memiliki kandungan flavonoid tertinggi dan ekstrak metanol daun temulawak memiliki kandungan total fenol tertinggi. Ekstrak metanol daun temulawak memiliki potensi antibakteri yang baik dengan nilai KHM dan KBM sebesar 15.63 μg/mL dan ekstrak etil asetat temu putih dengan nilai KHM=15.63 dan KBM=125 μg/mL. Aktivitas pendegradasi biofilm yang paling baik diperoleh dari nilai IC50 pada ekstrak metanol daun kapulaga sebesar 95.61 μg/mL.
Keyword: antibakteri, biofilm, fitokimia, Streptococcus mutans, Zingiberaceae.

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