Judul: Antioxidant Activity of Extract and Active Fraction of Temukunci (Boesenbergia pandurata).
Abstrak: Temukunci (Boesenbergia pandurata Roxb.) is one of the herbal plants in tropical Asian countries used for cooking and as medicine plant. The aim of this research is to determine antioxidant activity of extract and its active fractions. Antioxidant activity of temukunci was determined using the spectrophotometric 2,2’-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method. Active fraction was identified by spraying DPPH 0.04% in metanol using thin layer chromatography. IC50 of its extract was 100 ppm and its active fraction was 99 ppm. These values were higher than BHT (butylated hidroxytoluene) as positive control that was 6.46 ppm.
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Judul: Hubungan kada pigmen dan kadar senyawa fitokimia daun temu kunci (Boesenbergia pandurata) dengan aktivitas antioksidan
Abstrak: Hubungan kadar pigmen dan kadar senyawa fitokimia terhadap antioksidan daun temu kunci (Boesenbergia pandurata) telah ditentukanSpektroskopi ultraviolet-tampak digunakan dalam penentuan kadar klorofil, karotenoid, antosianin, total fenol, total flavonoid, dan total tanin. Aktivitas antioksidan ditentukan menggunakan metode 1,1- difenil-2-pikril hidrazil (DPPH), ferric reducing antioxidant capacity (FRAP), dan cupric ion reducing antioxidant capacity (CUPRAC). Kadar klorofil, karotenoid, dan antosianin berkorelasi negatif dengan ketiga aktivitas antioksidan, sedangkan total fenol, dan total tanin berkorelasi positif terhadap aktivitas antioksidan. Korelasi antioksidan metode DPPH dengan klorofil adalah R2=0.573, dengan karotenoid R2 =0.579, dan dengan antosianin R2 =0.020. Korelasi metode FRAP dengan klorofil adalah R2 =0.455, dengan karotenoid R2 =0.496, dan antosianin R2 =0.021. Korelasi metode CUPRAC dengan klorofil adalah R2 =0.180, dengan karotenoid R2 =0.139, dan dengan antosianin R2 =0.098. Dengan demikian, kandungan metabolit sekunder lebih berkorelasi dengan antioksidan dibandingkan pigmen pada daun temu kunci.
Keyword: antioxidant, CUPRAC, DPPH, FRAP, temu kunci

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