Judul: Profil Metabolit Volatil Rimpang Jahe Merah (Zingiber officianale var. Rubrum) yang Dipanen pada Waktu Berbeda
Abstrak: The effect of sunlight intensity to red ginger secondary metabolite has not been known properly. Metabolic profiling can be used to study the correlation between sunlight intensity and secondary metabolite. The profile of volatile metabolite substances from different harvesting time had been examined. Samples of red ginger were harvested in the morning and afternoon. Around 47 volatile substances has been detected using GCMS instrument. Major component that were identified from both harvesting time are camphene, cineol, z-citral, 2,6- octadienol, benzene and α-zingiberene. Antioxidant activity was carried out using DPPH assay. Ascorbic acid was employed as positive control. Essential oil of red ginger was tested using DPPH assay and showed inhibition activities against DPPH radical, nevertheless the inhibition percentage was low and there is not enough prove to show red ginger essential oil have potential as a source of antioxidant. There was no significant difference in radical inhibition activities between both essential oil samples. There was however, a difference in the composition of the volatile component from red ginger essential oil. α-zingiberene compound had showed a significant difference in quantity at different harvesting time under the confirmation of t-test with α=0,05. The quantity of α-zingiberene was higher in afternoon harvesting time.
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Judul: Antioxidant Activity of Ethanol Extract, Nanoparticles, and Microparticles of Red Ginger Rhizomes (Zingiber officinale var. Rubrum) from Sukabumi
Abstrak: Rimpang jahe merah telah terbukti memiliki potensi sebagai sumber antioksidan, sehingga diperlukan metode yang tepat untuk meningkatkan aktivitasnya. Penelitian ini bertujuan membandingkan aktivitas antioksidan dari ekstrak etanol, nanopartikel, dan mikropartikel rimpang jahe merah asal Sukabumi menggunakan metode DPPH. Ekstraksi dilakukan melalui metode maserasi menggunakan pelarut etanol 70%, sintesis nanopartikel menggunakan metode top down synthesis dengan Planetary Ball Mill (PBM), dan pembuatan mikropartikel melalui penyaringan simpisia jahe dengan ayakan berukuran 100 mesh. Hasil penelitian menunjukkan bahwa ekstrak etanol 70% menghasilkan kadar total fenolik tertinggi (35,012 ± 2,145 mg GAE/g) dibandingkan dengan sampel lainnya. Temuan ini sesuai dengan hasil uji aktivitas antioksidan yang menunjukkan bahwa ekstrak etanol memiliki aktivitas antioksidan terkuat dibandingkan dengan sampel lainnya, dengan nilai IC50 sebesar 185,561 ± 8,998 ppm. Metode ekstraksi terbukti lebih meningkatkan kadar total fenolik dan aktivitas antioksidan simpisia rimpang jahe merah, dibandingkan dengan hanya memperkecil ukuran partikel simpisia., Red ginger rhizome has been proven to have the potential as an antioxidant source, thus requiring an appropriate method to enhance its activity. This research aimed to compare the antioxidant activities of ethanol extract, nanoparticles, and microparticles of red ginger rhizome from Sukabumi using the DPPH method. The extraction was conducted through the maceration method using 70% ethanol solvent, nanoparticle synthesis was carried out using the top down synthesis method with Planetary Ball Mill (PBM), and microparticles were obtained through sieving the ginger simplicia using a 100-mesh sieve. The research results revealed that the 70% ethanol extract produced the highest total phenolic content (35,012 ± 2,145 mg GAE/g) compared to other samples. This finding is consistent with the antioxidant activity test results, which showed that the ethanol extract exhibited the strongest antioxidant activity compared to other samples, with an IC50 value of 185,561 ± 8,998 ppm. The extraction method proved to be more effective in increasing the total phenolic content and antioxidant activity of the red ginger rhizome simplicia compared to merely reducing the particle size of the simplicia.
Keyword: Antioxidant, extract, microparticles, nanoparticles, red ginger

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