Judul: Analisis Kemometrik Umur, Total Fenolik, dan Konsentrasi Pelarut Terhadap Aktivitas Antioksidan Daun Surian (Toona Sinensis).
Abstrak: Daun surian (Toona sinensi) mempunyai potensi untuk dikembangkan menjadi sumber obat herbal, khususnya sebagai antioksidan, sehingga perlu dilakukan optimasi dalam proses mengekstrak senyawa aktifnya, seperti umur panen tanaman dan konsentrasi pelarut (etanol) untuk mendapatkan aktivitas antioksidan daun surian paling optimum. Penelitian dilakukan bertujuan untuk mengoptimasi umur tanaman, konsentrasi pelarut (etanol), dan total fenolik terhadap aktivitas antioksidan (DPPH) daun surian menggunakan analisis Principal Component Analysis (PCA), Partial Least Squares Regression (PLS-R), dan Orthogonal Partial Least Squares (OPLS). Ekstraksi daun surian dilakukan dengan menggunakan metanol sebagai pelarut (1:10) menghasilkan rendemen untuk tanaman berumur 7, 10, 16, 27, dan 34 tahun berurutan sebesar 8.63%, 5.24%, 15.36%, 11.63%, dan 14.73%, serta kadar air (%) berurutan sebesar 1.43, 1.42, 1.59, 1.46, dan 1.19. Analisis kemometrik menghasilkan konsentrasi etanol optimal untuk analisis aktivitas antioksidan daun surian yakni 80%, diikuti oleh konsentrasi 70%, 96%, dan 90%. Umur dan total fenolik berkorelasi terhadap aktivitas antioksidan daun surian. Semakin tua umur tanaman dan tingginya kandungan fenolik, aktivitas antioksidannya akan semakin baik.
Keyword: antioksidan, fenolik, kemometrik, konsentrasi, Toona sinensis

Judul: Total Phenolic and Antioxidant Activity of Surian (Toona Sinensis) Leaves on Various Tree Age and Solvent Concentration
Abstrak: Ekstrak daun surian (Toona sinensis) memiliki kandungan senyawa fenolik yang dapat berpotensi sebagai antioksidan alami. Pengoptimalan umur panen tanaman serta konsentrasi pelarut (etanol) diperlukan untuk mendapatkan aktivitas antioksidan daun surian terbaik. Penelitian ini bertujuan menguji pengaruh dari variasi umur pohon dan konsentrasi pelarut etanol terhadap kadar total fenolik dan aktivitas antioksidan yang terkandung dalam sampel daun surian asal Sumedang menggunakan uji analisis in vitro. Kadar total fenolik diukur dengan menggunakan metode Folin-Ciocalteu, sedangkan aktivitas antioksidan diukur menggunakan metode 2,2-difenil-1-pikrilhidrazil (DPPH). Ekstrak daun surian umur 34 tahun menggunakan pelarut etanol 96% memiliki kadar total fenolik tertinggi yaitu sebesar 392.28 mg GAE/g bobot kering dan menghasilkan kapasitas antioksidan tertinggi yaitu sebesar 1130.26 μm TE/g bobot kering dengan nilai IC50 terkecil dibandingkan dengan sampel lainnya yaitu sebesar 4.19 μg/mL sehingga dapat dikatakan bahwa ekstrak daun surian 34 tahun menggunakan pelarut etanol 96% memiliki aktivitas antioksidan terbaik. Umur pohon dan konsentrasi pelarut etanol terbukti dapat mempengaruhi hasil kadar total fenolik dan aktivitas antioksidan daun surian., The extract of surian leaves (Toona sinensis) contains phenolic compounds that have the potential as natural antioxidants. Optimization of the plant harvesting age and solvent concentration (ethanol) is necessary to obtain the best antioxidant activity of surian leaves. This study aimed to examine the effect of variations in tree age and ethanol solvent concentration on the total phenolic content and antioxidant activity of surian leaves from Sumedang using in vitro analysis. The total phenolic content was measured using the Folin-Ciocalteu method, while the antioxidant activity was measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. The extract of 34-year-old surian leaves using 96% ethanol solvent had the highest total phenolic content of 392.28 mg GAE/g dry weight and also produced the highest antioxidant capacity of 1130.26 μm TE/g dry weight with the smallest IC50 value compared to other extracts, which was 4.19 μg/mL, indicating that the 34-year-old surian leaf extract using 96% ethanol solvent had the best antioxidant activity. Tree age and ethanol solvent concentration were proven to affect the total phenolic content and antioxidant activity of surian leaves.
Keyword: Antioksidan, kadar fenolik, metode DPPH, Toona Sinensis

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