Judul: Pengaruh Suhu dan Transparansi Kemasan terhadap Stabilitas Kapasitas Antioksidan sebagai Parameter Umur Simpan Bir Pletok
Abstrak: Bir Pletok is a Betawi traditional beverage product made from spices and herbs. Bir Pletok has many advantages, such as to keep body warm and to prevent cold . Bir pletok’s key benefit is related to its antioxidant capacity. The packaging and the storage environment are two important factors in the beverage industry include bir pletok. These factors could affect the antioxidant capacity. The antioxidant capacity in food could decrease due to high temperature and other specific conditions. In the present study the change of antioxidant capacity during the storage and the storage time of bir pletok in the bottle glass packaging with different transperancy and different storage temperature were evaluated. ASS method was used to find the storage time of bir pletok with temperature parameter and ESS method was used to find the storage time of bir pletok with packaging transperancy parameter , whereas the reduction of DPPH method was used to determine the antioxidant capacity of bir pletok during 8 weeks of storage. The storage time of bir pletok that had been storage in 300, 370C, and 500C were 29,45 days, 22,55 days, and 10,67 days respectively. Among the three levels of storage temperatures evaluated in this research, the best temperature for bir pletok storage is 300C. The storage time of bir pletok that had been storage in transparent, brown, and dark bottle glass were 19,28 days, 25,05 days, and 29,91 days respectively. The result of the study showed that the non-transparent packaging was the best condition for bir pletok storage.
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Judul: Kapasitas Antioksidan Bir Pletok pada Berbagai Rasio Kayu Manis, Secang, dan Sukrosa
Abstrak: Bir pletok merupakan minuman tradisional khas Betawi yang berpotensi menjadi salah satu minuman mengandung antioksidan, karena komposisinya yang terdiri atas banyak rempah-rempah. Bahan baku pembuatan bir pletok telah banyak dikaji terkait potensi antioksidannya. Pada proses pembuatan bir pletok, diketahui terdapat perbedaan teknik perebusan dan rasio rempah yang dapat bepengaruh terhadap kapasitas antioksidan bir pletok. Penelitian ini bertujuan membandingkan pengaruh perbedaan dua teknik perebusan, tiga rasio kayu manis dan secang, serta pengaruh penambahan gula pasir (sukrosa) terhadap kapasitas antioksidan bir pletok. Pada penelitian ini, bir pletok yang semua bahannya direbus selama lima belas menit dengan rasio secang 15 gram dan kayu manis 2 gram memiliki karakterisasi kimia yang lebih baik dibandingkan perlakuan lainnya. Bir pletok tersebut memiliki kapasitas antioksidan sebesar 0,40 mg AEAC/g bahan, total fenolik 3,19 mg GAE/g bahan, dan total flavonoid senilai 0,23 mg QE/g bahan. Secang memiliki kandungan fenolik dan flavonoid yang lebih tinggi dibandingkan kayu manis. Oleh karena itu, semakin besar rasio secang terhadap kayu manis, kapasitas antioksidan bir pletok juga semakin tinggi. Sukrosa yang ditambahkan dalam bir pletok menurunkan kapasitas antioksidannya. Penambahan 20% sukrosa menghasilkan kapasitas antioksidan yang lebih rendah yakni 0,37 mg AEAC/g bahan, dibandingkan bir pletok tanpa penambahan sukrosa yakni 0,40 mg AEAC/g. Hasil uji korelasi Pearson yang dilakukan, menunjukkan adanya korelasi yang kuat untuk setiap hasil pengukuran kapasitas antioksidan pada semua metode uji yang dilakukan. Semakin rendah kapasitas antioksidan metode DPPH dan FRAP, maka total fenolik dan flavonoid bir pletok semakin rendah.
Keyword: antioxidant, bir pletok, cinnamon, sappan wood, sucrose

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