Judul: Mempelajari Perubahan Kimia Dn Mikrobiologik Selama Permentasi Tempoyak
Abstrak: Tujuan penelitian ini adalah untuk mempelajari proses fementasi tradisional dalam pembuatan tempoyak, dengan mengamati pengaruh konsentrasi garam dan lama fermentasi ter- hadap perubahan kimia dan mikrobiologik dari tempoyak. Mikrobe yang aktif selama fermentasi tersebut adalah bakteri gram positif yang menghasilkan asam. Pertumbuhan bakteri tersebut mencapai maksimum pada hari kedua, dimana 9 total bakteri sekitar 2.1 x 10 koloni/g, bakteri gram positif 1.2 x 109 koloni/g dan bakteri asam laktat 0.9 x 109 ko- loni/g untuk 0.5 persen garam, sedangkan pada 1.0 persen ga- ram berturut-turut adalah 2.0 x 10 109 koloni/g, 1.3 x 109 kolo- ni/g dan 0.5 x 109 koloni/g. Selama fermentasi berlangsung tidak terdapat bakteri gram negatif, kapang dan khamir. Total asam meningkat selama fermentasi berlangsung dan mencapai nilai tertinggi untuk penambahan 0.5 persen garam pada hari kesepuluh, sebaliknya pola penurunan pH untuk 0.5 dan 1.0 persen garam relatif sama. Total padatan terlarut menurun selama proses fementasi sedangkan gula pereduksi cenderung meningkat. Kadar air dan volatile reducing substances tidak mengalami perubahan yang nyata selama fer- mentasi berlangsung.
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Judul: Perubahan kimia, aktivitas enzimatik dan mikrobiologi selama fermentasi garam pada pembuatan tauco secara tradisional
Abstrak: Tauco adalah produk pangan asal kedelai yang diolah secara tradisional dan dikenal serta disukai terutama karena citarasanya. Pembuatan tauco melalui 2 tahap fermentasi yaitu fermentasi oleh kapang dan fermentasi dalam larutan garam. Selama fermentasi tersebut terjadi perubahan kimia yang mempengaruhi pembentukan flavor pada tauco. Pada penelitian ini dipelajari perubahan kimia, aktivitas enzimatik maupun mikrobiologi selama fermentasi garam berlangsung. Kedelai yang sudah difermentasi diperoleh dari perusahaaan tauco cap Beruang. Selanjutnya dilakukan fermentasi dalam larutan garam pada kadar garam 20% (b/v) selama 4 minggu. Parameter yang diamati pada tauco selama fermentasi garam berlangsung meliputi kadar air, pH, total asam tertitrasi, total gula, kadar gula pereduksi, total nitrogen, kadar nitrogen terlarut, kadar amino nitrogen, aktivitas enzim amilase, aktivitas enzim protease, total kapang, total khamir dan total bakteri asam laktat. Selama fermentasi garam berlangsung dari awal fermentasi sampai minggu keempat terjadi penurunan pada kadar air, nilai pH, total nitrogen dan total gula, aktivitas enzim baik protease maupun amilase serta penurunan total kapang, khamir dan bakteri asam laktat. Sebaliknya untuk total asam tertitrasi, kadar nitrogen terlarut, kadar amino nitrogen, dan kadar gula pereduksi selama fermentasi garam terjadi peningkatan. ...
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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