Judul: Mempelajari peranan mikroba dalam pembuatan 'Tea Cider'
Abstrak: Tea cider' beberapa Bulgaria, sebagai minuman sudah cukup dikenal di negara, antara lain Rusia, Jepang, Polandia, Jerman, Mancuria, Indonesia dan beberapa negara lain. 'Tea cider' ini mempunyai rasa manis keasam-asaman dengan sedikit alkohol. Minuman ini adalah hasil proses fermentasi seduhan teh bergula dimana khamir dan bakteri berperan sebagai inokulumnya. Penelitian ini dilakukan untuk mempelajari pengaruh konsentrasi gula dan inokulum yang digunakan, selain itu juga dilakukan isolasi dan identifikasi mikroba yang terda- pat dalam kultur alami. Konsentrasi gula yang diterapkan adalah 10%, 15%, 20% atau 25%, sedangkan inokulum yang digunakan sebagai starter adalah kultur alami, kombinasi Saccharomyces cerevisiae, Saccharomycodes ludwigii, Aceto- bacter xylinum, kombinasi Saccharomyces cerevisiae, Aceto- bacter xylinum atau kombinasi Saccharomycodes ludwigii, Acetobacter xylinum. Inkubasi dilakukan pada suhu ruang (±25°C) selama lima hari secara aerob. Pengamatan 'tea cider dilakukan dengan pengukuran kadar alkohol, kadar gula pereduksi, total asam tertitrasi uji organoleptik terhadap aroma, rasa, warna, kejernihan dan penerimaan 'tea cider'. Perlakuan konsentrasi gula berpengaruh sangat nyata terhadap kadar gula pereduksi, rasa 'tea cider' dan penerimaan 'tea cider'. Perlakuan konsentrasi gula ini berpengaruh nyata terhadap total asam tertitrasi, aroma dan warna 'tea cider'. Perlakuan kombinasi mikroba starter berpengaruh nyata terhadap total asam tertitrasi, warna dan penerimaan 'tea cider', sedangkan terhadap kadar gula pereduksi kombinasi mikroba starter ini mempunyai pengaruh yang sangat nyata. Interaksi perlakuan konsentrasi gula dan kombinasi mikroba starter memberikan pengaruh yang sangat nyata terhadap kadar gula pereduksi. ...
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Judul: Pembuatan Cider Timun Suri (Cucumis meli L.)
Abstrak: Penelitian ini bertujuan untuk mempelajari cara pengolahan produk fermentasi yaitu pembuatan cider, serta pengaruh penambahan jenis dan konsentrasi starter, serta dan lama aging terhadap mutu cider yang dihasilkan. Kadar alkohol cider bervariasi tergantung pada jenis dan konsentrasi starter. Kadar alkohol tertinggi dipero- leh dengan penggunaan starter dari ragi roti dengan konsentrasi starter 10 persen. Lama aging berpengaruh terhadap pembentukan ester cider. Cider yang disukai adalah cider dengan kadar alkohol rendah. Total asam dan kadar vitamin C akan menurun selama aging berlangsung, sedangkan Kadar alkohol, gula pere- duksi, total padatan terlarut, akan meningkat pada awal aging, dan relatif konstan setelah hari ke-15. Kadar ester dan pH relatif meningkat selama aging, sedangkan kejernihan relatif konstan selama aging….
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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