Judul: Mempelajari pembuatan isoeugenol dari minyak daun cengkeh
Abstrak: Indonesia sebagai negara agraris berpotensi menghasilkan minyak atsiri. Ekspor minyak atsiri pada tahun 1985 1989 cenderung meningkat, dan pada tahun 1990 mencapai 2 904 ton dengan nilai USD26.69juta. Dari angka tersebut jumlah ekspor minyak daun cengkeh pada tahun yang sama tercatat 707.35 ton dengan nilaiUSD 1.66 juta (BPS, 1990). Di luar negeri minyak daun cengkeh diisolasi dan disintesis menjadi turunannya yang bernilai lebih tinggi, salah satu di antaranya adalah sintesis isoeugenol dari minyak daun cengkeh. Pengolahan lanjutan tersebut akan meningkatkan nilai tambah, memasok kebutuhan isoeugenol di dalam negeri dan sebagai komoditi ekspor non-migas. Penelitian ini bertujuan untuk mempelajari pembuatan isoeugenol dari minyak daun cengkeh, dalam rangka mendapatkan produk isoeugenol dengan rendemen dan tingkat kemurnian yang tinggi. ...
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Judul: Dimerisasi eugenol hasil isolasi dari minyak cengkeh menggunakan katalis asam padat
Abstrak: Indonesia merupakan salah satu penghasil minyak cengkeh terbesar di dunia. Pasokan minyak cengkeh Indonesia ke pasar dunia mencapai 60% kebutuhan dunia. Pada tahun 2000, dari 2.080 ton minyak cengkeh yang dipasarkan, Indonesia memasok 1.317 ton (Deptan, 2005). Minyak cengkeh merupakan minyak atsiri dengan komposisi utama golongan fenol yaitu eugenol sebesar 80%. Pemanfaatan minyak cengkeh terutama sebagai campuran dalam fragrant (pengharum) dan dalam produk-produk dan dalam produk konsumsi harian seperti parfum, produk perawatan kulit, deodoran, sabun, shampo, deterjen serta sebagaibahan intermediet dalam produksi vanilin sintetik. Sedangkan pada bidang farmasi pemanfaatannya masih kurang sehingga dilakukan penelitian untuk memberikan nilai tambah dari eugenol dengan proses derivatisasi yang dinamakan dimerisasi eugenol.
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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