Judul: Budidaya dan pengolahan teh hitam di PT.Perkebunan gunung mas / cikopo selatan PTP XII, kabupaten bogor, jawa barat
Abstrak: Teh diperoleh dari pengolahan pucuk daun tanaman teh (Camellia thea Link). Tanaman teh tergolong dalam famili theaceae. Ada 2 varietas teh yaitu varietas assamica dan varietas sinensis. Di Indonesia tanaman teh umumnya va rietas assamica. Tanaman teh diduga berasal dari daerah pegunungan hi- malaya, daerah yang terletak antara 25-35 derajat lintang utara dan 95-105 derajat bujur timur. Dapat tumbuh baik di daerah 250 m sampai 2000 m diatas permukaan laut, de- ngan curah hujan 2000-2500 mm setahun, dan suhu udara 14- 20°C. Sedang tanah yang cocok adalah yang berasal dari tanah vulkanik muda. Budidaya teh telah dimulai sejak tahun 780 di China, sedang di Jepang sejak tahun 800. Di Indonesia, budidaya teh mulai dilaksanakan tahun 1826, yaitu dengan pembukaan perkebunan di Bogor dan Garut. Saat ini budidaya teh di- lakukan di daerah-daerah dataran tinggi di Sumatera Utara, Sumatera Barat, Sumatera Selatan, Jawa Barat, Jawa Tengah dan Jawa Timur. Jawa Barat merupakan daerah utama produk- si teh. Budidaya tanaman teh diusahakan oleh perkebunan negara, perkebunan swasta dan juga oleh rakyat. Yang ter- akhir ini dikenal sebagai teh rakyat...
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Judul: Budidaya dan pengolahan teh hitam di perkebunan Gunung Gambir cs PTP XXIII - Jawa Timur
Abstrak: Teh diperoleh dari pengolahan daun tanaman teh (Came- llia sinensis L) dari familia Theaceae. Tanaman ini diperkirakan berasal dari daerah pegunungan Himalaya dan daerah- daerah pegunungan yang berbatasan dengan Republik Rakyat Cina, India dan Burma. Budidaya teh di Indonesia dimulai sejak awal tahun 1826 dan penanaman teh secara luas sebagai usaha perkebunan dilakukan sekitar tahun 1880. Tanaman teh dapat tumbuh pada ketinggian 2000 - 250 meter di atas permukaan laut di daerah tropik dan subtro- pik, menuntut cukup sinar matahari dan curah hujan 2500 mm yang merata sepanjang tahun. Di daerah yang rendah umum- nya tanaman teh dapat memberikan hasil yang cukup tinggi tetapi mutu teh yang dihasilkan rendah. Makin tinggi letak daerah penanaman teh umumnya diperoleh hasil yang lebih baik mutunya. Sebelum perang dunia ke dua, Indonesia (dahulu: Hin- dia Belanda) tergolong sebagai penghasil dan pengeksport teh di tiga di dunia (Siswoputranto, 1978). Penjajahan Je- pang pada tahun 1942 1945 menyebabkan mundurnya industri di Indonesia karena banyak kebun teh dibongkar untuk ke- mudian ditanami tanaman palawija.
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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