Judul: Penataan Sistem Pemangkasan Tanaman Teh Studi Kasus di Perkebunan Gunung Mas PT Perkebunan XII, Cisarua, Jawa Barat
Abstrak: Pemangkasan tanaman teh merupakan mlah satu bentuk pemeliharaan tananan teh di kebun,yang antara lain berguna untuk memudakan kembali ranting dan batang-batang pohon. Pemangkasan terhadap tanaman dilakukan rutin setiap sekitar 3-4 tahun. Iklim dan curah hujan serta pemupukan dan pemherantasa hama penyakit menimbulkan fluktuasi yang besar pada produksi pucuk teh di kebun. Fluktuasi yang besar berdampak timbulnya kesulitan manajerial, seperti ddlam memgatur jumlah tenaga kerja, jam kerja pabrik, penggudangan, dan lain-lain.
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Judul: Pengelolaan Pemangkasan Tanaman Teh (Camellia sinensis L. (O) Kuntze) di Perkebunan Purbasari, PT. Perkebunan Nusantara VIII, Pangalengan, Jawa Barat.
Abstrak: Tanaman teh adalah salah satu komoditas yang berkontribusi dalam devisa Indonesia. Kestabilan produksi dapat dicapai dengan pengelolaan kegiatan pemangkasan oleh perkebunan. Kegiatan magang dilaksanakan bulan Februari hingga Juni 2017 di Perkebunan Purbasari PTPN VIII Jawa Barat. Kegiatan magang bertujuan untuk meningkatkan pengetahuan dan pengalaman mahasiswa dalam aspek budidaya teh secara umum dan khusus mempelajari pengelolaan pemangkasan tanaman teh di Perkebunan Purbasari PTPN VIII Jawa Barat. Kegiatan magang yang dilakukan meliputi aspek teknis sebagai karyawan harian lepas (KHL) dan aspek manajerial sebagai pendamping mandor, serta pendamping mandor besar. Hasil pengamatan yang diperoleh dibandingkan dengan standar kebun, dianalisis kualitatif, kuantitatif dengan metode analisis deskriptif dan menggunakan uji t-student. Kegiatan pemangkasan di Perkebunan Purbasari sudah mengikuti standar operasional dengan ketinggian rata-rata sebelum kegiatan pemangkasan mencapai 163.81 cm. Kegiatan pemangkasan menghasilkan ketinggian 49.61 cm dengan persentase kerusakan cabang 12.66% yang dipengaruhi oleh usia tenaga kerja dan pengalaman kerja pemangkasan. Tipe pemangkasan produksi yang diterapkan adalah pemangkasan kepris karena keputusan manajemen terkait keterbatasan tenaga kerja dan pengguanaan alat pangkas berupa sabit pangkas. Pertumbuhan pucuk setelah kegiatan pemangkasan terjadi pada minggu ke-3 dan pemetikan setelah kegiatan pemangkasan dapat menghasilkan 9,761 kg pucuk setelah 3 bulan kegiatan pemangkasan.
Keyword: produksi, ketinggian, pangkasan, kepris, pucuk

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