Judul: Ketahanan Kayu Mindi (Melia azedarach L.) Dari Rayap Kayu Kering Cryptotermes cynocephalus setelah Perlakuan Pemanasan
Abstrak: This research aimed to analysist the effect of heat treatment on the resistance of mindi (Melia azedarach L.) wood from dry wood termites (Cryptotermes cynocephalus). This research utilized mindi wood obtained from five years old tree from Malimping, Banten. The durability evaluation on mindi wood againts the dry wood termites is based on SNI 01.7207-2006. The result of this research showed that the heating treatments in oven and oil increased the durability of mindi woods. Based on the weight loss analyses, mindi wood that heated at 150 °C for 8 hours in oil increased their durability class from III to II. Statistical test results obtained showed that factors significantly influence weight loss and mortality due to dry wood termite attack is the interaction of temperature, time, and type of heating. Based on the analysis of the combination weight loss and mortality increase in the durability of the real Mindi wood and most effectively produced by heating oil 150 ˚ C for 8 hours while the wood oven heating temperature of 150 ˚ C requires 5 hours resulted in 99.8% mortality and weight loss amounted to 5.15%.
Keyword: timber heating process, mindi wood, durability, dry wood termites

Judul: Sifat Fisis, Sifat Mekanis, dan Sifat Finishing Kayu Mindi (Melia azedarach L.) setelah Perlakuan Pemanasan
Abstrak: Mindi (Melia azedarach L.) is a fast-growing wood species which is quite prospective for wood industry but it should be supported with proper technology application to produce good quality wood products. This research was done to evaluate the effect of heating treatment with various times and temperatures on the physical, mechanical, and finishing properties of mindi wood. Wood heating in oven and oil were at temperatures of 120 °C, 150 °C, and 180 °C for 2, 5, and 8 hours. The results showed that the heating wood in various conditions increased wood dimensional stability in both tangensial and radial directions. The moisture content, density, and dimensional stability of wood heated in oil were better than those heated in oven. Heating at 180 °C reduced the mechanical properties of mindi wood. The finishing test with cross cut methode showed that the oven heating did not affect finishing quality, except the 8 hours oil heating at 180 °C that reduced the finishing quality.
Keyword: physical properties, mindi wood, mechanical properties, heat treatment, finishing peroperties

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