Judul: Sifat fisis mekanis papan gips dari limbah kertas koran
Abstrak: Tujuan penelitian ini ialah untuk mengetahui pengaruh kadar pulp kertas koran dalam campuran terhadap sifat fisis mekanis papan gips yang dihasilkan guna kemungkinan penggunaannya sebagai komponen bahan bangunan. Pembuatan dan pengujian papan gips dilakukan di Laboratorium Pengolahan Mekanis Fakultas Kehutanan Institut Pertanian Bogor dan di Laboratorium Produk Majemuk Pusat Penelitian dan Pengembangan Hasil Hutan Bogor. Sifat fisis mekanis papan gips yang diuji meliputi pengembangan tebal, pengembangan linier, daya serap air, kadar air, kerapatan, modulus patah, modulus lentur dan keteguhan tekan. Rancangan percobaan yang digunakan a- dalah faktorial 3 x 3 dalam pola acak lengkap dengan 3 kali ulangan. Untuk mengetahui hubungan pengaruh setiap faktor terhadap respon dilakukan analisis polinomial ortogonal. Hasil penelitian yang diperoleh dibandingkan dengan ketentuan yang ditetapkan oleh BISON untuk papan serat gips dan papan partikel gips hasil penelitian Febrianto, papan wol gips hasil penelitian Hidayati dan papan semen pulp hasil penelitian Alhasani.
Keyword: limbah kertas koran

Judul: Sifat fisis mekanis papan gips dari sabut kelapa
Abstrak: Tujuan penelitian ini adalah untuk memberikan alterna- tif mengenai kemungkinan penggunaan limbah sabut kelapa sebagai bahan baku papan gips serta untuk mengetahui pengaruh macam sabut kelapa dan tingkat kerapatan papan gips terhadap sifat fisis mekanis papan gips sabut kelapa. Pembuatan dan pengujian papan gips dilakukan di Laborato- rium Ilmu Kayu Fakultas Kehutanan IPB Bogor dan Laborato- rium Produk Majemuk Pusat Penelitian dan Pengembangan Hasil Hutan Bogor. Pengujian pendahuluan meliputi rendemen sabut kelapa, suhu hidratasi dan kelarutan sabut kelapa dalam air dingin dan air panas. Sifat Fisis Mekanis papan gips yang diuji meliputi pengembangan tebal, pengembangan linier, daya serap air, kadar air keseimbangan, kerapatan, modulus patah dan keteguhan tekan. Rancangan percobaan yang digunakan adalah rancangan percobaan faktorial 2 X dengan 3 kali ulangan. Faktor A (tingkat kerapatan papan gips) 1.0 terdiri dari 2 taraf yaitu kerapatan 0.7 g/cm³ dan g/cm³. Faktor B (macam sabut) terdiri dari 3 yaitu sabut bersih, sabut campuran, dan sabut kotor....
Keyword: 

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