Judul: Prototipe Sumber Energi Biolistrik dengan Sistem Microbial Fuel Cell pada Perairan Menggenang dan Mengalir
Abstrak: Prototipe microbial fuel cell merupakan rancangan alat aplikasi langsung dari sistem MFC yang bersifat modern dan ekonomis. Alat ini memiliki rangkaian satu bejana yang terdiri dari kombinasi elektroda katoda dan anoda berjumlah sepuluh pasang yang dirangkai secara seri. Penelitian ini bertujuan menentukan potensi kinerja prototipe microbial fuel cell dan membandingkan nilai elektrisitas pada kondisi perairan menggenang dan mengalir. Kandungan nilai BOD tertinggi terdapat pada perairan menggenang dengan nilai permukaan 73.52 ± 0.79 mg/L, kolom 84.03 ± 0.79 mg/L, dasar 91.33 ± 0.79 mg/L. Nilai COD tertinggi terdapat pada perairan menggenang dengan nilai permukaan 91.94 ± 0.25 mg/L, kolom 98.75 ± 0.25 mg/L, dasar 104.98 ± 0.25 mg/L. Nilai kecepatan arus sungai sebesar 0.5 m/s. Prototipe microbial fuel cell pada perairan menggenang dan mengalir memberikan potensi kinerja terhadap nilai tegangan listrik dari MFC. Nilai tegangan listrik dan arus listrik tertinggi terdapat pada perairan menggenang yaitu 3.56 V dan 0.06 mA. Kandungan nilai BOD dan COD yang tinggi pada perairan menggenang menghasilkan nilai tegangan listrik yang tinggi pada MFC.
Keyword: elektrisitas, karakteristik perairan, prototipe microbial fuel cell

Judul: Kinerja Membran Komposit Kitosan-Sodium Alginat pada Sistem Microbial Fuel Cell dalam Menghasilkan Biolistrik dari Limbah Pemindangan Ikan.
Abstrak: Microbial Fuel Cell (MFC) merupakan sumber energi alternatif sebagai penghasil energi listrik dan dapat berasal dari limbah cair perikanan. Membran yang umum digunakan pada MFC yaitu membran nafion tetapi harganya mahal dan harus impor. Alternatif lain yaitu membuat membran dari kitosan dan sodium alginat. Penelitian ini bertujuan menentukan kinerja MFC dalam menghasilkan elektrisitas menggunakan membran kitosan-sodium alginat. Penelitian ini dilakukan dengan empat tahapan yaitu melakukan karakterisasi limbah cair perikanan yang meliputi BOD, COD, pH dan TAN, membuat dan mengkarakterisasi membran komposit dengan perlakuan komposisi alginat dengan kitosan 1:1, 2:1, dan 3:1 (v/v), membuat desain MFC serta mengukur kinerja listrik MFC. Membran kitosan-sodium alginat 2:1 (v/v) menghasilkan nilai elektrisitas tertinggi yaitu tegangan sebesar 0,960±0,077 V, kuat arus sebesar 3,909±2,354 mA dan daya listrik sebesar 3,717±2,176 mW.
Keyword: energi listrik, membran kitosan-sodium alginat, microbial fuel cell

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