Judul: Dampak Pencemaran Pertambangan Emas Tanpa Ijin terhadap Ikan Baung (Mystus nemurus) di Sungai Cikaniki, Kawasan Pongkor, Bogor.
Abstrak: Penelitian ini bertujuan umtuk mengetahui kadar merkuri dalam air sungai, sedimen, daging ikan dan organ tubuh ikan (insang, hati, ginjal) secara hispotalogis.
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Judul: Pencemaran Merkuri di Air, Sedimen dan Katak Tegalan (Fejervarya limnocharis) di Areal Sekitar Penambangan Emas Bogor, Jawa Barat
Abstrak: Area sekitar Pongkor Kabupaten Bogor, Jawa Barat merupakan daerah penambangan emas legal maupun illegal. Penambangan legal oleh PT Aneka Tambang (ANTAM) menarik perhatian masyarakat yang tinggal di sekitar lokasi untuk melakukan kegiatan pertambangan emas tanpa izin (PETI). Proses pencucian emas illegal ini biasanya menggunakan merkuri dan membuang sisa air cucian ke Sungai Cikaniki yang digunakan kembali untuk pengairan sawah. Walaupun telah dilakukan penelitian pencemaran merkuri di lokasi ini, namun kondisi terkini tidak diketahui. Oleh karena itu dilakukan analisis akumulasi pencemaran merkuri di air sungai, sedimen, dan katak tegalan (Fejervarya limnocharis) di Sungai Cikaniki. Pengambilan sampel air, sedimen sungai dan sawah serta katak tegalan dilakukan di tiga stasiun yang terletak di stasiun 1 (hulu sungai sebelum lokasi PETI), stasiun 2 (tengah yang berdekatan dengan dengan PETI ) dan stasiun 3 (hilir, setelah lokasi PETI). Kandungan merkuri ditemukan pada sampel air dan sedimen di Sungai Cikaniki dan area persawahan stasiun 2 dan stasiun 3. Hasil yang ditemukan menunjukkan bahwa kandungan merkuri pada air dan sedimen masih di bawah ambang batas minimum 0,002 ppm dan 0,17 ppm. Namun demikian, sampel hati katak pada stasiun 2 dan stasiun 3 telah terkontaminasi oleh merkuri dengan nilai di atas ambang batas, sementara hanya sebagian katak di stasiun 1 yang terkontaminasi. Hal ini menunjukkan adanya bioakumulasi merkuri pada tubuh katak walaupun faktor bioakumulasi dari air ke sedimen persawahan maupun dari sedimen persawahan ke katak tegalan tergolong rendah. Merkuri yang terbawa oleh air sungai sebagian teradsorbsi di sedimen sungai, sebagian terbawa melalui pipa-pipa dan masuk ke area persawahan sehingga teradsorbsi di sedimen sawah. Katak tegalan dapat terpapar melalui pernafasan, kulit dan pakan yang terkontaminasi.
Keyword: katak tegalan, merkuri, penambangan emas, Sungai Cikaniki

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