Judul: Heavy Metal Content of Pb, Hg, and Cd in Water and Organs of Blackfin Grouper (Ephinepelus fasciatus Forsskål, 1775) in Bacan Island Waters, North Maluku
Abstrak: Perairan Pulau Bacan menjadi output akhir dari segala kegiatan yang ada di Pulau Bacan, seperti kegiatan pertambangan, kawasan pengembangan industri perikanan, maritim, perumahan dan pariwisata, yang dapat menyebabkan terkontaminasinya perairan dengan logam berat. Penelitian ini bertujuan untuk menganalisis kandungan logam berat (Pb, Hg, dan Cd) pada air dan akumulasi logam berat pada insang, daging, dan usus ikan kerapu di Perairan Pulau Bacan, Maluku Utara. Pengambilan sampel ikan kerapu dan air dilakukan pada 18 Februari 2022. Kandungan logam berat pada organ ikan kerapu dan air dianalisis menggunakan metode Atomic Absorption Spectrophotometer (AAS). Akumulasi logam berat diestimasi melalui bioaccumulation factor, maximum weekly intake, dan meta analysis. Hasil analisis kualitas air menunjukkan konsentrasi logam berat di perairan Pulau Bacan masih dalam baku mutu berdasarkan Peraturan Pemerintah Republik Indonesia No. 22 Tahun 2021. Hasil penelitian menunjukkan tingkat akumulasi logam berat pada ikan kerapu berada pada kategori rendah-sedang, dengan akumulasi tertinggi pada organ usus. Kandungan logam berat Pb dan Cd telah melebihi nilai ambang batas, sedangkan Hg ada di bawah ambang batas yang telah ditetapkan. Batas aman konsumsi ikan kerapu orang dewasa adalah 2,336 kg/minggu dan anak-anak sebesar 0,7 kg/minggu. Penelitian ini diharapkan dapat memberikan informasi mengenai kandungan logam berat pada air dan ikan kerapu di Perairan Pulau Bacan untuk pengelolaan sumberdaya ikan kerapu yang berkelanjutan di Pulau Bacan.
Keyword: heavy metals, Bacan Island water, Ephinepelus fasciatus, Accumulation

Judul: Kandungan  Logam Berat Pb, Hg, Cd pada Ikan Kurisi Nemipterus japonicus (Bloch, 1791)  di Perairan Pulau Bacan, Maluku Utara
Abstrak: Pulau Bacan merupakan wilayah yang mendapatkan pengaruh dari kegiatan antropogenik, seperti pertambangan dan industri lain berbasis logam. Kandungan logam berat di lingkungan yang berpotensi terakumulasi ke dalam tubuh organisme, seperti ikan kurisi (Nemipterus japonicus). Penelitian ini bertujuan menganalisis bioakumulasi logam berat Pb, Hg, Cd pada daging, insang, dan hati ikan kurisi (Nemipterus japonicus Bloch, 1791) yang berada di perairan Pulau Bacan, Maluku Utara. Pengambilan sampel kualitas air dan ikan kurisi dilakukan di tiga stasiun untuk mengetahui kualitas air dan kandungan logam berat di perairan dan ikan. Analisis kandungan logam berat dilakukan dengan menggunakan AAS (Atomic Absorption Spectrophotometer). Kandungan logam berat Pb, Hg, dan Cd di perairan telah melampaui baku mutu. Kandungan logam berat Pb, Hg, Cd pada ikan kurisi tertinggi pada hati. Bioakumulasi logam berat Pb, Hg, dan Cd pada daging ikan kurisi termasuk akumulasi yang rendah dan sedang., Bacan Island is an area affected by anthropogenic activities such as mining and other metal-based industries. The content of heavy metals in the environment has the potential to accumulate in body organisms, such as threadfin bream fish (Nemipterus japonicus). This study aims to analyze the bioaccumulation of heavy metals Pb, Hg and Cd in the meat, gills and liver of the threadfin bream fish (Nemipterus japonicus Bloch, 1791) in the waters of Bacan Island, North Maluku. Sampling of water quality and threadfin bream fish was carried out at three stations to determine water quality and heavy metal content in the waters and fish. Analysis of heavy metal content was using an AAS (Atomic Absorption Spectrophotometer). The content of heavy metals Pb, Hg and Cd exceeded the quality standards in waters. The content of heavy metals Pb, Hg, Cd in threadfin bream fish was highest in the liver. Bioaccumulation of heavy metals Pb, Hg, and Cd in threadfin bream fish meat includes low and moderate accumulation.
Keyword: : Bioaccumulation, water quality, quality standards

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