Judul: Endocrine Disrupting Chemicals (EDC) pada Komunitas Ikan di Sungai Brantas, Surabaya, Jawa Timur.
Abstrak: Sungai Brantas merupakan sungai terpanjang di Jawa Timur dengan panjang 320 km dan luas 12000 km2. Peningkatan jumlah aktivitas penduduk menyebabkan tingginya beban limbah di suatu perairan yang berasal dari kegiatan industri rumah tangga, rumah sakit, dan kegiatan pertanian yang berpengaruh terhadap kualitas airnya. Pencemaran yang terjadi pada biota ikan karena proses bioakumulasi di perairan. Tujuan penelitian ini untuk menentukan tingkat pencemaran EDC yang dapat mempengaruhi keberlanjutan hidup ikan. Penelitian ini dilakukan pada bulan Juli sampai November 2017 dengan dua stasiun yaitu daerah Karah (Stasiun I) dan Gubeng (Stasiun II) di Sungai Brantas Surabaya. Total ikan contoh yang diambil sebanyak 420 ekor. Uji kandungan EDC pada daging ikan menggunakan metode GC-MS. Jenis ikan yang banyak terakumulasi adalah ikan nila. Jenis EDC yang melebihi baku mutu pada tubuh ikan adalah pestisida klorpirifos. Kadar senyawa EDC yang paling tinggi terjadi pada musim kemarau.
Keyword: Bioakumulasi, ikan, toksik, Sungai Brantas

Judul: Nisbah Kelamin dan Perkembangan Gonad Beberapa Jenis Ikan di Sungai Surabaya.
Abstrak: Sungai Surabaya mendapat masukan limbah dari berbagai kegiatan yang diduga mengandung bahan pencemar Endocrine Disrupting Compounds (EDCs) yang dapat menyebabkan gangguan reproduksi pada ikan. Penelitian ini bertujuan untuk menganalisis kondisi nisbah kelamin dan status perkembangan gonad beberapa jenis ikan yang terdapat di sungai Surabaya. Penelitian ini dilaksanakan dari bulan Juli sampai November 2017 di Sungai Surabaya dan pengambilan contoh dilakukan pada bulan Juli, September dan Oktober. Hasil analisis nisbah kelamin tidak menunjukkan ketidaknormalan nisbah kelamin pada masingmasing ikan. Gonad ikan mengalami perkembangan dengan ditemukannya empat dari lima tingkat kematangan gonad dan lebih banyak ditemukan gonad yang belum matang. Ukuran pertama kali matang gonad ikan nila merupakan ukuran terkecil dibandingkan dengan jenis lainnya. Senyawa estradiol-17β tidak terdeteksi dalam penelitian ini. Tingkat pencemaran EDCs di Sungai Surabaya tidak menyebabkan ketidaknormalan nisbah kelamin namun menyebabkan penghambatan perkembangan gonad.
Keyword: EDCs, pencemaran, reproduksi, sungai

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