Judul: Karakteristik dan status kualitas air di cekungan Karst Cileungsi, Kabupaten Bogor, Jawa Barat
Abstrak: Kawasan karst merupakan suatu bentuk permukaan bumi dengan kondisi hidrologi yang khas akibat terdapatnya batuan yang mudah larut. Penelitian ini bertujuan mendeskripsikan karakteristik dan status kualitas air melalui pendekatan Indeks Kualitas Air (IKA-NSF) dan Indeks Pencemaran (IP). Penelitian dilakukan pada bulan Februari sampai Maret 2015. Pengambilan contoh air dilakukan tiga kali pada ketiga cekungan dengan interval dua minggu. Nilai Indeks Kualitas Air (IKA-NSF) pada cekungan Klapanunggal 1, 2, dan 3 berkisar antara 50,50-60,75. Tingkat status kualitas air pada ketiga cekungan tergolong dalam kategori sedang. Berdasarkan nilai Indeks Pencemaran (IP) untuk baku mutu kelas II dan III, hanya cekungan Klapanunggal 2 yang memenuhi baku mutu, sedangkan cekungan Klapanunggal 1 dan 3 tergolong tercemar ringan dengan parameter fosfat total dan fecal coliform yang melampaui baku mutu. Pada cekungan karst Cileungsi terdapat beberapa parameter yang nilainya relatif berbeda dengan nilai kualitas air pada perairan tawar lainnya seperti, alkalinitas, kesadahan, kalsium, magnesium, dan DHL.
Keyword: kasrt Cileungsi, water quality, WQI-NSF, Pollution Index

Judul: Inventarisasi Dan Karakterisasi Kondisi Fisika Kimia Perairan Karst Di Kabupaten Bogor, Jawa Barat
Abstrak: Karst merupakan kawasan berbatuan karbonat yang memiliki kandungan air melimpah. Langkah awal yang dilakukan dalam upaya pengelolaan adalah inventarisasi dan karakterisasi kondisi perairan karst terutama dalam hal fisikakimia perairan. Penelitian dilaksanakan pada bulan Januari sampai April 2015, di Kabupaten Bogor, Jawa Barat. Analisis data meliputi kesamaan karakteristik antar kawasan, analisis komponen utama, dan tingkat kesuburan perairan. Persebaran kawasan karst di Kabupaten Bogor dikelompokkan menjadi dua formasi utama diantaranya Formasi Klapanunggal (Klapanunggal, Cibinong, dan Citereup) dan Formasi Bojongmanik (Ciampea, Jasinga, Leuwiliang, Cigudeg, dan Ciseeng). Hasil analisis menunjukkan bahwa perairan dengan lokasi yang sama memiliki karakteristik yang sama. Tingkat kesuburan perairan Karst Ciampea dan Klapanunggal bersifat mesotrofik dan perairan Karst Ciseeng bersifat eutrofik. Karst Klapanunggal memiliki sumber bahan tambang dan mineral yang tinggi. Karst Ciseeng memiliki bentuk yang unik dan dimanfaatkan sebagai wisata pemandian air panas. Karst Ciampea dimanfaatkan untuk irigasi pertanian dan keperluan domestik.
Keyword: ekosistem perairan, karst, kualitas air, status kesuburan, potensi ekologis

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