Judul: Condition of Coral Reefs and Benthic Community Cover in Bontang City
Abstrak: ABSTRAK WAFIQ SALMAN ARROSADI. Kondisi Terumbu Karang dan Tutupan Komunitas Bentik di Kota Bontang. Dibimbing oleh BEGINER SUBHAN dan FERY KURNIAWAN. Indonesia merupakan negara dengan keanekaragaman hayati laut yang melimpah, memiliki sekitar 18% dari total luas terumbu karang di dunia dan dikenal sebagai salah satu titik pusat keanekaragaman hayati laut global. Terumbu karang, sebagai komponen penting dari ekosistem pesisir dan laut, sangat rentan terhadap gangguan. Penelitian ini bertujuan untuk mengevaluasi kondisi terumbu karang dan kualitas perairan di Perairan Kota Bontang, Kalimantan Timur. Data tutupan terumbu karang dianalisis dari sembilan stasiun pengamatan, sementara parameter kualitas air meliputi suhu, salinitas, pH, dan oksigen terlarut. Data yang digunakan dalam penelitian ini merupakan data sekunder yang diperoleh dari Pusat Kajian Sumberdaya Pesisir dan Lautan (PKSPL) IPB dan PT. Pupuk Kaltim. Data sekunder diperoleh dari sembilan stasiun pengamatan Hasil penelitian menunjukkan bahwa terumbu karang di kawasan ini umumnya mengalami degradasi, terutama ditandai dengan dominasi tutupan Rubble dan Dead Coral with Algae. Stasiun dengan tutupan karang hidup tertinggi adalah Stasiun 5 (22,67%), sedangkan Stasiun 4 menunjukkan tutupan terendah (0%). Lifeform karang keras yang dominan adalah Acropora tabulate dan Coral Mushroom. Meskipun demikian, kualitas air secara umum masih berada dalam batas toleransi, walaupun terdapat beberapa parameter yang tidak memenuhi baku mutu yang disarankan. Penelitian ini memberikan gambaran yang penting untuk memahami kondisi ekologis terumbu karang di Kota Bontang dan pentingnya upaya konservasi untuk memulihkan ekosistem ini di masa depan. Kata kunci: terumbu karang, kualitas air, Bontang, Kalimantan Timur, Indonesia., ABSTRACT WAFIQ SALMAN ARROSADI. Condition of Coral Reefs and Benthic Community Cover in Bontang City. Supervised by BEGINER SUBHAN and FERY KURNIAWAN. Indonesia is a country with abundant marine biodiversity, containing approximately 18% of the world's coral reefs and known as one of the global centers of marine biodiversity. Coral reefs, as a vital component of coastal and marine ecosystems, are highly vulnerable to disturbances. This study aims to evaluate the condition of coral reefs and water quality in the waters of Bontang City, East Kalimantan. Coral reef cover data were analyzed from nine observation stations, while water quality parameters included temperature, salinity, pH, and dissolved oxygen. The data used in this study were secondary data obtained from the Center for Coastal and Marine Resources Studies (PKSPL) at IPB University and PT. Pupuk Kaltim. Secondary data were collected from nine observation stations. The results indicate that the coral reefs in this area generally experience degradation, primarily marked by the dominance of Rubble and Dead Coral with Algae covers. Station 5 showed the highest live coral cover (22.67%), whereas Station 4 exhibited the lowest (0%). The dominant hard coral lifeforms were Acropora tabulate and Coral Mushroom. However, overall water quality remains within tolerance limits, although some parameters did not meet recommended standards. This research provides crucial insights into the ecological condition of coral reefs in Bontang City and underscores the importance of conservation efforts to restore this ecosystem in the future. Keywords: coral reefs, water quality, Bontang, East Kalimantan, Indonesia.
Keyword: terumbu karang, bentik, kota bontang

Judul: Coral Reef Health and  The Distribution of Soft Coral Abundance in Banten Bay
Abstrak: Teluk Banten berada di utara bagian barat Pulau Jawa yang memiliki terumbu karang di sekitarnya. Beberapa diantaranya adalah Pulau Panjang, Pulau Lima dan Pulau Pamujan Besar. Penelitian ini dilakukan sejak Oktober 2021 - Maret 2022 pada 9 titik pengamatan yang tersebar di ketiga pulau. Penelitian ini bertujuan untuk mengetahui kesehatan terumbu karang dan distribusi kelimpahan karang lunak tiga pulau tersebut. Data terumbu karang diambil melalui penyelaman dengan menggunakan metode Underwater Photo Transect (UPT). Transek garis dibentangkan sejajar garis pantai sepanjang 50 m. Data berupa foto diambil menggunakan transek kuadrat (58 cm x 44 cm) yang diletakkan selang-seling di setiap meternya. Berdasarkan hasil pengamatan keberadaan soft coral ditemukan pada 9 stasiun, masing-masing adalah 0.21%, 0.99%, 0.70%, 13.89%, 7.61%, 16.80%, 5.78%, dan 4.62%. Terumbu karang lunak ditemukan pada 8 stasiun dan tidak ditemukan pada 1 stasiun. Nilai kepadatan yang cukup besar ditemukan pada Stasiun 4 dan Stasiun 6, sedangkan nilai kepadatan yang kecil ditemukan pada Stasiun 1, Stasiun 2 dan Stasiun 3). Berdasarkan KEPMEN LH No. 4 Tahun 2001, terumbu karang di sekitar Pulau Panjang termasuk kategori buruk dan sedang (tidak sehat)., Banten Bay is located in the north west part of Java Island which has coral reefs around it. Some of them are Panjang Island, Lima Island, and Pamujan Besar Island. This study was carried out from October 2021 - March 2022 at 9 observation points spread across the islands. This study aims to determine the health of coral reefs and the distribution of soft coral abundance in the three islands. Coral reef data was taken through diving using the Underwater Photo Transect (UPT) method. Line transect was stretched parallel to the shoreline for a length of 50 m. The data in the form of photos were taken using a square transect (58 cm x 44 cm) which was placed alternately in each meter. Based on the observation, the presences of soft coral found at 9 Stastion, each is 0.21%, 0.99%, 0.70%, 13.89%, 7.61%, 16.80%, 5.78%, and 4.62%, respectively. Fairly large value of abundance was found at Station 4 and Station 6 while small value of abundances were found at Station 1, Station 3 dan Station 2 Based on Decree of Ministry of Environment No. 4 of 2001, the coral reefs around Pulau Panjang are categorized as bad and fair (unhealthy).
Keyword: Abundance, Panjang Island, Soft coral, Karang lunak, Kepadatan, Pulau Panjang

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