Judul: Analisis Hubungan Antara Tutupan Karang Keras dan Komunitas Bentik dengan Kelimpahan Ikan di Pulau Sangiang, Provinsi Banten
Abstrak: Pulau Sangiang merupakan pulau konservasi yang memiliki biodiversitas laut yang tinggi pada ekosistem terumbu karang. Variasi karang keras dan ikan karang yang tinggi menjadi daya tarik utama untuk wisata bahari, seperti penyelaman. Namun demikian, Pulau Sangiang rentan terhadap gangguan lingkungan alami seperti tsunami dan antropogenik seperti laju sedimentasi yang tinggi dan pariwisata bahari yang merusak karang. Transplantasi karang dilakukan untuk merehabilitasi dan melindungi ekosistem terumbu karang yang mengalami kerusakan. Tujuan dari penelitian ini adalah menganalisis hubungan karang keras dan komunitas bentik dengan kelimpahan ikan pada wilayah timur Pulau Sangiang. Lima kategori komunitas bentik ditemukan, dengan persentase tutupan tertinggi dimiliki oleh HC (52-90%) dan DCA (6-25%). Ditemukan 11 lifeform HC, dengan persetase tutupan tertinggi dimiliki oleh CF (34-59%) dan ACB (2-47%). Kelimpahan ikan karang yang ditemukan berkisar dari 1.195 individu di Legon Bajo dan 751 individu di Legon Waru. Kelompok trofik ikan dengan kelimpahan tertinggi dimiliki oleh omnivora dan planktivora. Hasil analisis koresponden (CA) memberikan informasi sebesar 78,17% dari sumbu 1 (F1), sumbu 2 (F2), dan sumbu 3 (F3). Pengelompokan menunjukkan ikan koralivora, karnivora, dan omnivora berkaitan erat pada wilayah dengan tutupan HC yang tinggi, sementara ikan herbivora berkaitan erat pada wilayah dengan tutupan karang mati dan alga yang tinggi., Sangiang Island is a conservation island that has high marine biodiversity in coral reef ecosystems. The high variety of hard corals and reef fish is the main attraction for marine tourism, such as diving. However, Sangiang Island is vulnerable to natural environmental disturbances such as tsunamis and anthropogenic disturbances such as high sedimentation rates and marine tourism which damages corals. Coral transplants are carried out to rehabilitate and protect damaged coral reef ecosystems. The purpose of this study was to analyze the relationship between hard corals and benthic communities with fish abundance in the eastern region of Sangiang Island. Five benthic community categories were found, with the highest percentage of cover belonging to HC (52-90%) and DCA (6-25%). 11 HC lifeforms were found, with the highest percentage cover belonging to CF (34-59%) and ACB (2-47%). The abundance of reef fish found ranged from 1,195 individuals in Legon Bajo and 751 individuals in Legon Waru. The trophic group of fish with the highest abundance belongs to omnivores and plankton. Correspondent analysis (CA) results provide information about 78.17% of axis 1 (F1), axis 2 (F2), and axis 3 (F3). Grouping shows that coralivorous, carnivorous, and omnivorous fish are closely related to areas with high HC cover, while herbivorous fish are closely related to areas with high dead coral and algae cover.
Keyword: Benthic Communities, Hard Coral, Fish Tropic Group, Grouping

Judul: Correlation Between Abundance of Herbivorous Reef Fish And Benthic Cover Condition in Tunda Island
Abstrak: Pulau Tunda termasuk dalam wilayah Kabupaten Serang, Provinsi Banten dan memiliki potensi ekosistem terumbu karang seperti ikan karang, sebagai penjaga keseimbangan ekosistem ekologis dan estetika lingkungan bawah air. Tujuan penelitian ini adalah menganalisis kelimpahan ikan karang herbivora di berbagai lokasi pengamatan dan hubungannya dengan komposisi komunitas bentik di Pulau Tunda. Metode pengamatan yang digunakan adalah Underwater Photo Transect (UPT) untuk komunitas bentik dan Underwater Visual Census (UVC) untuk komunitas ikan. Secara umum kondisi terumbu karang Pulau Tunda termasuk kategori sedang, dengan kekayaan jenis ikan 9 spesies dari 2 famili. Lima kategori bentik yang ditemukan dengan tutupan tertinggi oleh abiotik (44,06%-68,38%). Ada 14 lifeform karang keras dengan tutupan tertinggi pada coral massive (16,63%-39,23%). Kelimpahan ikan karang herbivora adalah 47 individu dari famili Scaridae dan Acanthuridae. Berdasarkan perilaku makan, ada kelompok ikan herbivora terbagi menjadi scrapers (66%) dan grazers (34%). Hasil analisis korespondensi menghubungkan grazers dengan Acropora Submassive (ACS), sedangkan scrapers dengan Acropora Tabulate (ACT) dan Dead Coral with Algae (DCA)., Tunda Island is part of the Serang District, Banten Province and has the potential in reef ecosystem such as reef fish, as a keeper of the ecological ecosystems balance and an underwater aesthetic. The purpose of this study is to analyze the abundance of herbivorous coral at various observation sites and its relationship with the bentic community on Tunda Island. The methods used are Underwater Photo Transect (UPT) for the benthic community and Underwater Visual Census (UVC) for fish communities. In general, coral reef conditions in Tunda Island categorized as moderate, with reef fish diversity of 9 species from 2 famili. Five categories of reefs were found with the highest percentage coverage owned by abiotic (44,06%-68,3866%). A total of 14 lifeforms of hard coral growth were found with the highest percentage coverage by massive corals (16,63%-39,23%). The study found 47 herbivorous reef fish, mainly scrapers (66%), and grazers (34%), belonging to the Scaridae and Acanthuridae families. This research highlighted grazers community corespondence to Acropora Submassive (ACS), while scrapers with Acropora Tabulate (ACT) and Dead Coral with Algae (DCA).
Keyword: Benthic Communities, Hard Coral, Herbivorous Reef Fish, Grouping

Judul: The Exploration of Discrete Logarithm over Finite Field GF(3m)
Abstrak: The security of many public~key algorithms is based on the problem of finding discrete logarithms. The generalized discrete logarithm problem is the following: given a finite cyclic group G of order n, a generator a of G, and an element fl E G, find the integer x, 0 ~ x ~ n - 1, such that 0: = fl. Algorithm for discrete logarithm problem focused on Menezes et al. (1997) that consist of exhaustive search algorithm, the baby-step giant-step algorithm, Pollard's rho algorithm, Pohlig-Hellman algorithm, and index-calculus algorithm. These algorithms are explorated to be used in discrete logarithm problem over finite field GF(3m ). The exploration also produces some algorithms, i.e. naif negative algorithm, baby-step mother-step algorithm, baby-step mother free-step algorithm, and baby-step free-step algorithm. All algorithms implemented using Maple 11. The Pohlig-Hellman and baby-step giant-step algorithms are efficient enough to be used in discrete logarithm problem over finite field GF(3m ) for m < 20.
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