Judul: The Relationship Between Plankton  Community Structure and Water Conditions in Margagiri Grenyang Beach,  Banten Bay
Abstrak: Pantai Margagiri-Grenyang memiliki berbagai kegiatan industri yang dapat mengganggu kestabilan kondisi perairan dan struktur komunitas organisme di wilayah tersebut. Penelitian ini bertujuan menganalisis komposisi dan kelimpahan jenis plankton, indeks keanekaragaman, keseragaman, dan dominansi, serta keterkaitannya dengan kualitas perairan di kawasan perairan tersebut. Penelitian ini dilakukan pada bulan Juli sampai November 2022 dengan enam stasiun. Parameter yang dianalisis meliputi kualitas air, fitoplankton dan zooplankton. Struktur komunitas plankton dianalisis menggunakan pendekatan indeks biologi. Fitoplankton dan zooplankton yang ditemukan berturut-turut terdiri dari enam kelas dan lima kelas. Genus fitoplankton yang mendominasi berasal dari Bacillariopyceae, sedangkan untuk zooplankton berasal dari genus Protozoa. Hasil pengamatan menunjukkan indeks keanekaragaman, keseragaman, dan dominansi fitoplankton secara berturut-turut sebesar 1,2733-2,5515; 0,3849-0,8003; dan 0,1106-0,4912. Adapun untuk zooplankton secara berturut-turut sebesar 1,6310-2,1476; 0,7723-0,8996 dan 0,1509-0,2414. Berdasarkan struktur komunitas yang terbentuk terlihat bahwa plankton masih dapat tumbuh dan berkembang. Struktur komunitas plankton di perairan Margagiri-Grenyang mencerminkan kondisi keadaan stabil dan terjadi tekanan ekologis terhadap biota di habitat tersebut., Margagiri-Grenyang Beach has various industrial activities that can destabilize the water conditions and community structure of organisms in the area. This study aims to analyze the composition and abundance of species plankton, diversity index, evennes, and dominance, and their relationship with water quality in the water area. This research was conducted from July to November 2022 with six stations. The parameters analyzed include water quality, phytoplankton, and zooplankton. The plankton community structure was analyzed using the biological index approach. Phytoplankton and zooplankton found consisted of six classes and five classes, respectively. The dominating phytoplankton genus comes from Bacillariopyceae, while for zooplankton comes from the genus Protozoa. The observation results showed that the indices of diversity, evennes, and dominance of phytoplankton were 1.2733-2.5515; 0.3849-0.8003; and 0.1106-0.4912, respectively. As for zooplankton, they were 1.6310-2.1476; 0.7723-0.8996 and 0.1509-0.2414, respectively. Based on the community structure formed, it appears that plankton can still grow and develop. The structure of the plankton community in the Margagiri-Grenyang waters reflects stable conditions and ecological pressure on the biota in the habitat.
Keyword: Banten Bay, plankton, structure community, water quality.

Judul: Plankton Community Structure in Bojonegara Beach and Surrounding Waters, Banten Bay
Abstrak: Teluk Banten mendapat tekanan dari industri dan penambangan pasir. Salah satu daerah yang banyak dimanfaatkan adalah Kecamatan Bojonegara. Tekanan ini dapat memicu perubahan kualitas perairan. Perubahan parameter fisika dan kimia dapat memengaruhi kehidupan biota akuatik, salah satunya plankton. Penelitian ini bertujuan menganalisis keterkaitan keberadaan plankton dengan parameter fisika dan kimia perairan. Penelitian ini dilakukan selama tiga bulan, mulai dari Oktober hingga Desember 2019 pada enam stasiun. Penelitian menunjukkan bahwa hasil Analisis Komponen Utama (PCA) membentuk dua hingga tiga kelompok kondisi perairan yang dicirikan oleh keberadaan Bacillariophyceae, Cyanophyceae, Dinophyceae, Chrysophyceae, dan Chlorophyceae. Biplot PCA zooplankton membentuk dua kelompok, yaitu protozoa dan rotifera. Berdasarkan struktur komunitas yang terbentuk pada musim hujan terlihat bahwa plankton masih dapat tumbuh dengan baik pada lokasi dan waktu pengamatan. Struktur komunitas fitoplankton dan zooplankton di perairan Bojonegara mencerminkan kondisi yang relatif kurang stabil, yang dipengaruhi oleh kondisi salinitas dan fosfat total., Banten Bay is under pressure from industry and sand mining. One area that is widely used is Bojonegara. This pressure can trigger changes in water quality. Changes in physical and chemical parameters can affect the life of aquatic biota, one of which is plankton. This study aims to analyze the relationship between the presence of plankton with physical and chemical parameters of the waters. This research was conducted for three months, from October to December 2019 at six stations. The research shows that the results of PCA form two to three groups of water conditions characterized by the presence of Bacillariophyceae, Cyanophyceae, Dinophyceae, Chrysophyceae, and Chlorophyceae. Biplot PCA zooplankton form two groups, namely protozoa and rotifers. Based on the community structure formed during the rainy season, it shows that plankton still grow well at the location and time of observation. The community structure of phytoplankton and zooplankton in Bojonegara waters reflects a relatively unstable condition, which is influenced by conditions of total salinity and phosphate.
Keyword: Bojonegara, Plankton, Struktur komunitas, Teluk Banten

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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