Judul: Spatial Distribution of Plankton in Jatigede Reservoir, Sumedang, West Java
Abstrak: Distribusi spasial plankton di perairan akan membentuk sebuah pola tertentu, seperti pola distribusi acak, seragam, atau mengelompok. Penelitian ini bertujuan menganalisis distribusi spasial plankton di perairan Waduk Jatigede, Sumedang, Jawa Barat. Pengambilan contoh dilakukan pada bulan Februari-April 2020 pada tujuh stasiun pengamatan. Distribusi plankton di perairan dianalisis menggunakan Indeks Morisita, kemudian hasilnya diuji dengan uji Chi-kuadrat. Waduk Jatigede terdiri dari tiga zona, yaitu zona riverine, zona transisi, dan zona lacustrine. Jumlah jenis fitoplankton didominasi oleh Chlorophyceae, sedangkan kelimpahan fitoplankton didominasi oleh Cyanophyceae. Zooplankton didominasi oleh Rotifera, baik berdasarkan jumlah jenis maupun kelimpahannya. Struktur komunitas fitoplankton dan zooplankton cenderung tidak stabil. Genus fitoplankton yang mendominasi perairan, yaitu Pseudoanabaena. Keseluruhan genus plankton, baik kelompok fitoplankton maupun zooplankton umumnya memiliki pola distribusi mengelompok pada seluruh zona di perairan Waduk Jatigede., The spatial distribution of plankton in the waters will form a certain pattern such as a random, uniform, or clumped distribution pattern. This study aims to analyze the spatial distribution of plankton in the waters of Jatigede Reservoir, Sumedang, West Java. Sampling was carried out in February-April 2020 at seven observation stations. The distribution of plankton in the waters was calculated using the Morisita Index, then the results are tested by Chi-square test. Jatigede Reservoir consists of three zones, namely riverine zone, transition zone, and lacustrine zone. The number of phytoplankton types is dominated by Chlorophyceae, while the abundance of phytoplankton is dominated by Cyanophyceae. Zooplankton is dominated by Rotifers, both based on the number of species and abundance. Phytoplankton and zooplankton community structures tend to be unstable. The phytoplankton genus that dominates the waters is Pseudoanabaena. The entire genus of plankton, both phytoplankton and zooplankton groups, generally have a clumped distribution pattern in all zones of Jatigede Reservoir.
Keyword: distribution pattern, phytoplankton, reservoir, spatial, zooplankton

Judul: Pola Suksesi Fitoplankton Pada Perairan Waduk Jatigede, Sumedang, Jawa Barat
Abstrak: Kegiatan antropogenik baik secara eksternal maupun internal di sekitar Waduk Jatigede dapat berpengaruh terhadap keberadaan bahan organik. Bahan organik yang masuk ke dalam perairan berpotensi menjadi nutrien, yang kemudian dimanfaatkan oleh plankton. Perubahan parameter kualitas air dapat memimbulkan adanya pola suksesi plankton. Penelitian ini bertujuan menganalisis keterkaitan suksesi fitoplankton dengan kualitas air di perairan Waduk Jatigede, Sumedang, Jawa Barat. Penelitian ini dilaksanakan pada bulan Februari–April 2021 di perairan Waduk Jatigede, Sumedang, Jawa Barat. Data yang digunakan pada penelitian ini yaitu data primer dan data skunder. Data primer yang diambil terdiri dari data pH, Amonia, nitit, nitrat, ortofosfat, suhu perairan, kedalaman perairan, kekeruhan, daya hantar listrik, kecerahan, dan data plankton. Pengambilan contoh dilakukan dengan metode purposive sampling. Data sekunder merupakan data curah hujan. Analisis pola suksesi dilakukan dengan penentuan stadia melalui pendekatan grafik suksesi Frontier. Kesamaan waktu penelitian ditentukan melalui Stander’s Similarity Index (SIMI), sedangkan laju suksesi ditentukan melalui Summed Difference Index (SDI). Kelimpahan plankton didominasi oleh kelompok Cyanophyceae dan Rotifera. Komposisi jenis tertinggi di dominansi oleh kelompok Chlorophyceae dan Rotifera. Secara umum komunitas fitoplankton di perairan Waduk Jatigede berada pada stadia 1 dan 2. Stadia 1 suksesi fitoplankton tidak berkorelasi dengan parameter nitir dan ortofosfat dan stadia 2 tidak berkorelasi dengan nitrat, suhu, dan DHL (p < 0,2). Secara umum kualitas air yang berkorelasi positif dengan suksesi fitoplankton yaitu nitrat, amonia, kecerahan, dan DHL., Anthropogenic activities both externally and internally around Jatigede Reservoir can affect the presence of organic matter. Organic matter that enters the water has the potential to become nutrients which are utilized by plankton. Changes in water quality parameters can cause a pattern of plankton succession. This study aims to analyze the relationship between phytoplankton succession and water quality in the water of Jatigede Reservoir, Sumedang, West Java. This research was carried out in February–April 2021 in the water of Jatigede Reservoir, Sumedang, West Java. The data used in this study are primary data and secondary data. Primary data consisted of data on pH, ammonia, nitrite, nitrate, orthophosphate, water temperature, water depth, turbidity, conductivity, brightness, and plankton data. Sampling was done by purposive sampling method. Secondary data is rainfall. Succession pattern analysis is done by determining stadia through the Frontier succession graph approach. Similarity of the research time was determined by Stander’s Similarity Index (SIMI), while the succession rate was determined by Summed Difference Index (SDI). Plankton abundance is dominated by Cyanophyceae and Rotifera. The highest species composition was dominated by Chlorophyceae and Rotifera. In general, phytoplankton community in Jatigede Reservoir was at stages 1 and 2. Stage 1 of phytoplankton succession did not correlate with nirite and orthophosphate and stage 2 did not correlate with nitrate, temperatur, and DHL (p < 0,2). In general, water quality is positively correlated with phytoplankton succession is nirate, ammonia, brightness, and DHL.
Keyword: Jatigede Reservoir, plankton, succession, succession rate, water quality

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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