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: Spatial Distribution of Nitrogen in the Waters of Jatigede Reservoir, Sumedang, West Java
Abstrak: Materi yang masuk ke dalam perairan dapat berupa bahan organik dan anorganik yang bermuatan nitrogen. Sumber masukan nitrogen yang beragam dapat memengaruhi pola penyebaran nitrogen di Waduk. Penelitian ini bertujuan untuk menganalisis distribusi nitrogen secara spasial di perairan Waduk Jatigede, Sumedang, Jawa Barat. Penelitian dilaksanakan pada bulan Februari-April 2021. Analisis data yang digunakan berupa uji signifikansi antara lapisan dan antarawaktu, penentuan musim, kesamaan karakteristik stasiun berdasarkan kualitas air, pemetaan sebaran spasial nitrogen, dan analisis korelasi nitrogen dengan parameter kualitas air. Waduk Jatigede terdiri dari tiga zona, yaitu Zona Riverin, transisi, dan lakustrin. Konsentrasi nitrat, nitrit, dan nitrogen total tinggi di Zona Riverin pada lapisan epilimnion dan di Zona Transisi pada lapisan hipolimnion. Konsentrasi amonia tertinggi di Zona Lakustrin pada lapisan epilimnion dan hipolimnion. Terdapat hubungan antaraa nitrogen dengan parameter kualitas air seperti COD, kekeruhan, TSS, dan DO. Konsentrasi tertinggi nitrogen terjadi pada lapisan hipolimnion. Nitrogen tersebar dengan konsentrasi bervariasi secara vertikal dan cenderung seragam secara horizontal. Nitrogen memiliki tingkat konsentrasi dengan kecenderungan lebih tinggi di Zona Riverin secara horizontal dan di lapisan hipolimnion secara vertikal. Secara spasial, tingkat konsentrasi nitrogen dipengaruhi oleh COD, kekeruhan, TSS, dan DO di perairan., Materials enter waters can be form of organic and inorganic containing nitrogen. Various sources of nitrogen input which can affect nitrogen distribution pattern. This study aims to analyze the nitrogen spatial distribution in Jatigede Reservoir, Sumedang, West Java. Research carried out in February-April 2021. Analysis of data used are test of significance between layers and over time, season determination, similarity of station characteristics based on water quality, mapping of nitrogen spatial distribution, and nitrogen correlation analysis with water quality parameters. Jatigede Reservoir consists of three zones, namely riverine, transition, and lacustrine zones. Concentrations of nitrate, nitrite, and total nitrogen were high in riverine in epilimnion and in transition in hypolimnion. The highest amonia concentration was in lacustrine in epilimnion and hypolimnion. There is relationship between nitrogen and water quality parameters such as COD, turbidity, TSS, and DO. The highest nitrogen concentration occurs in hypolimnion. Nitrogen is dispered with varying concentrations vertically and tends to be uniform horizontally. Nitrogen has a concentration tend to be higher in riverine horizontally and in hypolymnion vertically. Spatially, nitrogen concentration is influenced by COD, turbidity, TSS, and DO in waters.
Keyword: distribution, Jatigede Reservoir, nitrogen

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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