Judul: Size spectra of plankton biomass and its potential utilization for fish community at limnetic zone of the Ir. H. Djuanda Reservoir, West Java
Abstrak: The total area of Djuanda reservoir (8,300 ha) in West Java compose of 56-86% of limnetic zone and the rest of littoral zone. The limnetic zone of the reservoir mostly rich in plankton but rare in fish inhabiting this area. Eutrophication process of the reservoir is very intensiv e due to intensive activity of fish cage culture. Objectives of the research are to analyze and describe (1) plankton community structure and biomass; (2) fish community structure and biomass; (3) trophic efficiency of the food web in relation to the niche ecology; and (4) to analyze the research results of point 1, 2 and 3 in optimizing the utilization and management of the resources. The data were analyzed descriptively and statistically including of analyzing: (1) impact of N and P loading on the growth of phytoplankton; (2) the zooplankton grazing and filtration on the growth of the phytoplankton; (3) the flow efficiency of energy on the food web, and (4) the implication of ecosystem dynamics of the limnetic zone in relation to management option for fisheries development.
Keyword: Ekosistem pelagis, Pebgelolaan perikanan Waduk Djuanda, Grazing Zooplankton, Fitoplankton, Perikanan tangkap

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: Konstruksi aritmetika kurva eliptik F(2m) supersingular dan non-supersingular untuk skema kunci publik ElGamal
Abstrak: Algoritme ElGamal adalah salah satu algoritme kunci publik dengan aritmetik modular p yang mempunyai struktur grip siklik Z(p). Tingkat keanaman algoritme ini terletak pada pemecahan masalah logaritme diskret dari Z(p). Akan tetapi, tingkat keamanan tadi tahun ke tahun semakin menurun yang disebabkan kemampuan pemecahan algoritme diskret semakin meningkat. Untuk memenuhi tingkat keamanan yang memadai dibutuhkan p yang cukup besar yang menyebabkan proses enkripsi dan dekripsi menjadi lambat.
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