Judul: Macrozoobenthos Community Structure in the  Seagrass Ecosystem as an Indicator of Habitat Quality for Pramuka Island, Seribu  Islands
Abstrak: Aktivitas antropogenik di ekosistem lamun dapat menyebabkan pencemaran dan mempengaruhi biota di dalamnya, seperti makrozoobenthos dan lamun. Penelitian ini bertujuan untuk menganalisis struktur komunitas makrozoobenthos yang dikaitkan dengan kesehatan lamun, kualitas air dan substrat pada ekosistem lamun di Pulau Pramuka, Kepulauan Seribu. Metode yang digunakan yaitu analisis parameter kualitas air, kepadatan makrozoobenthos, indeks keanekaragaman, indeks keseragaman, indeks dominansi, tipe substrat, analisis komponen utama, dan analisis Spearman Rank. Makrozoobenthos yang diperoleh terdiri atas 6 kelas, yaitu Gastropoda, Bivalvia, Asteroidea, Malacostraca, Polychaeta, dan Echinoidea. Tipe substrat di Pulau Pramuka yaitu berpasir. Indeks keanekaragaman dan indeks keseragaman tergolong tinggi dan indeks dominansi tergolong rendah. Kualitas air tergolong masih baik dan masih di batas baku mutu air laut. Kepadatan lamun di Pulau Pramuka tergolong rendah atau rusak., Anthropogenic activities in seagrass ecosystems can cause pollution and affect the biota within them, such as macrozoobenthos and seagrass. This research aims to analyze the macrozoobenthos community structure which is associated with seagrass health, water and substrate quality in the seagrass ecosystem on Pramuka Island, Seribu Islands. The methods used are analysis of water quality parameters, macrozoobenthos density, diversity index, uniformity index, dominance index, substrate type, principal component analysis, and Spearman Rank analysis. The macrozoobenthos obtained consists of 6 classes, namely Gastropoda, Bivalvia, Asteroidea, Malacostraca, Polychaeta, and Echinoidea. The substrate type on Pramuka Island is sandy. The diversity index and uniformity index are relatively high and the dominance index is low. The water quality is still classified as good and still within the sea water quality standards. Seagrass density on Pramuka Island is classified as low or damaged.
Keyword: makrozoobentos, lamun, struktur komunitas, kepadatan, community structure, density, macrozoobenthos, seagrass

Judul: Macrozoobenthos Community Structure in the Intertidal Ecosystem of Pramuka Island, Seribu Islands
Abstrak: Aktivitas antropogenik yang ada di Pulau Pramuka berpotensi memberikan dampak terhadap kondisi perairan ekosistem intertidal, termasuk komunitas benthic. Penelitian ini bertujuan menganalisis komunitas makrozoobenthos pada ekosistem intertidal Pulau Pramuka. Pengambilan contoh dilakukan sebanyak tiga kali pada bulan Oktober-November dengan tiga titik stasiun. Pengambilan contoh makrozoobenthos dilakukan dengan metode transek kuadrat. Analisis Indeks Bray-Curtis digunakan untuk melihat pengelompokan stasiun. Hubungan makrozoobenthos dengan parameter kualitas air dianalisis menggunakan Principal Component Analysis (PCA). Jenis makrozoobenthos yang ditemukan terdiri dari tujuh kelas dan 38 genera. Makrozoobenthos dari Kelas Bivalvia, Gastropoda, dan Polychaeta merupakan jenis yang banyak ditemukan. Ekosistem intertidal yang dekat dengan permukiman memiliki keanekaragaman jenis yang tinggi dan distribusi individu antarjenis yang merata, sedangkan ekosistem intertidal di daerah pembuangan IPAL menunjukkan keanekaragaman jenis rendah dengan distribusi individu yang tidak merata dan terdapat dominansi. Pengelompokan stasiun berdasarkan kepadatan jenis makrozoobenthos antarstasiun terbentuk tiga kelompok stasiun. Kata Kunci: intertidal, keanekaragaman, makrozoobenthos, Anthropogenic activities in Pramuka Island have the potential to impact the condition of intertidal ecosystem waters, including benthic communities. This study aims to analyze the macrozoobenthos community in the intertidal ecosystem of Pramuka Island. Sampling was conducted three times in October-November with three station points. Sampling of macrozoobenthos was done by quadrat transect method. Bray-Curtis Index analysis was used to see station grouping. The relationship between macrozoobenthos and water quality parameters was analyzed using Principal Component Analysis (PCA). Macrozoobenthos species found consisted of seven classes and 38 genera. Macrozoobenthos from Bivalve, Gastropoda, and Polychaeta classes are the most common species found. Intertidal ecosystems close to settlements have high species diversity and even distribution of individuals between species, while intertidal ecosystems in the WWTP disposal area show low species diversity with uneven distribution of individuals and dominance. Station grouping based on the density of macrozoobenthos species between stations formed three groups of stations. Keywords : diversity, intertidal, macrozoobenthos
Keyword: struktur komunitas, Intertidal, Makrozoobenthos

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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